Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc

netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
       [not found] <bug-33502-10286@https.bugzilla.kernel.org/>
@ 2011-04-18 22:38 ` Andrew Morton
  2011-04-19  2:51   ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Andrew Morton @ 2011-04-18 22:38 UTC (permalink / raw)
  To: netdev
  Cc: bugzilla-daemon, bugme-daemon, casteyde.christian, Vegard Nossum,
	Pekka Enberg


(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Sun, 17 Apr 2011 19:29:39 GMT
bugzilla-daemon@bugzilla.kernel.org wrote:

> https://bugzilla.kernel.org/show_bug.cgi?id=33502
> 
>            Summary: Caught 64-bit read from uninitialized memory in
>                     __alloc_skb
>            Product: Networking
>            Version: 2.5
>     Kernel Version: 2.6.39-rc3
>           Platform: All
>         OS/Version: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: IPV4
>         AssignedTo: shemminger@linux-foundation.org
>         ReportedBy: casteyde.christian@free.fr
>         Regression: Yes
> 
> 
> Acer Aspire 1511LMi
> Athlon 64 3GHz in 64bits mode
> Slackware 64 13.1
> 
> Since 2.6.39-rc3 with kmemcheck enabled, I get the following warning:
> ...
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x0c0000-0x0fffff: excluding
> 0xc0000-0xfffff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0x60000000-0x60ffffff: excluding
> 0x60000000-0x
> 60ffffff
> pcmcia_socket pcmcia_socket0: cs: memory probe 0xa0000000-0xa0ffffff: excluding
> 0xa0000000-0x
> a0ffffff
> udev: renamed network interface wlan0 to eth1
> WARNING: kmemcheck: Caught 64-bit read from uninitialized memory
> (ffff88001b0bb800)
> 00b00b1b0088ffff0000000000000000cafe1dea20009b0000299a3100000000
>  u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u
>  ^
> 
> Pid: 1511, comm: udevd Not tainted 2.6.39-rc3 #1 Acer,Inc. Aspire 1510  /Aspire
> 1510
> RIP: 0010:[<ffffffff810c2f0c>]  [<ffffffff810c2f0c>]
> __kmalloc_track_caller+0xbc/0x1d0
> RSP: 0018:ffff88001d3a7a18  EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000010 RCX: 000000000000284f
> RDX: 000000000000284e RSI: ffff88001fe5b160 RDI: ffffffff8177e39a
> RBP: ffff88001d3a7a48 R08: 0000000000000000 R09: ffff88001b931100
> R10: 0000000000000000 R11: 0000000000000003 R12: ffff88001b0bb800
> R13: ffff88001f803840 R14: 00000000000004d0 R15: ffffffff814769c6
> FS:  00007f6ee81f1700(0000) GS:ffffffff81a1b000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> CR2: ffff88001d0b3938 CR3: 000000001d38b000 CR4: 00000000000006f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
>  [<ffffffff8147ccf2>] __alloc_skb+0x72/0x190
>  [<ffffffff814769c6>] sock_alloc_send_pskb+0x236/0x3a0
>  [<ffffffff81476b40>] sock_alloc_send_skb+0x10/0x20
>  [<ffffffff81523c18>] unix_dgram_sendmsg+0x298/0x770
>  [<ffffffff814715f3>] sock_sendmsg+0xe3/0x110
>  [<ffffffff81472603>] sys_sendmsg+0x243/0x3c0
>  [<ffffffff815e7238>] system_call_fastpath+0x16/0x1b
>  [<ffffffffffffffff>] 0xffffffffffffffff

hum.  I wonder if kmemcheck is disliking prefetchw()?

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-18 22:38 ` [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb Andrew Morton
@ 2011-04-19  2:51   ` Eric Dumazet
  2011-04-19  3:09     ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-19  2:51 UTC (permalink / raw)
  To: Andrew Morton
  Cc: netdev, bugzilla-daemon, bugme-daemon, casteyde.christian,
	Vegard Nossum, Pekka Enberg, Christoph Lameter

Le lundi 18 avril 2011 à 15:38 -0700, Andrew Morton a écrit :
> (switched to email.  Please respond via emailed reply-to-all, not via the
> bugzilla web interface).
> 
> On Sun, 17 Apr 2011 19:29:39 GMT
> bugzilla-daemon@bugzilla.kernel.org wrote:
> 
> > https://bugzilla.kernel.org/show_bug.cgi?id=33502
> > 
> >            Summary: Caught 64-bit read from uninitialized memory in
> >                     __alloc_skb
> >            Product: Networking
> >            Version: 2.5
> >     Kernel Version: 2.6.39-rc3
> >           Platform: All
> >         OS/Version: Linux
> >               Tree: Mainline
> >             Status: NEW
> >           Severity: normal
> >           Priority: P1
> >          Component: IPV4
> >         AssignedTo: shemminger@linux-foundation.org
> >         ReportedBy: casteyde.christian@free.fr
> >         Regression: Yes
> > 
> > 
> > Acer Aspire 1511LMi
> > Athlon 64 3GHz in 64bits mode
> > Slackware 64 13.1
> > 
> > Since 2.6.39-rc3 with kmemcheck enabled, I get the following warning:
> > ...
> > pcmcia_socket pcmcia_socket0: cs: memory probe 0x0c0000-0x0fffff: excluding
> > 0xc0000-0xfffff
> > pcmcia_socket pcmcia_socket0: cs: memory probe 0x60000000-0x60ffffff: excluding
> > 0x60000000-0x
> > 60ffffff
> > pcmcia_socket pcmcia_socket0: cs: memory probe 0xa0000000-0xa0ffffff: excluding
> > 0xa0000000-0x
> > a0ffffff
> > udev: renamed network interface wlan0 to eth1
> > WARNING: kmemcheck: Caught 64-bit read from uninitialized memory
> > (ffff88001b0bb800)
> > 00b00b1b0088ffff0000000000000000cafe1dea20009b0000299a3100000000
> >  u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u
> >  ^
> > 
> > Pid: 1511, comm: udevd Not tainted 2.6.39-rc3 #1 Acer,Inc. Aspire 1510  /Aspire
> > 1510
> > RIP: 0010:[<ffffffff810c2f0c>]  [<ffffffff810c2f0c>]
> > __kmalloc_track_caller+0xbc/0x1d0
> > RSP: 0018:ffff88001d3a7a18  EFLAGS: 00010246
> > RAX: 0000000000000000 RBX: 0000000000000010 RCX: 000000000000284f
> > RDX: 000000000000284e RSI: ffff88001fe5b160 RDI: ffffffff8177e39a
> > RBP: ffff88001d3a7a48 R08: 0000000000000000 R09: ffff88001b931100
> > R10: 0000000000000000 R11: 0000000000000003 R12: ffff88001b0bb800
> > R13: ffff88001f803840 R14: 00000000000004d0 R15: ffffffff814769c6
> > FS:  00007f6ee81f1700(0000) GS:ffffffff81a1b000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> > CR2: ffff88001d0b3938 CR3: 000000001d38b000 CR4: 00000000000006f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
> >  [<ffffffff8147ccf2>] __alloc_skb+0x72/0x190
> >  [<ffffffff814769c6>] sock_alloc_send_pskb+0x236/0x3a0
> >  [<ffffffff81476b40>] sock_alloc_send_skb+0x10/0x20
> >  [<ffffffff81523c18>] unix_dgram_sendmsg+0x298/0x770
> >  [<ffffffff814715f3>] sock_sendmsg+0xe3/0x110
> >  [<ffffffff81472603>] sys_sendmsg+0x243/0x3c0
> >  [<ffffffff815e7238>] system_call_fastpath+0x16/0x1b
> >  [<ffffffffffffffff>] 0xffffffffffffffff
> 
> hum.  I wonder if kmemcheck is disliking prefetchw()?

Nope, prefetchw() is OK versus kmemcheck.

This is in __kmalloc_track_caller(), not in networking stuff.

CC Christoph Lameter

I guess this_cpu_cmpxchg16b() is the offender.

A disassembly of __kmalloc_track_caller() would help, but I feel its the
read of s->cpu_slab->freelist

It seems to be at address 
0xffff88001b0bb800 and contains 0xffff88001b0bb000 but kmemcheck thinks
its not initialized.

Its located in percpu zone, maybe kmemcheck has a problem with it ?

alloc_kmem_cache_cpus() does a call to __alloc_percpu(), so this must
have been zeroed at the very beginning of kmem_cache life.


Hmm, looking at mm/slub.c, I wonder what prevents "object" from pointing
to a now freed and unreachable zone of memory. (Say we are interrupted,
object given to interrupt handler and this one wants to change page bits
to trap access)




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19  2:51   ` Eric Dumazet
@ 2011-04-19  3:09     ` Eric Dumazet
  2011-04-19  3:20       ` Eric Dumazet
  2011-04-19 17:09       ` Christoph Lameter
  0 siblings, 2 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-19  3:09 UTC (permalink / raw)
  To: Andrew Morton
  Cc: netdev, bugzilla-daemon, bugme-daemon, casteyde.christian,
	Vegard Nossum, Pekka Enberg, Christoph Lameter

Le mardi 19 avril 2011 à 04:51 +0200, Eric Dumazet a écrit :

> Hmm, looking at mm/slub.c, I wonder what prevents "object" from pointing
> to a now freed and unreachable zone of memory. (Say we are interrupted,
> object given to interrupt handler and this one wants to change page bits
> to trap access)


Yes, I suspect this whole business is not kmemcheck compatable, or
DEBUG_PAGEALLOC

get_freepointer(s, object) can access to freed memory and kmemcheck
triggers the fault, while this_cpu_cmpxchg_double() would presumably
detect a change of tid and would not perform the freelist/tid change.





^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19  3:09     ` Eric Dumazet
@ 2011-04-19  3:20       ` Eric Dumazet
  2011-04-19 17:10         ` Christoph Lameter
  2011-04-19 17:09       ` Christoph Lameter
  1 sibling, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-19  3:20 UTC (permalink / raw)
  To: Andrew Morton
  Cc: netdev, bugzilla-daemon, bugme-daemon, casteyde.christian,
	Vegard Nossum, Pekka Enberg, Christoph Lameter

Le mardi 19 avril 2011 à 05:09 +0200, Eric Dumazet a écrit :
> Le mardi 19 avril 2011 à 04:51 +0200, Eric Dumazet a écrit :
> 
> > Hmm, looking at mm/slub.c, I wonder what prevents "object" from pointing
> > to a now freed and unreachable zone of memory. (Say we are interrupted,
> > object given to interrupt handler and this one wants to change page bits
> > to trap access)
> 
> 
> Yes, I suspect this whole business is not kmemcheck compatable, or
> DEBUG_PAGEALLOC
> 
> get_freepointer(s, object) can access to freed memory and kmemcheck
> triggers the fault, while this_cpu_cmpxchg_double() would presumably
> detect a change of tid and would not perform the freelist/tid change.
> 
> 
> 

Christian, please try following patch, thanks

diff --git a/mm/slub.c b/mm/slub.c
index 94d2a33..84febe9 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1540,7 +1540,12 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
 	}
 }
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#if defined(CONFIG_CMPXCHG_LOCAL) && \
+	!defined(CONFIG_KMEMCHECK) && !defined(DEBUG_PAGEALLOC)
+#define SLUB_USE_CMPXCHG_DOUBLE
+#endif
+
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 #ifdef CONFIG_PREEMPT
 /*
  * Calculate the next globally unique transaction for disambiguiation
@@ -1604,7 +1609,7 @@ static inline void note_cmpxchg_failure(const char *n,
 
 void init_kmem_cache_cpus(struct kmem_cache *s)
 {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	int cpu;
 
 	for_each_possible_cpu(cpu)
@@ -1643,7 +1648,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 		page->inuse--;
 	}
 	c->page = NULL;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 #endif
 	unfreeze_slab(s, page, tail);
@@ -1780,7 +1785,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 {
 	void **object;
 	struct page *new;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -1819,7 +1824,7 @@ load_freelist:
 	c->node = page_to_nid(c->page);
 unlock_out:
 	slab_unlock(c->page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 	local_irq_restore(flags);
 #endif
@@ -1858,7 +1863,7 @@ new_slab:
 	}
 	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
 		slab_out_of_memory(s, gfpflags, node);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return NULL;
@@ -1887,7 +1892,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 {
 	void **object;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -1896,7 +1901,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 	if (slab_pre_alloc_hook(s, gfpflags))
 		return NULL;
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 #else
 redo:
@@ -1910,7 +1915,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * The transaction ids are globally unique per cpu and per operation on
 	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@@ -1927,7 +1932,7 @@ redo:
 		object = __slab_alloc(s, gfpflags, node, addr, c);
 
 	else {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		/*
 		 * The cmpxchg will only match if there was no additional
 		 * operation and if we are on the right processor.
@@ -1954,7 +1959,7 @@ redo:
 		stat(s, ALLOC_FASTPATH);
 	}
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 
@@ -2034,7 +2039,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 {
 	void *prior;
 	void **object = (void *)x;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -2070,7 +2075,7 @@ checks_ok:
 
 out_unlock:
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return;
@@ -2084,7 +2089,7 @@ slab_empty:
 		stat(s, FREE_REMOVE_PARTIAL);
 	}
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	stat(s, FREE_SLAB);
@@ -2113,7 +2118,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 {
 	void **object = (void *)x;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -2121,7 +2126,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 
 	slab_free_hook(s, x);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 
 #else
@@ -2136,7 +2141,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	tid = c->tid;
 	barrier();
 #endif
@@ -2144,7 +2149,7 @@ redo:
 	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
 		set_freepointer(s, object, c->freelist);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
@@ -2160,7 +2165,7 @@ redo:
 	} else
 		__slab_free(s, page, x, addr);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 }
@@ -2354,7 +2359,7 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
 	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
 			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * Must align to double word boundary for the double cmpxchg instructions
 	 * to work.



^ permalink raw reply related	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19  3:20       ` Eric Dumazet
@ 2011-04-19 17:10         ` Christoph Lameter
  2011-04-19 20:17           ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-04-19 17:10 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

On Tue, 19 Apr 2011, Eric Dumazet wrote:

>  	}
>  }
>
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#if defined(CONFIG_CMPXCHG_LOCAL) && \
> +	!defined(CONFIG_KMEMCHECK) && !defined(DEBUG_PAGEALLOC)
> +#define SLUB_USE_CMPXCHG_DOUBLE
> +#endif
> +
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  #ifdef CONFIG_PREEMPT
>  /*

Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
access is occurring?

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19 17:10         ` Christoph Lameter
@ 2011-04-19 20:17           ` Eric Dumazet
  2011-04-19 21:18             ` Christoph Lameter
  2011-04-20  5:56             ` Pekka Enberg
  0 siblings, 2 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-19 20:17 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

Le mardi 19 avril 2011 à 12:10 -0500, Christoph Lameter a écrit :
> On Tue, 19 Apr 2011, Eric Dumazet wrote:
> 
> >  	}
> >  }
> >
> > -#ifdef CONFIG_CMPXCHG_LOCAL
> > +#if defined(CONFIG_CMPXCHG_LOCAL) && \
> > +	!defined(CONFIG_KMEMCHECK) && !defined(DEBUG_PAGEALLOC)
> > +#define SLUB_USE_CMPXCHG_DOUBLE
> > +#endif
> > +
> > +#ifdef SLUB_USE_CMPXCHG_DOUBLE
> >  #ifdef CONFIG_PREEMPT
> >  /*
> 
> Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
> access is occurring?

Yes, here is a totally untested patch (only compiled here), to keep
kmemcheck & cmpxchg_double together.



diff --git a/mm/slub.c b/mm/slub.c
index 94d2a33..43c08c7 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -261,6 +261,14 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object)
 	return *(void **)(object + s->offset);
 }
 
+static inline void *get_freepointer_mark(struct kmem_cache *s, void *object)
+{
+	void *ptr = object + s->offset;
+
+	kmemcheck_mark_initialized(ptr, sizeof(void *));
+	return *(void **)ptr;
+}
+
 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 {
 	*(void **)(object + s->offset) = fp;
@@ -1540,7 +1548,11 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
 	}
 }
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(DEBUG_PAGEALLOC)
+#define SLUB_USE_CMPXCHG_DOUBLE
+#endif
+
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 #ifdef CONFIG_PREEMPT
 /*
  * Calculate the next globally unique transaction for disambiguiation
@@ -1604,7 +1616,7 @@ static inline void note_cmpxchg_failure(const char *n,
 
 void init_kmem_cache_cpus(struct kmem_cache *s)
 {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	int cpu;
 
 	for_each_possible_cpu(cpu)
@@ -1643,7 +1655,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 		page->inuse--;
 	}
 	c->page = NULL;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 #endif
 	unfreeze_slab(s, page, tail);
@@ -1780,7 +1792,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 {
 	void **object;
 	struct page *new;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -1819,7 +1831,7 @@ load_freelist:
 	c->node = page_to_nid(c->page);
 unlock_out:
 	slab_unlock(c->page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 	local_irq_restore(flags);
 #endif
@@ -1858,7 +1870,7 @@ new_slab:
 	}
 	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
 		slab_out_of_memory(s, gfpflags, node);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return NULL;
@@ -1887,7 +1899,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 {
 	void **object;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -1896,7 +1908,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 	if (slab_pre_alloc_hook(s, gfpflags))
 		return NULL;
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 #else
 redo:
@@ -1910,7 +1922,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * The transaction ids are globally unique per cpu and per operation on
 	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@@ -1927,7 +1939,7 @@ redo:
 		object = __slab_alloc(s, gfpflags, node, addr, c);
 
 	else {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		/*
 		 * The cmpxchg will only match if there was no additional
 		 * operation and if we are on the right processor.
@@ -1943,7 +1955,8 @@ redo:
 		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				object, tid,
-				get_freepointer(s, object), next_tid(tid)))) {
+				get_freepointer_mark(s, object),
+				next_tid(tid)))) {
 
 			note_cmpxchg_failure("slab_alloc", s, tid);
 			goto redo;
@@ -1954,7 +1967,7 @@ redo:
 		stat(s, ALLOC_FASTPATH);
 	}
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 
@@ -2034,7 +2047,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 {
 	void *prior;
 	void **object = (void *)x;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -2070,7 +2083,7 @@ checks_ok:
 
 out_unlock:
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return;
@@ -2084,7 +2097,7 @@ slab_empty:
 		stat(s, FREE_REMOVE_PARTIAL);
 	}
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	stat(s, FREE_SLAB);
@@ -2113,7 +2126,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 {
 	void **object = (void *)x;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -2121,7 +2134,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 
 	slab_free_hook(s, x);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 
 #else
@@ -2136,7 +2149,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	tid = c->tid;
 	barrier();
 #endif
@@ -2144,7 +2157,7 @@ redo:
 	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
 		set_freepointer(s, object, c->freelist);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
@@ -2160,7 +2173,7 @@ redo:
 	} else
 		__slab_free(s, page, x, addr);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 }
@@ -2354,7 +2367,7 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
 	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
 			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * Must align to double word boundary for the double cmpxchg instructions
 	 * to work.



^ permalink raw reply related	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19 20:17           ` Eric Dumazet
@ 2011-04-19 21:18             ` Christoph Lameter
  2011-04-20  5:04               ` Eric Dumazet
  2011-04-20  5:56             ` Pekka Enberg
  1 sibling, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-04-19 21:18 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

On Tue, 19 Apr 2011, Eric Dumazet wrote:

> > Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
> > access is occurring?
>
> Yes, here is a totally untested patch (only compiled here), to keep
> kmemcheck & cmpxchg_double together.

Ok looks somewhat saner. Why does DEBUG_PAGEALLOC need this? Pages are
never freed as long as a page is frozen and a page needs to be frozen to
be allocated from. I dont see how we could reference a free page.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19 21:18             ` Christoph Lameter
@ 2011-04-20  5:04               ` Eric Dumazet
  2011-04-20 14:04                 ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20  5:04 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

Le mardi 19 avril 2011 à 16:18 -0500, Christoph Lameter a écrit :
> On Tue, 19 Apr 2011, Eric Dumazet wrote:
> 
> > > Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
> > > access is occurring?
> >
> > Yes, here is a totally untested patch (only compiled here), to keep
> > kmemcheck & cmpxchg_double together.
> 
> Ok looks somewhat saner. Why does DEBUG_PAGEALLOC need this? Pages are
> never freed as long as a page is frozen and a page needs to be frozen to
> be allocated from. I dont see how we could reference a free page.

We run lockless and IRQ enabled, are you sure we cannot at this point :

CPU0 - Receive an IRQ
CPU0 - Allocate this same object consume the page(s) containing this object
CPU0 - Pass this object/memory to another cpu1
CPU1 - Free memory and free the page(s)
CPU0 - Return from IRQ
CPU0 - Access now unreachable memory ?




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  5:04               ` Eric Dumazet
@ 2011-04-20 14:04                 ` Christoph Lameter
  0 siblings, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-04-20 14:04 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1001 bytes --]

On Wed, 20 Apr 2011, Eric Dumazet wrote:

> Le mardi 19 avril 2011 à 16:18 -0500, Christoph Lameter a écrit :
> > On Tue, 19 Apr 2011, Eric Dumazet wrote:
> >
> > > > Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
> > > > access is occurring?
> > >
> > > Yes, here is a totally untested patch (only compiled here), to keep
> > > kmemcheck & cmpxchg_double together.
> >
> > Ok looks somewhat saner. Why does DEBUG_PAGEALLOC need this? Pages are
> > never freed as long as a page is frozen and a page needs to be frozen to
> > be allocated from. I dont see how we could reference a free page.
>
> We run lockless and IRQ enabled, are you sure we cannot at this point :
>
> CPU0 - Receive an IRQ
> CPU0 - Allocate this same object consume the page(s) containing this object
> CPU0 - Pass this object/memory to another cpu1
> CPU1 - Free memory and free the page(s)
> CPU0 - Return from IRQ
> CPU0 - Access now unreachable memory ?

True this can occur.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19 20:17           ` Eric Dumazet
  2011-04-19 21:18             ` Christoph Lameter
@ 2011-04-20  5:56             ` Pekka Enberg
  2011-04-20  6:04               ` Eric Dumazet
  1 sibling, 1 reply; 66+ messages in thread
From: Pekka Enberg @ 2011-04-20  5:56 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Andrew Morton, netdev, bugzilla-daemon,
	bugme-daemon, casteyde.christian, Vegard Nossum

On 4/19/11 11:17 PM, Eric Dumazet wrote:
> Le mardi 19 avril 2011 à 12:10 -0500, Christoph Lameter a écrit :
>> On Tue, 19 Apr 2011, Eric Dumazet wrote:
>>
>>>   	}
>>>   }
>>>
>>> -#ifdef CONFIG_CMPXCHG_LOCAL
>>> +#if defined(CONFIG_CMPXCHG_LOCAL)&&  \
>>> +	!defined(CONFIG_KMEMCHECK)&&  !defined(DEBUG_PAGEALLOC)
>>> +#define SLUB_USE_CMPXCHG_DOUBLE
>>> +#endif
>>> +
>>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>>   #ifdef CONFIG_PREEMPT
>>>   /*
>> Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
>> access is occurring?
> Yes, here is a totally untested patch (only compiled here), to keep
> kmemcheck&  cmpxchg_double together.

Looks good to me! Can we get someone to test it as well?

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  5:56             ` Pekka Enberg
@ 2011-04-20  6:04               ` Eric Dumazet
  2011-04-20  7:45                 ` casteyde.christian
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20  6:04 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Christoph Lameter, Andrew Morton, netdev, bugzilla-daemon,
	bugme-daemon, casteyde.christian, Vegard Nossum

Le mercredi 20 avril 2011 à 08:56 +0300, Pekka Enberg a écrit :
> On 4/19/11 11:17 PM, Eric Dumazet wrote:
> > Le mardi 19 avril 2011 à 12:10 -0500, Christoph Lameter a écrit :
> >> On Tue, 19 Apr 2011, Eric Dumazet wrote:
> >>
> >>>   	}
> >>>   }
> >>>
> >>> -#ifdef CONFIG_CMPXCHG_LOCAL
> >>> +#if defined(CONFIG_CMPXCHG_LOCAL)&&  \
> >>> +	!defined(CONFIG_KMEMCHECK)&&  !defined(DEBUG_PAGEALLOC)
> >>> +#define SLUB_USE_CMPXCHG_DOUBLE
> >>> +#endif
> >>> +
> >>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
> >>>   #ifdef CONFIG_PREEMPT
> >>>   /*
> >> Ugg.. Isnt there some way to indicate to kmemcheck that a speculative
> >> access is occurring?
> > Yes, here is a totally untested patch (only compiled here), to keep
> > kmemcheck&  cmpxchg_double together.
> 
> Looks good to me! Can we get someone to test it as well?

I tested first patch, but was not able to trigger the fault anyway
without it. I'll try a bit more today if time permits...

It would be nice if Christian can reproduce the initial problem easily
and give us the steps...




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  6:04               ` Eric Dumazet
@ 2011-04-20  7:45                 ` casteyde.christian
  2011-04-20  7:49                   ` Pekka Enberg
  0 siblings, 1 reply; 66+ messages in thread
From: casteyde.christian @ 2011-04-20  7:45 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Pekka Enberg, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, casteyde.christian, Vegard Nossum

Quoting Eric Dumazet <eric.dumazet@gmail.com>:

> > Looks good to me! Can we get someone to test it as well?
>
> I tested first patch, but was not able to trigger the fault anyway
> without it. I'll try a bit more today if time permits...
>
> It would be nice if Christian can reproduce the initial problem easily
> and give us the steps...
>
>
>
>

Indeed I can reproduce each time I boot, however I didn't managed to apply the
patch to test it on -rc3 (neither -rc4), only the first hunk passed.

I simply boot on this laptop with kmemcheck activated to get the warning, with
vanilla -rc3. I've also tested -rc4 yersterday (without the patch therefore),
the warning was not the same (it's a bit later, I will post the dmesg output on
bugzilla tonight).

For info, my laptop is single core if that matters, it is preemptible, with
slub, 64bits, on an old CPU (Athlon64 3000 pre- lahf in 64bits).

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  7:45                 ` casteyde.christian
@ 2011-04-20  7:49                   ` Pekka Enberg
  2011-04-20  8:09                     ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Pekka Enberg @ 2011-04-20  7:49 UTC (permalink / raw)
  To: casteyde.christian
  Cc: Eric Dumazet, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On 4/20/11 10:45 AM, casteyde.christian@free.fr wrote:
> Indeed I can reproduce each time I boot, however I didn't managed to apply the
> patch to test it on -rc3 (neither -rc4), only the first hunk passed.

That's odd. Eric?

> I simply boot on this laptop with kmemcheck activated to get the warning, with
> vanilla -rc3. I've also tested -rc4 yersterday (without the patch therefore),
> the warning was not the same (it's a bit later, I will post the dmesg output on
> bugzilla tonight).

That's expected. You're unlikely to see the problem in the exact same 
place across different kernel configs and versions.

			Pekka

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  7:49                   ` Pekka Enberg
@ 2011-04-20  8:09                     ` Eric Dumazet
  2011-04-20  8:21                       ` Pekka Enberg
  2011-04-20  9:07                       ` Eric Dumazet
  0 siblings, 2 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20  8:09 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: casteyde.christian, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 10:49 +0300, Pekka Enberg a écrit :
> On 4/20/11 10:45 AM, casteyde.christian@free.fr wrote:
> > Indeed I can reproduce each time I boot, however I didn't managed to apply the
> > patch to test it on -rc3 (neither -rc4), only the first hunk passed.
> 
> That's odd. Eric?
> 

I dont know, my patches were linux-2.6 based, and I pull tree very
often ;)

> > I simply boot on this laptop with kmemcheck activated to get the warning, with
> > vanilla -rc3. I've also tested -rc4 yersterday (without the patch therefore),
> > the warning was not the same (it's a bit later, I will post the dmesg output on
> > bugzilla tonight).
> 
> That's expected. You're unlikely to see the problem in the exact same 
> place across different kernel configs and versions.
> 

Christian, please send us your .config

Thanks



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  8:09                     ` Eric Dumazet
@ 2011-04-20  8:21                       ` Pekka Enberg
  2011-04-20  9:07                       ` Eric Dumazet
  1 sibling, 0 replies; 66+ messages in thread
From: Pekka Enberg @ 2011-04-20  8:21 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: casteyde.christian, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On 4/20/11 11:09 AM, Eric Dumazet wrote:
> Le mercredi 20 avril 2011 à 10:49 +0300, Pekka Enberg a écrit :
>> On 4/20/11 10:45 AM, casteyde.christian@free.fr wrote:
>>> Indeed I can reproduce each time I boot, however I didn't managed to apply the
>>> patch to test it on -rc3 (neither -rc4), only the first hunk passed.
>>
>> That's odd. Eric?
>>
>
> I dont know, my patches were linux-2.6 based, and I pull tree very
> often ;)

Btw, the patch applies fine here on top of 2.6.39-rc4.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  8:09                     ` Eric Dumazet
  2011-04-20  8:21                       ` Pekka Enberg
@ 2011-04-20  9:07                       ` Eric Dumazet
  2011-04-20 10:02                         ` Eric Dumazet
  1 sibling, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20  9:07 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: casteyde.christian, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum


I had one splat (before applying any patch), adding CONFIG_PREEMPT to my
build :

[   84.629936] WARNING: kmemcheck: Caught 64-bit read from uninitialized memory (ffff88011a7376f0)
[   84.629939] 5868ba1a0188ffff5868ba1a0188ffff7078731a0188ffffe0e1181a0188ffff
[   84.629952]  i i i i i i i i i i i i i i i i u u u u u u u u u u u u u u u u
[   84.629963]                                  ^
[   84.629964] 
[   84.629966] Pid: 2060, comm: 05-wait_for_sys Not tainted 2.6.39-rc4-00237-ge3de956-dirty #550 HP ProLiant BL460c G6
[   84.629969] RIP: 0010:[<ffffffff810f0e80>]  [<ffffffff810f0e80>] kmem_cache_alloc+0x50/0x190
[   84.629977] RSP: 0018:ffff88011a0b9988  EFLAGS: 00010286
[   84.629979] RAX: 0000000000000000 RBX: ffff88011a739a98 RCX: 0000000000620780
[   84.629980] RDX: 0000000000620740 RSI: 0000000000017400 RDI: ffffffff810db8f5
[   84.629982] RBP: ffff88011a0b99b8 R08: ffff88011a261dd8 R09: 0000000000000009
[   84.629983] R10: 0000000000000002 R11: ffff88011fffce00 R12: ffff88011b00a600
[   84.629985] R13: ffff88011a7376f0 R14: 00000000000000d0 R15: ffff88011abbb0c0
[   84.629987] FS:  0000000000000000(0000) GS:ffff88011fc00000(0063) knlGS:00000000f76ff6c0
[   84.629989] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[   84.629991] CR2: ffff88011998dab8 CR3: 000000011a13f000 CR4: 00000000000006f0
[   84.629992] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   84.629994] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
[   84.629995]  [<ffffffff810db8f5>] anon_vma_prepare+0x55/0x190
[   84.630000]  [<ffffffff810cfe90>] handle_pte_fault+0x470/0x6e0
[   84.630002]  [<ffffffff810d1654>] handle_mm_fault+0x124/0x1a0
[   84.630005]  [<ffffffff8147a510>] do_page_fault+0x160/0x560
[   84.630008]  [<ffffffff81477fcf>] page_fault+0x1f/0x30
[   84.630013]  [<ffffffff810b31f8>] generic_file_aio_read+0x528/0x740
[   84.630017]  [<ffffffff810f5461>] do_sync_read+0xd1/0x110
[   84.630021]  [<ffffffff810f5c36>] vfs_read+0xc6/0x160
[   84.630023]  [<ffffffff810f60b0>] sys_read+0x50/0x90
[   84.630025]  [<ffffffff8147f4e9>] sysenter_dispatch+0x7/0x27
[   84.630030]  [<ffffffffffffffff>] 0xffffffffffffffff

ffffffff810f0e6d:       0f 84 b5 00 00 00       je     ffffffff810f0f28 <kmem_cache_alloc+0xf8>
ffffffff810f0e73:       49 63 44 24 20          movslq 0x20(%r12),%rax
ffffffff810f0e78:       48 8d 4a 40             lea    0x40(%rdx),%rcx
ffffffff810f0e7c:       49 8b 34 24             mov    (%r12),%rsi
>>ffffffff810f0e80:       49 8b 5c 05 00          mov    0x0(%r13,%rax,1),%rbx
ffffffff810f0e85:       4c 89 e8                mov    %r13,%rax
ffffffff810f0e88:       e8 83 19 0e 00          callq  ffffffff811d2810 <this_cpu_cmpxchg16b_emu>
ffffffff810f0e8d:       0f 1f 40 00             nopl   0x0(%rax)
ffffffff810f0e91:       84 c0                   test   %al,%al
ffffffff810f0e93:       74 c1                   je     ffffffff810f0e56 <kmem_cache_alloc+0x26>


So this is definitely the access to object->next that triggers the fault.

Problem is : my (2nd) patch only reduces the window of occurrence of the bug, since we can
be preempted/interrupted between the kmemcheck_mark_initialized() and access to object->next :

The preempt/irq could allocate the object and free it again.

So KMEMCHECK would require us to block IRQ to be safe.

Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.

Christoph, please reconsider first version of patch (disabling SLUB_CMPXCHG_DOUBLE if
either KMEMCHECK or DEBUG_PAGEALLOC is defined)

Thanks



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20  9:07                       ` Eric Dumazet
@ 2011-04-20 10:02                         ` Eric Dumazet
  2011-04-20 14:05                           ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 10:02 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: casteyde.christian, Christoph Lameter, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 11:07 +0200, Eric Dumazet a écrit :
> I had one splat (before applying any patch), adding CONFIG_PREEMPT to my
> build :
> 
> [   84.629936] WARNING: kmemcheck: Caught 64-bit read from uninitialized memory (ffff88011a7376f0)
> [   84.629939] 5868ba1a0188ffff5868ba1a0188ffff7078731a0188ffffe0e1181a0188ffff
> [   84.629952]  i i i i i i i i i i i i i i i i u u u u u u u u u u u u u u u u
> [   84.629963]                                  ^
> [   84.629964] 
> [   84.629966] Pid: 2060, comm: 05-wait_for_sys Not tainted 2.6.39-rc4-00237-ge3de956-dirty #550 HP ProLiant BL460c G6
> [   84.629969] RIP: 0010:[<ffffffff810f0e80>]  [<ffffffff810f0e80>] kmem_cache_alloc+0x50/0x190
> [   84.629977] RSP: 0018:ffff88011a0b9988  EFLAGS: 00010286
> [   84.629979] RAX: 0000000000000000 RBX: ffff88011a739a98 RCX: 0000000000620780
> [   84.629980] RDX: 0000000000620740 RSI: 0000000000017400 RDI: ffffffff810db8f5
> [   84.629982] RBP: ffff88011a0b99b8 R08: ffff88011a261dd8 R09: 0000000000000009
> [   84.629983] R10: 0000000000000002 R11: ffff88011fffce00 R12: ffff88011b00a600
> [   84.629985] R13: ffff88011a7376f0 R14: 00000000000000d0 R15: ffff88011abbb0c0
> [   84.629987] FS:  0000000000000000(0000) GS:ffff88011fc00000(0063) knlGS:00000000f76ff6c0
> [   84.629989] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
> [   84.629991] CR2: ffff88011998dab8 CR3: 000000011a13f000 CR4: 00000000000006f0
> [   84.629992] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [   84.629994] DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
> [   84.629995]  [<ffffffff810db8f5>] anon_vma_prepare+0x55/0x190
> [   84.630000]  [<ffffffff810cfe90>] handle_pte_fault+0x470/0x6e0
> [   84.630002]  [<ffffffff810d1654>] handle_mm_fault+0x124/0x1a0
> [   84.630005]  [<ffffffff8147a510>] do_page_fault+0x160/0x560
> [   84.630008]  [<ffffffff81477fcf>] page_fault+0x1f/0x30
> [   84.630013]  [<ffffffff810b31f8>] generic_file_aio_read+0x528/0x740
> [   84.630017]  [<ffffffff810f5461>] do_sync_read+0xd1/0x110
> [   84.630021]  [<ffffffff810f5c36>] vfs_read+0xc6/0x160
> [   84.630023]  [<ffffffff810f60b0>] sys_read+0x50/0x90
> [   84.630025]  [<ffffffff8147f4e9>] sysenter_dispatch+0x7/0x27
> [   84.630030]  [<ffffffffffffffff>] 0xffffffffffffffff
> 
> ffffffff810f0e6d:       0f 84 b5 00 00 00       je     ffffffff810f0f28 <kmem_cache_alloc+0xf8>
> ffffffff810f0e73:       49 63 44 24 20          movslq 0x20(%r12),%rax
> ffffffff810f0e78:       48 8d 4a 40             lea    0x40(%rdx),%rcx
> ffffffff810f0e7c:       49 8b 34 24             mov    (%r12),%rsi
> >>ffffffff810f0e80:       49 8b 5c 05 00          mov    0x0(%r13,%rax,1),%rbx
> ffffffff810f0e85:       4c 89 e8                mov    %r13,%rax
> ffffffff810f0e88:       e8 83 19 0e 00          callq  ffffffff811d2810 <this_cpu_cmpxchg16b_emu>
> ffffffff810f0e8d:       0f 1f 40 00             nopl   0x0(%rax)
> ffffffff810f0e91:       84 c0                   test   %al,%al
> ffffffff810f0e93:       74 c1                   je     ffffffff810f0e56 <kmem_cache_alloc+0x26>
> 
> 
> So this is definitely the access to object->next that triggers the fault.
> 
> Problem is : my (2nd) patch only reduces the window of occurrence of the bug, since we can
> be preempted/interrupted between the kmemcheck_mark_initialized() and access to object->next :
> 
> The preempt/irq could allocate the object and free it again.
> 
> So KMEMCHECK would require us to block IRQ to be safe.
> 
> Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.
> 
> Christoph, please reconsider first version of patch (disabling SLUB_CMPXCHG_DOUBLE if
> either KMEMCHECK or DEBUG_PAGEALLOC is defined)

Or this alternate one : keep cmpxchg_double() stuff but block IRQ in
slab_alloc() if KMEMCHECK or DEBUG_PAGEALLOC

I tested it and got no kmemcheck splat

Thanks

[PATCH] slub: block IRQ in slab_alloc() if KMEMCHECK or DEBUG_PAGEALLOC

Christian Casteyde reported a KMEMCHECK splat in slub code.

Problem is now we are lockless and allow IRQ in slab_alloc, the object
we manipulate from freelist can be allocated and freed right before we
try to read object->next

Same problem can happen with DEBUG_PAGEALLOC

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |   16 ++++++++++++----
 1 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 94d2a33..9c34a2b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1881,7 +1881,13 @@ debug:
  * If not then __slab_alloc is called for slow processing.
  *
  * Otherwise we can simply pick the next object from the lockless free list.
+ * Since we access object->next, we must disable irqs if KMEMCHECK or
+ * DEBUG_PAGEALLOC is defined, since object could be allocated and freed
+ * under us.
  */
+#if !defined(CONFIG_CMPXCHG_LOCAL) || defined(CONFIG_KMEMCHECK) || defined(CONFIG_DEBUG_PAGEALLOC)
+#define MASK_IRQ_IN_SLAB_ALLOC
+#endif
 static __always_inline void *slab_alloc(struct kmem_cache *s,
 		gfp_t gfpflags, int node, unsigned long addr)
 {
@@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 	struct kmem_cache_cpu *c;
 #ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long tid;
-#else
+#endif
+#ifdef MASK_IRQ_IN_SLAB_ALLOC
 	unsigned long flags;
 #endif
 
 	if (slab_pre_alloc_hook(s, gfpflags))
 		return NULL;
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifdef MASK_IRQ_IN_SLAB_ALLOC
 	local_irq_save(flags);
-#else
+#endif
+#ifdef CONFIG_CMPXCHG_LOCAL
 redo:
 #endif
 
@@ -1954,7 +1962,7 @@ redo:
 		stat(s, ALLOC_FASTPATH);
 	}
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifdef MASK_IRQ_IN_SLAB_ALLOC
 	local_irq_restore(flags);
 #endif
 



^ permalink raw reply related	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 10:02                         ` Eric Dumazet
@ 2011-04-20 14:05                           ` Christoph Lameter
  2011-04-20 14:26                             ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-04-20 14:05 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On Wed, 20 Apr 2011, Eric Dumazet wrote:

> > Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.

Ok your first patch seems to be the sanest approach.

>  {
> @@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
>  	struct kmem_cache_cpu *c;
>  #ifdef CONFIG_CMPXCHG_LOCAL
>  	unsigned long tid;
> -#else
> +#endif
> +#ifdef MASK_IRQ_IN_SLAB_ALLOC
>  	unsigned long flags;
>  #endif
>

Yea well that does not bring us much.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 14:05                           ` Christoph Lameter
@ 2011-04-20 14:26                             ` Eric Dumazet
  2011-04-20 14:42                               ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 14:26 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 09:05 -0500, Christoph Lameter a écrit :
> On Wed, 20 Apr 2011, Eric Dumazet wrote:
> 
> > > Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.
> 
> Ok your first patch seems to be the sanest approach.
> 
> >  {
> > @@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
> >  	struct kmem_cache_cpu *c;
> >  #ifdef CONFIG_CMPXCHG_LOCAL
> >  	unsigned long tid;
> > -#else
> > +#endif
> > +#ifdef MASK_IRQ_IN_SLAB_ALLOC
> >  	unsigned long flags;
> >  #endif
> >
> 
> Yea well that does not bring us much.

Well, we keep the fast free path ?

only slab_alloc() would have to disable irqs for ~20 instructions.




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 14:26                             ` Eric Dumazet
@ 2011-04-20 14:42                               ` Christoph Lameter
  2011-04-20 15:01                                 ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-04-20 14:42 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

[-- Attachment #1: Type: TEXT/PLAIN, Size: 996 bytes --]

On Wed, 20 Apr 2011, Eric Dumazet wrote:

> Le mercredi 20 avril 2011 à 09:05 -0500, Christoph Lameter a écrit :
> > On Wed, 20 Apr 2011, Eric Dumazet wrote:
> >
> > > > Then, just disable SLUB_CMPXCHG_DOUBLE if KMEMCHECK is defined, as I did in my first patch.
> >
> > Ok your first patch seems to be the sanest approach.
> >
> > >  {
> > > @@ -1889,16 +1895,18 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
> > >  	struct kmem_cache_cpu *c;
> > >  #ifdef CONFIG_CMPXCHG_LOCAL
> > >  	unsigned long tid;
> > > -#else
> > > +#endif
> > > +#ifdef MASK_IRQ_IN_SLAB_ALLOC
> > >  	unsigned long flags;
> > >  #endif
> > >
> >
> > Yea well that does not bring us much.
>
> Well, we keep the fast free path ?
>
> only slab_alloc() would have to disable irqs for ~20 instructions.

Avoiding the irq handling yields the savings that improve the fastpath. if
you do both then there is only a regression left. So lets go with
disabling the CMPXCHG_LOCAL.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 14:42                               ` Christoph Lameter
@ 2011-04-20 15:01                                 ` Eric Dumazet
  2011-04-20 15:15                                   ` Vegard Nossum
                                                     ` (4 more replies)
  0 siblings, 5 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 15:01 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 09:42 -0500, Christoph Lameter a écrit :

> Avoiding the irq handling yields the savings that improve the fastpath. if
> you do both then there is only a regression left. So lets go with
> disabling the CMPXCHG_LOCAL.

OK, let's do that then.

Thanks

[PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC

Christian Casteyde reported a KMEMCHECK splat in slub code.

Problem is now we are lockless and allow IRQ in slab_alloc(), the object
we manipulate from freelist can be allocated and freed right before we
try to read object->next.

Same problem can happen with DEBUG_PAGEALLOC

Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
CONFIG_DEBUG_PAGEALLOC is defined.

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |   45 +++++++++++++++++++++++++--------------------
 1 files changed, 25 insertions(+), 20 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 94d2a33..f31ab2c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1540,7 +1540,12 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
 	}
 }
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(CONFIG_KMEMCHECK) && \
+				     !defined(CONFIG_DEBUG_PAGEALLOC)
+#define SLUB_USE_CMPXCHG_DOUBLE
+#endif
+
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 #ifdef CONFIG_PREEMPT
 /*
  * Calculate the next globally unique transaction for disambiguiation
@@ -1604,7 +1609,7 @@ static inline void note_cmpxchg_failure(const char *n,
 
 void init_kmem_cache_cpus(struct kmem_cache *s)
 {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	int cpu;
 
 	for_each_possible_cpu(cpu)
@@ -1643,7 +1648,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
 		page->inuse--;
 	}
 	c->page = NULL;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 #endif
 	unfreeze_slab(s, page, tail);
@@ -1780,7 +1785,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 {
 	void **object;
 	struct page *new;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -1819,7 +1824,7 @@ load_freelist:
 	c->node = page_to_nid(c->page);
 unlock_out:
 	slab_unlock(c->page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	c->tid = next_tid(c->tid);
 	local_irq_restore(flags);
 #endif
@@ -1858,7 +1863,7 @@ new_slab:
 	}
 	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
 		slab_out_of_memory(s, gfpflags, node);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return NULL;
@@ -1887,7 +1892,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 {
 	void **object;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -1896,7 +1901,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
 	if (slab_pre_alloc_hook(s, gfpflags))
 		return NULL;
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 #else
 redo:
@@ -1910,7 +1915,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * The transaction ids are globally unique per cpu and per operation on
 	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@@ -1927,7 +1932,7 @@ redo:
 		object = __slab_alloc(s, gfpflags, node, addr, c);
 
 	else {
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		/*
 		 * The cmpxchg will only match if there was no additional
 		 * operation and if we are on the right processor.
@@ -1954,7 +1959,7 @@ redo:
 		stat(s, ALLOC_FASTPATH);
 	}
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 
@@ -2034,7 +2039,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 {
 	void *prior;
 	void **object = (void *)x;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long flags;
 
 	local_irq_save(flags);
@@ -2070,7 +2075,7 @@ checks_ok:
 
 out_unlock:
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	return;
@@ -2084,7 +2089,7 @@ slab_empty:
 		stat(s, FREE_REMOVE_PARTIAL);
 	}
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 	stat(s, FREE_SLAB);
@@ -2113,7 +2118,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 {
 	void **object = (void *)x;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	unsigned long tid;
 #else
 	unsigned long flags;
@@ -2121,7 +2126,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
 
 	slab_free_hook(s, x);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_save(flags);
 
 #else
@@ -2136,7 +2141,7 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	tid = c->tid;
 	barrier();
 #endif
@@ -2144,7 +2149,7 @@ redo:
 	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
 		set_freepointer(s, object, c->freelist);
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 		if (unlikely(!this_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
@@ -2160,7 +2165,7 @@ redo:
 	} else
 		__slab_free(s, page, x, addr);
 
-#ifndef CONFIG_CMPXCHG_LOCAL
+#ifndef SLUB_USE_CMPXCHG_DOUBLE
 	local_irq_restore(flags);
 #endif
 }
@@ -2354,7 +2359,7 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
 	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
 			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
 
-#ifdef CONFIG_CMPXCHG_LOCAL
+#ifdef SLUB_USE_CMPXCHG_DOUBLE
 	/*
 	 * Must align to double word boundary for the double cmpxchg instructions
 	 * to work.



^ permalink raw reply related	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:01                                 ` Eric Dumazet
@ 2011-04-20 15:15                                   ` Vegard Nossum
  2011-04-20 15:34                                     ` Eric Dumazet
  2011-04-20 15:17                                   ` Christoph Lameter
                                                     ` (3 subsequent siblings)
  4 siblings, 1 reply; 66+ messages in thread
From: Vegard Nossum @ 2011-04-20 15:15 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Pekka Enberg, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon

 On Wed, 20 Apr 2011 17:01:27 +0200, Eric Dumazet 
 <eric.dumazet@gmail.com> wrote:
> Le mercredi 20 avril 2011 à 09:42 -0500, Christoph Lameter a écrit :
>
>> Avoiding the irq handling yields the savings that improve the 
>> fastpath. if
>> you do both then there is only a regression left. So lets go with
>> disabling the CMPXCHG_LOCAL.
>
> OK, let's do that then.
>
> Thanks
>
> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or 
> DEBUG_PAGEALLOC
>
> Christian Casteyde reported a KMEMCHECK splat in slub code.
>
> Problem is now we are lockless and allow IRQ in slab_alloc(), the 
> object
> we manipulate from freelist can be allocated and freed right before 
> we
> try to read object->next.
>
> Same problem can happen with DEBUG_PAGEALLOC
>
> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> CONFIG_DEBUG_PAGEALLOC is defined.
>
> Reported-by: Christian Casteyde <casteyde.christian@free.fr>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Pekka Enberg <penberg@cs.helsinki.fi>
> Cc: Vegard Nossum <vegardno@ifi.uio.no>
> Cc: Christoph Lameter <cl@linux.com>

 Thanks, guys. I wonder: Is it possible to make a reproducible test-case 
 (e.g. loadable module) for this?

 Also, pardon my ignorance, but can you explain why this is a bug with 
 kmemcheck/page-alloc debug and not without them?

 Thanks,


 Vegard

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:15                                   ` Vegard Nossum
@ 2011-04-20 15:34                                     ` Eric Dumazet
  0 siblings, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 15:34 UTC (permalink / raw)
  To: vegardno
  Cc: Christoph Lameter, Pekka Enberg, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon

Le mercredi 20 avril 2011 à 17:15 +0200, Vegard Nossum a écrit :

>  Thanks, guys. I wonder: Is it possible to make a reproducible test-case 
>  (e.g. loadable module) for this?
> 

Not easy to code a specific test-case, but just use regular workload,
(and network trafic to get interrupts). Use CONFIG_PREEMPT to trigger
preemptions.

>  Also, pardon my ignorance, but can you explain why this is a bug with 
>  kmemcheck/page-alloc debug and not without them?

Without them, we can read object->next without trigerring a fault.
We can read garbage data (if object is in use, it was overwritten with
user data), but this doesnt matter because cmpxchg_double() wont perform
its work (since tid will have change)

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:01                                 ` Eric Dumazet
  2011-04-20 15:15                                   ` Vegard Nossum
@ 2011-04-20 15:17                                   ` Christoph Lameter
  2011-04-20 15:30                                     ` Eric Dumazet
  2011-04-20 19:36                                   ` Christian Casteyde
                                                     ` (2 subsequent siblings)
  4 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-04-20 15:17 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On Wed, 20 Apr 2011, Eric Dumazet wrote:

> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC

Acked-by: Christoph Lameter <cl@linux.com>

>
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(CONFIG_KMEMCHECK) && \
> +				     !defined(CONFIG_DEBUG_PAGEALLOC)
> +#define SLUB_USE_CMPXCHG_DOUBLE

#undef CONFIG_CMPXCHG_LOCAL instead? Would reduce patch size but its kind
of hacky.


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:17                                   ` Christoph Lameter
@ 2011-04-20 15:30                                     ` Eric Dumazet
  0 siblings, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 15:30 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 10:17 -0500, Christoph Lameter a écrit :
> On Wed, 20 Apr 2011, Eric Dumazet wrote:
> 
> > [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
> 
> Acked-by: Christoph Lameter <cl@linux.com>
> 
> >
> > -#ifdef CONFIG_CMPXCHG_LOCAL
> > +#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(CONFIG_KMEMCHECK) && \
> > +				     !defined(CONFIG_DEBUG_PAGEALLOC)
> > +#define SLUB_USE_CMPXCHG_DOUBLE
> 
> #undef CONFIG_CMPXCHG_LOCAL instead? Would reduce patch size but its kind
> of hacky.
> 

Well, its definitely hacky :)

I chose a local definition (instead of Kconfig game), referring to
cmpxchg_double()




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:01                                 ` Eric Dumazet
  2011-04-20 15:15                                   ` Vegard Nossum
  2011-04-20 15:17                                   ` Christoph Lameter
@ 2011-04-20 19:36                                   ` Christian Casteyde
  2011-04-20 19:55                                     ` Eric Dumazet
  2011-05-05  6:18                                   ` Eric Dumazet
  2011-05-09 19:44                                   ` Pekka Enberg
  4 siblings, 1 reply; 66+ messages in thread
From: Christian Casteyde @ 2011-04-20 19:36 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Pekka Enberg, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

[-- Attachment #1: Type: Text/Plain, Size: 9311 bytes --]

Le mercredi 20 avril 2011 17:01:27, Eric Dumazet a écrit :
> Le mercredi 20 avril 2011 à 09:42 -0500, Christoph Lameter a écrit :
> > Avoiding the irq handling yields the savings that improve the fastpath.
> > if you do both then there is only a regression left. So lets go with
> > disabling the CMPXCHG_LOCAL.
> 
> OK, let's do that then.
> 
> Thanks
> 
> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
> 
> Christian Casteyde reported a KMEMCHECK splat in slub code.
> 
> Problem is now we are lockless and allow IRQ in slab_alloc(), the object
> we manipulate from freelist can be allocated and freed right before we
> try to read object->next.
> 
> Same problem can happen with DEBUG_PAGEALLOC
> 
> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> CONFIG_DEBUG_PAGEALLOC is defined.
> 
> Reported-by: Christian Casteyde <casteyde.christian@free.fr>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Pekka Enberg <penberg@cs.helsinki.fi>
> Cc: Vegard Nossum <vegardno@ifi.uio.no>
> Cc: Christoph Lameter <cl@linux.com>
> ---
>  mm/slub.c |   45 +++++++++++++++++++++++++--------------------
>  1 files changed, 25 insertions(+), 20 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 94d2a33..f31ab2c 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -1540,7 +1540,12 @@ static void unfreeze_slab(struct kmem_cache *s,
> struct page *page, int tail) }
>  }
> 
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(CONFIG_KMEMCHECK) && \
> +				     !defined(CONFIG_DEBUG_PAGEALLOC)
> +#define SLUB_USE_CMPXCHG_DOUBLE
> +#endif
> +
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  #ifdef CONFIG_PREEMPT
>  /*
>   * Calculate the next globally unique transaction for disambiguiation
> @@ -1604,7 +1609,7 @@ static inline void note_cmpxchg_failure(const char
> *n,
> 
>  void init_kmem_cache_cpus(struct kmem_cache *s)
>  {
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	int cpu;
> 
>  	for_each_possible_cpu(cpu)
> @@ -1643,7 +1648,7 @@ static void deactivate_slab(struct kmem_cache *s,
> struct kmem_cache_cpu *c) page->inuse--;
>  	}
>  	c->page = NULL;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	c->tid = next_tid(c->tid);
>  #endif
>  	unfreeze_slab(s, page, tail);
> @@ -1780,7 +1785,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t
> gfpflags, int node, {
>  	void **object;
>  	struct page *new;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long flags;
> 
>  	local_irq_save(flags);
> @@ -1819,7 +1824,7 @@ load_freelist:
>  	c->node = page_to_nid(c->page);
>  unlock_out:
>  	slab_unlock(c->page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	c->tid = next_tid(c->tid);
>  	local_irq_restore(flags);
>  #endif
> @@ -1858,7 +1863,7 @@ new_slab:
>  	}
>  	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
>  		slab_out_of_memory(s, gfpflags, node);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	return NULL;
> @@ -1887,7 +1892,7 @@ static __always_inline void *slab_alloc(struct
> kmem_cache *s, {
>  	void **object;
>  	struct kmem_cache_cpu *c;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long tid;
>  #else
>  	unsigned long flags;
> @@ -1896,7 +1901,7 @@ static __always_inline void *slab_alloc(struct
> kmem_cache *s, if (slab_pre_alloc_hook(s, gfpflags))
>  		return NULL;
> 
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_save(flags);
>  #else
>  redo:
> @@ -1910,7 +1915,7 @@ redo:
>  	 */
>  	c = __this_cpu_ptr(s->cpu_slab);
> 
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	/*
>  	 * The transaction ids are globally unique per cpu and per operation on
>  	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
> @@ -1927,7 +1932,7 @@ redo:
>  		object = __slab_alloc(s, gfpflags, node, addr, c);
> 
>  	else {
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  		/*
>  		 * The cmpxchg will only match if there was no additional
>  		 * operation and if we are on the right processor.
> @@ -1954,7 +1959,7 @@ redo:
>  		stat(s, ALLOC_FASTPATH);
>  	}
> 
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
> 
> @@ -2034,7 +2039,7 @@ static void __slab_free(struct kmem_cache *s, struct
> page *page, {
>  	void *prior;
>  	void **object = (void *)x;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long flags;
> 
>  	local_irq_save(flags);
> @@ -2070,7 +2075,7 @@ checks_ok:
> 
>  out_unlock:
>  	slab_unlock(page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	return;
> @@ -2084,7 +2089,7 @@ slab_empty:
>  		stat(s, FREE_REMOVE_PARTIAL);
>  	}
>  	slab_unlock(page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	stat(s, FREE_SLAB);
> @@ -2113,7 +2118,7 @@ static __always_inline void slab_free(struct
> kmem_cache *s, {
>  	void **object = (void *)x;
>  	struct kmem_cache_cpu *c;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long tid;
>  #else
>  	unsigned long flags;
> @@ -2121,7 +2126,7 @@ static __always_inline void slab_free(struct
> kmem_cache *s,
> 
>  	slab_free_hook(s, x);
> 
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_save(flags);
> 
>  #else
> @@ -2136,7 +2141,7 @@ redo:
>  	 */
>  	c = __this_cpu_ptr(s->cpu_slab);
> 
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	tid = c->tid;
>  	barrier();
>  #endif
> @@ -2144,7 +2149,7 @@ redo:
>  	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
>  		set_freepointer(s, object, c->freelist);
> 
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  		if (unlikely(!this_cpu_cmpxchg_double(
>  				s->cpu_slab->freelist, s->cpu_slab->tid,
>  				c->freelist, tid,
> @@ -2160,7 +2165,7 @@ redo:
>  	} else
>  		__slab_free(s, page, x, addr);
> 
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  }
> @@ -2354,7 +2359,7 @@ static inline int alloc_kmem_cache_cpus(struct
> kmem_cache *s) BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
>  			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
> 
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	/*
>  	 * Must align to double word boundary for the double cmpxchg instructions
>  	 * to work.


I applied this patch to 2.6.39-rc4 (sorry for the last test, it indeed applied 
correctly), I still get the following:

ADDRCONF(NETDEV_UP): eth1: link is not ready
b43-phy0: Loading firmware version 478.104 (2008-07-01 00:50:23)
ADDRCONF(NETDEV_UP): eth1: link is not ready
eth1: direct probe to 2e:94:8b:66:86:88 (try 1/3)
eth1: direct probe responded
eth1: authenticate with 2e:94:8b:66:86:88 (try 1)
eth1: authenticated
eth1: associate with 2e:94:8b:66:86:88 (try 1)
eth1: RX AssocResp from 2e:94:8b:66:86:88 (capab=0x411 status=0 aid=1)
eth1: associated
ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
eth1: no IPv6 routers present
WARNING: kmemcheck: Caught 64-bit read from uninitialized memory 
(ffff88001b000c00)
0008001b0088ffff0010000000000000c055530000eaffff0010000000000000
 u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u
 ^

Pid: 1874, comm: dhcpcd Not tainted 2.6.39-rc4 #4 Acer,Inc. Aspire 1510  
/Aspire 1510
RIP: 0010:[<ffffffff81263d9c>]  [<ffffffff81263d9c>] memmove+0x2c/0x190
RSP: 0018:ffff88001c17f8a0  EFLAGS: 00010206
RAX: ffff88001b000c00 RBX: ffff88001b070400 RCX: 0000000000000020
RDX: 000000000000016f RSI: ffff88001b000c00 RDI: ffff88001b000c00
RBP: ffff88001c17f8f8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000200 R14: 0000000000000000 R15: 0000000000000001
FS:  00007fd7df758700(0000) GS:ffffffff81a1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff88001d23a4b8 CR3: 000000001ba46000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff4ff0 DR7: 0000000000000400
 [<ffffffff815c7584>] ieee80211_skb_resize+0x94/0x120
 [<ffffffff815c97a4>] ieee80211_xmit+0xa4/0x280
 [<ffffffff815caf86>] ieee80211_subif_start_xmit+0x3e6/0x910
 [<ffffffff81486654>] dev_hard_start_xmit+0x384/0x6a0
 [<ffffffff8149d344>] sch_direct_xmit+0xd4/0x260
 [<ffffffff81486b4e>] dev_queue_xmit+0x1de/0x710
 [<ffffffff8156af23>] packet_sendmsg+0xa73/0xbe0
 [<ffffffff81471813>] sock_sendmsg+0xe3/0x110
 [<ffffffff81472154>] sys_sendto+0x134/0x180
 [<ffffffff815e74f8>] system_call_fastpath+0x16/0x1b
 [<ffffffffffffffff>] 0xffffffffffffffff


I'm not sure it's the same problem anyway as I've said previously.
I append my config file used to build this kernel.

[-- Attachment #2: config-debug --]
[-- Type: text/x-mpsub, Size: 65240 bytes --]

#
# Automatically generated make config: don't edit
# Linux/x86_64 2.6.39-rc3 Kernel Configuration
# Tue Apr 19 21:31:28 2011
#
CONFIG_64BIT=y
# CONFIG_X86_32 is not set
CONFIG_X86_64=y
CONFIG_X86=y
CONFIG_INSTRUCTION_DECODER=y
CONFIG_OUTPUT_FORMAT="elf64-x86-64"
CONFIG_ARCH_DEFCONFIG="arch/x86/configs/x86_64_defconfig"
CONFIG_GENERIC_CMOS_UPDATE=y
CONFIG_CLOCKSOURCE_WATCHDOG=y
CONFIG_GENERIC_CLOCKEVENTS=y
CONFIG_GENERIC_CLOCKEVENTS_BROADCAST=y
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_STACKTRACE_SUPPORT=y
CONFIG_HAVE_LATENCYTOP_SUPPORT=y
CONFIG_MMU=y
CONFIG_ZONE_DMA=y
CONFIG_NEED_DMA_MAP_STATE=y
CONFIG_NEED_SG_DMA_LENGTH=y
CONFIG_GENERIC_ISA_DMA=y
CONFIG_GENERIC_IOMAP=y
CONFIG_GENERIC_BUG=y
CONFIG_GENERIC_BUG_RELATIVE_POINTERS=y
CONFIG_GENERIC_HWEIGHT=y
CONFIG_ARCH_MAY_HAVE_PC_FDC=y
# CONFIG_RWSEM_GENERIC_SPINLOCK is not set
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_ARCH_HAS_CPU_IDLE_WAIT=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_GENERIC_TIME_VSYSCALL=y
CONFIG_ARCH_HAS_CPU_RELAX=y
CONFIG_ARCH_HAS_DEFAULT_IDLE=y
CONFIG_ARCH_HAS_CACHE_LINE_SIZE=y
CONFIG_HAVE_SETUP_PER_CPU_AREA=y
CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK=y
CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK=y
# CONFIG_HAVE_CPUMASK_OF_CPU_MAP is not set
CONFIG_ARCH_HIBERNATION_POSSIBLE=y
CONFIG_ARCH_SUSPEND_POSSIBLE=y
CONFIG_ZONE_DMA32=y
CONFIG_ARCH_POPULATES_NODE_MAP=y
CONFIG_AUDIT_ARCH=y
CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING=y
CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC=y
CONFIG_ARCH_HWEIGHT_CFLAGS="-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11"
# CONFIG_KTIME_SCALAR is not set
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
CONFIG_CONSTRUCTORS=y
CONFIG_HAVE_IRQ_WORK=y
CONFIG_IRQ_WORK=y

#
# General setup
#
CONFIG_EXPERIMENTAL=y
CONFIG_BROKEN_ON_SMP=y
CONFIG_INIT_ENV_ARG_LIMIT=32
CONFIG_CROSS_COMPILE=""
CONFIG_LOCALVERSION=""
CONFIG_LOCALVERSION_AUTO=y
CONFIG_HAVE_KERNEL_GZIP=y
CONFIG_HAVE_KERNEL_BZIP2=y
CONFIG_HAVE_KERNEL_LZMA=y
CONFIG_HAVE_KERNEL_XZ=y
CONFIG_HAVE_KERNEL_LZO=y
CONFIG_KERNEL_GZIP=y
# CONFIG_KERNEL_BZIP2 is not set
# CONFIG_KERNEL_LZMA is not set
# CONFIG_KERNEL_XZ is not set
# CONFIG_KERNEL_LZO is not set
CONFIG_SWAP=y
CONFIG_SYSVIPC=y
CONFIG_SYSVIPC_SYSCTL=y
CONFIG_POSIX_MQUEUE=y
CONFIG_POSIX_MQUEUE_SYSCTL=y
# CONFIG_BSD_PROCESS_ACCT is not set
# CONFIG_FHANDLE is not set
# CONFIG_TASKSTATS is not set
# CONFIG_AUDIT is not set
CONFIG_HAVE_GENERIC_HARDIRQS=y

#
# IRQ subsystem
#
CONFIG_GENERIC_HARDIRQS=y
CONFIG_HAVE_SPARSE_IRQ=y
CONFIG_GENERIC_IRQ_PROBE=y
CONFIG_GENERIC_IRQ_SHOW=y
CONFIG_IRQ_FORCED_THREADING=y
# CONFIG_SPARSE_IRQ is not set

#
# RCU Subsystem
#
CONFIG_TREE_PREEMPT_RCU=y
# CONFIG_TINY_RCU is not set
# CONFIG_TINY_PREEMPT_RCU is not set
CONFIG_PREEMPT_RCU=y
# CONFIG_RCU_TRACE is not set
CONFIG_RCU_FANOUT=64
# CONFIG_RCU_FANOUT_EXACT is not set
# CONFIG_TREE_RCU_TRACE is not set
CONFIG_IKCONFIG=y
CONFIG_IKCONFIG_PROC=y
CONFIG_LOG_BUF_SHIFT=17
CONFIG_HAVE_UNSTABLE_SCHED_CLOCK=y
CONFIG_CGROUPS=y
# CONFIG_CGROUP_DEBUG is not set
# CONFIG_CGROUP_NS is not set
# CONFIG_CGROUP_FREEZER is not set
# CONFIG_CGROUP_DEVICE is not set
# CONFIG_CPUSETS is not set
# CONFIG_CGROUP_CPUACCT is not set
# CONFIG_RESOURCE_COUNTERS is not set
# CONFIG_CGROUP_PERF is not set
CONFIG_CGROUP_SCHED=y
CONFIG_FAIR_GROUP_SCHED=y
# CONFIG_RT_GROUP_SCHED is not set
# CONFIG_BLK_CGROUP is not set
CONFIG_NAMESPACES=y
# CONFIG_UTS_NS is not set
# CONFIG_IPC_NS is not set
# CONFIG_USER_NS is not set
# CONFIG_PID_NS is not set
# CONFIG_NET_NS is not set
CONFIG_SCHED_AUTOGROUP=y
# CONFIG_SYSFS_DEPRECATED is not set
# CONFIG_RELAY is not set
# CONFIG_BLK_DEV_INITRD is not set
# CONFIG_CC_OPTIMIZE_FOR_SIZE is not set
CONFIG_SYSCTL=y
CONFIG_ANON_INODES=y
# CONFIG_EXPERT is not set
# CONFIG_EMBEDDED is not set
CONFIG_UID16=y
CONFIG_SYSCTL_SYSCALL=y
CONFIG_KALLSYMS=y
CONFIG_KALLSYMS_ALL=y
# CONFIG_KALLSYMS_EXTRA_PASS is not set
CONFIG_HOTPLUG=y
CONFIG_PRINTK=y
CONFIG_BUG=y
CONFIG_ELF_CORE=y
CONFIG_PCSPKR_PLATFORM=y
CONFIG_BASE_FULL=y
CONFIG_FUTEX=y
CONFIG_EPOLL=y
CONFIG_SIGNALFD=y
CONFIG_TIMERFD=y
CONFIG_EVENTFD=y
CONFIG_SHMEM=y
CONFIG_AIO=y
CONFIG_HAVE_PERF_EVENTS=y

#
# Kernel Performance Events And Counters
#
CONFIG_PERF_EVENTS=y
# CONFIG_PERF_COUNTERS is not set
# CONFIG_DEBUG_PERF_USE_VMALLOC is not set
CONFIG_VM_EVENT_COUNTERS=y
CONFIG_PCI_QUIRKS=y
CONFIG_SLUB_DEBUG=y
# CONFIG_COMPAT_BRK is not set
# CONFIG_SLAB is not set
CONFIG_SLUB=y
# CONFIG_PROFILING is not set
CONFIG_HAVE_OPROFILE=y
# CONFIG_KPROBES is not set
# CONFIG_JUMP_LABEL is not set
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS=y
CONFIG_HAVE_IOREMAP_PROT=y
CONFIG_HAVE_KPROBES=y
CONFIG_HAVE_KRETPROBES=y
CONFIG_HAVE_OPTPROBES=y
CONFIG_HAVE_ARCH_TRACEHOOK=y
CONFIG_HAVE_DMA_ATTRS=y
CONFIG_HAVE_REGS_AND_STACK_ACCESS_API=y
CONFIG_HAVE_DMA_API_DEBUG=y
CONFIG_HAVE_HW_BREAKPOINT=y
CONFIG_HAVE_MIXED_BREAKPOINTS_REGS=y
CONFIG_HAVE_USER_RETURN_NOTIFIER=y
CONFIG_HAVE_PERF_EVENTS_NMI=y
CONFIG_HAVE_ARCH_JUMP_LABEL=y

#
# GCOV-based kernel profiling
#
# CONFIG_HAVE_GENERIC_DMA_COHERENT is not set
CONFIG_SLABINFO=y
CONFIG_RT_MUTEXES=y
CONFIG_BASE_SMALL=0
CONFIG_MODULES=y
# CONFIG_MODULE_FORCE_LOAD is not set
CONFIG_MODULE_UNLOAD=y
# CONFIG_MODULE_FORCE_UNLOAD is not set
# CONFIG_MODVERSIONS is not set
# CONFIG_MODULE_SRCVERSION_ALL is not set
CONFIG_BLOCK=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_BLK_DEV_INTEGRITY is not set
CONFIG_BLOCK_COMPAT=y

#
# IO Schedulers
#
CONFIG_IOSCHED_NOOP=y
CONFIG_IOSCHED_DEADLINE=y
CONFIG_IOSCHED_CFQ=y
# CONFIG_DEFAULT_DEADLINE is not set
CONFIG_DEFAULT_CFQ=y
# CONFIG_DEFAULT_NOOP is not set
CONFIG_DEFAULT_IOSCHED="cfq"
# CONFIG_INLINE_SPIN_TRYLOCK is not set
# CONFIG_INLINE_SPIN_TRYLOCK_BH is not set
# CONFIG_INLINE_SPIN_LOCK is not set
# CONFIG_INLINE_SPIN_LOCK_BH is not set
# CONFIG_INLINE_SPIN_LOCK_IRQ is not set
# CONFIG_INLINE_SPIN_LOCK_IRQSAVE is not set
# CONFIG_INLINE_SPIN_UNLOCK is not set
# CONFIG_INLINE_SPIN_UNLOCK_BH is not set
# CONFIG_INLINE_SPIN_UNLOCK_IRQ is not set
# CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE is not set
# CONFIG_INLINE_READ_TRYLOCK is not set
# CONFIG_INLINE_READ_LOCK is not set
# CONFIG_INLINE_READ_LOCK_BH is not set
# CONFIG_INLINE_READ_LOCK_IRQ is not set
# CONFIG_INLINE_READ_LOCK_IRQSAVE is not set
# CONFIG_INLINE_READ_UNLOCK is not set
# CONFIG_INLINE_READ_UNLOCK_BH is not set
# CONFIG_INLINE_READ_UNLOCK_IRQ is not set
# CONFIG_INLINE_READ_UNLOCK_IRQRESTORE is not set
# CONFIG_INLINE_WRITE_TRYLOCK is not set
# CONFIG_INLINE_WRITE_LOCK is not set
# CONFIG_INLINE_WRITE_LOCK_BH is not set
# CONFIG_INLINE_WRITE_LOCK_IRQ is not set
# CONFIG_INLINE_WRITE_LOCK_IRQSAVE is not set
# CONFIG_INLINE_WRITE_UNLOCK is not set
# CONFIG_INLINE_WRITE_UNLOCK_BH is not set
# CONFIG_INLINE_WRITE_UNLOCK_IRQ is not set
# CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE is not set
# CONFIG_MUTEX_SPIN_ON_OWNER is not set
CONFIG_FREEZER=y

#
# Processor type and features
#
CONFIG_TICK_ONESHOT=y
CONFIG_NO_HZ=y
CONFIG_HIGH_RES_TIMERS=y
CONFIG_GENERIC_CLOCKEVENTS_BUILD=y
# CONFIG_SMP is not set
# CONFIG_X86_MPPARSE is not set
# CONFIG_X86_EXTENDED_PLATFORM is not set
CONFIG_X86_SUPPORTS_MEMORY_FAILURE=y
CONFIG_SCHED_OMIT_FRAME_POINTER=y
# CONFIG_PARAVIRT_GUEST is not set
CONFIG_NO_BOOTMEM=y
# CONFIG_MEMTEST is not set
CONFIG_MK8=y
# CONFIG_MPSC is not set
# CONFIG_MCORE2 is not set
# CONFIG_MATOM is not set
# CONFIG_GENERIC_CPU is not set
CONFIG_X86_INTERNODE_CACHE_SHIFT=6
CONFIG_X86_CMPXCHG=y
CONFIG_CMPXCHG_LOCAL=y
CONFIG_X86_L1_CACHE_SHIFT=6
CONFIG_X86_XADD=y
CONFIG_X86_WP_WORKS_OK=y
CONFIG_X86_INTEL_USERCOPY=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_X86_TSC=y
CONFIG_X86_CMPXCHG64=y
CONFIG_X86_CMOV=y
CONFIG_X86_MINIMUM_CPU_FAMILY=64
CONFIG_X86_DEBUGCTLMSR=y
CONFIG_CPU_SUP_INTEL=y
CONFIG_CPU_SUP_AMD=y
CONFIG_CPU_SUP_CENTAUR=y
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_DMI=y
CONFIG_GART_IOMMU=y
# CONFIG_CALGARY_IOMMU is not set
# CONFIG_AMD_IOMMU is not set
CONFIG_SWIOTLB=y
CONFIG_IOMMU_HELPER=y
# CONFIG_IOMMU_API is not set
CONFIG_NR_CPUS=1
# CONFIG_IRQ_TIME_ACCOUNTING is not set
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
# CONFIG_X86_REROUTE_FOR_BROKEN_BOOT_IRQS is not set
CONFIG_X86_MCE=y
# CONFIG_X86_MCE_INTEL is not set
CONFIG_X86_MCE_AMD=y
CONFIG_X86_MCE_THRESHOLD=y
# CONFIG_X86_MCE_INJECT is not set
# CONFIG_I8K is not set
# CONFIG_MICROCODE is not set
CONFIG_X86_MSR=y
CONFIG_X86_CPUID=y
CONFIG_ARCH_PHYS_ADDR_T_64BIT=y
CONFIG_ARCH_DMA_ADDR_T_64BIT=y
CONFIG_DIRECT_GBPAGES=y
CONFIG_ARCH_PROC_KCORE_TEXT=y
CONFIG_ARCH_SPARSEMEM_DEFAULT=y
CONFIG_ARCH_SPARSEMEM_ENABLE=y
CONFIG_ARCH_SELECT_MEMORY_MODEL=y
CONFIG_ILLEGAL_POINTER_VALUE=0xdead000000000000
CONFIG_SELECT_MEMORY_MODEL=y
CONFIG_SPARSEMEM_MANUAL=y
CONFIG_SPARSEMEM=y
CONFIG_HAVE_MEMORY_PRESENT=y
CONFIG_SPARSEMEM_EXTREME=y
CONFIG_SPARSEMEM_VMEMMAP_ENABLE=y
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER=y
CONFIG_SPARSEMEM_VMEMMAP=y
CONFIG_HAVE_MEMBLOCK=y
# CONFIG_MEMORY_HOTPLUG is not set
CONFIG_PAGEFLAGS_EXTENDED=y
CONFIG_SPLIT_PTLOCK_CPUS=999999
# CONFIG_COMPACTION is not set
CONFIG_PHYS_ADDR_T_64BIT=y
CONFIG_ZONE_DMA_FLAG=1
CONFIG_BOUNCE=y
CONFIG_VIRT_TO_BUS=y
# CONFIG_KSM is not set
CONFIG_DEFAULT_MMAP_MIN_ADDR=4096
CONFIG_ARCH_SUPPORTS_MEMORY_FAILURE=y
# CONFIG_MEMORY_FAILURE is not set
# CONFIG_TRANSPARENT_HUGEPAGE is not set
CONFIG_NEED_PER_CPU_KM=y
# CONFIG_X86_CHECK_BIOS_CORRUPTION is not set
CONFIG_X86_RESERVE_LOW=64
CONFIG_MTRR=y
CONFIG_MTRR_SANITIZER=y
CONFIG_MTRR_SANITIZER_ENABLE_DEFAULT=0
CONFIG_MTRR_SANITIZER_SPARE_REG_NR_DEFAULT=1
CONFIG_X86_PAT=y
CONFIG_ARCH_USES_PG_UNCACHED=y
# CONFIG_EFI is not set
CONFIG_SECCOMP=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
CONFIG_HZ_300=y
# CONFIG_HZ_1000 is not set
CONFIG_HZ=300
CONFIG_SCHED_HRTICK=y
# CONFIG_KEXEC is not set
# CONFIG_CRASH_DUMP is not set
CONFIG_PHYSICAL_START=0x1000000
# CONFIG_RELOCATABLE is not set
CONFIG_PHYSICAL_ALIGN=0x1000000
# CONFIG_COMPAT_VDSO is not set
# CONFIG_CMDLINE_BOOL is not set
CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG=y

#
# Power management and ACPI options
#
CONFIG_SUSPEND=y
CONFIG_SUSPEND_FREEZER=y
# CONFIG_HIBERNATION is not set
CONFIG_PM_SLEEP=y
CONFIG_PM_RUNTIME=y
CONFIG_PM=y
CONFIG_PM_DEBUG=y
# CONFIG_PM_VERBOSE is not set
# CONFIG_PM_ADVANCED_DEBUG is not set
# CONFIG_PM_TEST_SUSPEND is not set
CONFIG_CAN_PM_TRACE=y
# CONFIG_PM_TRACE_RTC is not set
CONFIG_ACPI=y
CONFIG_ACPI_SLEEP=y
CONFIG_ACPI_PROCFS=y
CONFIG_ACPI_PROCFS_POWER=y
# CONFIG_ACPI_POWER_METER is not set
# CONFIG_ACPI_EC_DEBUGFS is not set
CONFIG_ACPI_PROC_EVENT=y
CONFIG_ACPI_AC=y
CONFIG_ACPI_BATTERY=y
CONFIG_ACPI_BUTTON=y
CONFIG_ACPI_FAN=y
# CONFIG_ACPI_DOCK is not set
CONFIG_ACPI_PROCESSOR=y
# CONFIG_ACPI_PROCESSOR_AGGREGATOR is not set
CONFIG_ACPI_THERMAL=y
CONFIG_ACPI_CUSTOM_DSDT_FILE=""
# CONFIG_ACPI_CUSTOM_DSDT is not set
CONFIG_ACPI_BLACKLIST_YEAR=0
# CONFIG_ACPI_DEBUG is not set
# CONFIG_ACPI_PCI_SLOT is not set
CONFIG_X86_PM_TIMER=y
# CONFIG_ACPI_CONTAINER is not set
# CONFIG_ACPI_SBS is not set
# CONFIG_ACPI_HED is not set
# CONFIG_ACPI_APEI is not set
# CONFIG_SFI is not set

#
# CPU Frequency scaling
#
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_TABLE=y
# CONFIG_CPU_FREQ_DEBUG is not set
CONFIG_CPU_FREQ_STAT=y
# CONFIG_CPU_FREQ_STAT_DETAILS is not set
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND is not set
# CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE is not set
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
# CONFIG_CPU_FREQ_GOV_USERSPACE is not set
CONFIG_CPU_FREQ_GOV_ONDEMAND=y
# CONFIG_CPU_FREQ_GOV_CONSERVATIVE is not set

#
# CPUFreq processor drivers
#
# CONFIG_X86_PCC_CPUFREQ is not set
CONFIG_X86_ACPI_CPUFREQ=y
CONFIG_X86_POWERNOW_K8=y
# CONFIG_X86_SPEEDSTEP_CENTRINO is not set
# CONFIG_X86_P4_CLOCKMOD is not set

#
# shared options
#
# CONFIG_X86_SPEEDSTEP_LIB is not set
CONFIG_CPU_IDLE=y
CONFIG_CPU_IDLE_GOV_LADDER=y
CONFIG_CPU_IDLE_GOV_MENU=y
# CONFIG_INTEL_IDLE is not set

#
# Memory power savings
#
# CONFIG_I7300_IDLE is not set

#
# Bus options (PCI etc.)
#
CONFIG_PCI=y
CONFIG_PCI_DIRECT=y
CONFIG_PCI_MMCONFIG=y
CONFIG_PCI_DOMAINS=y
# CONFIG_PCI_CNB20LE_QUIRK is not set
# CONFIG_PCIEPORTBUS is not set
CONFIG_ARCH_SUPPORTS_MSI=y
# CONFIG_PCI_MSI is not set
# CONFIG_PCI_DEBUG is not set
# CONFIG_PCI_STUB is not set
CONFIG_HT_IRQ=y
# CONFIG_PCI_IOV is not set
CONFIG_PCI_IOAPIC=y
CONFIG_ISA_DMA_API=y
CONFIG_AMD_NB=y
CONFIG_PCCARD=y
CONFIG_PCMCIA=y
CONFIG_PCMCIA_LOAD_CIS=y
CONFIG_CARDBUS=y

#
# PC-card bridges
#
CONFIG_YENTA=y
CONFIG_YENTA_O2=y
CONFIG_YENTA_RICOH=y
CONFIG_YENTA_TI=y
CONFIG_YENTA_ENE_TUNE=y
CONFIG_YENTA_TOSHIBA=y
# CONFIG_PD6729 is not set
# CONFIG_I82092 is not set
CONFIG_PCCARD_NONSTATIC=y
# CONFIG_HOTPLUG_PCI is not set
# CONFIG_RAPIDIO is not set

#
# Executable file formats / Emulations
#
CONFIG_BINFMT_ELF=y
CONFIG_COMPAT_BINFMT_ELF=y
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
# CONFIG_HAVE_AOUT is not set
CONFIG_BINFMT_MISC=y
CONFIG_IA32_EMULATION=y
CONFIG_IA32_AOUT=y
CONFIG_COMPAT=y
CONFIG_COMPAT_FOR_U64_ALIGNMENT=y
CONFIG_SYSVIPC_COMPAT=y
CONFIG_HAVE_TEXT_POKE_SMP=y
CONFIG_NET=y
CONFIG_COMPAT_NETLINK_MESSAGES=y

#
# Networking options
#
CONFIG_PACKET=y
CONFIG_UNIX=y
CONFIG_XFRM=y
CONFIG_XFRM_USER=y
# CONFIG_XFRM_SUB_POLICY is not set
# CONFIG_XFRM_MIGRATE is not set
# CONFIG_XFRM_STATISTICS is not set
CONFIG_XFRM_IPCOMP=y
CONFIG_NET_KEY=y
# CONFIG_NET_KEY_MIGRATE is not set
CONFIG_INET=y
CONFIG_IP_MULTICAST=y
# CONFIG_IP_ADVANCED_ROUTER is not set
# CONFIG_IP_PNP is not set
# CONFIG_NET_IPIP is not set
# CONFIG_NET_IPGRE_DEMUX is not set
# CONFIG_IP_MROUTE is not set
# CONFIG_ARPD is not set
# CONFIG_SYN_COOKIES is not set
CONFIG_INET_AH=y
CONFIG_INET_ESP=y
CONFIG_INET_IPCOMP=y
CONFIG_INET_XFRM_TUNNEL=y
CONFIG_INET_TUNNEL=y
CONFIG_INET_XFRM_MODE_TRANSPORT=y
CONFIG_INET_XFRM_MODE_TUNNEL=y
CONFIG_INET_XFRM_MODE_BEET=y
# CONFIG_INET_LRO is not set
CONFIG_INET_DIAG=y
CONFIG_INET_TCP_DIAG=y
# CONFIG_TCP_CONG_ADVANCED is not set
CONFIG_TCP_CONG_CUBIC=y
CONFIG_DEFAULT_TCP_CONG="cubic"
# CONFIG_TCP_MD5SIG is not set
CONFIG_IPV6=y
CONFIG_IPV6_PRIVACY=y
# CONFIG_IPV6_ROUTER_PREF is not set
CONFIG_IPV6_OPTIMISTIC_DAD=y
CONFIG_INET6_AH=y
CONFIG_INET6_ESP=y
CONFIG_INET6_IPCOMP=y
CONFIG_IPV6_MIP6=y
CONFIG_INET6_XFRM_TUNNEL=y
CONFIG_INET6_TUNNEL=y
CONFIG_INET6_XFRM_MODE_TRANSPORT=y
CONFIG_INET6_XFRM_MODE_TUNNEL=y
CONFIG_INET6_XFRM_MODE_BEET=y
# CONFIG_INET6_XFRM_MODE_ROUTEOPTIMIZATION is not set
CONFIG_IPV6_SIT=y
# CONFIG_IPV6_SIT_6RD is not set
CONFIG_IPV6_NDISC_NODETYPE=y
# CONFIG_IPV6_TUNNEL is not set
# CONFIG_IPV6_MULTIPLE_TABLES is not set
# CONFIG_IPV6_MROUTE is not set
# CONFIG_NETWORK_SECMARK is not set
# CONFIG_NETWORK_PHY_TIMESTAMPING is not set
CONFIG_NETFILTER=y
# CONFIG_NETFILTER_DEBUG is not set
CONFIG_NETFILTER_ADVANCED=y

#
# Core Netfilter Configuration
#
CONFIG_NETFILTER_NETLINK=y
CONFIG_NETFILTER_NETLINK_QUEUE=y
# CONFIG_NETFILTER_NETLINK_LOG is not set
CONFIG_NF_CONNTRACK=y
# CONFIG_NF_CONNTRACK_MARK is not set
# CONFIG_NF_CONNTRACK_EVENTS is not set
# CONFIG_NF_CONNTRACK_TIMESTAMP is not set
# CONFIG_NF_CT_PROTO_DCCP is not set
# CONFIG_NF_CT_PROTO_SCTP is not set
# CONFIG_NF_CT_PROTO_UDPLITE is not set
# CONFIG_NF_CONNTRACK_AMANDA is not set
CONFIG_NF_CONNTRACK_FTP=y
CONFIG_NF_CONNTRACK_H323=y
# CONFIG_NF_CONNTRACK_IRC is not set
# CONFIG_NF_CONNTRACK_NETBIOS_NS is not set
# CONFIG_NF_CONNTRACK_SNMP is not set
# CONFIG_NF_CONNTRACK_PPTP is not set
# CONFIG_NF_CONNTRACK_SANE is not set
CONFIG_NF_CONNTRACK_SIP=y
# CONFIG_NF_CONNTRACK_TFTP is not set
# CONFIG_NF_CT_NETLINK is not set
CONFIG_NETFILTER_XTABLES=y

#
# Xtables combined modules
#
CONFIG_NETFILTER_XT_MARK=y
# CONFIG_NETFILTER_XT_CONNMARK is not set

#
# Xtables targets
#
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=y
# CONFIG_NETFILTER_XT_TARGET_CONNMARK is not set
# CONFIG_NETFILTER_XT_TARGET_IDLETIMER is not set
CONFIG_NETFILTER_XT_TARGET_MARK=y
# CONFIG_NETFILTER_XT_TARGET_NFLOG is not set
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=y
# CONFIG_NETFILTER_XT_TARGET_RATEEST is not set
# CONFIG_NETFILTER_XT_TARGET_TEE is not set
CONFIG_NETFILTER_XT_TARGET_TCPMSS=y

#
# Xtables matches
#
# CONFIG_NETFILTER_XT_MATCH_ADDRTYPE is not set
# CONFIG_NETFILTER_XT_MATCH_CLUSTER is not set
# CONFIG_NETFILTER_XT_MATCH_COMMENT is not set
# CONFIG_NETFILTER_XT_MATCH_CONNBYTES is not set
# CONFIG_NETFILTER_XT_MATCH_CONNLIMIT is not set
# CONFIG_NETFILTER_XT_MATCH_CONNMARK is not set
CONFIG_NETFILTER_XT_MATCH_CONNTRACK=y
# CONFIG_NETFILTER_XT_MATCH_CPU is not set
# CONFIG_NETFILTER_XT_MATCH_DCCP is not set
# CONFIG_NETFILTER_XT_MATCH_DEVGROUP is not set
# CONFIG_NETFILTER_XT_MATCH_DSCP is not set
CONFIG_NETFILTER_XT_MATCH_ESP=y
# CONFIG_NETFILTER_XT_MATCH_HASHLIMIT is not set
CONFIG_NETFILTER_XT_MATCH_HELPER=y
CONFIG_NETFILTER_XT_MATCH_HL=y
# CONFIG_NETFILTER_XT_MATCH_IPRANGE is not set
CONFIG_NETFILTER_XT_MATCH_LENGTH=y
CONFIG_NETFILTER_XT_MATCH_LIMIT=y
# CONFIG_NETFILTER_XT_MATCH_MAC is not set
# CONFIG_NETFILTER_XT_MATCH_MARK is not set
CONFIG_NETFILTER_XT_MATCH_MULTIPORT=y
# CONFIG_NETFILTER_XT_MATCH_OSF is not set
# CONFIG_NETFILTER_XT_MATCH_OWNER is not set
CONFIG_NETFILTER_XT_MATCH_POLICY=y
CONFIG_NETFILTER_XT_MATCH_PKTTYPE=y
# CONFIG_NETFILTER_XT_MATCH_QUOTA is not set
# CONFIG_NETFILTER_XT_MATCH_RATEEST is not set
# CONFIG_NETFILTER_XT_MATCH_REALM is not set
# CONFIG_NETFILTER_XT_MATCH_RECENT is not set
# CONFIG_NETFILTER_XT_MATCH_SCTP is not set
CONFIG_NETFILTER_XT_MATCH_STATE=y
# CONFIG_NETFILTER_XT_MATCH_STATISTIC is not set
# CONFIG_NETFILTER_XT_MATCH_STRING is not set
CONFIG_NETFILTER_XT_MATCH_TCPMSS=y
# CONFIG_NETFILTER_XT_MATCH_TIME is not set
# CONFIG_NETFILTER_XT_MATCH_U32 is not set
# CONFIG_IP_SET is not set
# CONFIG_IP_VS is not set

#
# IP: Netfilter Configuration
#
CONFIG_NF_DEFRAG_IPV4=y
CONFIG_NF_CONNTRACK_IPV4=y
CONFIG_NF_CONNTRACK_PROC_COMPAT=y
CONFIG_IP_NF_QUEUE=y
CONFIG_IP_NF_IPTABLES=y
CONFIG_IP_NF_MATCH_AH=y
# CONFIG_IP_NF_MATCH_ECN is not set
CONFIG_IP_NF_MATCH_TTL=y
CONFIG_IP_NF_FILTER=y
CONFIG_IP_NF_TARGET_REJECT=y
CONFIG_IP_NF_TARGET_LOG=y
# CONFIG_IP_NF_TARGET_ULOG is not set
# CONFIG_NF_NAT is not set
# CONFIG_IP_NF_MANGLE is not set
# CONFIG_IP_NF_RAW is not set
# CONFIG_IP_NF_ARPTABLES is not set

#
# IPv6: Netfilter Configuration
#
CONFIG_NF_DEFRAG_IPV6=y
CONFIG_NF_CONNTRACK_IPV6=y
# CONFIG_IP6_NF_QUEUE is not set
CONFIG_IP6_NF_IPTABLES=y
CONFIG_IP6_NF_MATCH_AH=y
# CONFIG_IP6_NF_MATCH_EUI64 is not set
# CONFIG_IP6_NF_MATCH_FRAG is not set
# CONFIG_IP6_NF_MATCH_OPTS is not set
# CONFIG_IP6_NF_MATCH_HL is not set
CONFIG_IP6_NF_MATCH_IPV6HEADER=y
# CONFIG_IP6_NF_MATCH_MH is not set
# CONFIG_IP6_NF_MATCH_RT is not set
# CONFIG_IP6_NF_TARGET_LOG is not set
CONFIG_IP6_NF_FILTER=y
# CONFIG_IP6_NF_TARGET_REJECT is not set
# CONFIG_IP6_NF_MANGLE is not set
# CONFIG_IP6_NF_RAW is not set
# CONFIG_IP_DCCP is not set
# CONFIG_IP_SCTP is not set
# CONFIG_RDS is not set
# CONFIG_TIPC is not set
# CONFIG_ATM is not set
# CONFIG_L2TP is not set
# CONFIG_BRIDGE is not set
# CONFIG_NET_DSA is not set
# CONFIG_VLAN_8021Q is not set
# CONFIG_DECNET is not set
# CONFIG_LLC2 is not set
# CONFIG_IPX is not set
# CONFIG_ATALK is not set
# CONFIG_X25 is not set
# CONFIG_LAPB is not set
# CONFIG_ECONET is not set
# CONFIG_WAN_ROUTER is not set
# CONFIG_PHONET is not set
# CONFIG_IEEE802154 is not set
# CONFIG_NET_SCHED is not set
# CONFIG_DCB is not set
# CONFIG_BATMAN_ADV is not set

#
# Network testing
#
# CONFIG_NET_PKTGEN is not set
# CONFIG_HAMRADIO is not set
# CONFIG_CAN is not set
CONFIG_IRDA=y

#
# IrDA protocols
#
CONFIG_IRLAN=y
CONFIG_IRNET=y
CONFIG_IRCOMM=y
# CONFIG_IRDA_ULTRA is not set

#
# IrDA options
#
# CONFIG_IRDA_CACHE_LAST_LSAP is not set
# CONFIG_IRDA_FAST_RR is not set
# CONFIG_IRDA_DEBUG is not set

#
# Infrared-port device drivers
#

#
# SIR device drivers
#
CONFIG_IRTTY_SIR=y

#
# Dongle support
#
# CONFIG_DONGLE is not set
# CONFIG_KINGSUN_DONGLE is not set
# CONFIG_KSDAZZLE_DONGLE is not set
# CONFIG_KS959_DONGLE is not set

#
# FIR device drivers
#
# CONFIG_USB_IRDA is not set
# CONFIG_SIGMATEL_FIR is not set
# CONFIG_NSC_FIR is not set
# CONFIG_WINBOND_FIR is not set
# CONFIG_SMC_IRCC_FIR is not set
# CONFIG_ALI_FIR is not set
# CONFIG_VLSI_FIR is not set
# CONFIG_VIA_FIR is not set
# CONFIG_MCS_FIR is not set
# CONFIG_BT is not set
# CONFIG_AF_RXRPC is not set
CONFIG_WIRELESS=y
CONFIG_WIRELESS_EXT=y
CONFIG_WEXT_CORE=y
CONFIG_WEXT_PROC=y
CONFIG_WEXT_PRIV=y
CONFIG_CFG80211=y
# CONFIG_NL80211_TESTMODE is not set
# CONFIG_CFG80211_DEVELOPER_WARNINGS is not set
# CONFIG_CFG80211_REG_DEBUG is not set
CONFIG_CFG80211_DEFAULT_PS=y
# CONFIG_CFG80211_INTERNAL_REGDB is not set
CONFIG_CFG80211_WEXT=y
CONFIG_WIRELESS_EXT_SYSFS=y
# CONFIG_LIB80211 is not set
CONFIG_MAC80211=y
CONFIG_MAC80211_HAS_RC=y
CONFIG_MAC80211_RC_MINSTREL=y
CONFIG_MAC80211_RC_MINSTREL_HT=y
CONFIG_MAC80211_RC_DEFAULT_MINSTREL=y
CONFIG_MAC80211_RC_DEFAULT="minstrel_ht"
# CONFIG_MAC80211_MESH is not set
# CONFIG_MAC80211_LEDS is not set
# CONFIG_MAC80211_DEBUG_MENU is not set
# CONFIG_WIMAX is not set
CONFIG_RFKILL=y
CONFIG_RFKILL_INPUT=y
# CONFIG_NET_9P is not set
# CONFIG_CAIF is not set
# CONFIG_CEPH_LIB is not set

#
# Device Drivers
#

#
# Generic Driver Options
#
CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
# CONFIG_DEVTMPFS is not set
# CONFIG_STANDALONE is not set
CONFIG_PREVENT_FIRMWARE_BUILD=y
CONFIG_FW_LOADER=y
CONFIG_FIRMWARE_IN_KERNEL=y
CONFIG_EXTRA_FIRMWARE=""
# CONFIG_DEBUG_DRIVER is not set
# CONFIG_DEBUG_DEVRES is not set
# CONFIG_SYS_HYPERVISOR is not set
CONFIG_ARCH_NO_SYSDEV_OPS=y
# CONFIG_CONNECTOR is not set
# CONFIG_MTD is not set
CONFIG_PARPORT=y
CONFIG_PARPORT_PC=y
# CONFIG_PARPORT_SERIAL is not set
CONFIG_PARPORT_PC_FIFO=y
# CONFIG_PARPORT_PC_SUPERIO is not set
# CONFIG_PARPORT_PC_PCMCIA is not set
# CONFIG_PARPORT_GSC is not set
# CONFIG_PARPORT_AX88796 is not set
CONFIG_PARPORT_1284=y
CONFIG_PNP=y
CONFIG_PNP_DEBUG_MESSAGES=y

#
# Protocols
#
CONFIG_PNPACPI=y
CONFIG_BLK_DEV=y
# CONFIG_BLK_DEV_FD is not set
# CONFIG_PARIDE is not set
# CONFIG_BLK_CPQ_DA is not set
# CONFIG_BLK_CPQ_CISS_DA is not set
# CONFIG_BLK_DEV_DAC960 is not set
# CONFIG_BLK_DEV_UMEM is not set
# CONFIG_BLK_DEV_COW_COMMON is not set
CONFIG_BLK_DEV_LOOP=y
# CONFIG_BLK_DEV_CRYPTOLOOP is not set

#
# DRBD disabled because PROC_FS, INET or CONNECTOR not selected
#
# CONFIG_BLK_DEV_NBD is not set
# CONFIG_BLK_DEV_SX8 is not set
# CONFIG_BLK_DEV_UB is not set
# CONFIG_BLK_DEV_RAM is not set
CONFIG_CDROM_PKTCDVD=y
CONFIG_CDROM_PKTCDVD_BUFFERS=8
# CONFIG_CDROM_PKTCDVD_WCACHE is not set
# CONFIG_ATA_OVER_ETH is not set
# CONFIG_BLK_DEV_HD is not set
# CONFIG_BLK_DEV_RBD is not set
# CONFIG_SENSORS_LIS3LV02D is not set
# CONFIG_MISC_DEVICES is not set
CONFIG_HAVE_IDE=y
# CONFIG_IDE is not set

#
# SCSI device support
#
CONFIG_SCSI_MOD=y
# CONFIG_RAID_ATTRS is not set
CONFIG_SCSI=y
CONFIG_SCSI_DMA=y
# CONFIG_SCSI_TGT is not set
# CONFIG_SCSI_NETLINK is not set
CONFIG_SCSI_PROC_FS=y

#
# SCSI support type (disk, tape, CD-ROM)
#
CONFIG_BLK_DEV_SD=y
# CONFIG_CHR_DEV_ST is not set
# CONFIG_CHR_DEV_OSST is not set
CONFIG_BLK_DEV_SR=y
CONFIG_BLK_DEV_SR_VENDOR=y
CONFIG_CHR_DEV_SG=y
# CONFIG_CHR_DEV_SCH is not set
CONFIG_SCSI_MULTI_LUN=y
# CONFIG_SCSI_CONSTANTS is not set
# CONFIG_SCSI_LOGGING is not set
# CONFIG_SCSI_SCAN_ASYNC is not set
CONFIG_SCSI_WAIT_SCAN=m

#
# SCSI Transports
#
# CONFIG_SCSI_SPI_ATTRS is not set
# CONFIG_SCSI_FC_ATTRS is not set
# CONFIG_SCSI_ISCSI_ATTRS is not set
# CONFIG_SCSI_SAS_ATTRS is not set
# CONFIG_SCSI_SAS_LIBSAS is not set
# CONFIG_SCSI_SRP_ATTRS is not set
# CONFIG_SCSI_LOWLEVEL is not set
# CONFIG_SCSI_LOWLEVEL_PCMCIA is not set
# CONFIG_SCSI_DH is not set
# CONFIG_SCSI_OSD_INITIATOR is not set
CONFIG_ATA=y
# CONFIG_ATA_NONSTANDARD is not set
CONFIG_ATA_VERBOSE_ERROR=y
CONFIG_ATA_ACPI=y
# CONFIG_SATA_PMP is not set

#
# Controllers with non-SFF native interface
#
# CONFIG_SATA_AHCI is not set
# CONFIG_SATA_AHCI_PLATFORM is not set
# CONFIG_SATA_INIC162X is not set
# CONFIG_SATA_ACARD_AHCI is not set
# CONFIG_SATA_SIL24 is not set
CONFIG_ATA_SFF=y

#
# SFF controllers with custom DMA interface
#
# CONFIG_PDC_ADMA is not set
# CONFIG_SATA_QSTOR is not set
# CONFIG_SATA_SX4 is not set
CONFIG_ATA_BMDMA=y

#
# SATA SFF controllers with BMDMA
#
# CONFIG_ATA_PIIX is not set
# CONFIG_SATA_MV is not set
# CONFIG_SATA_NV is not set
# CONFIG_SATA_PROMISE is not set
# CONFIG_SATA_SIL is not set
# CONFIG_SATA_SIS is not set
# CONFIG_SATA_SVW is not set
# CONFIG_SATA_ULI is not set
# CONFIG_SATA_VIA is not set
# CONFIG_SATA_VITESSE is not set

#
# PATA SFF controllers with BMDMA
#
# CONFIG_PATA_ALI is not set
CONFIG_PATA_AMD=y
# CONFIG_PATA_ARASAN_CF is not set
# CONFIG_PATA_ARTOP is not set
# CONFIG_PATA_ATIIXP is not set
# CONFIG_PATA_ATP867X is not set
# CONFIG_PATA_CMD64X is not set
# CONFIG_PATA_CS5520 is not set
# CONFIG_PATA_CS5530 is not set
# CONFIG_PATA_CS5536 is not set
# CONFIG_PATA_CYPRESS is not set
# CONFIG_PATA_EFAR is not set
# CONFIG_PATA_HPT366 is not set
# CONFIG_PATA_HPT37X is not set
# CONFIG_PATA_HPT3X2N is not set
# CONFIG_PATA_HPT3X3 is not set
# CONFIG_PATA_IT8213 is not set
# CONFIG_PATA_IT821X is not set
# CONFIG_PATA_JMICRON is not set
# CONFIG_PATA_MARVELL is not set
# CONFIG_PATA_NETCELL is not set
# CONFIG_PATA_NINJA32 is not set
# CONFIG_PATA_NS87415 is not set
# CONFIG_PATA_OLDPIIX is not set
# CONFIG_PATA_OPTIDMA is not set
# CONFIG_PATA_PDC2027X is not set
# CONFIG_PATA_PDC_OLD is not set
# CONFIG_PATA_RADISYS is not set
# CONFIG_PATA_RDC is not set
# CONFIG_PATA_SC1200 is not set
# CONFIG_PATA_SCH is not set
# CONFIG_PATA_SERVERWORKS is not set
# CONFIG_PATA_SIL680 is not set
# CONFIG_PATA_SIS is not set
# CONFIG_PATA_TOSHIBA is not set
# CONFIG_PATA_TRIFLEX is not set
# CONFIG_PATA_VIA is not set
# CONFIG_PATA_WINBOND is not set

#
# PIO-only SFF controllers
#
# CONFIG_PATA_CMD640_PCI is not set
# CONFIG_PATA_MPIIX is not set
# CONFIG_PATA_NS87410 is not set
# CONFIG_PATA_OPTI is not set
# CONFIG_PATA_PCMCIA is not set
# CONFIG_PATA_RZ1000 is not set

#
# Generic fallback / legacy drivers
#
# CONFIG_PATA_ACPI is not set
# CONFIG_ATA_GENERIC is not set
# CONFIG_PATA_LEGACY is not set
CONFIG_MD=y
# CONFIG_BLK_DEV_MD is not set
CONFIG_BLK_DEV_DM=y
# CONFIG_DM_DEBUG is not set
CONFIG_DM_CRYPT=y
# CONFIG_DM_SNAPSHOT is not set
# CONFIG_DM_MIRROR is not set
# CONFIG_DM_RAID is not set
# CONFIG_DM_ZERO is not set
# CONFIG_DM_MULTIPATH is not set
# CONFIG_DM_DELAY is not set
# CONFIG_DM_UEVENT is not set
# CONFIG_DM_FLAKEY is not set
# CONFIG_TARGET_CORE is not set
# CONFIG_FUSION is not set

#
# IEEE 1394 (FireWire) support
#
CONFIG_FIREWIRE=y
CONFIG_FIREWIRE_OHCI=y
CONFIG_FIREWIRE_OHCI_DEBUG=y
CONFIG_FIREWIRE_SBP2=y
CONFIG_FIREWIRE_NET=y
# CONFIG_FIREWIRE_NOSY is not set
# CONFIG_I2O is not set
# CONFIG_MACINTOSH_DRIVERS is not set
CONFIG_NETDEVICES=y
CONFIG_DUMMY=y
# CONFIG_BONDING is not set
# CONFIG_MACVLAN is not set
# CONFIG_EQUALIZER is not set
# CONFIG_TUN is not set
# CONFIG_VETH is not set
# CONFIG_NET_SB1000 is not set
# CONFIG_ARCNET is not set
CONFIG_MII=y
CONFIG_PHYLIB=y

#
# MII PHY device drivers
#
# CONFIG_MARVELL_PHY is not set
# CONFIG_DAVICOM_PHY is not set
# CONFIG_QSEMI_PHY is not set
# CONFIG_LXT_PHY is not set
# CONFIG_CICADA_PHY is not set
# CONFIG_VITESSE_PHY is not set
# CONFIG_SMSC_PHY is not set
# CONFIG_BROADCOM_PHY is not set
# CONFIG_BCM63XX_PHY is not set
# CONFIG_ICPLUS_PHY is not set
# CONFIG_REALTEK_PHY is not set
# CONFIG_NATIONAL_PHY is not set
# CONFIG_STE10XP is not set
# CONFIG_LSI_ET1011C_PHY is not set
# CONFIG_MICREL_PHY is not set
# CONFIG_FIXED_PHY is not set
# CONFIG_MDIO_BITBANG is not set
# CONFIG_NET_ETHERNET is not set
CONFIG_NETDEV_1000=y
# CONFIG_ACENIC is not set
# CONFIG_DL2K is not set
# CONFIG_E1000 is not set
# CONFIG_E1000E is not set
# CONFIG_IP1000 is not set
# CONFIG_IGB is not set
# CONFIG_IGBVF is not set
# CONFIG_NS83820 is not set
# CONFIG_HAMACHI is not set
# CONFIG_YELLOWFIN is not set
# CONFIG_R8169 is not set
# CONFIG_SIS190 is not set
# CONFIG_SKGE is not set
# CONFIG_SKY2 is not set
# CONFIG_VIA_VELOCITY is not set
CONFIG_TIGON3=y
# CONFIG_BNX2 is not set
# CONFIG_CNIC is not set
# CONFIG_QLA3XXX is not set
# CONFIG_ATL1 is not set
# CONFIG_ATL1E is not set
# CONFIG_ATL1C is not set
# CONFIG_JME is not set
# CONFIG_STMMAC_ETH is not set
# CONFIG_PCH_GBE is not set
# CONFIG_NETDEV_10000 is not set
# CONFIG_TR is not set
CONFIG_WLAN=y
# CONFIG_PCMCIA_RAYCS is not set
# CONFIG_LIBERTAS_THINFIRM is not set
# CONFIG_AIRO is not set
# CONFIG_ATMEL is not set
# CONFIG_AT76C50X_USB is not set
# CONFIG_AIRO_CS is not set
# CONFIG_PCMCIA_WL3501 is not set
# CONFIG_PRISM54 is not set
CONFIG_USB_ZD1201=y
# CONFIG_USB_NET_RNDIS_WLAN is not set
# CONFIG_RTL8180 is not set
# CONFIG_RTL8187 is not set
# CONFIG_ADM8211 is not set
# CONFIG_MAC80211_HWSIM is not set
# CONFIG_MWL8K is not set
# CONFIG_ATH_COMMON is not set
CONFIG_B43=y
CONFIG_B43_PCI_AUTOSELECT=y
CONFIG_B43_PCICORE_AUTOSELECT=y
# CONFIG_B43_PCMCIA is not set
CONFIG_B43_PIO=y
# CONFIG_B43_PHY_N is not set
CONFIG_B43_PHY_LP=y
CONFIG_B43_HWRNG=y
# CONFIG_B43_DEBUG is not set
# CONFIG_B43LEGACY is not set
# CONFIG_HOSTAP is not set
# CONFIG_IPW2100 is not set
# CONFIG_IPW2200 is not set
# CONFIG_IWLAGN is not set
# CONFIG_IWLWIFI_LEGACY is not set
# CONFIG_LIBERTAS is not set
# CONFIG_HERMES is not set
# CONFIG_P54_COMMON is not set
CONFIG_RT2X00=y
# CONFIG_RT2400PCI is not set
# CONFIG_RT2500PCI is not set
# CONFIG_RT61PCI is not set
# CONFIG_RT2800PCI is not set
CONFIG_RT2500USB=y
# CONFIG_RT73USB is not set
# CONFIG_RT2800USB is not set
CONFIG_RT2X00_LIB_USB=y
CONFIG_RT2X00_LIB=y
CONFIG_RT2X00_LIB_CRYPTO=y
CONFIG_RT2X00_LIB_LEDS=y
# CONFIG_RT2X00_DEBUG is not set
# CONFIG_RTL8192CE is not set
# CONFIG_RTL8192CU is not set
# CONFIG_WL1251 is not set
# CONFIG_WL12XX_MENU is not set
# CONFIG_ZD1211RW is not set

#
# Enable WiMAX (Networking options) to see the WiMAX drivers
#

#
# USB Network Adapters
#
# CONFIG_USB_CATC is not set
# CONFIG_USB_KAWETH is not set
# CONFIG_USB_PEGASUS is not set
# CONFIG_USB_RTL8150 is not set
CONFIG_USB_USBNET=y
# CONFIG_USB_NET_AX8817X is not set
CONFIG_USB_NET_CDCETHER=y
# CONFIG_USB_NET_CDC_EEM is not set
CONFIG_USB_NET_CDC_NCM=y
# CONFIG_USB_NET_DM9601 is not set
# CONFIG_USB_NET_SMSC75XX is not set
# CONFIG_USB_NET_SMSC95XX is not set
# CONFIG_USB_NET_GL620A is not set
# CONFIG_USB_NET_NET1080 is not set
# CONFIG_USB_NET_PLUSB is not set
# CONFIG_USB_NET_MCS7830 is not set
# CONFIG_USB_NET_RNDIS_HOST is not set
# CONFIG_USB_NET_CDC_SUBSET is not set
# CONFIG_USB_NET_ZAURUS is not set
# CONFIG_USB_NET_CX82310_ETH is not set
# CONFIG_USB_HSO is not set
# CONFIG_USB_NET_INT51X1 is not set
# CONFIG_USB_IPHETH is not set
# CONFIG_USB_SIERRA_NET is not set
# CONFIG_USB_VL600 is not set
# CONFIG_NET_PCMCIA is not set
# CONFIG_WAN is not set

#
# CAIF transport drivers
#
# CONFIG_FDDI is not set
# CONFIG_HIPPI is not set
# CONFIG_PLIP is not set
CONFIG_PPP=y
# CONFIG_PPP_MULTILINK is not set
CONFIG_PPP_FILTER=y
CONFIG_PPP_ASYNC=y
# CONFIG_PPP_SYNC_TTY is not set
CONFIG_PPP_DEFLATE=y
CONFIG_PPP_BSDCOMP=y
# CONFIG_PPP_MPPE is not set
CONFIG_PPPOE=y
# CONFIG_SLIP is not set
CONFIG_SLHC=y
# CONFIG_NET_FC is not set
# CONFIG_NETCONSOLE is not set
# CONFIG_NETPOLL is not set
# CONFIG_NET_POLL_CONTROLLER is not set
# CONFIG_VMXNET3 is not set
# CONFIG_ISDN is not set
# CONFIG_PHONE is not set

#
# Input device support
#
CONFIG_INPUT=y
# CONFIG_INPUT_FF_MEMLESS is not set
CONFIG_INPUT_POLLDEV=y
# CONFIG_INPUT_SPARSEKMAP is not set

#
# Userland interfaces
#
CONFIG_INPUT_MOUSEDEV=y
CONFIG_INPUT_MOUSEDEV_PSAUX=y
CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
# CONFIG_INPUT_JOYDEV is not set
CONFIG_INPUT_EVDEV=y
# CONFIG_INPUT_EVBUG is not set

#
# Input Device Drivers
#
CONFIG_INPUT_KEYBOARD=y
# CONFIG_KEYBOARD_ADP5588 is not set
CONFIG_KEYBOARD_ATKBD=y
# CONFIG_KEYBOARD_QT1070 is not set
# CONFIG_KEYBOARD_QT2160 is not set
# CONFIG_KEYBOARD_LKKBD is not set
# CONFIG_KEYBOARD_TCA6416 is not set
# CONFIG_KEYBOARD_LM8323 is not set
# CONFIG_KEYBOARD_MAX7359 is not set
# CONFIG_KEYBOARD_MCS is not set
# CONFIG_KEYBOARD_NEWTON is not set
# CONFIG_KEYBOARD_OPENCORES is not set
# CONFIG_KEYBOARD_STOWAWAY is not set
# CONFIG_KEYBOARD_SUNKBD is not set
# CONFIG_KEYBOARD_XTKBD is not set
CONFIG_INPUT_MOUSE=y
CONFIG_MOUSE_PS2=y
CONFIG_MOUSE_PS2_ALPS=y
CONFIG_MOUSE_PS2_LOGIPS2PP=y
CONFIG_MOUSE_PS2_SYNAPTICS=y
CONFIG_MOUSE_PS2_LIFEBOOK=y
CONFIG_MOUSE_PS2_TRACKPOINT=y
# CONFIG_MOUSE_PS2_ELANTECH is not set
# CONFIG_MOUSE_PS2_SENTELIC is not set
# CONFIG_MOUSE_PS2_TOUCHKIT is not set
# CONFIG_MOUSE_SERIAL is not set
# CONFIG_MOUSE_APPLETOUCH is not set
# CONFIG_MOUSE_BCM5974 is not set
# CONFIG_MOUSE_VSXXXAA is not set
# CONFIG_MOUSE_SYNAPTICS_I2C is not set
# CONFIG_INPUT_JOYSTICK is not set
# CONFIG_INPUT_TABLET is not set
# CONFIG_INPUT_TOUCHSCREEN is not set
CONFIG_INPUT_MISC=y
# CONFIG_INPUT_AD714X is not set
CONFIG_INPUT_PCSPKR=y
# CONFIG_INPUT_APANEL is not set
# CONFIG_INPUT_ATLAS_BTNS is not set
# CONFIG_INPUT_ATI_REMOTE is not set
# CONFIG_INPUT_ATI_REMOTE2 is not set
# CONFIG_INPUT_KEYSPAN_REMOTE is not set
# CONFIG_INPUT_POWERMATE is not set
# CONFIG_INPUT_YEALINK is not set
# CONFIG_INPUT_CM109 is not set
# CONFIG_INPUT_UINPUT is not set
# CONFIG_INPUT_PCF8574 is not set
# CONFIG_INPUT_ADXL34X is not set
# CONFIG_INPUT_CMA3000 is not set

#
# Hardware I/O ports
#
CONFIG_SERIO=y
CONFIG_SERIO_I8042=y
# CONFIG_SERIO_SERPORT is not set
# CONFIG_SERIO_CT82C710 is not set
# CONFIG_SERIO_PARKBD is not set
# CONFIG_SERIO_PCIPS2 is not set
CONFIG_SERIO_LIBPS2=y
# CONFIG_SERIO_RAW is not set
# CONFIG_SERIO_ALTERA_PS2 is not set
# CONFIG_SERIO_PS2MULT is not set
# CONFIG_GAMEPORT is not set

#
# Character devices
#
CONFIG_VT=y
CONFIG_CONSOLE_TRANSLATIONS=y
CONFIG_VT_CONSOLE=y
CONFIG_HW_CONSOLE=y
# CONFIG_VT_HW_CONSOLE_BINDING is not set
CONFIG_UNIX98_PTYS=y
# CONFIG_DEVPTS_MULTIPLE_INSTANCES is not set
CONFIG_LEGACY_PTYS=y
CONFIG_LEGACY_PTY_COUNT=256
# CONFIG_SERIAL_NONSTANDARD is not set
# CONFIG_NOZOMI is not set
# CONFIG_N_GSM is not set
CONFIG_DEVKMEM=y

#
# Serial drivers
#
CONFIG_SERIAL_8250=y
# CONFIG_SERIAL_8250_CONSOLE is not set
CONFIG_FIX_EARLYCON_MEM=y
CONFIG_SERIAL_8250_PCI=y
CONFIG_SERIAL_8250_PNP=y
# CONFIG_SERIAL_8250_CS is not set
CONFIG_SERIAL_8250_NR_UARTS=4
CONFIG_SERIAL_8250_RUNTIME_UARTS=4
# CONFIG_SERIAL_8250_EXTENDED is not set

#
# Non-8250 serial port support
#
# CONFIG_SERIAL_MFD_HSU is not set
CONFIG_SERIAL_CORE=y
# CONFIG_SERIAL_JSM is not set
# CONFIG_SERIAL_TIMBERDALE is not set
# CONFIG_SERIAL_ALTERA_JTAGUART is not set
# CONFIG_SERIAL_ALTERA_UART is not set
# CONFIG_SERIAL_PCH_UART is not set
CONFIG_PRINTER=y
# CONFIG_LP_CONSOLE is not set
# CONFIG_PPDEV is not set
# CONFIG_IPMI_HANDLER is not set
CONFIG_HW_RANDOM=y
# CONFIG_HW_RANDOM_TIMERIOMEM is not set
# CONFIG_HW_RANDOM_INTEL is not set
CONFIG_HW_RANDOM_AMD=y
CONFIG_HW_RANDOM_VIA=y
CONFIG_NVRAM=y
# CONFIG_R3964 is not set
# CONFIG_APPLICOM is not set

#
# PCMCIA character devices
#
# CONFIG_SYNCLINK_CS is not set
# CONFIG_CARDMAN_4000 is not set
# CONFIG_CARDMAN_4040 is not set
# CONFIG_IPWIRELESS is not set
# CONFIG_MWAVE is not set
# CONFIG_RAW_DRIVER is not set
CONFIG_HPET=y
CONFIG_HPET_MMAP=y
# CONFIG_HANGCHECK_TIMER is not set
# CONFIG_TCG_TPM is not set
# CONFIG_TELCLOCK is not set
CONFIG_DEVPORT=y
# CONFIG_RAMOOPS is not set
CONFIG_I2C=y
CONFIG_I2C_BOARDINFO=y
CONFIG_I2C_COMPAT=y
CONFIG_I2C_CHARDEV=y
# CONFIG_I2C_MUX is not set
CONFIG_I2C_HELPER_AUTO=y

#
# I2C Hardware Bus support
#

#
# PC SMBus host controller drivers
#
# CONFIG_I2C_ALI1535 is not set
# CONFIG_I2C_ALI1563 is not set
# CONFIG_I2C_ALI15X3 is not set
# CONFIG_I2C_AMD756 is not set
# CONFIG_I2C_AMD8111 is not set
# CONFIG_I2C_I801 is not set
# CONFIG_I2C_ISCH is not set
# CONFIG_I2C_PIIX4 is not set
CONFIG_I2C_NFORCE2=y
# CONFIG_I2C_NFORCE2_S4985 is not set
# CONFIG_I2C_SIS5595 is not set
# CONFIG_I2C_SIS630 is not set
# CONFIG_I2C_SIS96X is not set
# CONFIG_I2C_VIA is not set
# CONFIG_I2C_VIAPRO is not set

#
# ACPI drivers
#
# CONFIG_I2C_SCMI is not set

#
# I2C system bus drivers (mostly embedded / system-on-chip)
#
# CONFIG_I2C_INTEL_MID is not set
# CONFIG_I2C_OCORES is not set
# CONFIG_I2C_PCA_PLATFORM is not set
# CONFIG_I2C_PXA_PCI is not set
# CONFIG_I2C_SIMTEC is not set
# CONFIG_I2C_XILINX is not set
# CONFIG_I2C_EG20T is not set

#
# External I2C/SMBus adapter drivers
#
# CONFIG_I2C_DIOLAN_U2C is not set
# CONFIG_I2C_PARPORT is not set
# CONFIG_I2C_PARPORT_LIGHT is not set
# CONFIG_I2C_TAOS_EVM is not set
# CONFIG_I2C_TINY_USB is not set

#
# Other I2C/SMBus bus drivers
#
# CONFIG_I2C_STUB is not set
# CONFIG_I2C_DEBUG_CORE is not set
# CONFIG_I2C_DEBUG_ALGO is not set
# CONFIG_I2C_DEBUG_BUS is not set
# CONFIG_SPI is not set

#
# PPS support
#
# CONFIG_PPS is not set

#
# PPS generators support
#
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB=y
# CONFIG_GPIOLIB is not set
# CONFIG_W1 is not set
CONFIG_POWER_SUPPLY=y
# CONFIG_POWER_SUPPLY_DEBUG is not set
# CONFIG_PDA_POWER is not set
# CONFIG_TEST_POWER is not set
# CONFIG_BATTERY_DS2782 is not set
# CONFIG_BATTERY_BQ20Z75 is not set
# CONFIG_BATTERY_BQ27x00 is not set
# CONFIG_BATTERY_MAX17040 is not set
# CONFIG_BATTERY_MAX17042 is not set
CONFIG_HWMON=y
# CONFIG_HWMON_VID is not set
# CONFIG_HWMON_DEBUG_CHIP is not set

#
# Native drivers
#
# CONFIG_SENSORS_ABITUGURU is not set
# CONFIG_SENSORS_ABITUGURU3 is not set
# CONFIG_SENSORS_AD7414 is not set
# CONFIG_SENSORS_AD7418 is not set
# CONFIG_SENSORS_ADM1021 is not set
# CONFIG_SENSORS_ADM1025 is not set
# CONFIG_SENSORS_ADM1026 is not set
# CONFIG_SENSORS_ADM1029 is not set
# CONFIG_SENSORS_ADM1031 is not set
# CONFIG_SENSORS_ADM9240 is not set
# CONFIG_SENSORS_ADT7411 is not set
# CONFIG_SENSORS_ADT7462 is not set
# CONFIG_SENSORS_ADT7470 is not set
# CONFIG_SENSORS_ADT7475 is not set
# CONFIG_SENSORS_ASC7621 is not set
CONFIG_SENSORS_K8TEMP=y
# CONFIG_SENSORS_K10TEMP is not set
# CONFIG_SENSORS_ASB100 is not set
# CONFIG_SENSORS_ATXP1 is not set
# CONFIG_SENSORS_DS620 is not set
# CONFIG_SENSORS_DS1621 is not set
# CONFIG_SENSORS_I5K_AMB is not set
# CONFIG_SENSORS_F71805F is not set
# CONFIG_SENSORS_F71882FG is not set
# CONFIG_SENSORS_F75375S is not set
# CONFIG_SENSORS_FSCHMD is not set
# CONFIG_SENSORS_G760A is not set
# CONFIG_SENSORS_GL518SM is not set
# CONFIG_SENSORS_GL520SM is not set
# CONFIG_SENSORS_CORETEMP is not set
# CONFIG_SENSORS_PKGTEMP is not set
# CONFIG_SENSORS_IT87 is not set
# CONFIG_SENSORS_JC42 is not set
# CONFIG_SENSORS_LINEAGE is not set
# CONFIG_SENSORS_LM63 is not set
# CONFIG_SENSORS_LM73 is not set
# CONFIG_SENSORS_LM75 is not set
# CONFIG_SENSORS_LM77 is not set
# CONFIG_SENSORS_LM78 is not set
# CONFIG_SENSORS_LM80 is not set
# CONFIG_SENSORS_LM83 is not set
# CONFIG_SENSORS_LM85 is not set
# CONFIG_SENSORS_LM87 is not set
# CONFIG_SENSORS_LM90 is not set
# CONFIG_SENSORS_LM92 is not set
# CONFIG_SENSORS_LM93 is not set
# CONFIG_SENSORS_LTC4151 is not set
# CONFIG_SENSORS_LTC4215 is not set
# CONFIG_SENSORS_LTC4245 is not set
# CONFIG_SENSORS_LTC4261 is not set
# CONFIG_SENSORS_LM95241 is not set
# CONFIG_SENSORS_MAX1619 is not set
# CONFIG_SENSORS_MAX6639 is not set
# CONFIG_SENSORS_MAX6650 is not set
# CONFIG_SENSORS_PC87360 is not set
# CONFIG_SENSORS_PC87427 is not set
# CONFIG_SENSORS_PCF8591 is not set
# CONFIG_PMBUS is not set
# CONFIG_SENSORS_SHT21 is not set
# CONFIG_SENSORS_SIS5595 is not set
# CONFIG_SENSORS_SMM665 is not set
# CONFIG_SENSORS_DME1737 is not set
# CONFIG_SENSORS_EMC1403 is not set
# CONFIG_SENSORS_EMC2103 is not set
# CONFIG_SENSORS_SMSC47M1 is not set
# CONFIG_SENSORS_SMSC47M192 is not set
# CONFIG_SENSORS_SMSC47B397 is not set
# CONFIG_SENSORS_SCH5627 is not set
# CONFIG_SENSORS_ADS1015 is not set
# CONFIG_SENSORS_ADS7828 is not set
# CONFIG_SENSORS_AMC6821 is not set
# CONFIG_SENSORS_THMC50 is not set
# CONFIG_SENSORS_TMP102 is not set
# CONFIG_SENSORS_TMP401 is not set
# CONFIG_SENSORS_TMP421 is not set
# CONFIG_SENSORS_VIA_CPUTEMP is not set
# CONFIG_SENSORS_VIA686A is not set
# CONFIG_SENSORS_VT1211 is not set
# CONFIG_SENSORS_VT8231 is not set
# CONFIG_SENSORS_W83781D is not set
# CONFIG_SENSORS_W83791D is not set
# CONFIG_SENSORS_W83792D is not set
# CONFIG_SENSORS_W83793 is not set
# CONFIG_SENSORS_W83795 is not set
# CONFIG_SENSORS_W83L785TS is not set
# CONFIG_SENSORS_W83L786NG is not set
# CONFIG_SENSORS_W83627HF is not set
# CONFIG_SENSORS_W83627EHF is not set
# CONFIG_SENSORS_APPLESMC is not set

#
# ACPI drivers
#
# CONFIG_SENSORS_ATK0110 is not set
CONFIG_THERMAL=y
# CONFIG_THERMAL_HWMON is not set
# CONFIG_WATCHDOG is not set
CONFIG_SSB_POSSIBLE=y

#
# Sonics Silicon Backplane
#
CONFIG_SSB=y
CONFIG_SSB_SPROM=y
CONFIG_SSB_BLOCKIO=y
CONFIG_SSB_PCIHOST_POSSIBLE=y
CONFIG_SSB_PCIHOST=y
CONFIG_SSB_B43_PCI_BRIDGE=y
CONFIG_SSB_PCMCIAHOST_POSSIBLE=y
# CONFIG_SSB_PCMCIAHOST is not set
# CONFIG_SSB_DEBUG is not set
CONFIG_SSB_DRIVER_PCICORE_POSSIBLE=y
CONFIG_SSB_DRIVER_PCICORE=y
CONFIG_MFD_SUPPORT=y
# CONFIG_MFD_CORE is not set
# CONFIG_MFD_88PM860X is not set
# CONFIG_MFD_SM501 is not set
# CONFIG_HTC_PASIC3 is not set
# CONFIG_TPS6105X is not set
# CONFIG_TPS6507X is not set
# CONFIG_TWL4030_CORE is not set
# CONFIG_MFD_STMPE is not set
# CONFIG_MFD_TC3589X is not set
# CONFIG_MFD_TMIO is not set
# CONFIG_PMIC_DA903X is not set
# CONFIG_PMIC_ADP5520 is not set
# CONFIG_MFD_MAX8925 is not set
# CONFIG_MFD_MAX8997 is not set
# CONFIG_MFD_MAX8998 is not set
# CONFIG_MFD_WM8400 is not set
# CONFIG_MFD_WM831X_I2C is not set
# CONFIG_MFD_WM8350_I2C is not set
# CONFIG_MFD_WM8994 is not set
# CONFIG_MFD_PCF50633 is not set
# CONFIG_ABX500_CORE is not set
# CONFIG_MFD_CS5535 is not set
# CONFIG_LPC_SCH is not set
# CONFIG_MFD_RDC321X is not set
# CONFIG_MFD_JANZ_CMODIO is not set
# CONFIG_MFD_VX855 is not set
# CONFIG_MFD_WL1273_CORE is not set
# CONFIG_REGULATOR is not set
# CONFIG_MEDIA_SUPPORT is not set

#
# Graphics support
#
CONFIG_AGP=y
CONFIG_AGP_AMD64=y
# CONFIG_AGP_INTEL is not set
# CONFIG_AGP_SIS is not set
# CONFIG_AGP_VIA is not set
CONFIG_VGA_ARB=y
CONFIG_VGA_ARB_MAX_GPUS=16
# CONFIG_VGA_SWITCHEROO is not set
# CONFIG_DRM is not set
# CONFIG_STUB_POULSBO is not set
# CONFIG_VGASTATE is not set
# CONFIG_VIDEO_OUTPUT_CONTROL is not set
# CONFIG_FB is not set
# CONFIG_BACKLIGHT_LCD_SUPPORT is not set

#
# Display device support
#
# CONFIG_DISPLAY_SUPPORT is not set

#
# Console display driver support
#
CONFIG_VGA_CONSOLE=y
CONFIG_VGACON_SOFT_SCROLLBACK=y
CONFIG_VGACON_SOFT_SCROLLBACK_SIZE=64
CONFIG_DUMMY_CONSOLE=y
CONFIG_SOUND=y
CONFIG_SOUND_OSS_CORE=y
CONFIG_SOUND_OSS_CORE_PRECLAIM=y
CONFIG_SND=y
CONFIG_SND_TIMER=y
CONFIG_SND_PCM=y
CONFIG_SND_HWDEP=y
CONFIG_SND_RAWMIDI=y
CONFIG_SND_SEQUENCER=y
# CONFIG_SND_SEQ_DUMMY is not set
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_PCM_OSS_PLUGINS=y
CONFIG_SND_SEQUENCER_OSS=y
# CONFIG_SND_HRTIMER is not set
# CONFIG_SND_DYNAMIC_MINORS is not set
CONFIG_SND_SUPPORT_OLD_API=y
CONFIG_SND_VERBOSE_PROCFS=y
# CONFIG_SND_VERBOSE_PRINTK is not set
# CONFIG_SND_DEBUG is not set
CONFIG_SND_VMASTER=y
CONFIG_SND_DMA_SGBUF=y
CONFIG_SND_RAWMIDI_SEQ=y
# CONFIG_SND_OPL3_LIB_SEQ is not set
# CONFIG_SND_OPL4_LIB_SEQ is not set
# CONFIG_SND_SBAWE_SEQ is not set
# CONFIG_SND_EMU10K1_SEQ is not set
CONFIG_SND_AC97_CODEC=y
CONFIG_SND_DRIVERS=y
# CONFIG_SND_PCSP is not set
# CONFIG_SND_DUMMY is not set
# CONFIG_SND_ALOOP is not set
# CONFIG_SND_VIRMIDI is not set
# CONFIG_SND_MTPAV is not set
# CONFIG_SND_MTS64 is not set
# CONFIG_SND_SERIAL_U16550 is not set
# CONFIG_SND_MPU401 is not set
# CONFIG_SND_PORTMAN2X4 is not set
# CONFIG_SND_AC97_POWER_SAVE is not set
CONFIG_SND_PCI=y
# CONFIG_SND_AD1889 is not set
# CONFIG_SND_ALS300 is not set
# CONFIG_SND_ALS4000 is not set
# CONFIG_SND_ALI5451 is not set
# CONFIG_SND_ASIHPI is not set
# CONFIG_SND_ATIIXP is not set
# CONFIG_SND_ATIIXP_MODEM is not set
# CONFIG_SND_AU8810 is not set
# CONFIG_SND_AU8820 is not set
# CONFIG_SND_AU8830 is not set
# CONFIG_SND_AW2 is not set
# CONFIG_SND_AZT3328 is not set
# CONFIG_SND_BT87X is not set
# CONFIG_SND_CA0106 is not set
# CONFIG_SND_CMIPCI is not set
# CONFIG_SND_OXYGEN is not set
# CONFIG_SND_CS4281 is not set
# CONFIG_SND_CS46XX is not set
# CONFIG_SND_CS5530 is not set
# CONFIG_SND_CS5535AUDIO is not set
# CONFIG_SND_CTXFI is not set
# CONFIG_SND_DARLA20 is not set
# CONFIG_SND_GINA20 is not set
# CONFIG_SND_LAYLA20 is not set
# CONFIG_SND_DARLA24 is not set
# CONFIG_SND_GINA24 is not set
# CONFIG_SND_LAYLA24 is not set
# CONFIG_SND_MONA is not set
# CONFIG_SND_MIA is not set
# CONFIG_SND_ECHO3G is not set
# CONFIG_SND_INDIGO is not set
# CONFIG_SND_INDIGOIO is not set
# CONFIG_SND_INDIGODJ is not set
# CONFIG_SND_INDIGOIOX is not set
# CONFIG_SND_INDIGODJX is not set
# CONFIG_SND_EMU10K1 is not set
# CONFIG_SND_EMU10K1X is not set
# CONFIG_SND_ENS1370 is not set
# CONFIG_SND_ENS1371 is not set
# CONFIG_SND_ES1938 is not set
# CONFIG_SND_ES1968 is not set
# CONFIG_SND_FM801 is not set
# CONFIG_SND_HDA_INTEL is not set
# CONFIG_SND_HDSP is not set
# CONFIG_SND_HDSPM is not set
# CONFIG_SND_ICE1712 is not set
# CONFIG_SND_ICE1724 is not set
CONFIG_SND_INTEL8X0=y
CONFIG_SND_INTEL8X0M=y
# CONFIG_SND_KORG1212 is not set
# CONFIG_SND_LX6464ES is not set
# CONFIG_SND_MAESTRO3 is not set
# CONFIG_SND_MIXART is not set
# CONFIG_SND_NM256 is not set
# CONFIG_SND_PCXHR is not set
# CONFIG_SND_RIPTIDE is not set
# CONFIG_SND_RME32 is not set
# CONFIG_SND_RME96 is not set
# CONFIG_SND_RME9652 is not set
# CONFIG_SND_SONICVIBES is not set
# CONFIG_SND_TRIDENT is not set
# CONFIG_SND_VIA82XX is not set
# CONFIG_SND_VIA82XX_MODEM is not set
# CONFIG_SND_VIRTUOSO is not set
# CONFIG_SND_VX222 is not set
# CONFIG_SND_YMFPCI is not set
CONFIG_SND_USB=y
CONFIG_SND_USB_AUDIO=y
# CONFIG_SND_USB_UA101 is not set
# CONFIG_SND_USB_USX2Y is not set
# CONFIG_SND_USB_CAIAQ is not set
# CONFIG_SND_USB_US122L is not set
# CONFIG_SND_USB_6FIRE is not set
CONFIG_SND_FIREWIRE=y
# CONFIG_SND_FIREWIRE_SPEAKERS is not set
# CONFIG_SND_PCMCIA is not set
# CONFIG_SND_SOC is not set
# CONFIG_SOUND_PRIME is not set
CONFIG_AC97_BUS=y
CONFIG_HID_SUPPORT=y
CONFIG_HID=y
# CONFIG_HIDRAW is not set

#
# USB Input Devices
#
CONFIG_USB_HID=y
# CONFIG_HID_PID is not set
CONFIG_USB_HIDDEV=y

#
# Special HID drivers
#
# CONFIG_HID_3M_PCT is not set
CONFIG_HID_A4TECH=y
# CONFIG_HID_ACRUX is not set
CONFIG_HID_APPLE=y
CONFIG_HID_BELKIN=y
# CONFIG_HID_CANDO is not set
CONFIG_HID_CHERRY=y
CONFIG_HID_CHICONY=y
# CONFIG_HID_PRODIKEYS is not set
CONFIG_HID_CYPRESS=y
CONFIG_HID_DRAGONRISE=y
# CONFIG_DRAGONRISE_FF is not set
# CONFIG_HID_EMS_FF is not set
CONFIG_HID_EZKEY=y
# CONFIG_HID_KEYTOUCH is not set
CONFIG_HID_KYE=y
# CONFIG_HID_UCLOGIC is not set
# CONFIG_HID_WALTOP is not set
CONFIG_HID_GYRATION=y
CONFIG_HID_TWINHAN=y
CONFIG_HID_KENSINGTON=y
# CONFIG_HID_LCPOWER is not set
CONFIG_HID_LOGITECH=y
# CONFIG_LOGITECH_FF is not set
# CONFIG_LOGIRUMBLEPAD2_FF is not set
# CONFIG_LOGIG940_FF is not set
# CONFIG_LOGIWII_FF is not set
CONFIG_HID_MICROSOFT=y
# CONFIG_HID_MOSART is not set
CONFIG_HID_MONTEREY=y
# CONFIG_HID_MULTITOUCH is not set
CONFIG_HID_NTRIG=y
# CONFIG_HID_ORTEK is not set
CONFIG_HID_PANTHERLORD=y
# CONFIG_PANTHERLORD_FF is not set
CONFIG_HID_PETALYNX=y
# CONFIG_HID_PICOLCD is not set
# CONFIG_HID_QUANTA is not set
# CONFIG_HID_ROCCAT is not set
# CONFIG_HID_ROCCAT_ARVO is not set
# CONFIG_HID_ROCCAT_KONE is not set
# CONFIG_HID_ROCCAT_KONEPLUS is not set
# CONFIG_HID_ROCCAT_KOVAPLUS is not set
# CONFIG_HID_ROCCAT_PYRA is not set
CONFIG_HID_SAMSUNG=y
CONFIG_HID_SONY=y
# CONFIG_HID_STANTUM is not set
CONFIG_HID_SUNPLUS=y
CONFIG_HID_GREENASIA=y
# CONFIG_GREENASIA_FF is not set
CONFIG_HID_SMARTJOYPLUS=y
# CONFIG_SMARTJOYPLUS_FF is not set
CONFIG_HID_TOPSEED=y
CONFIG_HID_THRUSTMASTER=y
# CONFIG_THRUSTMASTER_FF is not set
CONFIG_HID_ZEROPLUS=y
# CONFIG_ZEROPLUS_FF is not set
# CONFIG_HID_ZYDACRON is not set
CONFIG_USB_SUPPORT=y
CONFIG_USB_ARCH_HAS_HCD=y
CONFIG_USB_ARCH_HAS_OHCI=y
CONFIG_USB_ARCH_HAS_EHCI=y
CONFIG_USB=y
# CONFIG_USB_DEBUG is not set
# CONFIG_USB_ANNOUNCE_NEW_DEVICES is not set

#
# Miscellaneous USB options
#
# CONFIG_USB_DEVICEFS is not set
CONFIG_USB_DEVICE_CLASS=y
# CONFIG_USB_DYNAMIC_MINORS is not set
CONFIG_USB_SUSPEND=y
# CONFIG_USB_OTG is not set
CONFIG_USB_MON=y
# CONFIG_USB_WUSB is not set
# CONFIG_USB_WUSB_CBAF is not set

#
# USB Host Controller Drivers
#
# CONFIG_USB_C67X00_HCD is not set
# CONFIG_USB_XHCI_HCD is not set
CONFIG_USB_EHCI_HCD=y
# CONFIG_USB_EHCI_ROOT_HUB_TT is not set
# CONFIG_USB_EHCI_TT_NEWSCHED is not set
# CONFIG_USB_OXU210HP_HCD is not set
# CONFIG_USB_ISP116X_HCD is not set
# CONFIG_USB_ISP1760_HCD is not set
# CONFIG_USB_ISP1362_HCD is not set
CONFIG_USB_OHCI_HCD=y
# CONFIG_USB_OHCI_HCD_SSB is not set
# CONFIG_USB_OHCI_BIG_ENDIAN_DESC is not set
# CONFIG_USB_OHCI_BIG_ENDIAN_MMIO is not set
CONFIG_USB_OHCI_LITTLE_ENDIAN=y
# CONFIG_USB_UHCI_HCD is not set
# CONFIG_USB_SL811_HCD is not set
# CONFIG_USB_R8A66597_HCD is not set
# CONFIG_USB_WHCI_HCD is not set
# CONFIG_USB_HWA_HCD is not set

#
# USB Device Class drivers
#
# CONFIG_USB_ACM is not set
CONFIG_USB_PRINTER=y
# CONFIG_USB_WDM is not set
# CONFIG_USB_TMC is not set

#
# NOTE: USB_STORAGE depends on SCSI but BLK_DEV_SD may
#

#
# also be needed; see USB_STORAGE Help for more info
#
CONFIG_USB_STORAGE=y
# CONFIG_USB_STORAGE_DEBUG is not set
# CONFIG_USB_STORAGE_REALTEK is not set
# CONFIG_USB_STORAGE_DATAFAB is not set
# CONFIG_USB_STORAGE_FREECOM is not set
# CONFIG_USB_STORAGE_ISD200 is not set
# CONFIG_USB_STORAGE_USBAT is not set
# CONFIG_USB_STORAGE_SDDR09 is not set
# CONFIG_USB_STORAGE_SDDR55 is not set
# CONFIG_USB_STORAGE_JUMPSHOT is not set
# CONFIG_USB_STORAGE_ALAUDA is not set
# CONFIG_USB_STORAGE_ONETOUCH is not set
# CONFIG_USB_STORAGE_KARMA is not set
# CONFIG_USB_STORAGE_CYPRESS_ATACB is not set
# CONFIG_USB_STORAGE_ENE_UB6250 is not set
# CONFIG_USB_UAS is not set
# CONFIG_USB_LIBUSUAL is not set

#
# USB Imaging devices
#
# CONFIG_USB_MDC800 is not set
# CONFIG_USB_MICROTEK is not set

#
# USB port drivers
#
# CONFIG_USB_USS720 is not set
# CONFIG_USB_SERIAL is not set

#
# USB Miscellaneous drivers
#
# CONFIG_USB_EMI62 is not set
# CONFIG_USB_EMI26 is not set
# CONFIG_USB_ADUTUX is not set
# CONFIG_USB_SEVSEG is not set
# CONFIG_USB_RIO500 is not set
# CONFIG_USB_LEGOTOWER is not set
# CONFIG_USB_LCD is not set
# CONFIG_USB_LED is not set
# CONFIG_USB_CYPRESS_CY7C63 is not set
# CONFIG_USB_CYTHERM is not set
# CONFIG_USB_IDMOUSE is not set
# CONFIG_USB_FTDI_ELAN is not set
# CONFIG_USB_APPLEDISPLAY is not set
# CONFIG_USB_SISUSBVGA is not set
# CONFIG_USB_LD is not set
# CONFIG_USB_TRANCEVIBRATOR is not set
# CONFIG_USB_IOWARRIOR is not set
# CONFIG_USB_TEST is not set
# CONFIG_USB_ISIGHTFW is not set
# CONFIG_USB_YUREX is not set
# CONFIG_USB_GADGET is not set

#
# OTG and related infrastructure
#
# CONFIG_NOP_USB_XCEIV is not set
# CONFIG_UWB is not set
# CONFIG_MMC is not set
# CONFIG_MEMSTICK is not set
CONFIG_NEW_LEDS=y
CONFIG_LEDS_CLASS=y

#
# LED drivers
#
# CONFIG_LEDS_LM3530 is not set
# CONFIG_LEDS_ALIX2 is not set
# CONFIG_LEDS_PCA9532 is not set
# CONFIG_LEDS_LP3944 is not set
# CONFIG_LEDS_LP5521 is not set
# CONFIG_LEDS_LP5523 is not set
# CONFIG_LEDS_CLEVO_MAIL is not set
# CONFIG_LEDS_PCA955X is not set
# CONFIG_LEDS_BD2802 is not set
# CONFIG_LEDS_INTEL_SS4200 is not set
# CONFIG_LEDS_DELL_NETBOOKS is not set
# CONFIG_LEDS_TRIGGERS is not set

#
# LED Triggers
#
# CONFIG_NFC_DEVICES is not set
# CONFIG_ACCESSIBILITY is not set
# CONFIG_INFINIBAND is not set
# CONFIG_EDAC is not set
CONFIG_RTC_LIB=y
CONFIG_RTC_CLASS=y
CONFIG_RTC_HCTOSYS=y
CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
# CONFIG_RTC_DEBUG is not set

#
# RTC interfaces
#
CONFIG_RTC_INTF_SYSFS=y
CONFIG_RTC_INTF_PROC=y
CONFIG_RTC_INTF_DEV=y
# CONFIG_RTC_INTF_DEV_UIE_EMUL is not set
# CONFIG_RTC_DRV_TEST is not set

#
# I2C RTC drivers
#
# CONFIG_RTC_DRV_DS1307 is not set
# CONFIG_RTC_DRV_DS1374 is not set
# CONFIG_RTC_DRV_DS1672 is not set
# CONFIG_RTC_DRV_DS3232 is not set
# CONFIG_RTC_DRV_MAX6900 is not set
# CONFIG_RTC_DRV_RS5C372 is not set
# CONFIG_RTC_DRV_ISL1208 is not set
# CONFIG_RTC_DRV_ISL12022 is not set
# CONFIG_RTC_DRV_X1205 is not set
# CONFIG_RTC_DRV_PCF8563 is not set
# CONFIG_RTC_DRV_PCF8583 is not set
# CONFIG_RTC_DRV_M41T80 is not set
# CONFIG_RTC_DRV_BQ32K is not set
# CONFIG_RTC_DRV_S35390A is not set
# CONFIG_RTC_DRV_FM3130 is not set
# CONFIG_RTC_DRV_RX8581 is not set
# CONFIG_RTC_DRV_RX8025 is not set

#
# SPI RTC drivers
#

#
# Platform RTC drivers
#
CONFIG_RTC_DRV_CMOS=y
# CONFIG_RTC_DRV_DS1286 is not set
# CONFIG_RTC_DRV_DS1511 is not set
# CONFIG_RTC_DRV_DS1553 is not set
# CONFIG_RTC_DRV_DS1742 is not set
# CONFIG_RTC_DRV_STK17TA8 is not set
# CONFIG_RTC_DRV_M48T86 is not set
# CONFIG_RTC_DRV_M48T35 is not set
# CONFIG_RTC_DRV_M48T59 is not set
# CONFIG_RTC_DRV_MSM6242 is not set
# CONFIG_RTC_DRV_BQ4802 is not set
# CONFIG_RTC_DRV_RP5C01 is not set
# CONFIG_RTC_DRV_V3020 is not set

#
# on-CPU RTC drivers
#
# CONFIG_DMADEVICES is not set
# CONFIG_AUXDISPLAY is not set
# CONFIG_UIO is not set
# CONFIG_STAGING is not set
CONFIG_X86_PLATFORM_DEVICES=y
# CONFIG_ASUS_LAPTOP is not set
# CONFIG_DELL_WMI is not set
# CONFIG_DELL_WMI_AIO is not set
# CONFIG_HP_ACCEL is not set
# CONFIG_HP_WMI is not set
# CONFIG_SONY_LAPTOP is not set
# CONFIG_IDEAPAD_LAPTOP is not set
# CONFIG_THINKPAD_ACPI is not set
# CONFIG_SENSORS_HDAPS is not set
# CONFIG_INTEL_MENLOW is not set
CONFIG_ACPI_WMI=y
# CONFIG_ACPI_ASUS is not set
# CONFIG_TOPSTAR_LAPTOP is not set
# CONFIG_TOSHIBA_BT_RFKILL is not set
# CONFIG_ACPI_CMPC is not set
# CONFIG_INTEL_IPS is not set
# CONFIG_IBM_RTL is not set
# CONFIG_XO15_EBOOK is not set

#
# Firmware Drivers
#
# CONFIG_EDD is not set
CONFIG_FIRMWARE_MEMMAP=y
# CONFIG_DELL_RBU is not set
# CONFIG_DCDBAS is not set
CONFIG_DMIID=y
# CONFIG_DMI_SYSFS is not set
# CONFIG_ISCSI_IBFT_FIND is not set
# CONFIG_SIGMA is not set

#
# File systems
#
CONFIG_EXT2_FS=y
CONFIG_EXT2_FS_XATTR=y
CONFIG_EXT2_FS_POSIX_ACL=y
# CONFIG_EXT2_FS_SECURITY is not set
CONFIG_EXT2_FS_XIP=y
CONFIG_EXT3_FS=y
# CONFIG_EXT3_DEFAULTS_TO_ORDERED is not set
CONFIG_EXT3_FS_XATTR=y
CONFIG_EXT3_FS_POSIX_ACL=y
# CONFIG_EXT3_FS_SECURITY is not set
CONFIG_EXT4_FS=y
CONFIG_EXT4_FS_XATTR=y
CONFIG_EXT4_FS_POSIX_ACL=y
# CONFIG_EXT4_FS_SECURITY is not set
# CONFIG_EXT4_DEBUG is not set
CONFIG_FS_XIP=y
CONFIG_JBD=y
CONFIG_JBD2=y
CONFIG_FS_MBCACHE=y
# CONFIG_REISERFS_FS is not set
# CONFIG_JFS_FS is not set
CONFIG_XFS_FS=y
# CONFIG_XFS_QUOTA is not set
CONFIG_XFS_POSIX_ACL=y
CONFIG_XFS_RT=y
# CONFIG_XFS_DEBUG is not set
# CONFIG_GFS2_FS is not set
# CONFIG_OCFS2_FS is not set
# CONFIG_BTRFS_FS is not set
# CONFIG_NILFS2_FS is not set
CONFIG_FS_POSIX_ACL=y
CONFIG_EXPORTFS=y
CONFIG_FILE_LOCKING=y
CONFIG_FSNOTIFY=y
CONFIG_DNOTIFY=y
CONFIG_INOTIFY_USER=y
# CONFIG_FANOTIFY is not set
# CONFIG_QUOTA is not set
# CONFIG_QUOTACTL is not set
CONFIG_AUTOFS4_FS=y
CONFIG_FUSE_FS=y
# CONFIG_CUSE is not set
CONFIG_GENERIC_ACL=y

#
# Caches
#
# CONFIG_FSCACHE is not set

#
# CD-ROM/DVD Filesystems
#
CONFIG_ISO9660_FS=y
CONFIG_JOLIET=y
# CONFIG_ZISOFS is not set
CONFIG_UDF_FS=y
CONFIG_UDF_NLS=y

#
# DOS/FAT/NT Filesystems
#
CONFIG_FAT_FS=y
CONFIG_MSDOS_FS=y
CONFIG_VFAT_FS=y
CONFIG_FAT_DEFAULT_CODEPAGE=850
CONFIG_FAT_DEFAULT_IOCHARSET="iso8859-1"
# CONFIG_NTFS_FS is not set

#
# Pseudo filesystems
#
CONFIG_PROC_FS=y
CONFIG_PROC_KCORE=y
CONFIG_PROC_SYSCTL=y
CONFIG_PROC_PAGE_MONITOR=y
CONFIG_SYSFS=y
CONFIG_TMPFS=y
CONFIG_TMPFS_POSIX_ACL=y
# CONFIG_HUGETLBFS is not set
# CONFIG_HUGETLB_PAGE is not set
CONFIG_CONFIGFS_FS=y
CONFIG_MISC_FILESYSTEMS=y
# CONFIG_ADFS_FS is not set
# CONFIG_AFFS_FS is not set
# CONFIG_HFS_FS is not set
# CONFIG_HFSPLUS_FS is not set
# CONFIG_BEFS_FS is not set
# CONFIG_BFS_FS is not set
# CONFIG_EFS_FS is not set
# CONFIG_LOGFS is not set
# CONFIG_CRAMFS is not set
# CONFIG_SQUASHFS is not set
# CONFIG_VXFS_FS is not set
# CONFIG_MINIX_FS is not set
# CONFIG_OMFS_FS is not set
# CONFIG_QNX4FS_FS is not set
# CONFIG_ROMFS_FS is not set
# CONFIG_PSTORE is not set
# CONFIG_SYSV_FS is not set
# CONFIG_UFS_FS is not set
CONFIG_NETWORK_FILESYSTEMS=y
# CONFIG_NFS_FS is not set
# CONFIG_NFSD is not set
# CONFIG_CEPH_FS is not set
# CONFIG_CIFS is not set
# CONFIG_NCP_FS is not set
# CONFIG_CODA_FS is not set
# CONFIG_AFS_FS is not set

#
# Partition Types
#
# CONFIG_PARTITION_ADVANCED is not set
CONFIG_MSDOS_PARTITION=y
CONFIG_NLS=y
CONFIG_NLS_DEFAULT="iso8859-1"
CONFIG_NLS_CODEPAGE_437=y
# CONFIG_NLS_CODEPAGE_737 is not set
# CONFIG_NLS_CODEPAGE_775 is not set
CONFIG_NLS_CODEPAGE_850=y
# CONFIG_NLS_CODEPAGE_852 is not set
# CONFIG_NLS_CODEPAGE_855 is not set
# CONFIG_NLS_CODEPAGE_857 is not set
# CONFIG_NLS_CODEPAGE_860 is not set
# CONFIG_NLS_CODEPAGE_861 is not set
# CONFIG_NLS_CODEPAGE_862 is not set
# CONFIG_NLS_CODEPAGE_863 is not set
# CONFIG_NLS_CODEPAGE_864 is not set
# CONFIG_NLS_CODEPAGE_865 is not set
# CONFIG_NLS_CODEPAGE_866 is not set
# CONFIG_NLS_CODEPAGE_869 is not set
# CONFIG_NLS_CODEPAGE_936 is not set
# CONFIG_NLS_CODEPAGE_950 is not set
# CONFIG_NLS_CODEPAGE_932 is not set
# CONFIG_NLS_CODEPAGE_949 is not set
# CONFIG_NLS_CODEPAGE_874 is not set
# CONFIG_NLS_ISO8859_8 is not set
# CONFIG_NLS_CODEPAGE_1250 is not set
# CONFIG_NLS_CODEPAGE_1251 is not set
# CONFIG_NLS_ASCII is not set
CONFIG_NLS_ISO8859_1=y
# CONFIG_NLS_ISO8859_2 is not set
# CONFIG_NLS_ISO8859_3 is not set
# CONFIG_NLS_ISO8859_4 is not set
# CONFIG_NLS_ISO8859_5 is not set
# CONFIG_NLS_ISO8859_6 is not set
# CONFIG_NLS_ISO8859_7 is not set
# CONFIG_NLS_ISO8859_9 is not set
# CONFIG_NLS_ISO8859_13 is not set
# CONFIG_NLS_ISO8859_14 is not set
CONFIG_NLS_ISO8859_15=y
# CONFIG_NLS_KOI8_R is not set
# CONFIG_NLS_KOI8_U is not set
CONFIG_NLS_UTF8=y
# CONFIG_DLM is not set

#
# Kernel hacking
#
CONFIG_TRACE_IRQFLAGS_SUPPORT=y
# CONFIG_PRINTK_TIME is not set
CONFIG_DEFAULT_MESSAGE_LOGLEVEL=4
# CONFIG_ENABLE_WARN_DEPRECATED is not set
# CONFIG_ENABLE_MUST_CHECK is not set
CONFIG_FRAME_WARN=2048
# CONFIG_MAGIC_SYSRQ is not set
# CONFIG_STRIP_ASM_SYMS is not set
# CONFIG_UNUSED_SYMBOLS is not set
# CONFIG_DEBUG_FS is not set
# CONFIG_HEADERS_CHECK is not set
# CONFIG_DEBUG_SECTION_MISMATCH is not set
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_SHIRQ=y
# CONFIG_LOCKUP_DETECTOR is not set
# CONFIG_HARDLOCKUP_DETECTOR is not set
# CONFIG_DETECT_HUNG_TASK is not set
CONFIG_SCHED_DEBUG=y
# CONFIG_SCHEDSTATS is not set
# CONFIG_TIMER_STATS is not set
CONFIG_DEBUG_OBJECTS=y
# CONFIG_DEBUG_OBJECTS_SELFTEST is not set
CONFIG_DEBUG_OBJECTS_FREE=y
CONFIG_DEBUG_OBJECTS_TIMERS=y
CONFIG_DEBUG_OBJECTS_WORK=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
# CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER is not set
CONFIG_DEBUG_OBJECTS_ENABLE_DEFAULT=1
# CONFIG_SLUB_STATS is not set
# CONFIG_DEBUG_KMEMLEAK is not set
CONFIG_DEBUG_PREEMPT=y
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_PI_LIST=y
# CONFIG_RT_MUTEX_TESTER is not set
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
# CONFIG_PROVE_RCU_REPEATEDLY is not set
# CONFIG_SPARSE_RCU_POINTER is not set
CONFIG_LOCKDEP=y
# CONFIG_LOCK_STAT is not set
# CONFIG_DEBUG_LOCKDEP is not set
CONFIG_TRACE_IRQFLAGS=y
CONFIG_DEBUG_SPINLOCK_SLEEP=y
# CONFIG_DEBUG_LOCKING_API_SELFTESTS is not set
CONFIG_STACKTRACE=y
# CONFIG_DEBUG_KOBJECT is not set
CONFIG_DEBUG_BUGVERBOSE=y
CONFIG_DEBUG_INFO=y
# CONFIG_DEBUG_INFO_REDUCED is not set
CONFIG_DEBUG_VM=y
CONFIG_DEBUG_VIRTUAL=y
CONFIG_DEBUG_WRITECOUNT=y
CONFIG_DEBUG_MEMORY_INIT=y
CONFIG_DEBUG_LIST=y
# CONFIG_TEST_LIST_SORT is not set
CONFIG_DEBUG_SG=y
CONFIG_DEBUG_NOTIFIERS=y
CONFIG_DEBUG_CREDENTIALS=y
CONFIG_ARCH_WANT_FRAME_POINTERS=y
CONFIG_FRAME_POINTER=y
# CONFIG_BOOT_PRINTK_DELAY is not set
# CONFIG_RCU_TORTURE_TEST is not set
# CONFIG_RCU_CPU_STALL_DETECTOR is not set
# CONFIG_BACKTRACE_SELF_TEST is not set
# CONFIG_DEBUG_BLOCK_EXT_DEVT is not set
# CONFIG_DEBUG_FORCE_WEAK_PER_CPU is not set
# CONFIG_FAULT_INJECTION is not set
# CONFIG_LATENCYTOP is not set
CONFIG_SYSCTL_SYSCALL_CHECK=y
CONFIG_USER_STACKTRACE_SUPPORT=y
CONFIG_HAVE_FUNCTION_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_TRACER=y
CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST=y
CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST=y
CONFIG_HAVE_DYNAMIC_FTRACE=y
CONFIG_HAVE_FTRACE_MCOUNT_RECORD=y
CONFIG_HAVE_SYSCALL_TRACEPOINTS=y
CONFIG_HAVE_C_RECORDMCOUNT=y
CONFIG_TRACING_SUPPORT=y
# CONFIG_FTRACE is not set
# CONFIG_PROVIDE_OHCI1394_DMA_INIT is not set
# CONFIG_FIREWIRE_OHCI_REMOTE_DMA is not set
CONFIG_DMA_API_DEBUG=y
# CONFIG_ATOMIC64_SELFTEST is not set
# CONFIG_SAMPLES is not set
CONFIG_HAVE_ARCH_KGDB=y
# CONFIG_KGDB is not set
CONFIG_HAVE_ARCH_KMEMCHECK=y
CONFIG_KMEMCHECK=y
# CONFIG_KMEMCHECK_DISABLED_BY_DEFAULT is not set
# CONFIG_KMEMCHECK_ENABLED_BY_DEFAULT is not set
CONFIG_KMEMCHECK_ONESHOT_BY_DEFAULT=y
CONFIG_KMEMCHECK_QUEUE_SIZE=64
CONFIG_KMEMCHECK_SHADOW_COPY_SHIFT=5
CONFIG_KMEMCHECK_PARTIAL_OK=y
CONFIG_KMEMCHECK_BITOPS_OK=y
# CONFIG_TEST_KSTRTOX is not set
# CONFIG_STRICT_DEVMEM is not set
# CONFIG_X86_VERBOSE_BOOTUP is not set
CONFIG_EARLY_PRINTK=y
# CONFIG_EARLY_PRINTK_DBGP is not set
CONFIG_DEBUG_STACKOVERFLOW=y
# CONFIG_DEBUG_STACK_USAGE is not set
# CONFIG_X86_PTDUMP is not set
CONFIG_DEBUG_RODATA=y
CONFIG_DEBUG_RODATA_TEST=y
# CONFIG_DEBUG_SET_MODULE_RONX is not set
# CONFIG_DEBUG_NX_TEST is not set
# CONFIG_IOMMU_DEBUG is not set
# CONFIG_IOMMU_STRESS is not set
CONFIG_HAVE_MMIOTRACE_SUPPORT=y
CONFIG_IO_DELAY_TYPE_0X80=0
CONFIG_IO_DELAY_TYPE_0XED=1
CONFIG_IO_DELAY_TYPE_UDELAY=2
CONFIG_IO_DELAY_TYPE_NONE=3
CONFIG_IO_DELAY_0X80=y
# CONFIG_IO_DELAY_0XED is not set
# CONFIG_IO_DELAY_UDELAY is not set
# CONFIG_IO_DELAY_NONE is not set
CONFIG_DEFAULT_IO_DELAY_TYPE=0
# CONFIG_CPA_DEBUG is not set
# CONFIG_OPTIMIZE_INLINING is not set
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS=y

#
# Security options
#
# CONFIG_KEYS is not set
# CONFIG_SECURITY_DMESG_RESTRICT is not set
# CONFIG_SECURITY is not set
# CONFIG_SECURITYFS is not set
CONFIG_DEFAULT_SECURITY_DAC=y
CONFIG_DEFAULT_SECURITY=""
CONFIG_CRYPTO=y

#
# Crypto core or helper
#
CONFIG_CRYPTO_ALGAPI=y
CONFIG_CRYPTO_ALGAPI2=y
CONFIG_CRYPTO_AEAD=y
CONFIG_CRYPTO_AEAD2=y
CONFIG_CRYPTO_BLKCIPHER=y
CONFIG_CRYPTO_BLKCIPHER2=y
CONFIG_CRYPTO_HASH=y
CONFIG_CRYPTO_HASH2=y
CONFIG_CRYPTO_RNG2=y
CONFIG_CRYPTO_PCOMP2=y
CONFIG_CRYPTO_MANAGER=y
CONFIG_CRYPTO_MANAGER2=y
CONFIG_CRYPTO_MANAGER_DISABLE_TESTS=y
# CONFIG_CRYPTO_GF128MUL is not set
CONFIG_CRYPTO_NULL=y
CONFIG_CRYPTO_WORKQUEUE=y
# CONFIG_CRYPTO_CRYPTD is not set
CONFIG_CRYPTO_AUTHENC=y
# CONFIG_CRYPTO_TEST is not set

#
# Authenticated Encryption with Associated Data
#
# CONFIG_CRYPTO_CCM is not set
# CONFIG_CRYPTO_GCM is not set
# CONFIG_CRYPTO_SEQIV is not set

#
# Block modes
#
CONFIG_CRYPTO_CBC=y
# CONFIG_CRYPTO_CTR is not set
# CONFIG_CRYPTO_CTS is not set
CONFIG_CRYPTO_ECB=y
# CONFIG_CRYPTO_LRW is not set
# CONFIG_CRYPTO_PCBC is not set
# CONFIG_CRYPTO_XTS is not set

#
# Hash modes
#
CONFIG_CRYPTO_HMAC=y
# CONFIG_CRYPTO_XCBC is not set
# CONFIG_CRYPTO_VMAC is not set

#
# Digest
#
CONFIG_CRYPTO_CRC32C=y
# CONFIG_CRYPTO_CRC32C_INTEL is not set
# CONFIG_CRYPTO_GHASH is not set
# CONFIG_CRYPTO_MD4 is not set
CONFIG_CRYPTO_MD5=y
CONFIG_CRYPTO_MICHAEL_MIC=y
# CONFIG_CRYPTO_RMD128 is not set
# CONFIG_CRYPTO_RMD160 is not set
# CONFIG_CRYPTO_RMD256 is not set
# CONFIG_CRYPTO_RMD320 is not set
CONFIG_CRYPTO_SHA1=y
CONFIG_CRYPTO_SHA256=y
CONFIG_CRYPTO_SHA512=y
# CONFIG_CRYPTO_TGR192 is not set
# CONFIG_CRYPTO_WP512 is not set
# CONFIG_CRYPTO_GHASH_CLMUL_NI_INTEL is not set

#
# Ciphers
#
CONFIG_CRYPTO_AES=y
CONFIG_CRYPTO_AES_X86_64=y
# CONFIG_CRYPTO_AES_NI_INTEL is not set
# CONFIG_CRYPTO_ANUBIS is not set
CONFIG_CRYPTO_ARC4=y
CONFIG_CRYPTO_BLOWFISH=y
# CONFIG_CRYPTO_CAMELLIA is not set
# CONFIG_CRYPTO_CAST5 is not set
# CONFIG_CRYPTO_CAST6 is not set
CONFIG_CRYPTO_DES=y
# CONFIG_CRYPTO_FCRYPT is not set
# CONFIG_CRYPTO_KHAZAD is not set
# CONFIG_CRYPTO_SALSA20 is not set
# CONFIG_CRYPTO_SALSA20_X86_64 is not set
# CONFIG_CRYPTO_SEED is not set
CONFIG_CRYPTO_SERPENT=y
# CONFIG_CRYPTO_TEA is not set
# CONFIG_CRYPTO_TWOFISH is not set
CONFIG_CRYPTO_TWOFISH_COMMON=y
CONFIG_CRYPTO_TWOFISH_X86_64=y

#
# Compression
#
CONFIG_CRYPTO_DEFLATE=y
# CONFIG_CRYPTO_ZLIB is not set
# CONFIG_CRYPTO_LZO is not set

#
# Random Number Generation
#
# CONFIG_CRYPTO_ANSI_CPRNG is not set
# CONFIG_CRYPTO_USER_API_HASH is not set
# CONFIG_CRYPTO_USER_API_SKCIPHER is not set
CONFIG_CRYPTO_HW=y
# CONFIG_CRYPTO_DEV_PADLOCK is not set
# CONFIG_CRYPTO_DEV_HIFN_795X is not set
CONFIG_HAVE_KVM=y
# CONFIG_VIRTUALIZATION is not set
# CONFIG_BINARY_PRINTF is not set

#
# Library routines
#
CONFIG_BITREVERSE=y
CONFIG_GENERIC_FIND_FIRST_BIT=y
CONFIG_GENERIC_FIND_NEXT_BIT=y
CONFIG_GENERIC_FIND_LAST_BIT=y
CONFIG_CRC_CCITT=y
CONFIG_CRC16=y
CONFIG_CRC_T10DIF=y
CONFIG_CRC_ITU_T=y
CONFIG_CRC32=y
# CONFIG_CRC7 is not set
CONFIG_LIBCRC32C=y
CONFIG_ZLIB_INFLATE=y
CONFIG_ZLIB_DEFLATE=y
# CONFIG_XZ_DEC is not set
# CONFIG_XZ_DEC_BCJ is not set
CONFIG_HAS_IOMEM=y
CONFIG_HAS_IOPORT=y
CONFIG_HAS_DMA=y
CONFIG_NLATTR=y
CONFIG_AVERAGE=y

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 19:36                                   ` Christian Casteyde
@ 2011-04-20 19:55                                     ` Eric Dumazet
  2011-04-20 20:32                                       ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 19:55 UTC (permalink / raw)
  To: Christian Casteyde
  Cc: Christoph Lameter, Pekka Enberg, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 21:36 +0200, Christian Casteyde a écrit :

> I'm not sure it's the same problem anyway as I've said previously.
> I append my config file used to build this kernel.

This is not the same problem, and is a known false positive from skb
reallocation. (skb_reserve() doesnt mark memory as initialized) 




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 19:55                                     ` Eric Dumazet
@ 2011-04-20 20:32                                       ` Eric Dumazet
  0 siblings, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-04-20 20:32 UTC (permalink / raw)
  To: Christian Casteyde
  Cc: Christoph Lameter, Pekka Enberg, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum, Changli Gao

Le mercredi 20 avril 2011 à 21:55 +0200, Eric Dumazet a écrit :
> Le mercredi 20 avril 2011 à 21:36 +0200, Christian Casteyde a écrit :
> 
> > I'm not sure it's the same problem anyway as I've said previously.
> > I append my config file used to build this kernel.
> 
> This is not the same problem, and is a known false positive from skb
> reallocation. (skb_reserve() doesnt mark memory as initialized) 
> 
> 

Please try following patch. It's a bit tricky, because network stack has
different functions to fill bytes in skb and change pointers/offsets in
it.

Alternative would be to change pskb_expand_head() to not copy zone
between skb->head and skb->data (might contain unitialized data)

Thanks


diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 79aafbb..3f2cba4 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1252,6 +1252,7 @@ static inline int skb_tailroom(const struct sk_buff *skb)
  */
 static inline void skb_reserve(struct sk_buff *skb, int len)
 {
+	kmemcheck_mark_initialized(skb->data, len);
 	skb->data += len;
 	skb->tail += len;
 }



^ permalink raw reply related	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:01                                 ` Eric Dumazet
                                                     ` (2 preceding siblings ...)
  2011-04-20 19:36                                   ` Christian Casteyde
@ 2011-05-05  6:18                                   ` Eric Dumazet
  2011-05-05  6:22                                     ` Pekka Enberg
  2011-05-09 19:44                                   ` Pekka Enberg
  4 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-05  6:18 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mercredi 20 avril 2011 à 17:01 +0200, Eric Dumazet a écrit :
> Le mercredi 20 avril 2011 à 09:42 -0500, Christoph Lameter a écrit :
> 
> > Avoiding the irq handling yields the savings that improve the fastpath. if
> > you do both then there is only a regression left. So lets go with
> > disabling the CMPXCHG_LOCAL.
> 
> OK, let's do that then.
> 
> Thanks
> 
> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
> 
> Christian Casteyde reported a KMEMCHECK splat in slub code.
> 
> Problem is now we are lockless and allow IRQ in slab_alloc(), the object
> we manipulate from freelist can be allocated and freed right before we
> try to read object->next.
> 
> Same problem can happen with DEBUG_PAGEALLOC
> 
> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> CONFIG_DEBUG_PAGEALLOC is defined.
> 
> Reported-by: Christian Casteyde <casteyde.christian@free.fr>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Pekka Enberg <penberg@cs.helsinki.fi>
> Cc: Vegard Nossum <vegardno@ifi.uio.no>
> Cc: Christoph Lameter <cl@linux.com>
> ---
>  mm/slub.c |   45 +++++++++++++++++++++++++--------------------
>  1 files changed, 25 insertions(+), 20 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 94d2a33..f31ab2c 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -1540,7 +1540,12 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
>  	}
>  }
>  
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#if defined(CONFIG_CMPXCHG_LOCAL) && !defined(CONFIG_KMEMCHECK) && \
> +				     !defined(CONFIG_DEBUG_PAGEALLOC)
> +#define SLUB_USE_CMPXCHG_DOUBLE
> +#endif
> +
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  #ifdef CONFIG_PREEMPT
>  /*
>   * Calculate the next globally unique transaction for disambiguiation
> @@ -1604,7 +1609,7 @@ static inline void note_cmpxchg_failure(const char *n,
>  
>  void init_kmem_cache_cpus(struct kmem_cache *s)
>  {
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	int cpu;
>  
>  	for_each_possible_cpu(cpu)
> @@ -1643,7 +1648,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
>  		page->inuse--;
>  	}
>  	c->page = NULL;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	c->tid = next_tid(c->tid);
>  #endif
>  	unfreeze_slab(s, page, tail);
> @@ -1780,7 +1785,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
>  {
>  	void **object;
>  	struct page *new;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long flags;
>  
>  	local_irq_save(flags);
> @@ -1819,7 +1824,7 @@ load_freelist:
>  	c->node = page_to_nid(c->page);
>  unlock_out:
>  	slab_unlock(c->page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	c->tid = next_tid(c->tid);
>  	local_irq_restore(flags);
>  #endif
> @@ -1858,7 +1863,7 @@ new_slab:
>  	}
>  	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
>  		slab_out_of_memory(s, gfpflags, node);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	return NULL;
> @@ -1887,7 +1892,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
>  {
>  	void **object;
>  	struct kmem_cache_cpu *c;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long tid;
>  #else
>  	unsigned long flags;
> @@ -1896,7 +1901,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
>  	if (slab_pre_alloc_hook(s, gfpflags))
>  		return NULL;
>  
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_save(flags);
>  #else
>  redo:
> @@ -1910,7 +1915,7 @@ redo:
>  	 */
>  	c = __this_cpu_ptr(s->cpu_slab);
>  
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	/*
>  	 * The transaction ids are globally unique per cpu and per operation on
>  	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
> @@ -1927,7 +1932,7 @@ redo:
>  		object = __slab_alloc(s, gfpflags, node, addr, c);
>  
>  	else {
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  		/*
>  		 * The cmpxchg will only match if there was no additional
>  		 * operation and if we are on the right processor.
> @@ -1954,7 +1959,7 @@ redo:
>  		stat(s, ALLOC_FASTPATH);
>  	}
>  
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  
> @@ -2034,7 +2039,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
>  {
>  	void *prior;
>  	void **object = (void *)x;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long flags;
>  
>  	local_irq_save(flags);
> @@ -2070,7 +2075,7 @@ checks_ok:
>  
>  out_unlock:
>  	slab_unlock(page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	return;
> @@ -2084,7 +2089,7 @@ slab_empty:
>  		stat(s, FREE_REMOVE_PARTIAL);
>  	}
>  	slab_unlock(page);
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  	stat(s, FREE_SLAB);
> @@ -2113,7 +2118,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
>  {
>  	void **object = (void *)x;
>  	struct kmem_cache_cpu *c;
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	unsigned long tid;
>  #else
>  	unsigned long flags;
> @@ -2121,7 +2126,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
>  
>  	slab_free_hook(s, x);
>  
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_save(flags);
>  
>  #else
> @@ -2136,7 +2141,7 @@ redo:
>  	 */
>  	c = __this_cpu_ptr(s->cpu_slab);
>  
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	tid = c->tid;
>  	barrier();
>  #endif
> @@ -2144,7 +2149,7 @@ redo:
>  	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
>  		set_freepointer(s, object, c->freelist);
>  
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  		if (unlikely(!this_cpu_cmpxchg_double(
>  				s->cpu_slab->freelist, s->cpu_slab->tid,
>  				c->freelist, tid,
> @@ -2160,7 +2165,7 @@ redo:
>  	} else
>  		__slab_free(s, page, x, addr);
>  
> -#ifndef CONFIG_CMPXCHG_LOCAL
> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>  	local_irq_restore(flags);
>  #endif
>  }
> @@ -2354,7 +2359,7 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
>  	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
>  			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
>  
> -#ifdef CONFIG_CMPXCHG_LOCAL
> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>  	/*
>  	 * Must align to double word boundary for the double cmpxchg instructions
>  	 * to work.
> 


Is anybody taking the patch and sending it upstream ?

Thanks



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-05  6:18                                   ` Eric Dumazet
@ 2011-05-05  6:22                                     ` Pekka Enberg
  2011-05-05  6:50                                       ` Eric Dumazet
  2011-05-05 18:40                                       ` Christoph Lameter
  0 siblings, 2 replies; 66+ messages in thread
From: Pekka Enberg @ 2011-05-05  6:22 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On 5/5/11 9:18 AM, Eric Dumazet wrote:
> Le mercredi 20 avril 2011 à 17:01 +0200, Eric Dumazet a écrit :
>> Le mercredi 20 avril 2011 à 09:42 -0500, Christoph Lameter a écrit :
>>
>>> Avoiding the irq handling yields the savings that improve the fastpath. if
>>> you do both then there is only a regression left. So lets go with
>>> disabling the CMPXCHG_LOCAL.
>>
>> OK, let's do that then.
>>
>> Thanks
>>
>> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
>>
>> Christian Casteyde reported a KMEMCHECK splat in slub code.
>>
>> Problem is now we are lockless and allow IRQ in slab_alloc(), the object
>> we manipulate from freelist can be allocated and freed right before we
>> try to read object->next.
>>
>> Same problem can happen with DEBUG_PAGEALLOC
>>
>> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
>> CONFIG_DEBUG_PAGEALLOC is defined.
>>
>> Reported-by: Christian Casteyde<casteyde.christian@free.fr>
>> Signed-off-by: Eric Dumazet<eric.dumazet@gmail.com>
>> Cc: Andrew Morton<akpm@linux-foundation.org>
>> Cc: Pekka Enberg<penberg@cs.helsinki.fi>
>> Cc: Vegard Nossum<vegardno@ifi.uio.no>
>> Cc: Christoph Lameter<cl@linux.com>
>> ---
>>   mm/slub.c |   45 +++++++++++++++++++++++++--------------------
>>   1 files changed, 25 insertions(+), 20 deletions(-)
>>
>> diff --git a/mm/slub.c b/mm/slub.c
>> index 94d2a33..f31ab2c 100644
>> --- a/mm/slub.c
>> +++ b/mm/slub.c
>> @@ -1540,7 +1540,12 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
>>   	}
>>   }
>>
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#if defined(CONFIG_CMPXCHG_LOCAL)&&  !defined(CONFIG_KMEMCHECK)&&  \
>> +				     !defined(CONFIG_DEBUG_PAGEALLOC)
>> +#define SLUB_USE_CMPXCHG_DOUBLE
>> +#endif
>> +
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   #ifdef CONFIG_PREEMPT
>>   /*
>>    * Calculate the next globally unique transaction for disambiguiation
>> @@ -1604,7 +1609,7 @@ static inline void note_cmpxchg_failure(const char *n,
>>
>>   void init_kmem_cache_cpus(struct kmem_cache *s)
>>   {
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	int cpu;
>>
>>   	for_each_possible_cpu(cpu)
>> @@ -1643,7 +1648,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
>>   		page->inuse--;
>>   	}
>>   	c->page = NULL;
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	c->tid = next_tid(c->tid);
>>   #endif
>>   	unfreeze_slab(s, page, tail);
>> @@ -1780,7 +1785,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
>>   {
>>   	void **object;
>>   	struct page *new;
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	unsigned long flags;
>>
>>   	local_irq_save(flags);
>> @@ -1819,7 +1824,7 @@ load_freelist:
>>   	c->node = page_to_nid(c->page);
>>   unlock_out:
>>   	slab_unlock(c->page);
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	c->tid = next_tid(c->tid);
>>   	local_irq_restore(flags);
>>   #endif
>> @@ -1858,7 +1863,7 @@ new_slab:
>>   	}
>>   	if (!(gfpflags&  __GFP_NOWARN)&&  printk_ratelimit())
>>   		slab_out_of_memory(s, gfpflags, node);
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_restore(flags);
>>   #endif
>>   	return NULL;
>> @@ -1887,7 +1892,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
>>   {
>>   	void **object;
>>   	struct kmem_cache_cpu *c;
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	unsigned long tid;
>>   #else
>>   	unsigned long flags;
>> @@ -1896,7 +1901,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
>>   	if (slab_pre_alloc_hook(s, gfpflags))
>>   		return NULL;
>>
>> -#ifndef CONFIG_CMPXCHG_LOCAL
>> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_save(flags);
>>   #else
>>   redo:
>> @@ -1910,7 +1915,7 @@ redo:
>>   	 */
>>   	c = __this_cpu_ptr(s->cpu_slab);
>>
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	/*
>>   	 * The transaction ids are globally unique per cpu and per operation on
>>   	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
>> @@ -1927,7 +1932,7 @@ redo:
>>   		object = __slab_alloc(s, gfpflags, node, addr, c);
>>
>>   	else {
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   		/*
>>   		 * The cmpxchg will only match if there was no additional
>>   		 * operation and if we are on the right processor.
>> @@ -1954,7 +1959,7 @@ redo:
>>   		stat(s, ALLOC_FASTPATH);
>>   	}
>>
>> -#ifndef CONFIG_CMPXCHG_LOCAL
>> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_restore(flags);
>>   #endif
>>
>> @@ -2034,7 +2039,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
>>   {
>>   	void *prior;
>>   	void **object = (void *)x;
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	unsigned long flags;
>>
>>   	local_irq_save(flags);
>> @@ -2070,7 +2075,7 @@ checks_ok:
>>
>>   out_unlock:
>>   	slab_unlock(page);
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_restore(flags);
>>   #endif
>>   	return;
>> @@ -2084,7 +2089,7 @@ slab_empty:
>>   		stat(s, FREE_REMOVE_PARTIAL);
>>   	}
>>   	slab_unlock(page);
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_restore(flags);
>>   #endif
>>   	stat(s, FREE_SLAB);
>> @@ -2113,7 +2118,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
>>   {
>>   	void **object = (void *)x;
>>   	struct kmem_cache_cpu *c;
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	unsigned long tid;
>>   #else
>>   	unsigned long flags;
>> @@ -2121,7 +2126,7 @@ static __always_inline void slab_free(struct kmem_cache *s,
>>
>>   	slab_free_hook(s, x);
>>
>> -#ifndef CONFIG_CMPXCHG_LOCAL
>> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_save(flags);
>>
>>   #else
>> @@ -2136,7 +2141,7 @@ redo:
>>   	 */
>>   	c = __this_cpu_ptr(s->cpu_slab);
>>
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	tid = c->tid;
>>   	barrier();
>>   #endif
>> @@ -2144,7 +2149,7 @@ redo:
>>   	if (likely(page == c->page&&  c->node != NUMA_NO_NODE)) {
>>   		set_freepointer(s, object, c->freelist);
>>
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   		if (unlikely(!this_cpu_cmpxchg_double(
>>   				s->cpu_slab->freelist, s->cpu_slab->tid,
>>   				c->freelist, tid,
>> @@ -2160,7 +2165,7 @@ redo:
>>   	} else
>>   		__slab_free(s, page, x, addr);
>>
>> -#ifndef CONFIG_CMPXCHG_LOCAL
>> +#ifndef SLUB_USE_CMPXCHG_DOUBLE
>>   	local_irq_restore(flags);
>>   #endif
>>   }
>> @@ -2354,7 +2359,7 @@ static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
>>   	BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE<
>>   			SLUB_PAGE_SHIFT * sizeof(struct kmem_cache_cpu));
>>
>> -#ifdef CONFIG_CMPXCHG_LOCAL
>> +#ifdef SLUB_USE_CMPXCHG_DOUBLE
>>   	/*
>>   	 * Must align to double word boundary for the double cmpxchg instructions
>>   	 * to work.
>>
>
>
> Is anybody taking the patch and sending it upstream ?

Oh, sorry, it got lost in my inbox. I can take care of it.

			Pekka

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-05  6:22                                     ` Pekka Enberg
@ 2011-05-05  6:50                                       ` Eric Dumazet
  2011-05-05 18:40                                       ` Christoph Lameter
  1 sibling, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-05-05  6:50 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le jeudi 05 mai 2011 à 09:22 +0300, Pekka Enberg a écrit :

> Oh, sorry, it got lost in my inbox. I can take care of it.
> 

Thanks Pekka !



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-05  6:22                                     ` Pekka Enberg
  2011-05-05  6:50                                       ` Eric Dumazet
@ 2011-05-05 18:40                                       ` Christoph Lameter
  2011-05-05 18:48                                         ` Eric Dumazet
  1 sibling, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-05 18:40 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Eric Dumazet, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On Thu, 5 May 2011, Pekka Enberg wrote:

> > > -#ifdef CONFIG_CMPXCHG_LOCAL
> > > +#ifdef SLUB_USE_CMPXCHG_DOUBLE
> > >   	/*
> > >   	 * Must align to double word boundary for the double cmpxchg
> > > instructions
> > >   	 * to work.
> > >
> >
> >
> > Is anybody taking the patch and sending it upstream ?
>
> Oh, sorry, it got lost in my inbox. I can take care of it.

Combining this one with the patch I sent to remove the #ifdeffery would
make this much simpler.


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-05 18:40                                       ` Christoph Lameter
@ 2011-05-05 18:48                                         ` Eric Dumazet
  2011-05-05 19:05                                           ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-05 18:48 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le jeudi 05 mai 2011 à 13:40 -0500, Christoph Lameter a écrit :
> On Thu, 5 May 2011, Pekka Enberg wrote:
> 
> > > > -#ifdef CONFIG_CMPXCHG_LOCAL
> > > > +#ifdef SLUB_USE_CMPXCHG_DOUBLE
> > > >   	/*
> > > >   	 * Must align to double word boundary for the double cmpxchg
> > > > instructions
> > > >   	 * to work.
> > > >
> > >
> > >
> > > Is anybody taking the patch and sending it upstream ?
> >
> > Oh, sorry, it got lost in my inbox. I can take care of it.
> 
> Combining this one with the patch I sent to remove the #ifdeffery would
> make this much simpler.

I must missed it, could you please resend it ?

Thanks



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-05 18:48                                         ` Eric Dumazet
@ 2011-05-05 19:05                                           ` Christoph Lameter
  0 siblings, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-05 19:05 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Pekka Enberg, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On Thu, 5 May 2011, Eric Dumazet wrote:

> > Combining this one with the patch I sent to remove the #ifdeffery would
> > make this much simpler.
>
> I must missed it, could you please resend it ?


Subject: slub: Remove CONFIG_CMPXCHG_LOCAL ifdeffery

Remove the #ifdefs. This means that the irqsafe_cpu_cmpxchg_double() is used
everywhere.

There may be performance implications since:

A. We now have to manage a transaction ID for all arches

B. The interrupt holdoff for arches not supporting CONFIG_CMPXCHG_LOCAL is reduced
to a very short irqoff section.

There are no multiple irqoff/irqon sequences as a result of this change. Even in the fallback
case we only have to do one disable and enable like before.

Signed-off-by: Christoph Lameter <cl@linux.com>

---
 include/linux/slub_def.h |    2 -
 mm/slub.c                |   56 -----------------------------------------------
 2 files changed, 58 deletions(-)

Index: linux-2.6/include/linux/slub_def.h
===================================================================
--- linux-2.6.orig/include/linux/slub_def.h	2011-05-04 09:33:08.000000000 -0500
+++ linux-2.6/include/linux/slub_def.h	2011-05-04 09:42:05.000000000 -0500
@@ -37,9 +37,7 @@ enum stat_item {

 struct kmem_cache_cpu {
 	void **freelist;	/* Pointer to next available object */
-#ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long tid;	/* Globally unique transaction id */
-#endif
 	struct page *page;	/* The slab from which we are allocating */
 	int node;		/* The node of the page (or -1 for debug) */
 #ifdef CONFIG_SLUB_STATS
Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-05-04 09:41:59.000000000 -0500
+++ linux-2.6/mm/slub.c	2011-05-04 09:48:11.000000000 -0500
@@ -1540,7 +1540,6 @@ static void unfreeze_slab(struct kmem_ca
 	}
 }

-#ifdef CONFIG_CMPXCHG_LOCAL
 #ifdef CONFIG_PREEMPT
 /*
  * Calculate the next globally unique transaction for disambiguiation
@@ -1600,17 +1599,12 @@ static inline void note_cmpxchg_failure(
 	stat(s, CMPXCHG_DOUBLE_CPU_FAIL);
 }

-#endif
-
 void init_kmem_cache_cpus(struct kmem_cache *s)
 {
-#ifdef CONFIG_CMPXCHG_LOCAL
 	int cpu;

 	for_each_possible_cpu(cpu)
 		per_cpu_ptr(s->cpu_slab, cpu)->tid = init_tid(cpu);
-#endif
-
 }
 /*
  * Remove the cpu slab
@@ -1643,9 +1637,7 @@ static void deactivate_slab(struct kmem_
 		page->inuse--;
 	}
 	c->page = NULL;
-#ifdef CONFIG_CMPXCHG_LOCAL
 	c->tid = next_tid(c->tid);
-#endif
 	unfreeze_slab(s, page, tail);
 }

@@ -1780,7 +1772,6 @@ static void *__slab_alloc(struct kmem_ca
 {
 	void **object;
 	struct page *new;
-#ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long flags;

 	local_irq_save(flags);
@@ -1792,7 +1783,6 @@ static void *__slab_alloc(struct kmem_ca
 	 */
 	c = this_cpu_ptr(s->cpu_slab);
 #endif
-#endif

 	/* We handle __GFP_ZERO in the caller */
 	gfpflags &= ~__GFP_ZERO;
@@ -1819,10 +1809,8 @@ load_freelist:
 	c->node = page_to_nid(c->page);
 unlock_out:
 	slab_unlock(c->page);
-#ifdef CONFIG_CMPXCHG_LOCAL
 	c->tid = next_tid(c->tid);
 	local_irq_restore(flags);
-#endif
 	stat(s, ALLOC_SLOWPATH);
 	return object;

@@ -1858,9 +1846,7 @@ new_slab:
 	}
 	if (!(gfpflags & __GFP_NOWARN) && printk_ratelimit())
 		slab_out_of_memory(s, gfpflags, node);
-#ifdef CONFIG_CMPXCHG_LOCAL
 	local_irq_restore(flags);
-#endif
 	return NULL;
 debug:
 	if (!alloc_debug_processing(s, c->page, object, addr))
@@ -1887,20 +1873,12 @@ static __always_inline void *slab_alloc(
 {
 	void **object;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long tid;
-#else
-	unsigned long flags;
-#endif

 	if (slab_pre_alloc_hook(s, gfpflags))
 		return NULL;

-#ifndef CONFIG_CMPXCHG_LOCAL
-	local_irq_save(flags);
-#else
 redo:
-#endif

 	/*
 	 * Must read kmem_cache cpu data via this cpu ptr. Preemption is
@@ -1910,7 +1888,6 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);

-#ifdef CONFIG_CMPXCHG_LOCAL
 	/*
 	 * The transaction ids are globally unique per cpu and per operation on
 	 * a per cpu queue. Thus they can be guarantee that the cmpxchg_double
@@ -1919,7 +1896,6 @@ redo:
 	 */
 	tid = c->tid;
 	barrier();
-#endif

 	object = c->freelist;
 	if (unlikely(!object || !node_match(c, node)))
@@ -1927,7 +1903,6 @@ redo:
 		object = __slab_alloc(s, gfpflags, node, addr, c);

 	else {
-#ifdef CONFIG_CMPXCHG_LOCAL
 		/*
 		 * The cmpxchg will only match if there was no additional
 		 * operation and if we are on the right processor.
@@ -1948,16 +1923,9 @@ redo:
 			note_cmpxchg_failure("slab_alloc", s, tid);
 			goto redo;
 		}
-#else
-		c->freelist = get_freepointer(s, object);
-#endif
 		stat(s, ALLOC_FASTPATH);
 	}

-#ifndef CONFIG_CMPXCHG_LOCAL
-	local_irq_restore(flags);
-#endif
-
 	if (unlikely(gfpflags & __GFP_ZERO) && object)
 		memset(object, 0, s->objsize);

@@ -2034,11 +2002,9 @@ static void __slab_free(struct kmem_cach
 {
 	void *prior;
 	void **object = (void *)x;
-#ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long flags;

 	local_irq_save(flags);
-#endif
 	slab_lock(page);
 	stat(s, FREE_SLOWPATH);

@@ -2070,9 +2036,7 @@ checks_ok:

 out_unlock:
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
 	local_irq_restore(flags);
-#endif
 	return;

 slab_empty:
@@ -2084,9 +2048,7 @@ slab_empty:
 		stat(s, FREE_REMOVE_PARTIAL);
 	}
 	slab_unlock(page);
-#ifdef CONFIG_CMPXCHG_LOCAL
 	local_irq_restore(flags);
-#endif
 	stat(s, FREE_SLAB);
 	discard_slab(s, page);
 	return;
@@ -2113,20 +2075,11 @@ static __always_inline void slab_free(st
 {
 	void **object = (void *)x;
 	struct kmem_cache_cpu *c;
-#ifdef CONFIG_CMPXCHG_LOCAL
 	unsigned long tid;
-#else
-	unsigned long flags;
-#endif

 	slab_free_hook(s, x);

-#ifndef CONFIG_CMPXCHG_LOCAL
-	local_irq_save(flags);
-
-#else
 redo:
-#endif

 	/*
 	 * Determine the currently cpus per cpu slab.
@@ -2136,15 +2089,12 @@ redo:
 	 */
 	c = __this_cpu_ptr(s->cpu_slab);

-#ifdef CONFIG_CMPXCHG_LOCAL
 	tid = c->tid;
 	barrier();
-#endif

 	if (likely(page == c->page && c->node != NUMA_NO_NODE)) {
 		set_freepointer(s, object, c->freelist);

-#ifdef CONFIG_CMPXCHG_LOCAL
 		if (unlikely(!irqsafe_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				c->freelist, tid,
@@ -2153,16 +2103,10 @@ redo:
 			note_cmpxchg_failure("slab_free", s, tid);
 			goto redo;
 		}
-#else
-		c->freelist = object;
-#endif
 		stat(s, FREE_FASTPATH);
 	} else
 		__slab_free(s, page, x, addr);

-#ifndef CONFIG_CMPXCHG_LOCAL
-	local_irq_restore(flags);
-#endif
 }

 void kmem_cache_free(struct kmem_cache *s, void *x)

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-20 15:01                                 ` Eric Dumazet
                                                     ` (3 preceding siblings ...)
  2011-05-05  6:18                                   ` Eric Dumazet
@ 2011-05-09 19:44                                   ` Pekka Enberg
  2011-05-09 20:04                                     ` Christoph Lameter
  4 siblings, 1 reply; 66+ messages in thread
From: Pekka Enberg @ 2011-05-09 19:44 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Pekka Enberg, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	Vegard Nossum

On Wed, 20 Apr 2011, Eric Dumazet wrote:
> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
>
> Christian Casteyde reported a KMEMCHECK splat in slub code.
>
> Problem is now we are lockless and allow IRQ in slab_alloc(), the object
> we manipulate from freelist can be allocated and freed right before we
> try to read object->next.
>
> Same problem can happen with DEBUG_PAGEALLOC
>
> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> CONFIG_DEBUG_PAGEALLOC is defined.

Christoph, Eric, is this still relevant after commit 1759415 ("slub: 
Remove CONFIG_CMPXCHG_LOCAL ifdeffery") in slab/next of slab.git?

 			Pekka


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-09 19:44                                   ` Pekka Enberg
@ 2011-05-09 20:04                                     ` Christoph Lameter
  2011-05-09 20:06                                       ` Pekka Enberg
  2011-05-10  8:43                                       ` Eric Dumazet
  0 siblings, 2 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-09 20:04 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Eric Dumazet, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon, Vegard Nossum

On Mon, 9 May 2011, Pekka Enberg wrote:

> On Wed, 20 Apr 2011, Eric Dumazet wrote:
> > [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
> >
> > Christian Casteyde reported a KMEMCHECK splat in slub code.
> >
> > Problem is now we are lockless and allow IRQ in slab_alloc(), the object
> > we manipulate from freelist can be allocated and freed right before we
> > try to read object->next.
> >
> > Same problem can happen with DEBUG_PAGEALLOC
> >
> > Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> > CONFIG_DEBUG_PAGEALLOC is defined.
>
> Christoph, Eric, is this still relevant after commit 1759415 ("slub: Remove
> CONFIG_CMPXCHG_LOCAL ifdeffery") in slab/next of slab.git?

There is still an issue and now you can no longer fix the thing through
CONFIG_CMPXCHG_LOCAL.

It needs to be legal for slub to deref the counter even if the object has
been freed.


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-09 20:04                                     ` Christoph Lameter
@ 2011-05-09 20:06                                       ` Pekka Enberg
  2011-05-10  8:43                                       ` Eric Dumazet
  1 sibling, 0 replies; 66+ messages in thread
From: Pekka Enberg @ 2011-05-09 20:06 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Eric Dumazet, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon, Vegard Nossum

On Mon, 9 May 2011, Christoph Lameter wrote:
> There is still an issue and now you can no longer fix the thing through
> CONFIG_CMPXCHG_LOCAL.
>
> It needs to be legal for slub to deref the counter even if the object has
> been freed.

We can use kmemcheck_mark_initialized() for that.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-09 20:04                                     ` Christoph Lameter
  2011-05-09 20:06                                       ` Pekka Enberg
@ 2011-05-10  8:43                                       ` Eric Dumazet
  2011-05-10  9:47                                         ` Pekka Enberg
  2011-05-10 10:03                                         ` Pekka Enberg
  1 sibling, 2 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10  8:43 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Pekka Enberg, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon, Vegard Nossum

Le lundi 09 mai 2011 à 15:04 -0500, Christoph Lameter a écrit :
> On Mon, 9 May 2011, Pekka Enberg wrote:
> 
> > On Wed, 20 Apr 2011, Eric Dumazet wrote:
> > > [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
> > >
> > > Christian Casteyde reported a KMEMCHECK splat in slub code.
> > >
> > > Problem is now we are lockless and allow IRQ in slab_alloc(), the object
> > > we manipulate from freelist can be allocated and freed right before we
> > > try to read object->next.
> > >
> > > Same problem can happen with DEBUG_PAGEALLOC
> > >
> > > Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
> > > CONFIG_DEBUG_PAGEALLOC is defined.
> >
> > Christoph, Eric, is this still relevant after commit 1759415 ("slub: Remove
> > CONFIG_CMPXCHG_LOCAL ifdeffery") in slab/next of slab.git?
> 
> There is still an issue and now you can no longer fix the thing through
> CONFIG_CMPXCHG_LOCAL.
> 
> It needs to be legal for slub to deref the counter even if the object has
> been freed.
> 

I am trying to follow things but honestly I am lost.

Isnt commit 1759415e63 planned for 2.6.40 ?
( ref :
http://git.kernel.org/?p=linux/kernel/git/penberg/slab-2.6.git;a=commitdiff;h=1759415e630e5db0dd2390df9f94892cbfb9a8a2 )

How shall we fix things for 2.6.39 ? I thought my patch was OK for that.


Its a bit hard to work with you on this stuff, for a report I made ages
ago, I find it incredible its not yet fixed in linux-2.6.

Christoph, is your plan to make SLUB not compatable with
CONFIG_DEBUG_PAGEALLOC ? Luckily we still have SLAB ;)

I am a bit surprised of 1759415e63 commit. Its obviously wrong for
DEBUG_PAGEALLOG. Sure KMEMCHECK could be handled differently (since we
are !SMP in this case)

???




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10  8:43                                       ` Eric Dumazet
@ 2011-05-10  9:47                                         ` Pekka Enberg
  2011-05-10 10:03                                           ` Eric Dumazet
  2011-05-10 10:03                                         ` Pekka Enberg
  1 sibling, 1 reply; 66+ messages in thread
From: Pekka Enberg @ 2011-05-10  9:47 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Pekka Enberg, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	Vegard Nossum

On 5/10/11 11:43 AM, Eric Dumazet wrote:
> I am trying to follow things but honestly I am lost.
> Isnt commit 1759415e63 planned for 2.6.40 ?
> ( ref :
> http://git.kernel.org/?p=linux/kernel/git/penberg/slab-2.6.git;a=commitdiff;h=1759415e630e5db0dd2390df9f94892cbfb9a8a2 )

Yes, it's for 2.6.40.

> How shall we fix things for 2.6.39 ? I thought my patch was OK for that.
>

It's so late in the release cycle that I think the best option is to fix 
it in 2.6.40 and backport it to -stable together with the above commit.

> Its a bit hard to work with you on this stuff, for a report I made ages
> ago, I find it incredible its not yet fixed in linux-2.6.

It's not incredible, I simply managed to miss your patch. Sorry about that.

                     Pekka

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10  9:47                                         ` Pekka Enberg
@ 2011-05-10 10:03                                           ` Eric Dumazet
  2011-05-10 10:10                                             ` Pekka Enberg
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 10:03 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mardi 10 mai 2011 à 12:47 +0300, Pekka Enberg a écrit :
> On 5/10/11 11:43 AM, Eric Dumazet wrote:
> > I am trying to follow things but honestly I am lost.
> > Isnt commit 1759415e63 planned for 2.6.40 ?
> > ( ref :
> > http://git.kernel.org/?p=linux/kernel/git/penberg/slab-2.6.git;a=commitdiff;h=1759415e630e5db0dd2390df9f94892cbfb9a8a2 )
> 
> Yes, it's for 2.6.40.
> 
> > How shall we fix things for 2.6.39 ? I thought my patch was OK for that.
> >
> 
> It's so late in the release cycle that I think the best option is to fix 
> it in 2.6.40 and backport it to -stable together with the above commit.
> 
> > Its a bit hard to work with you on this stuff, for a report I made ages
> > ago, I find it incredible its not yet fixed in linux-2.6.
> 
> It's not incredible, I simply managed to miss your patch. Sorry about that.
> 

Pekka, my word was probably too strong, sorry for that.

What I meant is I dont understand how Christoph expect to solve this
problem if irqsafe_cpu_cmpxchg_double() is used everywhere.





^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:03                                           ` Eric Dumazet
@ 2011-05-10 10:10                                             ` Pekka Enberg
  0 siblings, 0 replies; 66+ messages in thread
From: Pekka Enberg @ 2011-05-10 10:10 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Hi Eric,

On 5/10/11 1:03 PM, Eric Dumazet wrote:
> What I meant is I dont understand how Christoph expect to solve this
> problem if irqsafe_cpu_cmpxchg_double() is used everywhere.

Do you see any problem with annotating the freelist pointers with 
kmemcheck_mark_initialized() in set_freepointer()?

The #ifdef removal was requested by Linus et al when we fixed a bug that 
was causing problems during boot on certain CPUs. So even though it 
invalidates your fix, it's the way to go forward.

			Pekka

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10  8:43                                       ` Eric Dumazet
  2011-05-10  9:47                                         ` Pekka Enberg
@ 2011-05-10 10:03                                         ` Pekka Enberg
  2011-05-10 10:17                                           ` Eric Dumazet
  1 sibling, 1 reply; 66+ messages in thread
From: Pekka Enberg @ 2011-05-10 10:03 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, Pekka Enberg, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	Vegard Nossum

On 5/10/11 11:43 AM, Eric Dumazet wrote:
> Le lundi 09 mai 2011 à 15:04 -0500, Christoph Lameter a écrit :
>> On Mon, 9 May 2011, Pekka Enberg wrote:
>>
>>> On Wed, 20 Apr 2011, Eric Dumazet wrote:
>>>> [PATCH v4] slub: dont use cmpxchg_double if KMEMCHECK or DEBUG_PAGEALLOC
>>>>
>>>> Christian Casteyde reported a KMEMCHECK splat in slub code.
>>>>
>>>> Problem is now we are lockless and allow IRQ in slab_alloc(), the object
>>>> we manipulate from freelist can be allocated and freed right before we
>>>> try to read object->next.
>>>>
>>>> Same problem can happen with DEBUG_PAGEALLOC
>>>>
>>>> Just dont use cmpxchg_double() if either CONFIG_KMEMCHECK or
>>>> CONFIG_DEBUG_PAGEALLOC is defined.
>>> Christoph, Eric, is this still relevant after commit 1759415 ("slub: Remove
>>> CONFIG_CMPXCHG_LOCAL ifdeffery") in slab/next of slab.git?
>> There is still an issue and now you can no longer fix the thing through
>> CONFIG_CMPXCHG_LOCAL.
>>
>> It needs to be legal for slub to deref the counter even if the object has
>> been freed.
>>
> I am trying to follow things but honestly I am lost.
>
> Isnt commit 1759415e63 planned for 2.6.40 ?
> ( ref :
> http://git.kernel.org/?p=linux/kernel/git/penberg/slab-2.6.git;a=commitdiff;h=1759415e630e5db0dd2390df9f94892cbfb9a8a2 )
>
> How shall we fix things for 2.6.39 ? I thought my patch was OK for that.
>
>
> Its a bit hard to work with you on this stuff, for a report I made ages
> ago, I find it incredible its not yet fixed in linux-2.6.
>
Can't we fix the issue by putting kmemcheck_mark_initialized() to 
set_freepointer()?

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:03                                         ` Pekka Enberg
@ 2011-05-10 10:17                                           ` Eric Dumazet
  2011-05-10 10:19                                             ` Pekka Enberg
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 10:17 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :

> Can't we fix the issue by putting kmemcheck_mark_initialized() to 
> set_freepointer()?

This would solve kmemcheck problem, not DEBUG_PAGEALLOC




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:17                                           ` Eric Dumazet
@ 2011-05-10 10:19                                             ` Pekka Enberg
  2011-05-10 11:52                                               ` Eric Dumazet
                                                                 ` (2 more replies)
  0 siblings, 3 replies; 66+ messages in thread
From: Pekka Enberg @ 2011-05-10 10:19 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

On 5/10/11 1:17 PM, Eric Dumazet wrote:
> Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :
>
>> Can't we fix the issue by putting kmemcheck_mark_initialized() to
>> set_freepointer()?
>
> This would solve kmemcheck problem, not DEBUG_PAGEALLOC

Oh, right. Christoph? We need to support DEBUG_PAGEALLOC with SLUB.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:19                                             ` Pekka Enberg
@ 2011-05-10 11:52                                               ` Eric Dumazet
  2011-05-10 12:24                                               ` Vegard Nossum
  2011-05-10 16:33                                               ` Christoph Lameter
  2 siblings, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 11:52 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Christoph Lameter, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

Le mardi 10 mai 2011 à 13:19 +0300, Pekka Enberg a écrit :
> On 5/10/11 1:17 PM, Eric Dumazet wrote:
> > Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :
> >
> >> Can't we fix the issue by putting kmemcheck_mark_initialized() to
> >> set_freepointer()?
> >
> > This would solve kmemcheck problem, not DEBUG_PAGEALLOC
> 
> Oh, right. Christoph? We need to support DEBUG_PAGEALLOC with SLUB.


Maybe have a special version of "irqsafe_cpu_cmpxchg_double" and make it
use something like :


local_irq_save(flags);
if (probe_kernel_address(...)) {
	res = false;
} else {
	res = unsafe_cpu_cmpxchg_double(...)
	}
local_irq_restore(flags);

Just the idea, I dont have time to cook a patch.



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:19                                             ` Pekka Enberg
  2011-05-10 11:52                                               ` Eric Dumazet
@ 2011-05-10 12:24                                               ` Vegard Nossum
  2011-05-10 16:39                                                 ` Christoph Lameter
  2011-05-10 16:33                                               ` Christoph Lameter
  2 siblings, 1 reply; 66+ messages in thread
From: Vegard Nossum @ 2011-05-10 12:24 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Eric Dumazet, Christoph Lameter, casteyde.christian,
	Andrew Morton, netdev, bugzilla-daemon, bugme-daemon

 On Tue, 10 May 2011 13:19:35 +0300, Pekka Enberg 
 <penberg@cs.helsinki.fi> wrote:
> On 5/10/11 1:17 PM, Eric Dumazet wrote:
>> Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :
>>
>>> Can't we fix the issue by putting kmemcheck_mark_initialized() to
>>> set_freepointer()?
>>
>> This would solve kmemcheck problem, not DEBUG_PAGEALLOC
>
> Oh, right. Christoph? We need to support DEBUG_PAGEALLOC with SLUB.

 Hi,

 Disclaimer: I don't know how the algorithm is supposed to work, so 
 please excuse me if this makes no sense at all. But here goes:

 Presumably the problem is that the page can get freed, and that with 
 DEBUG_PAGEALLOC, the page will therefore not be present and subsequently 
 trigger a page fault when doing this cmpxchg() on the possibly freed 
 object.

 Regardless of DEBUG_PAGEALLOC or kmemcheck, what happens if the page 
 gets freed, then allocated again for a completely different purpose in 
 another part of the kernel, and new user of the page by chance writes 
 the same "tid" number that the cmpxchg() is expecting?

 I guess I'm asking: Are we relying on the fact that this has a 
 negligible probability of happening? Or did I just misunderstand what 
 the algorithm does, and it is in fact provable (in theory) that nothing 
 wrong can happen?

 Thanks,

 Vegard

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 12:24                                               ` Vegard Nossum
@ 2011-05-10 16:39                                                 ` Christoph Lameter
  2011-05-10 17:14                                                   ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 16:39 UTC (permalink / raw)
  To: Vegard Nossum
  Cc: Pekka Enberg, Eric Dumazet, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Tue, 10 May 2011, Vegard Nossum wrote:

> Presumably the problem is that the page can get freed, and that with
> DEBUG_PAGEALLOC, the page will therefore not be present and subsequently
> trigger a page fault when doing this cmpxchg() on the possibly freed object.

The problem is not the cmpxchg. The cmpxchg is occurring on the per cpu
structure for the slab and that remains even if the page is freed.

The problem is the speculative fetch of the address of the following
object from a pointer into the page. The cmpxchg will fail in that case
because the TID was incremented and the result of the address fetch will
be discarded.

> Regardless of DEBUG_PAGEALLOC or kmemcheck, what happens if the page gets
> freed, then allocated again for a completely different purpose in another part
> of the kernel, and new user of the page by chance writes the same "tid" number
> that the cmpxchg() is expecting?

The tid is not stored in the page struct but in a per cpu structure.

Doing an explicit check if this is an illegal address in the PAGE_ALLOC
case and redoing the loop will address the issue.

So

#ifdef CONFIG_DEBUG_PAGE_ALLOC
	if (illegal_page_alloc-address(object))
		goto redo;
#endif

before the cmpxchg should do the trick.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 16:39                                                 ` Christoph Lameter
@ 2011-05-10 17:14                                                   ` Eric Dumazet
  2011-05-10 17:30                                                     ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 17:14 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 11:39 -0500, Christoph Lameter a écrit :

> #ifdef CONFIG_DEBUG_PAGE_ALLOC
> 	if (illegal_page_alloc-address(object))
> 		goto redo;
> #endif
> 
> before the cmpxchg should do the trick.
> 

Again, it wont work...

You can have an IRQ right after the check and before cmpxchg

This interrupt can allocate this block of memory, free it, and unmap
page from memory.

cmpxchg() reads unmapped memory -> BUG




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 17:14                                                   ` Eric Dumazet
@ 2011-05-10 17:30                                                     ` Christoph Lameter
  2011-05-10 17:43                                                       ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 17:30 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1022 bytes --]

On Tue, 10 May 2011, Eric Dumazet wrote:

> Le mardi 10 mai 2011 à 11:39 -0500, Christoph Lameter a écrit :
>
> > #ifdef CONFIG_DEBUG_PAGE_ALLOC
> > 	if (illegal_page_alloc-address(object))
> > 		goto redo;
> > #endif
> >
> > before the cmpxchg should do the trick.
> >
>
> Again, it wont work...
>
> You can have an IRQ right after the check and before cmpxchg

Ok guess then we also need to disable irq if CONFIG_PAGE_ALLOC is set?

The cmpxchg is not the problem. The problem is the following expression
which retrieves the pointer to the next available object from the object
on the page:

get_freepointer(s, object)

In the CONFIG_PAGE_ALLOC case we could disable interrupts, then do the
check, then fetch the pointer and then reenable interrupts.

All of this can occur before the cmpxchg.

> This interrupt can allocate this block of memory, free it, and unmap
> page from memory.
>
> cmpxchg() reads unmapped memory -> BUG

The cmpxchg is not accessing any memory on the page.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 17:30                                                     ` Christoph Lameter
@ 2011-05-10 17:43                                                       ` Christoph Lameter
  2011-05-10 18:05                                                         ` Eric Dumazet
  2011-05-10 18:07                                                         ` [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb Christoph Lameter
  0 siblings, 2 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 17:43 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon


Draft for a patch


Subject: slub: Make CONFIG_PAGE_ALLOC work with new fastpath

Fastpath can do a speculative access to a page that CONFIG_PAGE_ALLOC may have
marked as invalid to retrieve the pointer to the next free object.

Probe that address before dereferencing the pointer to the page.
All of that needs to occur with interrupts disabled since an interrupt
could cause the page status to change (as pointed out by Eric).

Signed-off-by: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |   23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-05-10 12:35:30.000000000 -0500
+++ linux-2.6/mm/slub.c	2011-05-10 12:38:53.000000000 -0500
@@ -261,6 +261,27 @@ static inline void *get_freepointer(stru
 	return *(void **)(object + s->offset);
 }

+static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
+{
+	void *p;
+
+#ifdef CONFIG_PAGE_ALLOC
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	if (probe_kernel_address(object))
+		p = NULL;	/* Invalid */
+	else
+		p = get_freepointer(s, object);
+
+	local_irq_restore(flags);
+#else
+	p = get_freepointer(s, object);
+#endif
+	return p;
+}
+
 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 {
 	*(void **)(object + s->offset) = fp;
@@ -1933,7 +1954,7 @@ redo:
 		if (unlikely(!irqsafe_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				object, tid,
-				get_freepointer(s, object), next_tid(tid)))) {
+				get_freepointer_safe(s, object), next_tid(tid)))) {

 			note_cmpxchg_failure("slab_alloc", s, tid);
 			goto redo;

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 17:43                                                       ` Christoph Lameter
@ 2011-05-10 18:05                                                         ` Eric Dumazet
  2011-05-10 18:28                                                           ` Christoph Lameter
  2011-05-10 18:07                                                         ` [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb Christoph Lameter
  1 sibling, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 18:05 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 12:43 -0500, Christoph Lameter a écrit :
> Draft for a patch
> 
> 
> Subject: slub: Make CONFIG_PAGE_ALLOC work with new fastpath
> 
> Fastpath can do a speculative access to a page that CONFIG_PAGE_ALLOC may have
> marked as invalid to retrieve the pointer to the next free object.
> 
> Probe that address before dereferencing the pointer to the page.
> All of that needs to occur with interrupts disabled since an interrupt
> could cause the page status to change (as pointed out by Eric).
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>
> ---
>  mm/slub.c |   23 ++++++++++++++++++++++-
>  1 file changed, 22 insertions(+), 1 deletion(-)
> 
> Index: linux-2.6/mm/slub.c
> ===================================================================
> --- linux-2.6.orig/mm/slub.c	2011-05-10 12:35:30.000000000 -0500
> +++ linux-2.6/mm/slub.c	2011-05-10 12:38:53.000000000 -0500
> @@ -261,6 +261,27 @@ static inline void *get_freepointer(stru
>  	return *(void **)(object + s->offset);
>  }
> 
> +static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
> +{
> +	void *p;
> +
> +#ifdef CONFIG_PAGE_ALLOC
> +	unsigned long flags;
> +
> +	local_irq_save(flags);
> +
> +	if (probe_kernel_address(object))
> +		p = NULL;	/* Invalid */
> +	else
> +		p = get_freepointer(s, object);
> +
> +	local_irq_restore(flags);
> +#else
> +	p = get_freepointer(s, object);
> +#endif
> +	return p;
> +}
> +
>  static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
>  {
>  	*(void **)(object + s->offset) = fp;
> @@ -1933,7 +1954,7 @@ redo:
>  		if (unlikely(!irqsafe_cpu_cmpxchg_double(
>  				s->cpu_slab->freelist, s->cpu_slab->tid,
>  				object, tid,
> -				get_freepointer(s, object), next_tid(tid)))) {
> +				get_freepointer_safe(s, object), next_tid(tid)))) {
> 
>  			note_cmpxchg_failure("slab_alloc", s, tid);
>  			goto redo;


Really this wont work Stephen

You have to disable IRQ _before_ even fetching 'object'

Or else, you can have an IRQ, allocate this object, pass to another cpu.

This other cpu can free the object and unmap page right after you did
the probe_kernel_address(object) (successfully), and before your cpu :

p = get_freepointer(s, object); << BUG >>

I really dont understand your motivation to keep the buggy commit.




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 18:05                                                         ` Eric Dumazet
@ 2011-05-10 18:28                                                           ` Christoph Lameter
  2011-05-10 19:05                                                             ` Christoph Lameter
  2011-05-10 19:32                                                             ` Eric Dumazet
  0 siblings, 2 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 18:28 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Tue, 10 May 2011, Eric Dumazet wrote:

> > +	else
> > +		p = get_freepointer(s, object);
> > +
> > +	local_irq_restore(flags);
> > +#else
> > +	p = get_freepointer(s, object);
> > +#endif
> > +	return p;
> > +}
> > +
> >  static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
> >  {
> >  	*(void **)(object + s->offset) = fp;
> > @@ -1933,7 +1954,7 @@ redo:
> >  		if (unlikely(!irqsafe_cpu_cmpxchg_double(
> >  				s->cpu_slab->freelist, s->cpu_slab->tid,
> >  				object, tid,
> > -				get_freepointer(s, object), next_tid(tid)))) {
> > +				get_freepointer_safe(s, object), next_tid(tid)))) {
> >
> >  			note_cmpxchg_failure("slab_alloc", s, tid);
> >  			goto redo;
>
>
> Really this wont work Stephen

I am not Stephen.

> You have to disable IRQ _before_ even fetching 'object'

The object pointer is being obtained from a per cpu structure and
not from the page. What is the problem with fetching the object pointer?

> Or else, you can have an IRQ, allocate this object, pass to another cpu.

If that occurs then TID is being incremented and we will restart the loop
getting the new object pointer from the per cpu structure. The object
pointer that we were considering is irrelevant.

> This other cpu can free the object and unmap page right after you did
> the probe_kernel_address(object) (successfully), and before your cpu :
>
> p = get_freepointer(s, object); << BUG >>

If the other cpu frees the object and unmaps the page then
get_freepointer_safe() can obtain an arbitrary value since the TID was
incremented. We will restart the loop and discard the value retrieved.


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 18:28                                                           ` Christoph Lameter
@ 2011-05-10 19:05                                                             ` Christoph Lameter
  2011-05-10 19:32                                                             ` Eric Dumazet
  1 sibling, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 19:05 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Tue, 10 May 2011, Christoph Lameter wrote:

> > This other cpu can free the object and unmap page right after you did
> > the probe_kernel_address(object) (successfully), and before your cpu :
> >
> > p = get_freepointer(s, object); << BUG >>
>
> If the other cpu frees the object and unmaps the page then
> get_freepointer_safe() can obtain an arbitrary value since the TID was
> incremented. We will restart the loop and discard the value retrieved.

Ok. Forgot the element there of a different cpu. A different cpu cannot
unmap the page or free the page since the page is in a frozen state while
we allocate from it.

The page is only handled by the cpu it was assigned to until the cpu which
froze it releases it.

The only case that we need to protect against here is the case when an
interrupt or reschedule causes the *same* cpu to release the page. In that
case the TID must have been incremented.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 18:28                                                           ` Christoph Lameter
  2011-05-10 19:05                                                             ` Christoph Lameter
@ 2011-05-10 19:32                                                             ` Eric Dumazet
  2011-05-10 19:38                                                               ` Christoph Lameter
  1 sibling, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 19:32 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 13:28 -0500, Christoph Lameter a écrit :
> On Tue, 10 May 2011, Eric Dumazet wrote:
> 
> > > +	else
> > > +		p = get_freepointer(s, object);
> > > +
> > > +	local_irq_restore(flags);
> > > +#else
> > > +	p = get_freepointer(s, object);
> > > +#endif
> > > +	return p;
> > > +}
> > > +
> > >  static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
> > >  {
> > >  	*(void **)(object + s->offset) = fp;
> > > @@ -1933,7 +1954,7 @@ redo:
> > >  		if (unlikely(!irqsafe_cpu_cmpxchg_double(
> > >  				s->cpu_slab->freelist, s->cpu_slab->tid,
> > >  				object, tid,
> > > -				get_freepointer(s, object), next_tid(tid)))) {
> > > +				get_freepointer_safe(s, object), next_tid(tid)))) {
> > >
> > >  			note_cmpxchg_failure("slab_alloc", s, tid);
> > >  			goto redo;
> >
> >
> > Really this wont work Stephen
> 
> I am not Stephen.
> 

Yes, sorry Christoph.

> > You have to disable IRQ _before_ even fetching 'object'
> 
> The object pointer is being obtained from a per cpu structure and
> not from the page. What is the problem with fetching the object pointer?
> 
> > Or else, you can have an IRQ, allocate this object, pass to another cpu.
> 
> If that occurs then TID is being incremented and we will restart the loop
> getting the new object pointer from the per cpu structure. The object
> pointer that we were considering is irrelevant.
> 

Problem is not restart the loop, but avoiding accessing a non valid
memory area.

> > This other cpu can free the object and unmap page right after you did
> > the probe_kernel_address(object) (successfully), and before your cpu :
> >
> > p = get_freepointer(s, object); << BUG >>
> 
> If the other cpu frees the object and unmaps the page then
> get_freepointer_safe() can obtain an arbitrary value since the TID was
> incremented. We will restart the loop and discard the value retrieved.
> 



In current code I see :

tid = c->tid;
barrier();
object = c->freelist;

There is no guarantee c->tid is fetched before c->freelist by cpu.

You need rmb() here.


I claim all this would be far more simple disabling IRQ before fetching
c->tid and c->freelist, in DEBUG_PAGE_ALLOC case.

You would not even need to use magic probe_kernel_read()


Why do you try so _hard_ trying to optimize this, I really wonder.
Nobody is able to read this code anymore and prove its correct.




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 19:32                                                             ` Eric Dumazet
@ 2011-05-10 19:38                                                               ` Christoph Lameter
  2011-05-10 20:06                                                                 ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 19:38 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Tue, 10 May 2011, Eric Dumazet wrote:

> > > You have to disable IRQ _before_ even fetching 'object'
> >
> > The object pointer is being obtained from a per cpu structure and
> > not from the page. What is the problem with fetching the object pointer?
> >
> > > Or else, you can have an IRQ, allocate this object, pass to another cpu.
> >
> > If that occurs then TID is being incremented and we will restart the loop
> > getting the new object pointer from the per cpu structure. The object
> > pointer that we were considering is irrelevant.
> >
>
> Problem is not restart the loop, but avoiding accessing a non valid
> memory area.

Yes and could you please explain clearly what the problem is?

>
> > > This other cpu can free the object and unmap page right after you did
> > > the probe_kernel_address(object) (successfully), and before your cpu :
> > >
> > > p = get_freepointer(s, object); << BUG >>
> >
> > If the other cpu frees the object and unmaps the page then
> > get_freepointer_safe() can obtain an arbitrary value since the TID was
> > incremented. We will restart the loop and discard the value retrieved.
> >
>
>
>
> In current code I see :
>
> tid = c->tid;
> barrier();
> object = c->freelist;
>
> There is no guarantee c->tid is fetched before c->freelist by cpu.
>
> You need rmb() here.

Nope. This is not processor to processor concurrency. this_cpu operations
only deal with concurrency issues on the same processor. I.e. interrupts
and preemption.

> I claim all this would be far more simple disabling IRQ before fetching
> c->tid and c->freelist, in DEBUG_PAGE_ALLOC case.
>
> You would not even need to use magic probe_kernel_read()
>
>
> Why do you try so _hard_ trying to optimize this, I really wonder.
> Nobody is able to read this code anymore and prove its correct.

Optimizing? You think about this as concurrency issue between multiple
cpus. That is fundamentally wrong. This is dealing with access to per cpu
data and the concurrency issues are only with code running on the *same*
cpu.


^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 19:38                                                               ` Christoph Lameter
@ 2011-05-10 20:06                                                                 ` Eric Dumazet
  2011-05-10 20:33                                                                   ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 20:06 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 14:38 -0500, Christoph Lameter a écrit :

> Optimizing? You think about this as concurrency issue between multiple
> cpus. That is fundamentally wrong. This is dealing with access to per cpu
> data and the concurrency issues are only with code running on the *same*
> cpu.
> 

If you enable irqs, then this object can be allocated by _this_ cpu and
given to another one.

Another cpu can free the page, forcing you to call a very expensive
function, that might give obsolete result as soon it returns.

Maybe I am just tired tonight, this seems very obvious, I must miss
something.




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 20:06                                                                 ` Eric Dumazet
@ 2011-05-10 20:33                                                                   ` Christoph Lameter
  2011-05-10 20:45                                                                     ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 20:33 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

[-- Attachment #1: Type: TEXT/PLAIN, Size: 943 bytes --]

On Tue, 10 May 2011, Eric Dumazet wrote:

> Le mardi 10 mai 2011 à 14:38 -0500, Christoph Lameter a écrit :
>
> > Optimizing? You think about this as concurrency issue between multiple
> > cpus. That is fundamentally wrong. This is dealing with access to per cpu
> > data and the concurrency issues are only with code running on the *same*
> > cpu.
> >
>
> If you enable irqs, then this object can be allocated by _this_ cpu and
> given to another one.

That will cause an incrementing of the tid.

> Another cpu can free the page, forcing you to call a very expensive
> function, that might give obsolete result as soon it returns.

No the other cpu cannot free the page since the page is pinned by
the current cpu (see PageFrozen()).

> Maybe I am just tired tonight, this seems very obvious, I must miss
> something.

Yeah you are way off thinking about cpu to cpu concurrency issues that do
not apply here.



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 20:33                                                                   ` Christoph Lameter
@ 2011-05-10 20:45                                                                     ` Eric Dumazet
  2011-05-10 21:22                                                                       ` Christoph Lameter
  0 siblings, 1 reply; 66+ messages in thread
From: Eric Dumazet @ 2011-05-10 20:45 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 15:33 -0500, Christoph Lameter a écrit :
> On Tue, 10 May 2011, Eric Dumazet wrote:
> 
> > Le mardi 10 mai 2011 à 14:38 -0500, Christoph Lameter a écrit :
> >
> > > Optimizing? You think about this as concurrency issue between multiple
> > > cpus. That is fundamentally wrong. This is dealing with access to per cpu
> > > data and the concurrency issues are only with code running on the *same*
> > > cpu.
> > >
> >
> > If you enable irqs, then this object can be allocated by _this_ cpu and
> > given to another one.
> 
> That will cause an incrementing of the tid.
> 
> > Another cpu can free the page, forcing you to call a very expensive
> > function, that might give obsolete result as soon it returns.
> 
> No the other cpu cannot free the page since the page is pinned by
> the current cpu (see PageFrozen()).
> 

What happens then ? Other cpu calls kfree() on last nonfreed object for
this slab, and yet the page stay frozen ? How this page is going to be
freed at all ?

> > Maybe I am just tired tonight, this seems very obvious, I must miss
> > something.
> 
> Yeah you are way off thinking about cpu to cpu concurrency issues that do
> not apply here.

I fail to understand how current cpu can assert page ownership, if IRQs
are enabled, this seems obvious it cannot.




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 20:45                                                                     ` Eric Dumazet
@ 2011-05-10 21:22                                                                       ` Christoph Lameter
  2011-05-11  3:12                                                                         ` Eric Dumazet
  0 siblings, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 21:22 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Tue, 10 May 2011, Eric Dumazet wrote:

> > No the other cpu cannot free the page since the page is pinned by
> > the current cpu (see PageFrozen()).
> >
>
> What happens then ? Other cpu calls kfree() on last nonfreed object for
> this slab, and yet the page stay frozen ? How this page is going to be
> freed at all ?

Yes the page stays frozen. The freed objects are used to replenish the
percpu free list when it becomes empty.

The page is going to be freed when a kmalloc() finds that the per cpu
freelist is empty and that the freelist of the page is also empty. Then
interrupts are disabled, the old page is unfrozen and a new
page is acquired for allocation.

> > > Maybe I am just tired tonight, this seems very obvious, I must miss
> > > something.
> >
> > Yeah you are way off thinking about cpu to cpu concurrency issues that do
> > not apply here.
>
> I fail to understand how current cpu can assert page ownership, if IRQs
> are enabled, this seems obvious it cannot.

The cpu sets a page flag called PageFrozen() and points a per cpu pointer
to the page.



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 21:22                                                                       ` Christoph Lameter
@ 2011-05-11  3:12                                                                         ` Eric Dumazet
  2011-05-12 14:36                                                                           ` Christoph Lameter
  2011-05-13 21:15                                                                           ` [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath Christoph Lameter
  0 siblings, 2 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-05-11  3:12 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le mardi 10 mai 2011 à 16:22 -0500, Christoph Lameter a écrit :
> On Tue, 10 May 2011, Eric Dumazet wrote:
> 
> > > No the other cpu cannot free the page since the page is pinned by
> > > the current cpu (see PageFrozen()).
> > >
> >
> > What happens then ? Other cpu calls kfree() on last nonfreed object for
> > this slab, and yet the page stay frozen ? How this page is going to be
> > freed at all ?
> 
> Yes the page stays frozen. The freed objects are used to replenish the
> percpu free list when it becomes empty.
> 
> The page is going to be freed when a kmalloc() finds that the per cpu
> freelist is empty and that the freelist of the page is also empty. Then
> interrupts are disabled, the old page is unfrozen and a new
> page is acquired for allocation.
> 
> > > > Maybe I am just tired tonight, this seems very obvious, I must miss
> > > > something.
> > >
> > > Yeah you are way off thinking about cpu to cpu concurrency issues that do
> > > not apply here.
> >
> > I fail to understand how current cpu can assert page ownership, if IRQs
> > are enabled, this seems obvious it cannot.
> 
> The cpu sets a page flag called PageFrozen() and points a per cpu pointer
> to the page.
> 
> 

So, if I understand you, there is no problem at all and no patch even
needed ? I can start a stress test and you guarantee there wont be a
crash ?

Sorry, its 5h11 in the morning here ;)




^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-11  3:12                                                                         ` Eric Dumazet
@ 2011-05-12 14:36                                                                           ` Christoph Lameter
  2011-05-13 21:15                                                                           ` [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath Christoph Lameter
  1 sibling, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-12 14:36 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

On Wed, 11 May 2011, Eric Dumazet wrote:

> > The cpu sets a page flag called PageFrozen() and points a per cpu pointer
> > to the page.
> >
> >
>
> So, if I understand you, there is no problem at all and no patch even
> needed ? I can start a stress test and you guarantee there wont be a
> crash ?
>
> Sorry, its 5h11 in the morning here ;)

There is a problem if an interrupt or a preemption occurs and there is no
object left on the page. Then the current page will be unfrozen and a new
page put into place for allocation. The old page may then be freed by some other
process on another processor before we continue the interrupted
slab_alloc().

When slab_alloc() resumes in this scenario then it will ultimately see
that the tid was incremented and so the cmpxchg will fail. But before we
do the cmpxchgwe determine the pointer to the next object. And for that
we access the old page. The access must not cause a page fault (which it
currently does with CONFIG_DEBUG_PAGEALLOC). That is why we need the patch introducing

	get_freepointer_safe()

The result does not matter since we will repeat the cmpxchg loop.

^ permalink raw reply	[flat|nested] 66+ messages in thread

* [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath
  2011-05-11  3:12                                                                         ` Eric Dumazet
  2011-05-12 14:36                                                                           ` Christoph Lameter
@ 2011-05-13 21:15                                                                           ` Christoph Lameter
  2011-05-13 21:26                                                                             ` Eric Dumazet
  1 sibling, 1 reply; 66+ messages in thread
From: Christoph Lameter @ 2011-05-13 21:15 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

I ran this with hackbench under KVM with CONFIG_DEBUG_PAGEALLOC and I saw
no failures.


Subject: slub: Make CONFIG_PAGE_ALLOC work with new fastpath

Fastpath can do a speculative access to a page that CONFIG_PAGE_ALLOC may have
marked as invalid to retrieve the pointer to the next free object.

Use probe_kernel_read in that case in order not to cause a page fault.

Signed-off-by: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-05-10 14:31:28.000000000 -0500
+++ linux-2.6/mm/slub.c	2011-05-10 14:31:35.000000000 -0500
@@ -261,6 +261,18 @@ static inline void *get_freepointer(stru
 	return *(void **)(object + s->offset);
 }

+static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
+{
+	void *p;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
+#else
+	p = get_freepointer(s, object);
+#endif
+	return p;
+}
+
 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 {
 	*(void **)(object + s->offset) = fp;
@@ -1933,7 +1945,7 @@ redo:
 		if (unlikely(!irqsafe_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				object, tid,
-				get_freepointer(s, object), next_tid(tid)))) {
+				get_freepointer_safe(s, object), next_tid(tid)))) {

 			note_cmpxchg_failure("slab_alloc", s, tid);
 			goto redo;

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath
  2011-05-13 21:15                                                                           ` [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath Christoph Lameter
@ 2011-05-13 21:26                                                                             ` Eric Dumazet
  0 siblings, 0 replies; 66+ messages in thread
From: Eric Dumazet @ 2011-05-13 21:26 UTC (permalink / raw)
  To: Christoph Lameter
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

Le vendredi 13 mai 2011 à 16:15 -0500, Christoph Lameter a écrit :
> I ran this with hackbench under KVM with CONFIG_DEBUG_PAGEALLOC and I saw
> no failures.
> 
> 
> Subject: slub: Make CONFIG_PAGE_ALLOC work with new fastpath
> 
> Fastpath can do a speculative access to a page that CONFIG_PAGE_ALLOC may have
> marked as invalid to retrieve the pointer to the next free object.
> 
> Use probe_kernel_read in that case in order not to cause a page fault.
> 
> Signed-off-by: Christoph Lameter <cl@linux.com>

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

Thanks !



^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 17:43                                                       ` Christoph Lameter
  2011-05-10 18:05                                                         ` Eric Dumazet
@ 2011-05-10 18:07                                                         ` Christoph Lameter
  1 sibling, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 18:07 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Vegard Nossum, Pekka Enberg, casteyde.christian, Andrew Morton,
	netdev, bugzilla-daemon, bugme-daemon

There is a simpler version and we can get away without interrupt disable I
think. The value that we get from the read does not matter since the TID
will not match.


Subject: slub: Make CONFIG_PAGE_ALLOC work with new fastpath

Fastpath can do a speculative access to a page that CONFIG_PAGE_ALLOC may have
marked as invalid to retrieve the pointer to the next free object.

Probe that address before dereferencing the pointer to the page.

Signed-off-by: Christoph Lameter <cl@linux.com>
---
 mm/slub.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-05-10 12:54:00.000000000 -0500
+++ linux-2.6/mm/slub.c	2011-05-10 13:04:18.000000000 -0500
@@ -261,6 +261,18 @@ static inline void *get_freepointer(stru
 	return *(void **)(object + s->offset);
 }

+static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
+{
+	void *p;
+
+#ifdef CONFIG_DEBUG_PAGEALLOC
+	probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
+#else
+	p = get_freepointer(s, object);
+#endif
+	return p;
+}
+
 static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
 {
 	*(void **)(object + s->offset) = fp;
@@ -1943,7 +1955,7 @@ redo:
 		if (unlikely(!irqsafe_cpu_cmpxchg_double(
 				s->cpu_slab->freelist, s->cpu_slab->tid,
 				object, tid,
-				get_freepointer(s, object), next_tid(tid)))) {
+				get_freepointer_safe(s, object), next_tid(tid)))) {

 			note_cmpxchg_failure("slab_alloc", s, tid);
 			goto redo;

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-05-10 10:19                                             ` Pekka Enberg
  2011-05-10 11:52                                               ` Eric Dumazet
  2011-05-10 12:24                                               ` Vegard Nossum
@ 2011-05-10 16:33                                               ` Christoph Lameter
  2 siblings, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-05-10 16:33 UTC (permalink / raw)
  To: Pekka Enberg
  Cc: Eric Dumazet, casteyde.christian, Andrew Morton, netdev,
	bugzilla-daemon, bugme-daemon, Vegard Nossum

[-- Attachment #1: Type: TEXT/PLAIN, Size: 522 bytes --]

On Tue, 10 May 2011, Pekka Enberg wrote:

> On 5/10/11 1:17 PM, Eric Dumazet wrote:
> > Le mardi 10 mai 2011 à 13:03 +0300, Pekka Enberg a écrit :
> >
> > > Can't we fix the issue by putting kmemcheck_mark_initialized() to
> > > set_freepointer()?
> >
> > This would solve kmemcheck problem, not DEBUG_PAGEALLOC
>
> Oh, right. Christoph? We need to support DEBUG_PAGEALLOC with SLUB.

Well back to the #ifdef then? Or has DEBUG_PAGEALLOC some override
mechanism that we can do a speculative memory access?

^ permalink raw reply	[flat|nested] 66+ messages in thread

* Re: [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb
  2011-04-19  3:09     ` Eric Dumazet
  2011-04-19  3:20       ` Eric Dumazet
@ 2011-04-19 17:09       ` Christoph Lameter
  1 sibling, 0 replies; 66+ messages in thread
From: Christoph Lameter @ 2011-04-19 17:09 UTC (permalink / raw)
  To: Eric Dumazet
  Cc: Andrew Morton, netdev, bugzilla-daemon, bugme-daemon,
	casteyde.christian, Vegard Nossum, Pekka Enberg

On Tue, 19 Apr 2011, Eric Dumazet wrote:

> get_freepointer(s, object) can access to freed memory and kmemcheck
> triggers the fault, while this_cpu_cmpxchg_double() would presumably
> detect a change of tid and would not perform the freelist/tid change.

Sounds right. The new lockless patchset for slub that uses a locked
cmpxchg16b will make this behavior even more common since it will do more
speculative accesses.


^ permalink raw reply	[flat|nested] 66+ messages in thread

end of thread, other threads:[~2011-05-13 21:26 UTC | newest]

Thread overview: 66+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <bug-33502-10286@https.bugzilla.kernel.org/>
2011-04-18 22:38 ` [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb Andrew Morton
2011-04-19  2:51   ` Eric Dumazet
2011-04-19  3:09     ` Eric Dumazet
2011-04-19  3:20       ` Eric Dumazet
2011-04-19 17:10         ` Christoph Lameter
2011-04-19 20:17           ` Eric Dumazet
2011-04-19 21:18             ` Christoph Lameter
2011-04-20  5:04               ` Eric Dumazet
2011-04-20 14:04                 ` Christoph Lameter
2011-04-20  5:56             ` Pekka Enberg
2011-04-20  6:04               ` Eric Dumazet
2011-04-20  7:45                 ` casteyde.christian
2011-04-20  7:49                   ` Pekka Enberg
2011-04-20  8:09                     ` Eric Dumazet
2011-04-20  8:21                       ` Pekka Enberg
2011-04-20  9:07                       ` Eric Dumazet
2011-04-20 10:02                         ` Eric Dumazet
2011-04-20 14:05                           ` Christoph Lameter
2011-04-20 14:26                             ` Eric Dumazet
2011-04-20 14:42                               ` Christoph Lameter
2011-04-20 15:01                                 ` Eric Dumazet
2011-04-20 15:15                                   ` Vegard Nossum
2011-04-20 15:34                                     ` Eric Dumazet
2011-04-20 15:17                                   ` Christoph Lameter
2011-04-20 15:30                                     ` Eric Dumazet
2011-04-20 19:36                                   ` Christian Casteyde
2011-04-20 19:55                                     ` Eric Dumazet
2011-04-20 20:32                                       ` Eric Dumazet
2011-05-05  6:18                                   ` Eric Dumazet
2011-05-05  6:22                                     ` Pekka Enberg
2011-05-05  6:50                                       ` Eric Dumazet
2011-05-05 18:40                                       ` Christoph Lameter
2011-05-05 18:48                                         ` Eric Dumazet
2011-05-05 19:05                                           ` Christoph Lameter
2011-05-09 19:44                                   ` Pekka Enberg
2011-05-09 20:04                                     ` Christoph Lameter
2011-05-09 20:06                                       ` Pekka Enberg
2011-05-10  8:43                                       ` Eric Dumazet
2011-05-10  9:47                                         ` Pekka Enberg
2011-05-10 10:03                                           ` Eric Dumazet
2011-05-10 10:10                                             ` Pekka Enberg
2011-05-10 10:03                                         ` Pekka Enberg
2011-05-10 10:17                                           ` Eric Dumazet
2011-05-10 10:19                                             ` Pekka Enberg
2011-05-10 11:52                                               ` Eric Dumazet
2011-05-10 12:24                                               ` Vegard Nossum
2011-05-10 16:39                                                 ` Christoph Lameter
2011-05-10 17:14                                                   ` Eric Dumazet
2011-05-10 17:30                                                     ` Christoph Lameter
2011-05-10 17:43                                                       ` Christoph Lameter
2011-05-10 18:05                                                         ` Eric Dumazet
2011-05-10 18:28                                                           ` Christoph Lameter
2011-05-10 19:05                                                             ` Christoph Lameter
2011-05-10 19:32                                                             ` Eric Dumazet
2011-05-10 19:38                                                               ` Christoph Lameter
2011-05-10 20:06                                                                 ` Eric Dumazet
2011-05-10 20:33                                                                   ` Christoph Lameter
2011-05-10 20:45                                                                     ` Eric Dumazet
2011-05-10 21:22                                                                       ` Christoph Lameter
2011-05-11  3:12                                                                         ` Eric Dumazet
2011-05-12 14:36                                                                           ` Christoph Lameter
2011-05-13 21:15                                                                           ` [PATCH] slub: Make CONFIG_PAGE_ALLOC work with new fastpath Christoph Lameter
2011-05-13 21:26                                                                             ` Eric Dumazet
2011-05-10 18:07                                                         ` [Bugme-new] [Bug 33502] New: Caught 64-bit read from uninitialized memory in __alloc_skb Christoph Lameter
2011-05-10 16:33                                               ` Christoph Lameter
2011-04-19 17:09       ` Christoph Lameter

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).