LinuxPPC-Dev Archive on lore.kernel.org
 help / color / mirror / Atom feed

* Re: [PATCH] powerpc/64: Make VDSO32 track COMPAT on 64-bit
From: Michael Ellerman @ 2020-09-08 23:32 UTC (permalink / raw)
  To: Christophe Leroy, linuxppc-dev; +Cc: msuchanek
In-Reply-To: <f5ca915b-81b5-aa7b-727e-e43681ab825f@csgroup.eu>

Christophe Leroy <christophe.leroy@csgroup.eu> writes:
> Le 08/09/2020 à 14:58, Michael Ellerman a écrit :
>> When we added the VDSO32 kconfig symbol, which controls building of
>> the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit).
>> 
>> That was because back then COMPAT was always enabled for 64-bit, so
>> depending on it would have left the 32-bit VDSO always enabled, which
>> we didn't want.
>> 
>> But since then we have made COMPAT selectable, and off by default for
>> ppc64le, so VDSO32 should really depend on that.
>> 
>> For most people this makes no difference, none of the defconfigs
>> change, it's only if someone is building ppc64le with COMPAT=y, they
>> will now also get VDSO32. If they've enabled COMPAT in order to run
>> 32-bit binaries they presumably also want the 32-bit VDSO.
>> 
>> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>
>
> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>
> Michael, please note that christophe.leroy@c-s.fr is a deprecated 
> address that will one day not work anymore. Please use the new one 
> whenever possible.

OK, I had the old one in my ~/.mailrc, fixed now.

cheers

^ permalink raw reply

* Re: [PATCH] selftests/seccomp: fix ptrace tests on powerpc
From: Kees Cook @ 2020-09-08 23:18 UTC (permalink / raw)
  To: Thadeu Lima de Souza Cascardo
  Cc: linuxppc-dev, Shuah Khan, Oleg Nesterov, linux-kselftest
In-Reply-To: <20200630164739.1268222-1-cascardo@canonical.com>

On Tue, Jun 30, 2020 at 01:47:39PM -0300, Thadeu Lima de Souza Cascardo wrote:
> As pointed out by Michael Ellerman, the ptrace ABI on powerpc does not
> allow or require the return code to be set on syscall entry when
> skipping the syscall. It will always return ENOSYS and the return code
> must be set on syscall exit.
> 
> This code does that, behaving more similarly to strace. It still sets
> the return code on entry, which is overridden on powerpc, and it will
> always repeat the same on exit. Also, on powerpc, the errno is not
> inverted, and depends on ccr.so being set.
> 
> This has been tested on powerpc and amd64.
> 
> Cc: Michael Ellerman <mpe@ellerman.id.au>
> Cc: Kees Cook <keescook@google.com>
> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

Yikes, I missed this from a while ago. I apologize for responding so
late!

This appears still unfixed; is that correct?

> ---
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 24 +++++++++++++++----
>  1 file changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c
> index 252140a52553..b90a9190ba88 100644
> --- a/tools/testing/selftests/seccomp/seccomp_bpf.c
> +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c
> @@ -1738,6 +1738,14 @@ void change_syscall(struct __test_metadata *_metadata,
>  		TH_LOG("Can't modify syscall return on this architecture");
>  #else
>  		regs.SYSCALL_RET = result;
> +# if defined(__powerpc__)
> +		if (result < 0) {
> +			regs.SYSCALL_RET = -result;
> +			regs.ccr |= 0x10000000;
> +		} else {
> +			regs.ccr &= ~0x10000000;
> +		}
> +# endif
>  #endif

Just so I understand correctly: for ppc to "see" this result, it needs
to be both negative AND have this specific register set?

>  
>  #ifdef HAVE_GETREGS
> @@ -1796,6 +1804,7 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
>  	int ret, nr;
>  	unsigned long msg;
>  	static bool entry;
> +	int *syscall_nr = args;
>  
>  	/*
>  	 * The traditional way to tell PTRACE_SYSCALL entry/exit
> @@ -1809,10 +1818,15 @@ void tracer_ptrace(struct __test_metadata *_metadata, pid_t tracee,
>  	EXPECT_EQ(entry ? PTRACE_EVENTMSG_SYSCALL_ENTRY
>  			: PTRACE_EVENTMSG_SYSCALL_EXIT, msg);
>  
> -	if (!entry)
> +	if (!entry && !syscall_nr)
>  		return;
>  
> -	nr = get_syscall(_metadata, tracee);
> +	if (entry)
> +		nr = get_syscall(_metadata, tracee);
> +	else
> +		nr = *syscall_nr;

This is weird? Shouldn't get_syscall() be modified to do the right thing
here instead of depending on the extra arg?

> +	if (syscall_nr)
> +		*syscall_nr = nr;
>  
>  	if (nr == __NR_getpid)
>  		change_syscall(_metadata, tracee, __NR_getppid, 0);
> @@ -1889,9 +1903,10 @@ TEST_F(TRACE_syscall, ptrace_syscall_redirected)
>  
>  TEST_F(TRACE_syscall, ptrace_syscall_errno)
>  {
> +	int syscall_nr = -1;
>  	/* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
>  	teardown_trace_fixture(_metadata, self->tracer);
> -	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
> +	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, &syscall_nr,
>  					   true);
>  
>  	/* Tracer should skip the open syscall, resulting in ESRCH. */
> @@ -1900,9 +1915,10 @@ TEST_F(TRACE_syscall, ptrace_syscall_errno)
>  
>  TEST_F(TRACE_syscall, ptrace_syscall_faked)
>  {
> +	int syscall_nr = -1;
>  	/* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */
>  	teardown_trace_fixture(_metadata, self->tracer);
> -	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL,
> +	self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, &syscall_nr,
>  					   true);
>  
>  	/* Tracer should skip the gettid syscall, resulting fake pid. */
> -- 
> 2.25.1
> 

-- 
Kees Cook

^ permalink raw reply

* Re: [PATCH v2] dt-bindings: vendor-prefixes: Add Cisco Meraki vendor prefix
From: Rob Herring @ 2020-09-08 21:48 UTC (permalink / raw)
  To: Christian Lamparter
  Cc: devicetree, f.fainelli, Arnd Bergmann, linuxppc-dev,
	Linus Walleij, Rob Herring, Mark Brown, Sam Ravnborg,
	linux-arm-kernel
In-Reply-To: <20200822154045.16036-1-chunkeey@gmail.com>

On Sat, 22 Aug 2020 17:40:45 +0200, Christian Lamparter wrote:
> Meraki was founded in 2006. The start-up quickly rose to prominence
> by being based in part on the MIT Roofnet Project.
> In December 2012, Cisco Systems, Inc. bought Meraki.
> The "Meraki" branding is still around to this day.
> 
> Web site of the company: https://meraki.cisco.com/
> 
> Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
> ---
> 
> v1 -> v2:
> 	Split from Meraki MR32 upstreaming attempt. (Florian Fainelli)
> 	(This patch will be needed for the MR24 upstreaming series as well)
> ---
>  Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
>  1 file changed, 2 insertions(+)
> 

Applied, thanks!

^ permalink raw reply

* Re: [PATCH v2] powerpc/papr_scm: Limit the readability of 'perf_stats' sysfs attribute
From: Ira Weiny @ 2020-09-08 21:27 UTC (permalink / raw)
  To: Vaibhav Jain
  Cc: Santosh Sivaraj, linux-nvdimm, Aneesh Kumar K . V,
	Oliver O'Halloran, Dan Williams, linuxppc-dev
In-Reply-To: <20200907110540.21349-1-vaibhav@linux.ibm.com>

On Mon, Sep 07, 2020 at 04:35:40PM +0530, Vaibhav Jain wrote:
> The newly introduced 'perf_stats' attribute uses the default access
> mode of 0444 letting non-root users access performance stats of an
> nvdimm and potentially force the kernel into issuing large number of
> expensive HCALLs. Since the information exposed by this attribute
> cannot be cached hence its better to ward of access to this attribute
	                                   ^^^
                                           off?

> from users who don't need to access these performance statistics.
> 
> Hence this patch updates access mode of 'perf_stats' attribute to
> be only readable by root users.

Generally it is bad form to say "this patch".  See 4c here:

	-- https://www.ozlabs.org/~akpm/stuff/tpp.txt

But I'm not picky...  :-D

With the s/of/off/ change:

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> 
> Fixes: 2d02bf835e573 ('powerpc/papr_scm: Fetch nvdimm performance stats from PHYP')
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
> ---
> Change-log:
> 
> v2:
> * Instead of checking for perfmon_capable() inside show_perf_stats()
>   set the attribute as DEVICE_ATTR_ADMIN_RO [ Aneesh ]
> * Update patch description
> ---
>  arch/powerpc/platforms/pseries/papr_scm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c
> index f439f0dfea7d1..a88a707a608aa 100644
> --- a/arch/powerpc/platforms/pseries/papr_scm.c
> +++ b/arch/powerpc/platforms/pseries/papr_scm.c
> @@ -822,7 +822,7 @@ static ssize_t perf_stats_show(struct device *dev,
>  	kfree(stats);
>  	return rc ? rc : seq_buf_used(&s);
>  }
> -DEVICE_ATTR_RO(perf_stats);
> +DEVICE_ATTR_ADMIN_RO(perf_stats);
>  
>  static ssize_t flags_show(struct device *dev,
>  			  struct device_attribute *attr, char *buf)
> -- 
> 2.26.2
> 

^ permalink raw reply

* [PATCH v2 3/7] mm/memory_hotplug: prepare passing flags to add_memory() and friends
From: David Hildenbrand @ 2020-09-08 20:10 UTC (permalink / raw)
  To: linux-kernel
  Cc: linux-hyperv, Michal Hocko, David Hildenbrand, Jason Wang,
	Pingfan Liu, virtualization, linux-mm, Paul Mackerras,
	K. Y. Srinivasan, Boris Ostrovsky, linux-s390, Wei Liu,
	Stefano Stabellini, Dave Jiang, Baoquan He, linux-nvdimm,
	Jason Gunthorpe, Michael S. Tsirkin, linux-acpi, xen-devel,
	Heiko Carstens, Len Brown, Nathan Lynch, Vasily Gorbik,
	Leonardo Bras, Haiyang Zhang, Stephen Hemminger, Dan Williams,
	Christian Borntraeger, Juergen Gross, Pankaj Gupta,
	Libor Pechacek, Greg Kroah-Hartman, Rafael J. Wysocki, Wei Yang,
	Vishal Verma, Oliver O'Halloran, Andrew Morton, linuxppc-dev
In-Reply-To: <20200908201012.44168-1-david@redhat.com>

We soon want to pass flags, e.g., to mark added System RAM resources.
mergeable. Prepare for that.

This patch is based on a similar patch by Oscar Salvador:

https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@suse.de

Acked-by: Wei Liu <wei.liu@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Leonardo Bras <leobras.c@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: linux-hyperv@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 arch/powerpc/platforms/powernv/memtrace.c       |  2 +-
 arch/powerpc/platforms/pseries/hotplug-memory.c |  2 +-
 drivers/acpi/acpi_memhotplug.c                  |  2 +-
 drivers/base/memory.c                           |  2 +-
 drivers/dax/kmem.c                              |  2 +-
 drivers/hv/hv_balloon.c                         |  2 +-
 drivers/s390/char/sclp_cmd.c                    |  2 +-
 drivers/virtio/virtio_mem.c                     |  2 +-
 drivers/xen/balloon.c                           |  2 +-
 include/linux/memory_hotplug.h                  | 10 ++++++----
 mm/memory_hotplug.c                             | 15 ++++++++-------
 11 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index 13b369d2cc454..a7475d18c671c 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -224,7 +224,7 @@ static int memtrace_online(void)
 			ent->mem = 0;
 		}
 
-		if (add_memory(ent->nid, ent->start, ent->size)) {
+		if (add_memory(ent->nid, ent->start, ent->size, 0)) {
 			pr_err("Failed to add trace memory to node %d\n",
 				ent->nid);
 			ret += 1;
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 5d545b78111f9..54a888ea7f751 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -606,7 +606,7 @@ static int dlpar_add_lmb(struct drmem_lmb *lmb)
 	block_sz = memory_block_size_bytes();
 
 	/* Add the memory */
-	rc = __add_memory(lmb->nid, lmb->base_addr, block_sz);
+	rc = __add_memory(lmb->nid, lmb->base_addr, block_sz, 0);
 	if (rc) {
 		invalidate_lmb_associativity_index(lmb);
 		return rc;
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index e294f44a78504..d91b3584d4b2b 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -207,7 +207,7 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
 		if (node < 0)
 			node = memory_add_physaddr_to_nid(info->start_addr);
 
-		result = __add_memory(node, info->start_addr, info->length);
+		result = __add_memory(node, info->start_addr, info->length, 0);
 
 		/*
 		 * If the memory block has been used by the kernel, add_memory()
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 4db3c660de831..2287bcf86480e 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -432,7 +432,7 @@ static ssize_t probe_store(struct device *dev, struct device_attribute *attr,
 
 	nid = memory_add_physaddr_to_nid(phys_addr);
 	ret = __add_memory(nid, phys_addr,
-			   MIN_MEMORY_BLOCK_SIZE * sections_per_block);
+			   MIN_MEMORY_BLOCK_SIZE * sections_per_block, 0);
 
 	if (ret)
 		goto out;
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 7dcb2902e9b1b..8e66b28ef5bc6 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -95,7 +95,7 @@ int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 		 * this as RAM automatically.
 		 */
 		rc = add_memory_driver_managed(numa_node, range.start,
-				range_len(&range), kmem_name);
+				range_len(&range), kmem_name, 0);
 
 		res->flags |= IORESOURCE_BUSY;
 		if (rc) {
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 32e3bc0aa665a..0194bed1a5736 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -726,7 +726,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,
 
 		nid = memory_add_physaddr_to_nid(PFN_PHYS(start_pfn));
 		ret = add_memory(nid, PFN_PHYS((start_pfn)),
-				(HA_CHUNK << PAGE_SHIFT));
+				(HA_CHUNK << PAGE_SHIFT), 0);
 
 		if (ret) {
 			pr_err("hot_add memory failed error is %d\n", ret);
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index a864b21af602a..a6a908244c742 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -406,7 +406,7 @@ static void __init add_memory_merged(u16 rn)
 	if (!size)
 		goto skip_add;
 	for (addr = start; addr < start + size; addr += block_size)
-		add_memory(0, addr, block_size);
+		add_memory(0, addr, block_size, 0);
 skip_add:
 	first_rn = rn;
 	num = 1;
diff --git a/drivers/virtio/virtio_mem.c b/drivers/virtio/virtio_mem.c
index 834b7c13ef3dc..314ab753139d1 100644
--- a/drivers/virtio/virtio_mem.c
+++ b/drivers/virtio/virtio_mem.c
@@ -424,7 +424,7 @@ static int virtio_mem_mb_add(struct virtio_mem *vm, unsigned long mb_id)
 
 	dev_dbg(&vm->vdev->dev, "adding memory block: %lu\n", mb_id);
 	return add_memory_driver_managed(nid, addr, memory_block_size_bytes(),
-					 vm->resource_name);
+					 vm->resource_name, 0);
 }
 
 /*
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index 51427c752b37b..7bac38764513d 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -331,7 +331,7 @@ static enum bp_state reserve_additional_memory(void)
 	mutex_unlock(&balloon_mutex);
 	/* add_memory_resource() requires the device_hotplug lock */
 	lock_device_hotplug();
-	rc = add_memory_resource(nid, resource);
+	rc = add_memory_resource(nid, resource, 0);
 	unlock_device_hotplug();
 	mutex_lock(&balloon_mutex);
 
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 51a877fec8da8..5cd48332ce119 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -345,11 +345,13 @@ extern void set_zone_contiguous(struct zone *zone);
 extern void clear_zone_contiguous(struct zone *zone);
 
 extern void __ref free_area_init_core_hotplug(int nid);
-extern int __add_memory(int nid, u64 start, u64 size);
-extern int add_memory(int nid, u64 start, u64 size);
-extern int add_memory_resource(int nid, struct resource *resource);
+extern int __add_memory(int nid, u64 start, u64 size, unsigned long flags);
+extern int add_memory(int nid, u64 start, u64 size, unsigned long flags);
+extern int add_memory_resource(int nid, struct resource *resource,
+			       unsigned long flags);
 extern int add_memory_driver_managed(int nid, u64 start, u64 size,
-				     const char *resource_name);
+				     const char *resource_name,
+				     unsigned long flags);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 				   unsigned long nr_pages,
 				   struct vmem_altmap *altmap, int migratetype);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 8e1cd18b5cf14..64b07f006bc10 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1039,7 +1039,8 @@ static int online_memory_block(struct memory_block *mem, void *arg)
  *
  * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG
  */
-int __ref add_memory_resource(int nid, struct resource *res)
+int __ref add_memory_resource(int nid, struct resource *res,
+			      unsigned long flags)
 {
 	struct mhp_params params = { .pgprot = PAGE_KERNEL };
 	u64 start, size;
@@ -1118,7 +1119,7 @@ int __ref add_memory_resource(int nid, struct resource *res)
 }
 
 /* requires device_hotplug_lock, see add_memory_resource() */
-int __ref __add_memory(int nid, u64 start, u64 size)
+int __ref __add_memory(int nid, u64 start, u64 size, unsigned long flags)
 {
 	struct resource *res;
 	int ret;
@@ -1127,18 +1128,18 @@ int __ref __add_memory(int nid, u64 start, u64 size)
 	if (IS_ERR(res))
 		return PTR_ERR(res);
 
-	ret = add_memory_resource(nid, res);
+	ret = add_memory_resource(nid, res, flags);
 	if (ret < 0)
 		release_memory_resource(res);
 	return ret;
 }
 
-int add_memory(int nid, u64 start, u64 size)
+int add_memory(int nid, u64 start, u64 size, unsigned long flags)
 {
 	int rc;
 
 	lock_device_hotplug();
-	rc = __add_memory(nid, start, size);
+	rc = __add_memory(nid, start, size, flags);
 	unlock_device_hotplug();
 
 	return rc;
@@ -1167,7 +1168,7 @@ EXPORT_SYMBOL_GPL(add_memory);
  * "System RAM ($DRIVER)".
  */
 int add_memory_driver_managed(int nid, u64 start, u64 size,
-			      const char *resource_name)
+			      const char *resource_name, unsigned long flags)
 {
 	struct resource *res;
 	int rc;
@@ -1185,7 +1186,7 @@ int add_memory_driver_managed(int nid, u64 start, u64 size,
 		goto out_unlock;
 	}
 
-	rc = add_memory_resource(nid, res);
+	rc = add_memory_resource(nid, res, flags);
 	if (rc < 0)
 		release_memory_resource(res);
 
-- 
2.26.2


^ permalink raw reply related

* Re: [PATCH] powerpc/boot/dts: Fix dtc "pciex" warnings
From: Christian Lamparter @ 2020-09-08 18:52 UTC (permalink / raw)
  To: Michael Ellerman
  Cc: linuxppc-dev,
	open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
	Chris Blake, sfr
In-Reply-To: <87mu20spxd.fsf@mpe.ellerman.id.au>

Hello,

On Tue, Sep 8, 2020 at 9:12 AM Michael Ellerman <mpe@ellerman.id.au> wrote:
> Christian Lamparter <chunkeey@gmail.com> writes:
> > On 2020-06-23 15:03, Michael Ellerman wrote:
> >> With CONFIG_OF_ALL_DTBS=y, as set by eg. allmodconfig, we see lots of
> >> warnings about our dts files, such as:
> >>
> >>    arch/powerpc/boot/dts/glacier.dts:492.26-532.5:
> >>    Warning (pci_bridge): /plb/pciex@d00000000: node name is not "pci"
> >>    or "pcie"
> >>
> >
> >
> > Unfortunately yes. This patch will break uboot code in Meraki MX60(W) / MX60.
> >
> >  > https://github.com/riptidewave93/meraki-uboot/blob/mx60w-20180413/board/amcc/bluestone/bluestone.c#L1178
> >
> > | if (!pci_available()) {
> > |     fdt_find_and_setprop(blob, "/plb/pciex@d00000000", "status",
> > |                   "disabled", sizeof("disabled"), 1);
> > | }
> >
> >
> > Backstory: There are two version of the Meraki MX60. The MX60
> > and the MX60W. The difference is that the MX60W has a populated
> > mini-pcie slot on the PCB for a >W<ireless card.
> >
> > That said, this is not earth shattering.
>
> I'm happy to revert that hunk if you think any one is actually booting
> mainline on those.

The MX60(W) or APM82181 in general?

The APM82181 devices run really well on the kernel 5.8. The APM82181
had some bitrot and missing pieces. But I started at around 4.4 with
upstreaming various bits and stuff. For proof, I can post a bootlog from
my MyBook Live dev station running my mbl-debian on this weekend:
<https://github.com/chunkeey/mbl-debian>.

This WD MyBook Live project really only needs
 - vanilla 5.8 (I got rid of the make-kpkg hack by switching to make bindeb-pkg)
 - the MyBookLive DTS.
 - kernel config is based on arch/powerpc/configs/44x/bluestone_defconfig +
   (I enabled dwc2 (USB-Port on the DUO), SATA, ext4(+squashfs),
   gpio-support, leds-support, crypto44x)
 - a powerpc32 userspace (debian's sid still builds up-to-date powerpc packages)

For the MX60(W): We have those two supported in OpenWrt. Currently they
are running a OpenWrt kernel based on stable 5.4 series. The missing "bit"
is upstream support for the AR8327 ethernet switch. I know that the chip
can be supported by qca8k: <https://www.spinics.net/lists/netdev/msg420810.html>

....

But of course: My future work with the MX60(W) (and AR8327) depends on how
this series goes. I'm testing the waters with the Meraki MR24 AP and the
WD MyBook Live series. Reason being that both devices are well supported.
They are available in great quantities... and all the core functions
are working.

Cheers,
Christian

^ permalink raw reply

* Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding
From: Gerald Schaefer @ 2020-09-08 17:59 UTC (permalink / raw)
  To: Dave Hansen
  Cc: Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
	linux-sparc, Alexander Gordeev, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Christian Borntraeger,
	Richard Weinberger, linux-x86, Russell King, Jason Gunthorpe,
	Ingo Molnar, Catalin Marinas, Andrey Ryabinin, Heiko Carstens,
	Arnd Bergmann, John Hubbard, Jeff Dike, linux-um, Borislav Petkov,
	Andy Lutomirski, Thomas Gleixner, linux-arm, linux-power, LKML,
	Andrew Morton, Linus Torvalds, Mike Rapoport
In-Reply-To: <0dbc6ec8-45ea-0853-4856-2bc1e661a5a5@intel.com>

On Tue, 8 Sep 2020 07:30:50 -0700
Dave Hansen <dave.hansen@intel.com> wrote:

> On 9/7/20 11:00 AM, Gerald Schaefer wrote:
> > Commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast
> > code") introduced a subtle but severe bug on s390 with gup_fast, due to
> > dynamic page table folding.
> 
> Would it be fair to say that the "fake" page table entries s390
> allocates on the stack are what's causing the trouble here?  That might
> be a nice thing to open up with here.  "Dynamic page table folding"
> really means nothing to me.

We do not really allocate anything on the stack, it is the generic logic
from gup_fast that passes over pXd values (read once before), and using
pointers to such (stack) variables instead of real pXd pointers.
That, combined with the fact that we just return the passed in pointer in
pXd_offset() for folded levels.

That works similar on x86 IIUC, but with static folding, and thus also
proper pXd_addr_end() results because of statically (and correspondingly)
defined Pxd_INDEX/SHIFT. We always have static 5-level PxD_INDEX/SHIFT, and
that cannot really be made dynamic, so we just make pXd_addr_end()
dynamic instead, and that requires the pXd value to determine the correct
pagetable level.

Still makes my head spin when trying to explain, sorry. It is a very
special s390 oddity, or lets call it "feature", because I don't think any
other architecture has "dynamic pagetable folding" capability, depending
on process requirements, for whatever it is worth...

> 
> > @@ -2521,7 +2521,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
> >  	do {
> >  		pmd_t pmd = READ_ONCE(*pmdp);
> >  
> > -		next = pmd_addr_end(addr, end);
> > +		next = pmd_addr_end_folded(pmd, addr, end);
> >  		if (!pmd_present(pmd))
> >  			return 0;
> 
> It looks like you fix this up later, but this would be a problem if left
> this way.  There's no documentation for whether I use
> pmd_addr_end_folded() or pmd_addr_end() when writing a page table walker.

Yes, that is very unfortunate. We did have some lengthy comment in
include/linux/pgtable.h where the pXd_addr_end(_folded) were defined.
But that was moved to arch/s390/include/asm/pgtable.h in this version,
probably because we already had the generalization in mind, where we
would not need such explanation in common header any more.

So, it might help better understand the issue that we have with
dynamic page table folding and READ_ONCE-style pagetable walkers
when looking at that comment.

Thanks for pointing out, that comment should definitely go into
include/linux/pgtable.h again. At least if we would still go for
that "s390 fix first, generalization second" approach, but it
seems we have other / better options now.

^ permalink raw reply

* Re: [PATCH -next] fork: silence a false postive warning in __mmdrop
From: peterz @ 2020-09-08 17:58 UTC (permalink / raw)
  To: Qian Cai; +Cc: mark.rutland, linux-kernel, linux-mm, akpm, linuxppc-dev
In-Reply-To: <20200908165043.GD5147@lca.pw>

On Tue, Sep 08, 2020 at 12:50:44PM -0400, Qian Cai wrote:
> > No, you're talking nonsense. We must not free @mm when
> > 'current->active_mm == mm', never.
> 
> Yes, you are right. It still trigger this below on powerpc with today's
> linux-next by fuzzing for a while (saw a few times on recent linux-next before
> as well but so far mostly reproducible on powerpc here). Any idea?

If you can reliably reproduce this, the next thing is to trace mm_count
and figure out where it goes side-ways. I suppose we're looking for an
'extra' decrement.

Mark tried this for a while but gave up because he couldn't reliably
reproduce.

^ permalink raw reply

* Re: [RFC PATCH v2 0/3] mm/gup: fix gup_fast with dynamic page table folding
From: Gerald Schaefer @ 2020-09-08 17:36 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Alexander Gordeev, Claudio Imbrenda,
	Will Deacon, linux-arch, linux-s390, Vasily Gorbik,
	Jason Gunthorpe, Richard Weinberger, linux-x86, Russell King,
	Christian Borntraeger, Ingo Molnar, Andrey Ryabinin, Jeff Dike,
	Arnd Bergmann, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <9bde9857-fdfd-e384-ea27-a14e5a06f1e6@csgroup.eu>

On Tue, 8 Sep 2020 07:22:39 +0200
Christophe Leroy <christophe.leroy@csgroup.eu> wrote:

> 
> 
> Le 07/09/2020 à 22:12, Mike Rapoport a écrit :
> > On Mon, Sep 07, 2020 at 08:00:55PM +0200, Gerald Schaefer wrote:
> >> This is v2 of an RFC previously discussed here:
> >> https://lore.kernel.org/lkml/20200828140314.8556-1-gerald.schaefer@linux.ibm.com/
> >>
> >> Patch 1 is a fix for a regression in gup_fast on s390, after our conversion
> >> to common gup_fast code. It will introduce special helper functions
> >> pXd_addr_end_folded(), which have to be used in places where pagetable walk
> >> is done w/o lock and with READ_ONCE, so currently only in gup_fast.
> >>
> >> Patch 2 is an attempt to make that more generic, i.e. change pXd_addr_end()
> >> themselves by adding an extra pXd value parameter. That was suggested by
> >> Jason during v1 discussion, because he is already thinking of some other
> >> places where he might want to switch to the READ_ONCE logic for pagetable
> >> walks. In general, that would be the cleanest / safest solution, but there
> >> is some impact on other architectures and common code, hence the new and
> >> greatly enlarged recipient list.
> >>
> >> Patch 3 is a "nice to have" add-on, which makes pXd_addr_end() inline
> >> functions instead of #defines, so that we get some type checking for the
> >> new pXd value parameter.
> >>
> >> Not sure about Fixes/stable tags for the generic solution. Only patch 1
> >> fixes a real bug on s390, and has Fixes/stable tags. Patches 2 + 3 might
> >> still be nice to have in stable, to ease future backports, but I guess
> >> "nice to have" does not really qualify for stable backports.
> > 
> > I also think that adding pXd parameter to pXd_addr_end() is a cleaner
> > way and with this patch 1 is not really required. I would even merge
> > patches 2 and 3 into a single patch and use only it as the fix.
> 
> Why not merging patches 2 and 3, but I would keep patch 1 separate but 
> after the generic changes, so that we first do the generic changes, then 
> we do the specific S390 use of it.

Yes, we thought about that approach too. It would at least allow to
get all into stable, more or less nicely, as prerequisite for the s390
fix.

Two concerns kept us from going that way. For once, it might not be
the nicest way to get it all in stable, and we would not want to risk
further objections due to the imminent and rather scary data corruption
issue that we want to fix asap.

For the same reason, we thought that the generalization part might
need more time and agreement from various people, so that we could at
least get the first patch as short-term solution.

It seems now that the generalization is very well accepted so far,
apart from some apparent issues on arm. Also, merging 2 + 3 and
putting them first seems to be acceptable, so we could do that for
v3, if there are no objections.

Of course, we first need to address the few remaining issues for
arm(32?), which do look quite confusing to me so far. BTW, sorry for
the compile error with patch 3, I guess we did the cross-compile only
for 1 + 2 applied, to see the bloat-o-meter changes. But I guess
patch 3 already proved its usefulness by that :-)

^ permalink raw reply

* Re: [PATCH V2] ASoC: fsl: imx-es8328: add missing put_device() call in imx_es8328_probe()
From: Mark Brown @ 2020-09-08 17:20 UTC (permalink / raw)
  To: kernel, lgirdwood, xobs, nicoleotsuka, linux-imx, shengjiu.wang,
	tiwai, s.hauer, timur, festevam, perex, Yu Kuai, shawnguo,
	Xiubo.Lee
  Cc: alsa-devel, linuxppc-dev, linux-kernel, linux-arm-kernel,
	yi.zhang
In-Reply-To: <20200825130224.1488694-1-yukuai3@huawei.com>

On Tue, 25 Aug 2020 21:02:24 +0800, Yu Kuai wrote:
> if of_find_device_by_node() succeed, imx_es8328_probe() doesn't have
> a corresponding put_device(). Thus add a jump target to fix the exception
> handling for this function implementation.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: fsl: imx-es8328: add missing put_device() call in imx_es8328_probe()
      commit: e525db7e4b44c5b2b5aac0dad24e23cb58c54d22

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

^ permalink raw reply

* Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
From: Christophe Leroy @ 2020-09-08 17:20 UTC (permalink / raw)
  To: Alexander Gordeev
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Christian Borntraeger,
	Richard Weinberger, linux-x86, Russell King, Jason Gunthorpe,
	Ingo Molnar, Andrey Ryabinin, Gerald Schaefer, Jeff Dike,
	Arnd Bergmann, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <20200908154859.GA11583@oc3871087118.ibm.com>



Le 08/09/2020 à 17:48, Alexander Gordeev a écrit :
> On Tue, Sep 08, 2020 at 07:19:38AM +0200, Christophe Leroy wrote:
> 
> [...]
> 
>>> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
>>> index 67ebc22cf83d..d9e7d16c2263 100644
>>> --- a/include/linux/pgtable.h
>>> +++ b/include/linux/pgtable.h
>>> @@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm,
>>>    */
>>>   #ifndef pgd_addr_end
>>> -#define pgd_addr_end(pgd, addr, end)					\
>>> -({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
>>> -	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
>>> -})
>>> +#define pgd_addr_end pgd_addr_end
>>
>> I think that #define is pointless, usually there is no such #define
>> for the default case.
> 
> Default pgd_addr_end() gets overriden on s390 (arch/s390/include/asm/pgtable.h):
> 
> #define pgd_addr_end pgd_addr_end
> static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
> {
> 	return rste_addr_end_folded(pgd_val(pgd), addr, end);
> }

Yes, there in s390 the #define is needed to hit the #ifndef pgd_addr_end 
that's in include/linux/pgtable.h

But in include/linux/pgtable.h, there is no need of an #define 
pgd_addr_end pgd_addr_end I think

> 
>>> +static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
>>> +{	unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK;
>>> +	return (__boundary - 1 < end - 1) ? __boundary : end;
>>> +}


Christophe

^ permalink raw reply

* Re: [PATCH -next] fork: silence a false postive warning in __mmdrop
From: Qian Cai @ 2020-09-08 16:50 UTC (permalink / raw)
  To: Peter Zijlstra; +Cc: mark.rutland, linux-kernel, linux-mm, akpm, linuxppc-dev
In-Reply-To: <20200722134406.GN10769@hirez.programming.kicks-ass.net>

On Wed, Jul 22, 2020 at 03:44:06PM +0200, Peter Zijlstra wrote:
> On Wed, Jul 22, 2020 at 09:19:00AM -0400, Qian Cai wrote:
> > On Wed, Jul 22, 2020 at 12:06:37PM +0200, peterz@infradead.org wrote:
> > > On Thu, Jun 04, 2020 at 11:03:44AM -0400, Qian Cai wrote:
> > > > The linux-next commit bf2c59fce407 ("sched/core: Fix illegal RCU from
> > > > offline CPUs") delayed,
> > > > 
> > > > idle->active_mm = &init_mm;
> > > > 
> > > > into finish_cpu() instead of idle_task_exit() which results in a false
> > > > positive warning that was originally designed in the commit 3eda69c92d47
> > > > ("kernel/fork.c: detect early free of a live mm").
> > > > 
> > > >  WARNING: CPU: 127 PID: 72976 at kernel/fork.c:697
> > > >  __mmdrop+0x230/0x2c0
> > > >  do_exit+0x424/0xfa0
> > > >  Call Trace:
> > > >  do_exit+0x424/0xfa0
> > > >  do_group_exit+0x64/0xd0
> > > >  sys_exit_group+0x24/0x30
> > > >  system_call_exception+0x108/0x1d0
> > > >  system_call_common+0xf0/0x278
> > > 
> > > Please explain; because afaict this is a use-after-free.
> > > 
> > > The thing is __mmdrop() is going to actually free the mm, so then what
> > > is finish_cpu()'s mmdrop() going to do?
> > > 
> > > ->active_mm() should have a refcount on the mm.
> > 
> > Well, the refcount issue you mentioned then happens all before bf2c59fce407 was
> > introduced as well, but then it looks harmless because mmdrop() in finish_cpu()
> > will do,
> > 
> > 	if (unlikely(atomic_dec_and_test(&mm->mm_count)))
> > 		__mmdrop(mm);
> 
> That's not harmless, that's a use-after-free. Those can cause memory
> corruption bugs and the like at best. Who knows what's at the location
> of mm->mm_count after we've already freed it.
> 
> > where that atomic_dec_and_test() see the negative refcount and will not involve
> > __mmdrop() again. It is not clear to me that once the CPU is offline if it
> > needs to care about its idle thread mm_count at all. Even if this refcount
> > issue is finally addressed, it could hit this warning in finish_cpu() without
> > this patch.
> > 
> > On the other hand, if you look at the commit 3eda69c92d47, it is clearly that
> > the assumption of,
> > 
> >    WARN_ON_ONCE(mm == current->active_mm);
> > 
> > is totally gone due to bf2c59fce407. Thus, the patch is to fix that discrepancy
> > first and then I'll look at that the imbalance mmdrop()/mmgrab() elsewhere.
> 
> No, you're talking nonsense. We must not free @mm when
> 'current->active_mm == mm', never.

Yes, you are right. It still trigger this below on powerpc with today's
linux-next by fuzzing for a while (saw a few times on recent linux-next before
as well but so far mostly reproducible on powerpc here). Any idea?

[12802.547809][T191552] BUG mm_struct (Tainted: G           O     ): Poison overwritten
[12802.547824][T191552] -----------------------------------------------------------------------------
[12802.547824][T191552] 
[12802.547843][T191552] Disabling lock debugging due to kernel taint
[12802.547867][T191552] INFO: 0x000000000e2a54ec-0x000000000e2a54ec @offset=96464. First byte 0x6a instead of 0x6b
[12802.547889][T191552] INFO: Allocated in dup_mm+0x48/0x6d0 age=955 cpu=108 pid=191552
[12802.547915][T191552] 	__slab_alloc+0xa4/0xf0
[12802.547937][T191552] 	kmem_cache_alloc+0x314/0x4a0
[12802.547959][T191552] 	dup_mm+0x48/0x6d0
dup_mm at kernel/fork.c:1344
[12802.547978][T191552] 	copy_process+0x11bc/0x19a0
[12802.548010][T191552] 	kernel_clone+0x120/0xb80
[12802.548031][T191552] 	__do_sys_clone+0x88/0xd0
[12802.548055][T191552] 	system_call_exception+0xf8/0x1d0
[12802.548083][T191552] 	system_call_common+0xe8/0x218
[12802.548093][T191552] INFO: Freed in __mmdrop+0x144/0x250 age=942 cpu=69 pid=882503
[12802.548140][T191552] 	kmem_cache_free+0x47c/0x500
[12802.548161][T191552] 	__mmdrop+0x144/0x250
__mmdrop at kernel/fork.c:685
[12802.548170][T191552] 	do_exit+0x3f4/0xed0
[12802.548212][T191552] 	do_group_exit+0x5c/0xd0
[12802.548244][T191552] 	sys_exit_group+0x1c/0x20
[12802.548277][T191552] 	system_call_exception+0xf8/0x1d0
[12802.548309][T191552] 	system_call_common+0xe8/0x218
[12802.548342][T191552] INFO: Slab 0x0000000048df84af objects=64 used=64 fp=0x0000000000000000 flags=0x87fff8000010200
[12802.548379][T191552] INFO: Object 0x00000000583c5ba3 @offset=96384 fp=0x00000000681f5d04
[12802.548379][T191552] 
[12802.548419][T191552] Redzone 000000004a1ea01e: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548445][T191552] Redzone 0000000037d12952: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548471][T191552] Redzone 000000008124eae0: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548511][T191552] Redzone 000000009b782382: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548559][T191552] Redzone 0000000005c781f2: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548608][T191552] Redzone 00000000f334982a: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548645][T191552] Redzone 0000000018372bc6: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548706][T191552] Redzone 00000000de34ccbe: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[12802.548755][T191552] Object 00000000583c5ba3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.548804][T191552] Object 000000007701f6eb: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.548864][T191552] Object 00000000796c61b2: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.548912][T191552] Object 00000000d5d3e0a7: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.548960][T191552] Object 00000000be4c7347: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.548997][T191552] Object 000000000e2a54ec: 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  jkkkkkkkkkkkkkkk
[12802.549034][T191552] Object 000000005f2499ea: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549093][T191552] Object 000000007dfc6e96: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549120][T191552] Object 0000000033cbf36a: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549135][T191552] Object 00000000b62c5d59: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549172][T191552] Object 00000000fc047f4a: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549210][T191552] Object 00000000c28e582c: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549258][T191552] Object 0000000058ab5b6a: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549316][T191552] Object 000000005a56e917: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549364][T191552] Object 000000005a3db061: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549426][T191552] Object 00000000831930db: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549464][T191552] Object 00000000dfbae818: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549500][T191552] Object 000000007c1d0838: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549548][T191552] Object 0000000061011d8a: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549585][T191552] Object 000000000e949754: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549634][T191552] Object 000000006413f485: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549671][T191552] Object 00000000c2345eaa: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549718][T191552] Object 0000000092085813: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549755][T191552] Object 00000000bd1573c3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549813][T191552] Object 00000000ea86aa44: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549862][T191552] Object 00000000f6c1034d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549910][T191552] Object 000000001d90fa29: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.549958][T191552] Object 000000001397fc70: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550016][T191552] Object 0000000073b0be2d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550053][T191552] Object 00000000887c2ae9: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550101][T191552] Object 00000000b662d1ef: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550183][T191552] Object 000000000f9f4844: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550280][T191552] Object 0000000030f51915: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550406][T191552] Object 0000000055fe92a1: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550518][T191552] Object 0000000018acbccc: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550641][T191552] Object 0000000003bc1e0d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550755][T191552] Object 000000002d3ab81e: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.550879][T191552] Object 000000008e60297f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551005][T191552] Object 00000000816738aa: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551104][T191552] Object 000000001418ad0f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551226][T191552] Object 00000000f753b837: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551363][T191552] Object 000000003456e3f7: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551489][T191552] Object 000000006e6ba90f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551609][T191552] Object 00000000731663e1: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551730][T191552] Object 00000000c3364461: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551854][T191552] Object 00000000eebcf88b: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.551956][T191552] Object 000000004de29fa4: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552067][T191552] Object 000000005bd1967e: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552184][T191552] Object 00000000d8d1d981: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552321][T191552] Object 00000000fd01955d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552447][T191552] Object 000000005aad9974: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552555][T191552] Object 000000007fa2efe4: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552653][T191552] Object 000000001e6bbc3d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552782][T191552] Object 000000004e7b9320: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.552913][T191552] Object 000000007660c732: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553024][T191552] Object 0000000005fe5824: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553125][T191552] Object 000000007072b5da: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553257][T191552] Object 00000000ce50558d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553375][T191552] Object 00000000ee40426b: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553508][T191552] Object 00000000151dd063: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553588][T191552] Object 000000006dde4155: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553719][T191552] Object 00000000bba9c8b4: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553835][T191552] Object 0000000081fef250: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.553952][T191552] Object 00000000db9d7aa0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554078][T191552] Object 00000000513748d5: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554190][T191552] Object 000000001b7e4b57: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554313][T191552] Object 00000000969509b3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554430][T191552] Object 00000000df85a9df: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554558][T191552] Object 00000000d526fda8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554664][T191552] Object 000000008be58260: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554784][T191552] Object 000000006a8d52b0: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.554911][T191552] Object 00000000ad1dfd55: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555005][T191552] Object 00000000873b52ea: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555134][T191552] Object 000000009716c879: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555249][T191552] Object 00000000eca252fd: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555371][T191552] Object 000000002d09f068: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555493][T191552] Object 0000000095d7f3b1: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555617][T191552] Object 000000009b66f877: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555728][T191552] Object 00000000d4d0da23: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555848][T191552] Object 00000000545dfae3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.555965][T191552] Object 00000000c686086a: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556093][T191552] Object 0000000076efef7b: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556213][T191552] Object 000000007642cc9f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556313][T191552] Object 00000000a2c7182e: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556431][T191552] Object 00000000d8508993: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556570][T191552] Object 0000000007078b31: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556676][T191552] Object 000000002111128f: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556769][T191552] Object 0000000096a989ba: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.556904][T191552] Object 00000000078fa309: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557025][T191552] Object 00000000b68d0e77: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557158][T191552] Object 00000000144b15b3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557247][T191552] Object 00000000a806800d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557351][T191552] Object 000000005edb4355: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557484][T191552] Object 0000000049aaca1e: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557600][T191552] Object 000000000eb0b7f9: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[12802.557727][T191552] Object 000000008fdb29be: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
[12802.557831][T191552] Redzone 00000000c5a61231: bb bb bb bb bb bb bb bb                          ........
[12802.557947][T191552] Padding 000000003163b13a: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[12802.558076][T191552] Padding 0000000092412b1a: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[12802.558187][T191552] Padding 00000000319fa8cb: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[12802.558314][T191552] Padding 00000000963c7ce8: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[12802.558432][T191552] CPU: 71 PID: 191552 Comm: trinity-main Tainted: G    B      O      5.9.0-rc4-next-20200908+ #1
[12802.558551][T191552] Call Trace:
[12802.558590][T191552] [c000201cb3427620] [c000000000701758] dump_stack+0xec/0x144 (unreliable)
[12802.558691][T191552] [c000201cb3427660] [c0000000003cb53c] print_trailer+0x278/0x2a0
[12802.558794][T191552] [c000201cb34276f0] [c0000000003c0d14] check_bytes_and_report+0x184/0x1b0
[12802.558900][T191552] [c000201cb34277a0] [c0000000003c1000] check_object+0x2c0/0x330
[12802.558990][T191552] [c000201cb3427800] [c0000000003c11ec] alloc_debug_processing+0x17c/0x1e0
[12802.559096][T191552] [c000201cb3427880] [c0000000003c5468] ___slab_alloc+0xb78/0xc60
[12802.559190][T191552] [c000201cb3427980] [c0000000003c55f4] __slab_alloc+0xa4/0xf0
[12802.559284][T191552] [c000201cb34279d0] [c0000000003c5954] kmem_cache_alloc+0x314/0x4a0
[12802.559362][T191552] [c000201cb3427a50] [c0000000000c4818] dup_mm+0x48/0x6d0
[12802.559445][T191552] [c000201cb3427b00] [c0000000000c665c] copy_process+0x11bc/0x19a0
[12802.559528][T191552] [c000201cb3427c20] [c0000000000c7210] kernel_clone+0x120/0xb80
[12802.559630][T191552] [c000201cb3427d00] [c0000000000c7cf8] __do_sys_clone+0x88/0xd0
[12802.559714][T191552] [c000201cb3427dc0] [c00000000002c748] system_call_exception+0xf8/0x1d0
[12802.559810][T191552] [c000201cb3427e20] [c00000000000d0a8] system_call_common+0xe8/0x218
[12802.559906][T191552] FIX mm_struct: Restoring 0x000000000e2a54ec-0x000000000e2a54ec=0x6b
[12802.559906][T191552] 
[12802.560030][T191552] FIX mm_struct: Marking all objects used

^ permalink raw reply

* Re: [RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions
From: Alexander Gordeev @ 2020-09-08 15:48 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Christian Borntraeger,
	Richard Weinberger, linux-x86, Russell King, Jason Gunthorpe,
	Ingo Molnar, Andrey Ryabinin, Gerald Schaefer, Jeff Dike,
	Arnd Bergmann, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <4c101685-5b29-dace-9dd2-b6f0ae193a9c@csgroup.eu>

On Tue, Sep 08, 2020 at 07:19:38AM +0200, Christophe Leroy wrote:

[...]

> >diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> >index 67ebc22cf83d..d9e7d16c2263 100644
> >--- a/include/linux/pgtable.h
> >+++ b/include/linux/pgtable.h
> >@@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm,
> >   */
> >  #ifndef pgd_addr_end
> >-#define pgd_addr_end(pgd, addr, end)					\
> >-({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
> >-	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
> >-})
> >+#define pgd_addr_end pgd_addr_end
> 
> I think that #define is pointless, usually there is no such #define
> for the default case.

Default pgd_addr_end() gets overriden on s390 (arch/s390/include/asm/pgtable.h):

#define pgd_addr_end pgd_addr_end
static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
{
	return rste_addr_end_folded(pgd_val(pgd), addr, end);
}

> >+static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
> >+{	unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK;
> >+	return (__boundary - 1 < end - 1) ? __boundary : end;
> >+}

^ permalink raw reply

* Re: [PATCH v4 00/13] mm/debug_vm_pgtable fixes
From: Gerald Schaefer @ 2020-09-08 15:39 UTC (permalink / raw)
  To: Anshuman Khandual
  Cc: linux-s390@vger.kernel.org, Aneesh Kumar K.V, linux-mm,
	Vineet Gupta, akpm, linux-snps-arc@lists.infradead.org,
	linuxppc-dev, linux-riscv, Gerald Schaefer
In-Reply-To: <20200904180115.07ee5f00@thinkpad>

On Fri, 4 Sep 2020 18:01:15 +0200
Gerald Schaefer <gerald.schaefer@linux.ibm.com> wrote:

[...]
> 
> BTW2, a quick test with this change (so far) made the issues on s390
> go away:
> 
> @@ -1069,7 +1074,7 @@ static int __init debug_vm_pgtable(void)
>         spin_unlock(ptl);
> 
>  #ifndef CONFIG_PPC_BOOK3S_64
> -       hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
> +       hugetlb_advanced_tests(mm, vma, (pte_t *) pmdp, pmd_aligned, vaddr, prot);
>  #endif
> 
>         spin_lock(&mm->page_table_lock);
> 
> That would more match the "pte_t pointer" usage for hugetlb code,
> i.e. just cast a pmd_t pointer to it. Also changed to pmd_aligned,
> but I think the root cause is the pte_t pointer.
> 
> Not entirely sure though if that would really be the correct fix.
> I somehow lost whatever little track I had about what these tests
> really want to check, and if that would still be valid with that
> change.

Uh oh, wasn't aware that this (or some predecessor) already went
upstream, and broke our debug kernel today.

I found out now what goes (horribly) wrong on s390, see below for
more details. In short, using hugetlb primitives with ptep pointers
that do _not_ point to a pmd or pud entry will not work on s390.
It also seems to make no sense to verify / test such a thing in general,
as it would also be a severe bug if any kernel code would do that.
After all, with hugepages, there are no pte tables, only pmd etc.
tables.

My change above would fix the issue for s390, but I can still not
completely judge if that would not break other things for your
tests. In general, for normal kernel code, much of what you do would
be very broken, but I guess your tests are doing such "special" things
because they can. E.g. because they operate on some "sandbox" mm
and page tables, and you also do not need properly populated page
tables for some exit / free cleanup, you just throw them away
explicitly with pXd_free at the end. So it might just be "the right
thing" to pass a casted pmd pointer to hugetlb_advanced_tests(),
to simulate and test (proper) usage of the hugetlb primitives.
I also see no other way to make this work for s390, than using a
proper pmd/pud pointer. If not possible, please add us to the
#ifndef.

So, for all those interested, here is what goes wrong on s390.
huge_ptep_get_and_clear() uses the "idte" instruction for the
clearing (and TLB invalidation) part. That instruction expects
a "region or segment table" origin, which is a pmd/pud/p4d/pgd,
but not a pte table. Even worse, when we calculate the table
origin from the given ptep (which *should* not point to a pte),
due to different table sizes for pte / pXd tables, we end up
at some place before the given pte table.

The "idte" instruction also gets the virtual address, and does
corresponding index addition to the given table origin. Depending
on the pmd_index we now end up either within the pte table again,
in which case we see a panic because idte complains about seeing
a pte value. If we are unlucky, then we end up outside the pte
table, and depending on the content of that memory location, idte
might succeed, effectively corrupting that memory.

That explains why we only see the panic sometimes, depending on
random vaddr, other symptoms other times, and probably completely
silent memory corruption for the rest...

^ permalink raw reply

* Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware
From: Dave Hansen @ 2020-09-08 14:33 UTC (permalink / raw)
  To: Gerald Schaefer, Jason Gunthorpe, John Hubbard
  Cc: Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
	linux-sparc, Alexander Gordeev, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Richard Weinberger,
	linux-x86, Russell King, Christian Borntraeger, Ingo Molnar,
	Catalin Marinas, Andrey Ryabinin, Heiko Carstens, Arnd Bergmann,
	Jeff Dike, linux-um, Borislav Petkov, Andy Lutomirski,
	Thomas Gleixner, linux-arm, linux-power, LKML, Andrew Morton,
	Linus Torvalds, Mike Rapoport
In-Reply-To: <20200907180058.64880-3-gerald.schaefer@linux.ibm.com>

On 9/7/20 11:00 AM, Gerald Schaefer wrote:
> x86:
> add/remove: 0/0 grow/shrink: 2/0 up/down: 10/0 (10)
> Function                                     old     new   delta
> vmemmap_populate                             587     592      +5
> munlock_vma_pages_range                      556     561      +5
> Total: Before=15534694, After=15534704, chg +0.00%
...
>  arch/x86/mm/init_64.c                    | 15 ++++-----
>  arch/x86/mm/kasan_init_64.c              | 16 +++++-----

I didn't do a super thorough review on this, but it generally looks OK
and the benefits of sharing more code between arches certainly outweigh
a few bytes of binary growth.  For the x86 bits at least, feel free to
add my ack.

^ permalink raw reply

* Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding
From: Dave Hansen @ 2020-09-08 14:30 UTC (permalink / raw)
  To: Gerald Schaefer, Jason Gunthorpe, John Hubbard
  Cc: Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
	linux-sparc, Alexander Gordeev, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Richard Weinberger,
	linux-x86, Russell King, Christian Borntraeger, Ingo Molnar,
	Catalin Marinas, Andrey Ryabinin, Heiko Carstens, Arnd Bergmann,
	Jeff Dike, linux-um, Borislav Petkov, Andy Lutomirski,
	Thomas Gleixner, linux-arm, linux-power, LKML, Andrew Morton,
	Linus Torvalds, Mike Rapoport
In-Reply-To: <20200907180058.64880-2-gerald.schaefer@linux.ibm.com>

On 9/7/20 11:00 AM, Gerald Schaefer wrote:
> Commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast
> code") introduced a subtle but severe bug on s390 with gup_fast, due to
> dynamic page table folding.

Would it be fair to say that the "fake" page table entries s390
allocates on the stack are what's causing the trouble here?  That might
be a nice thing to open up with here.  "Dynamic page table folding"
really means nothing to me.

> @@ -2521,7 +2521,7 @@ static int gup_pmd_range(pud_t pud, unsigned long addr, unsigned long end,
>  	do {
>  		pmd_t pmd = READ_ONCE(*pmdp);
>  
> -		next = pmd_addr_end(addr, end);
> +		next = pmd_addr_end_folded(pmd, addr, end);
>  		if (!pmd_present(pmd))
>  			return 0;

It looks like you fix this up later, but this would be a problem if left
this way.  There's no documentation for whether I use
pmd_addr_end_folded() or pmd_addr_end() when writing a page table walker.


^ permalink raw reply

* Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware
From: Alexander Gordeev @ 2020-09-08 14:25 UTC (permalink / raw)
  To: Christophe Leroy, Michael Ellerman
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Christian Borntraeger,
	Richard Weinberger, linux-x86, Russell King, Jason Gunthorpe,
	Ingo Molnar, Andrey Ryabinin, Gerald Schaefer, Jeff Dike,
	Arnd Bergmann, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <31dfb3ed-a0cc-3024-d389-ab9bd19e881f@csgroup.eu>

On Tue, Sep 08, 2020 at 07:14:38AM +0200, Christophe Leroy wrote:
[...]
> You forgot arch/powerpc/mm/book3s64/subpage_prot.c it seems.

If this one would be okay?

diff --git a/arch/powerpc/mm/book3s64/subpage_prot.c b/arch/powerpc/mm/book3s64/subpage_prot.c
index 60c6ea16..3690d22 100644
--- a/arch/powerpc/mm/book3s64/subpage_prot.c
+++ b/arch/powerpc/mm/book3s64/subpage_prot.c
@@ -88,6 +88,7 @@ static void hpte_flush_range(struct mm_struct *mm, unsigned long addr,
 static void subpage_prot_clear(unsigned long addr, unsigned long len)
 {
 	struct mm_struct *mm = current->mm;
+	pmd_t *pmd = pmd_off(mm, addr);
 	struct subpage_prot_table *spt;
 	u32 **spm, *spp;
 	unsigned long i;
@@ -103,8 +104,8 @@ static void subpage_prot_clear(unsigned long addr, unsigned long len)
 	limit = addr + len;
 	if (limit > spt->maxaddr)
 		limit = spt->maxaddr;
-	for (; addr < limit; addr = next) {
-		next = pmd_addr_end(addr, limit);
+	for (; addr < limit; addr = next, pmd++) {
+		next = pmd_addr_end(*pmd, addr, limit);
 		if (addr < 0x100000000UL) {
 			spm = spt->low_prot;
 		} else {
@@ -191,6 +192,7 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
 		unsigned long, len, u32 __user *, map)
 {
 	struct mm_struct *mm = current->mm;
+	pmd_t *pmd = pmd_off(mm, addr);
 	struct subpage_prot_table *spt;
 	u32 **spm, *spp;
 	unsigned long i;
@@ -236,8 +238,8 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,
 	}
 
 	subpage_mark_vma_nohuge(mm, addr, len);
-	for (limit = addr + len; addr < limit; addr = next) {
-		next = pmd_addr_end(addr, limit);
+	for (limit = addr + len; addr < limit; addr = next, pmd++) {
+		next = pmd_addr_end(*pmd, addr, limit);
 		err = -ENOMEM;
 		if (addr < 0x100000000UL) {
 			spm = spt->low_prot;

Thanks!

> Christophe

^ permalink raw reply related

* Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware
From: Alexander Gordeev @ 2020-09-08 14:15 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Arnd Bergmann, Christian Borntraeger,
	Richard Weinberger, linux-x86, Russell King, Jason Gunthorpe,
	Ingo Molnar, Andrey Ryabinin, Gerald Schaefer, Jeff Dike,
	Vasily Gorbik, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <5d4f5546-afd0-0b8f-664d-700ae346b9ec@csgroup.eu>

On Tue, Sep 08, 2020 at 10:16:49AM +0200, Christophe Leroy wrote:
> >Yes, and also two more sources :/
> >	arch/powerpc/mm/kasan/8xx.c
> >	arch/powerpc/mm/kasan/kasan_init_32.c
> >
> >But these two are not quite obvious wrt pgd_addr_end() used
> >while traversing pmds. Could you please clarify a bit?
> >
> >
> >diff --git a/arch/powerpc/mm/kasan/8xx.c b/arch/powerpc/mm/kasan/8xx.c
> >index 2784224..89c5053 100644
> >--- a/arch/powerpc/mm/kasan/8xx.c
> >+++ b/arch/powerpc/mm/kasan/8xx.c
> >@@ -15,8 +15,8 @@
> >  	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
> >  		pte_basic_t *new;
> >-		k_next = pgd_addr_end(k_cur, k_end);
> >-		k_next = pgd_addr_end(k_next, k_end);
> >+		k_next = pmd_addr_end(k_cur, k_end);
> >+		k_next = pmd_addr_end(k_next, k_end);
> 
> No, I don't think so.
> On powerpc32 we have only two levels, so pgd and pmd are more or
> less the same.
> But pmd_addr_end() as defined in include/asm-generic/pgtable-nopmd.h
> is a no-op, so I don't think it will work.
> 
> It is likely that this function should iterate on pgd, then you get
> pmd = pmd_offset(pud_offset(p4d_offset(pgd)));

It looks like the code iterates over single pmd table while using
pgd_addr_end() only to skip all the middle levels and bail out
from the loop.

I would be wary for switching from pmds to pgds, since we are
trying to minimize impact (especially functional) and the
rework does not seem that obvious.

Assuming pmd and pgd are the same would actually such approach
work for now?

diff --git a/arch/powerpc/mm/kasan/8xx.c b/arch/powerpc/mm/kasan/8xx.c
index 2784224..94466cc 100644
--- a/arch/powerpc/mm/kasan/8xx.c
+++ b/arch/powerpc/mm/kasan/8xx.c
@@ -15,8 +15,8 @@
 	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
 		pte_basic_t *new;
 
-		k_next = pgd_addr_end(k_cur, k_end);
-		k_next = pgd_addr_end(k_next, k_end);
+		k_next = pgd_addr_end(__pgd(pmd_val(*pmd)), k_cur, k_end);
+		k_next = pgd_addr_end(__pgd(pmd_val(*(pmd + 1))), k_next, k_end);
 		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
 			continue;
 
diff --git a/arch/powerpc/mm/kasan/kasan_init_32.c b/arch/powerpc/mm/kasan/kasan_init_32.c
index fb29404..c0bcd64 100644
--- a/arch/powerpc/mm/kasan/kasan_init_32.c
+++ b/arch/powerpc/mm/kasan/kasan_init_32.c
@@ -38,7 +38,7 @@ int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_
 	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
 		pte_t *new;
 
-		k_next = pgd_addr_end(k_cur, k_end);
+		k_next = pgd_addr_end(__pgd(pmd_val(*pmd)), k_cur, k_end);
 		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
 			continue;
 
@@ -196,7 +196,7 @@ void __init kasan_early_init(void)
 	kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);
 
 	do {
-		next = pgd_addr_end(addr, end);
+		next = pgd_addr_end(__pgd(pmd_val(*pmd)), addr, end);
 		pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
 	} while (pmd++, addr = next, addr != end);
 

Alternatively we could pass invalid pgd to keep the code structure
intact, but that of course is less nice.

Thanks!

> Christophe

^ permalink raw reply related

* Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding
From: Gerald Schaefer @ 2020-09-08 13:38 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Alexander Gordeev, Claudio Imbrenda,
	Will Deacon, linux-arch, linux-s390, Vasily Gorbik,
	Christian Borntraeger, Richard Weinberger, linux-x86,
	Russell King, Jason Gunthorpe, Ingo Molnar, Andrey Ryabinin,
	Jeff Dike, Arnd Bergmann, John Hubbard, Heiko Carstens, linux-um,
	Borislav Petkov, Andy Lutomirski, Thomas Gleixner, linux-arm,
	Linus Torvalds, LKML, Andrew Morton, linux-power, Mike Rapoport
In-Reply-To: <96b80926-cf5b-1afa-9b7a-949a2188e61f@csgroup.eu>

On Tue, 8 Sep 2020 14:40:10 +0200
Christophe Leroy <christophe.leroy@csgroup.eu> wrote:

> 
> 
> Le 08/09/2020 à 14:09, Christian Borntraeger a écrit :
> > 
> > 
> > On 08.09.20 07:06, Christophe Leroy wrote:
> >>
> >>
> >> Le 07/09/2020 à 20:00, Gerald Schaefer a écrit :
> >>> From: Alexander Gordeev <agordeev@linux.ibm.com>
> >>>
> >>> Commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast
> >>> code") introduced a subtle but severe bug on s390 with gup_fast, due to
> >>> dynamic page table folding.
> >>>
> >>> The question "What would it require for the generic code to work for s390"
> >>> has already been discussed here
> >>> https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1
> >>> and ended with a promising approach here
> >>> https://lkml.kernel.org/r/20190419153307.4f2911b5@mschwideX1
> >>> which in the end unfortunately didn't quite work completely.
> >>>
> >>> We tried to mimic static level folding by changing pgd_offset to always
> >>> calculate top level page table offset, and do nothing in folded pXd_offset.
> >>> What has been overlooked is that PxD_SIZE/MASK and thus pXd_addr_end do
> >>> not reflect this dynamic behaviour, and still act like static 5-level
> >>> page tables.
> >>>
> >>
> >> [...]
> >>
> >>>
> >>> Fix this by introducing new pXd_addr_end_folded helpers, which take an
> >>> additional pXd entry value parameter, that can be used on s390
> >>> to determine the correct page table level and return corresponding
> >>> end / boundary. With that, the pointer iteration will always
> >>> happen in gup_pgd_range for s390. No change for other architectures
> >>> introduced.
> >>
> >> Not sure pXd_addr_end_folded() is the best understandable name, allthough I don't have any alternative suggestion at the moment.
> >> Maybe could be something like pXd_addr_end_fixup() as it will disappear in the next patch, or pXd_addr_end_gup() ?
> >>
> >> Also, if it happens to be acceptable to get patch 2 in stable, I think you should switch patch 1 and patch 2 to avoid the step through pXd_addr_end_folded()
> > 
> > given that this fixes a data corruption issue, wouldnt it be the best to go forward
> > with this patch ASAP and then handle the other patches on top with all the time that
> > we need?
> 
> I have no strong opinion on this, but I feel rather tricky to have to 
> change generic part of GUP to use a new fonction then revert that change 
> in the following patch, just because you want the first patch in stable 
> and not the second one.
> 
> Regardless, I was wondering, why do we need a reference to the pXd at 
> all when calling pXd_addr_end() ?
> 
> Couldn't S390 retrieve the pXd by using the pXd_offset() dance with the 
> passed addr ?

Apart from performance impact when re-doing that what has already been
done by the caller, I think we would also break the READ_ONCE semantics.
After all, the pXd_offset() would also require some pXd pointer input,
which we don't have. So we would need to start over again from mm->pgd.

Also, it seems to be more in line with other primitives that take
a pXd value or pointer.

^ permalink raw reply

* Re: [RFC PATCH v2 2/3] mm: make pXd_addr_end() functions page-table entry aware
From: Jason Gunthorpe @ 2020-09-08 13:26 UTC (permalink / raw)
  To: Gerald Schaefer
  Cc: Peter Zijlstra, Dave Hansen, linux-mm, Paul Mackerras,
	linux-sparc, Alexander Gordeev, Claudio Imbrenda, Will Deacon,
	linux-arch, linux-s390, Vasily Gorbik, Richard Weinberger,
	linux-x86, Russell King, Christian Borntraeger, Ingo Molnar,
	Catalin Marinas, Andrey Ryabinin, Heiko Carstens, Arnd Bergmann,
	John Hubbard, Jeff Dike, linux-um, Borislav Petkov,
	Andy Lutomirski, Thomas Gleixner, linux-arm, linux-power, LKML,
	Andrew Morton, Linus Torvalds, Mike Rapoport
In-Reply-To: <20200907180058.64880-3-gerald.schaefer@linux.ibm.com>

On Mon, Sep 07, 2020 at 08:00:57PM +0200, Gerald Schaefer wrote:
> From: Alexander Gordeev <agordeev@linux.ibm.com>
> 
> Unlike all other page-table abstractions pXd_addr_end() do not take
> into account a particular table entry in which context the functions
> are called. On architectures with dynamic page-tables folding that
> might lead to lack of necessary information that is difficult to
> obtain other than from the table entry itself. That already led to
> a subtle memory corruption issue on s390.
> 
> By letting pXd_addr_end() functions know about the page-table entry
> we allow archs not only make extra checks, but also optimizations.
> 
> As result of this change the pXd_addr_end_folded() functions used
> in gup_fast traversal code become unnecessary and get replaced with
> universal pXd_addr_end() variants.
> 
> The arch-specific updates not only add dereferencing of page-table
> entry pointers, but also small changes to the code flow to make those
> dereferences possible, at least for x86 and powerpc. Also for arm64,
> but in way that should not have any impact.
> 
> So, even though the dereferenced page-table entries are not used on
> archs other than s390, and are optimized out by the compiler, there
> is a small change in kernel size and this is what bloat-o-meter reports:

This looks pretty clean and straightfoward, only
__munlock_pagevec_fill() had any real increased complexity.

Thanks,
Jason

^ permalink raw reply

* Re: [PATCH] powerpc/64: Make VDSO32 track COMPAT on 64-bit
From: Christophe Leroy @ 2020-09-08 13:11 UTC (permalink / raw)
  To: Michael Ellerman, linuxppc-dev; +Cc: msuchanek
In-Reply-To: <20200908125850.407939-1-mpe@ellerman.id.au>



Le 08/09/2020 à 14:58, Michael Ellerman a écrit :
> When we added the VDSO32 kconfig symbol, which controls building of
> the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit).
> 
> That was because back then COMPAT was always enabled for 64-bit, so
> depending on it would have left the 32-bit VDSO always enabled, which
> we didn't want.
> 
> But since then we have made COMPAT selectable, and off by default for
> ppc64le, so VDSO32 should really depend on that.
> 
> For most people this makes no difference, none of the defconfigs
> change, it's only if someone is building ppc64le with COMPAT=y, they
> will now also get VDSO32. If they've enabled COMPAT in order to run
> 32-bit binaries they presumably also want the 32-bit VDSO.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>


Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>

Michael, please note that christophe.leroy@c-s.fr is a deprecated 
address that will one day not work anymore. Please use the new one 
whenever possible.

Christophe


> ---
>   arch/powerpc/platforms/Kconfig.cputype | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
> index 87737ec86d39..a80ad0ef436e 100644
> --- a/arch/powerpc/platforms/Kconfig.cputype
> +++ b/arch/powerpc/platforms/Kconfig.cputype
> @@ -490,13 +490,12 @@ endmenu
>   
>   config VDSO32
>   	def_bool y
> -	depends on PPC32 || CPU_BIG_ENDIAN
> +	depends on PPC32 || COMPAT
>   	help
>   	  This symbol controls whether we build the 32-bit VDSO. We obviously
>   	  want to do that if we're building a 32-bit kernel. If we're building
> -	  a 64-bit kernel then we only want a 32-bit VDSO if we're building for
> -	  big endian. That is because the only little endian configuration we
> -	  support is ppc64le which is 64-bit only.
> +	  a 64-bit kernel then we only want a 32-bit VDSO if we're also enabling
> +	  COMPAT.
>   
>   choice
>   	prompt "Endianness selection"
> 

^ permalink raw reply

* [PATCH] powerpc/64: Make VDSO32 track COMPAT on 64-bit
From: Michael Ellerman @ 2020-09-08 12:58 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: christophe.leroy, msuchanek

When we added the VDSO32 kconfig symbol, which controls building of
the 32-bit VDSO, we made it depend on CPU_BIG_ENDIAN (for 64-bit).

That was because back then COMPAT was always enabled for 64-bit, so
depending on it would have left the 32-bit VDSO always enabled, which
we didn't want.

But since then we have made COMPAT selectable, and off by default for
ppc64le, so VDSO32 should really depend on that.

For most people this makes no difference, none of the defconfigs
change, it's only if someone is building ppc64le with COMPAT=y, they
will now also get VDSO32. If they've enabled COMPAT in order to run
32-bit binaries they presumably also want the 32-bit VDSO.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/platforms/Kconfig.cputype | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 87737ec86d39..a80ad0ef436e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -490,13 +490,12 @@ endmenu
 
 config VDSO32
 	def_bool y
-	depends on PPC32 || CPU_BIG_ENDIAN
+	depends on PPC32 || COMPAT
 	help
 	  This symbol controls whether we build the 32-bit VDSO. We obviously
 	  want to do that if we're building a 32-bit kernel. If we're building
-	  a 64-bit kernel then we only want a 32-bit VDSO if we're building for
-	  big endian. That is because the only little endian configuration we
-	  support is ppc64le which is 64-bit only.
+	  a 64-bit kernel then we only want a 32-bit VDSO if we're also enabling
+	  COMPAT.
 
 choice
 	prompt "Endianness selection"
-- 
2.25.1


^ permalink raw reply related

* Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding
From: Christophe Leroy @ 2020-09-08 12:40 UTC (permalink / raw)
  To: Christian Borntraeger, Gerald Schaefer, Jason Gunthorpe,
	John Hubbard
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Alexander Gordeev, Claudio Imbrenda,
	Will Deacon, linux-arch, linux-s390, Vasily Gorbik,
	Richard Weinberger, linux-x86, Russell King, Ingo Molnar,
	Andrey Ryabinin, Jeff Dike, Arnd Bergmann, Heiko Carstens,
	linux-um, Borislav Petkov, Andy Lutomirski, Thomas Gleixner,
	linux-arm, Linus Torvalds, LKML, Andrew Morton, linux-power,
	Mike Rapoport
In-Reply-To: <70a3dcb5-5ed1-6efa-6158-d0573d6927da@de.ibm.com>



Le 08/09/2020 à 14:09, Christian Borntraeger a écrit :
> 
> 
> On 08.09.20 07:06, Christophe Leroy wrote:
>>
>>
>> Le 07/09/2020 à 20:00, Gerald Schaefer a écrit :
>>> From: Alexander Gordeev <agordeev@linux.ibm.com>
>>>
>>> Commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast
>>> code") introduced a subtle but severe bug on s390 with gup_fast, due to
>>> dynamic page table folding.
>>>
>>> The question "What would it require for the generic code to work for s390"
>>> has already been discussed here
>>> https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1
>>> and ended with a promising approach here
>>> https://lkml.kernel.org/r/20190419153307.4f2911b5@mschwideX1
>>> which in the end unfortunately didn't quite work completely.
>>>
>>> We tried to mimic static level folding by changing pgd_offset to always
>>> calculate top level page table offset, and do nothing in folded pXd_offset.
>>> What has been overlooked is that PxD_SIZE/MASK and thus pXd_addr_end do
>>> not reflect this dynamic behaviour, and still act like static 5-level
>>> page tables.
>>>
>>
>> [...]
>>
>>>
>>> Fix this by introducing new pXd_addr_end_folded helpers, which take an
>>> additional pXd entry value parameter, that can be used on s390
>>> to determine the correct page table level and return corresponding
>>> end / boundary. With that, the pointer iteration will always
>>> happen in gup_pgd_range for s390. No change for other architectures
>>> introduced.
>>
>> Not sure pXd_addr_end_folded() is the best understandable name, allthough I don't have any alternative suggestion at the moment.
>> Maybe could be something like pXd_addr_end_fixup() as it will disappear in the next patch, or pXd_addr_end_gup() ?
>>
>> Also, if it happens to be acceptable to get patch 2 in stable, I think you should switch patch 1 and patch 2 to avoid the step through pXd_addr_end_folded()
> 
> given that this fixes a data corruption issue, wouldnt it be the best to go forward
> with this patch ASAP and then handle the other patches on top with all the time that
> we need?

I have no strong opinion on this, but I feel rather tricky to have to 
change generic part of GUP to use a new fonction then revert that change 
in the following patch, just because you want the first patch in stable 
and not the second one.

Regardless, I was wondering, why do we need a reference to the pXd at 
all when calling pXd_addr_end() ?

Couldn't S390 retrieve the pXd by using the pXd_offset() dance with the 
passed addr ?

Christophe

^ permalink raw reply

* Re: [PATCH kernel] powerpc/dma: Fix dma_map_ops::get_required_mask
From: Christoph Hellwig @ 2020-09-08 12:19 UTC (permalink / raw)
  To: Alexey Kardashevskiy
  Cc: Oliver O'Halloran, linuxppc-dev, Christoph Hellwig,
	Cédric Le Goater
In-Reply-To: <94353228-2262-cfa1-7177-7eed2288ca63@ozlabs.ru>

On Tue, Sep 08, 2020 at 10:06:56PM +1000, Alexey Kardashevskiy wrote:
> On 08/09/2020 15:44, Christoph Hellwig wrote:
>> On Tue, Sep 08, 2020 at 11:51:06AM +1000, Alexey Kardashevskiy wrote:
>>> What is dma_get_required_mask() for anyway? What "requires" what here?
>>
>> Yes, it is a really odd API.  It comes from classic old PCI where
>> 64-bit addressing required an additional bus cycle, and various devices
>> had different addressing schemes, with the smaller addresses beeing
>> more efficient.  So this allows the driver to request the "required"
>> addressing mode to address all memory.  "preferred" might be a better
>> name as we'll bounce buffer if it isn't met.  I also don't really see
>> why a driver would ever want to use it for a modern PCIe device.
>
>
> a-ha, this makes more sense, thanks. Then I guess we need to revert that 
> one bit from yours f1565c24b596, do not we?

Why?  The was the original intent of the API, but now we also use
internally to check the addressing capabilities.

^ permalink raw reply

* Re: [RFC PATCH v2 1/3] mm/gup: fix gup_fast with dynamic page table folding
From: Christian Borntraeger @ 2020-09-08 12:09 UTC (permalink / raw)
  To: Christophe Leroy, Gerald Schaefer, Jason Gunthorpe, John Hubbard
  Cc: Peter Zijlstra, Catalin Marinas, Dave Hansen, linux-mm,
	Paul Mackerras, linux-sparc, Alexander Gordeev, Claudio Imbrenda,
	Will Deacon, linux-arch, linux-s390, Vasily Gorbik,
	Richard Weinberger, linux-x86, Russell King, Ingo Molnar,
	Andrey Ryabinin, Jeff Dike, Arnd Bergmann, Heiko Carstens,
	linux-um, Borislav Petkov, Andy Lutomirski, Thomas Gleixner,
	linux-arm, Linus Torvalds, LKML, Andrew Morton, linux-power,
	Mike Rapoport
In-Reply-To: <82fbe8f9-f199-5fc2-4168-eb43ad0b0346@csgroup.eu>



On 08.09.20 07:06, Christophe Leroy wrote:
> 
> 
> Le 07/09/2020 à 20:00, Gerald Schaefer a écrit :
>> From: Alexander Gordeev <agordeev@linux.ibm.com>
>>
>> Commit 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast
>> code") introduced a subtle but severe bug on s390 with gup_fast, due to
>> dynamic page table folding.
>>
>> The question "What would it require for the generic code to work for s390"
>> has already been discussed here
>> https://lkml.kernel.org/r/20190418100218.0a4afd51@mschwideX1
>> and ended with a promising approach here
>> https://lkml.kernel.org/r/20190419153307.4f2911b5@mschwideX1
>> which in the end unfortunately didn't quite work completely.
>>
>> We tried to mimic static level folding by changing pgd_offset to always
>> calculate top level page table offset, and do nothing in folded pXd_offset.
>> What has been overlooked is that PxD_SIZE/MASK and thus pXd_addr_end do
>> not reflect this dynamic behaviour, and still act like static 5-level
>> page tables.
>>
> 
> [...]
> 
>>
>> Fix this by introducing new pXd_addr_end_folded helpers, which take an
>> additional pXd entry value parameter, that can be used on s390
>> to determine the correct page table level and return corresponding
>> end / boundary. With that, the pointer iteration will always
>> happen in gup_pgd_range for s390. No change for other architectures
>> introduced.
> 
> Not sure pXd_addr_end_folded() is the best understandable name, allthough I don't have any alternative suggestion at the moment.
> Maybe could be something like pXd_addr_end_fixup() as it will disappear in the next patch, or pXd_addr_end_gup() ?
> 
> Also, if it happens to be acceptable to get patch 2 in stable, I think you should switch patch 1 and patch 2 to avoid the step through pXd_addr_end_folded()

given that this fixes a data corruption issue, wouldnt it be the best to go forward
with this patch ASAP and then handle the other patches on top with all the time that
we need?
> 
> 
>>
>> Fixes: 1a42010cdc26 ("s390/mm: convert to the generic get_user_pages_fast code")
>> Cc: <stable@vger.kernel.org> # 5.2+
>> Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
>> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
>> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
>> ---
>>   arch/s390/include/asm/pgtable.h | 42 +++++++++++++++++++++++++++++++++
>>   include/linux/pgtable.h         | 16 +++++++++++++
>>   mm/gup.c                        |  8 +++----
>>   3 files changed, 62 insertions(+), 4 deletions(-)
>>
>> diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
>> index 7eb01a5459cd..027206e4959d 100644
>> --- a/arch/s390/include/asm/pgtable.h
>> +++ b/arch/s390/include/asm/pgtable.h
>> @@ -512,6 +512,48 @@ static inline bool mm_pmd_folded(struct mm_struct *mm)
>>   }
>>   #define mm_pmd_folded(mm) mm_pmd_folded(mm)
>>   +/*
>> + * With dynamic page table levels on s390, the static pXd_addr_end() functions
>> + * will not return corresponding dynamic boundaries. This is no problem as long
>> + * as only pXd pointers are passed down during page table walk, because
>> + * pXd_offset() will simply return the given pointer for folded levels, and the
>> + * pointer iteration over a range simply happens at the correct page table
>> + * level.
>> + * It is however a problem with gup_fast, or other places walking the page
>> + * tables w/o locks using READ_ONCE(), and passing down the pXd values instead
>> + * of pointers. In this case, the pointer given to pXd_offset() is a pointer to
>> + * a stack variable, which cannot be used for pointer iteration at the correct
>> + * level. Instead, the iteration then has to happen by going up to pgd level
>> + * again. To allow this, provide pXd_addr_end_folded() functions with an
>> + * additional pXd value parameter, which can be used on s390 to determine the
>> + * folding level and return the corresponding boundary.
>> + */
>> +static inline unsigned long rste_addr_end_folded(unsigned long rste, unsigned long addr, unsigned long end)
> 
> What does 'rste' stands for ?
> 
> Isn't this line a bit long ?

this is region/segment table entry according to the architecture. 
On our platform we do have the pagetables with a different format that
next levels (segment table -> 1MB granularity, region 3rd table -> 2 GB
granularity, region 2nd table -> 4TB granularity, region 1st table -> 8 PB
granularity. ST,R3,R2,R1 have the same format and are thus often called
crste (combined region and segment table entry).

^ permalink raw reply

page: next (older) | prev (newer) | latest
- recent:[subjects (threaded)|topics (new)|topics (active)]

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox