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* [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs()
@ 2009-12-28  8:26 Pekka Enberg
  2009-12-28 10:07 ` [tip:x86/urgent] " tip-bot for Pekka Enberg
  2009-12-28 19:47 ` [RFC/PATCH] " Joe Perches
  0 siblings, 2 replies; 5+ messages in thread
From: Pekka Enberg @ 2009-12-28  8:26 UTC (permalink / raw)
  To: mingo; +Cc: vegard.nossum, akpm, x86, linux-kernel

From: Pekka Enberg <penberg@cs.helsinki.fi>

Andrew Morton reported a strange looking kmemcheck warning:

  WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20)
  0000000000000000310000000000000000000000000000002413000000c9ffff
   u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u

   [<ffffffff810af3aa>] kmemleak_scan+0x25a/0x540
   [<ffffffff810afbcb>] kmemleak_scan_thread+0x5b/0xe0
   [<ffffffff8104d0fe>] kthread+0x9e/0xb0
   [<ffffffff81003074>] kernel_thread_helper+0x4/0x10
   [<ffffffffffffffff>] 0xffffffffffffffff

The above printout is missing register dump completely. The problem here is
that the output comes from syslog which doesn't show KERN_INFO log-level
messages. We didn't see this before because both of us were testing on 32-bit
kernels which use the _default_ log-level.

Fix that up by explicitly using KERN_DEFAULT log-level for __show_regs()
printks.

Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
---
 arch/x86/kernel/process.c    |    4 ++--
 arch/x86/kernel/process_32.c |   14 +++++++-------
 arch/x86/kernel/process_64.c |   24 ++++++++++++------------
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 98c2cde..c6ee241 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -103,8 +103,8 @@ void show_regs_common(void)
 	if (!product)
 		product = "";
 
-	printk("\n");
-	printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
+	printk(KERN_CONT "\n");
+	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
 		current->pid, current->comm, print_tainted(),
 		init_utsname()->release,
 		(int)strcspn(init_utsname()->version, " "),
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 9c517b5..37ad1e0 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -139,16 +139,16 @@ void __show_regs(struct pt_regs *regs, int all)
 
 	show_regs_common();
 
-	printk("EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
+	printk(KERN_DEFAULT "EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
 			(u16)regs->cs, regs->ip, regs->flags,
 			smp_processor_id());
 	print_symbol("EIP is at %s\n", regs->ip);
 
-	printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
+	printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
 		regs->ax, regs->bx, regs->cx, regs->dx);
-	printk("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
+	printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
 		regs->si, regs->di, regs->bp, sp);
-	printk(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
+	printk(KERN_DEFAULT " DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
 	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);
 
 	if (!all)
@@ -158,19 +158,19 @@ void __show_regs(struct pt_regs *regs, int all)
 	cr2 = read_cr2();
 	cr3 = read_cr3();
 	cr4 = read_cr4_safe();
-	printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
+	printk(KERN_DEFAULT "CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
 			cr0, cr2, cr3, cr4);
 
 	get_debugreg(d0, 0);
 	get_debugreg(d1, 1);
 	get_debugreg(d2, 2);
 	get_debugreg(d3, 3);
-	printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
+	printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
 			d0, d1, d2, d3);
 
 	get_debugreg(d6, 6);
 	get_debugreg(d7, 7);
-	printk("DR6: %08lx DR7: %08lx\n",
+	printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n",
 			d6, d7);
 }
 
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 52fbd0c..f9e0331 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -161,19 +161,19 @@ void __show_regs(struct pt_regs *regs, int all)
 	unsigned int ds, cs, es;
 
 	show_regs_common();
-	printk(KERN_INFO "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
+	printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
 	printk_address(regs->ip, 1);
-	printk(KERN_INFO "RSP: %04lx:%016lx  EFLAGS: %08lx\n", regs->ss,
+	printk(KERN_DEFAULT "RSP: %04lx:%016lx  EFLAGS: %08lx\n", regs->ss,
 			regs->sp, regs->flags);
-	printk(KERN_INFO "RAX: %016lx RBX: %016lx RCX: %016lx\n",
+	printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
 	       regs->ax, regs->bx, regs->cx);
-	printk(KERN_INFO "RDX: %016lx RSI: %016lx RDI: %016lx\n",
+	printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
 	       regs->dx, regs->si, regs->di);
-	printk(KERN_INFO "RBP: %016lx R08: %016lx R09: %016lx\n",
+	printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n",
 	       regs->bp, regs->r8, regs->r9);
-	printk(KERN_INFO "R10: %016lx R11: %016lx R12: %016lx\n",
+	printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n",
 	       regs->r10, regs->r11, regs->r12);
-	printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
+	printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n",
 	       regs->r13, regs->r14, regs->r15);
 
 	asm("movl %%ds,%0" : "=r" (ds));
@@ -194,21 +194,21 @@ void __show_regs(struct pt_regs *regs, int all)
 	cr3 = read_cr3();
 	cr4 = read_cr4();
 
-	printk(KERN_INFO "FS:  %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
+	printk(KERN_DEFAULT "FS:  %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
 	       fs, fsindex, gs, gsindex, shadowgs);
-	printk(KERN_INFO "CS:  %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
+	printk(KERN_DEFAULT "CS:  %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
 			es, cr0);
-	printk(KERN_INFO "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
+	printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
 			cr4);
 
 	get_debugreg(d0, 0);
 	get_debugreg(d1, 1);
 	get_debugreg(d2, 2);
-	printk(KERN_INFO "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
+	printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
 	get_debugreg(d3, 3);
 	get_debugreg(d6, 6);
 	get_debugreg(d7, 7);
-	printk(KERN_INFO "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
+	printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
 }
 
 void show_regs(struct pt_regs *regs)
-- 
1.6.0.4




^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [tip:x86/urgent] x86: Use KERN_DEFAULT log-level in __show_regs()
  2009-12-28  8:26 [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs() Pekka Enberg
@ 2009-12-28 10:07 ` tip-bot for Pekka Enberg
  2009-12-28 19:47 ` [RFC/PATCH] " Joe Perches
  1 sibling, 0 replies; 5+ messages in thread
From: tip-bot for Pekka Enberg @ 2009-12-28 10:07 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: linux-kernel, hpa, mingo, torvalds, penberg, vegard.nossum, arjan,
	akpm, tglx, mingo

Commit-ID:  d015a092989d673df44a5ad6866dc5d5006b7a2a
Gitweb:     http://git.kernel.org/tip/d015a092989d673df44a5ad6866dc5d5006b7a2a
Author:     Pekka Enberg <penberg@cs.helsinki.fi>
AuthorDate: Mon, 28 Dec 2009 10:26:59 +0200
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 28 Dec 2009 09:40:21 +0100

x86: Use KERN_DEFAULT log-level in __show_regs()

Andrew Morton reported a strange looking kmemcheck warning:

  WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20)
  0000000000000000310000000000000000000000000000002413000000c9ffff
   u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u

   [<ffffffff810af3aa>] kmemleak_scan+0x25a/0x540
   [<ffffffff810afbcb>] kmemleak_scan_thread+0x5b/0xe0
   [<ffffffff8104d0fe>] kthread+0x9e/0xb0
   [<ffffffff81003074>] kernel_thread_helper+0x4/0x10
   [<ffffffffffffffff>] 0xffffffffffffffff

The above printout is missing register dump completely. The
problem here is that the output comes from syslog which doesn't
show KERN_INFO log-level messages. We didn't see this before
because both of us were testing on 32-bit kernels which use the
_default_ log-level.

Fix that up by explicitly using KERN_DEFAULT log-level for
__show_regs() printks.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1261988819.4641.2.camel@penberg-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/process.c    |    4 ++--
 arch/x86/kernel/process_32.c |   14 +++++++-------
 arch/x86/kernel/process_64.c |   24 ++++++++++++------------
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 98c2cde..c6ee241 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -103,8 +103,8 @@ void show_regs_common(void)
 	if (!product)
 		product = "";
 
-	printk("\n");
-	printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
+	printk(KERN_CONT "\n");
+	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
 		current->pid, current->comm, print_tainted(),
 		init_utsname()->release,
 		(int)strcspn(init_utsname()->version, " "),
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 9c517b5..37ad1e0 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -139,16 +139,16 @@ void __show_regs(struct pt_regs *regs, int all)
 
 	show_regs_common();
 
-	printk("EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
+	printk(KERN_DEFAULT "EIP: %04x:[<%08lx>] EFLAGS: %08lx CPU: %d\n",
 			(u16)regs->cs, regs->ip, regs->flags,
 			smp_processor_id());
 	print_symbol("EIP is at %s\n", regs->ip);
 
-	printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
+	printk(KERN_DEFAULT "EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
 		regs->ax, regs->bx, regs->cx, regs->dx);
-	printk("ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
+	printk(KERN_DEFAULT "ESI: %08lx EDI: %08lx EBP: %08lx ESP: %08lx\n",
 		regs->si, regs->di, regs->bp, sp);
-	printk(" DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
+	printk(KERN_DEFAULT " DS: %04x ES: %04x FS: %04x GS: %04x SS: %04x\n",
 	       (u16)regs->ds, (u16)regs->es, (u16)regs->fs, gs, ss);
 
 	if (!all)
@@ -158,19 +158,19 @@ void __show_regs(struct pt_regs *regs, int all)
 	cr2 = read_cr2();
 	cr3 = read_cr3();
 	cr4 = read_cr4_safe();
-	printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
+	printk(KERN_DEFAULT "CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n",
 			cr0, cr2, cr3, cr4);
 
 	get_debugreg(d0, 0);
 	get_debugreg(d1, 1);
 	get_debugreg(d2, 2);
 	get_debugreg(d3, 3);
-	printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
+	printk(KERN_DEFAULT "DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
 			d0, d1, d2, d3);
 
 	get_debugreg(d6, 6);
 	get_debugreg(d7, 7);
-	printk("DR6: %08lx DR7: %08lx\n",
+	printk(KERN_DEFAULT "DR6: %08lx DR7: %08lx\n",
 			d6, d7);
 }
 
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 52fbd0c..f9e0331 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -161,19 +161,19 @@ void __show_regs(struct pt_regs *regs, int all)
 	unsigned int ds, cs, es;
 
 	show_regs_common();
-	printk(KERN_INFO "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
+	printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
 	printk_address(regs->ip, 1);
-	printk(KERN_INFO "RSP: %04lx:%016lx  EFLAGS: %08lx\n", regs->ss,
+	printk(KERN_DEFAULT "RSP: %04lx:%016lx  EFLAGS: %08lx\n", regs->ss,
 			regs->sp, regs->flags);
-	printk(KERN_INFO "RAX: %016lx RBX: %016lx RCX: %016lx\n",
+	printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
 	       regs->ax, regs->bx, regs->cx);
-	printk(KERN_INFO "RDX: %016lx RSI: %016lx RDI: %016lx\n",
+	printk(KERN_DEFAULT "RDX: %016lx RSI: %016lx RDI: %016lx\n",
 	       regs->dx, regs->si, regs->di);
-	printk(KERN_INFO "RBP: %016lx R08: %016lx R09: %016lx\n",
+	printk(KERN_DEFAULT "RBP: %016lx R08: %016lx R09: %016lx\n",
 	       regs->bp, regs->r8, regs->r9);
-	printk(KERN_INFO "R10: %016lx R11: %016lx R12: %016lx\n",
+	printk(KERN_DEFAULT "R10: %016lx R11: %016lx R12: %016lx\n",
 	       regs->r10, regs->r11, regs->r12);
-	printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
+	printk(KERN_DEFAULT "R13: %016lx R14: %016lx R15: %016lx\n",
 	       regs->r13, regs->r14, regs->r15);
 
 	asm("movl %%ds,%0" : "=r" (ds));
@@ -194,21 +194,21 @@ void __show_regs(struct pt_regs *regs, int all)
 	cr3 = read_cr3();
 	cr4 = read_cr4();
 
-	printk(KERN_INFO "FS:  %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
+	printk(KERN_DEFAULT "FS:  %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
 	       fs, fsindex, gs, gsindex, shadowgs);
-	printk(KERN_INFO "CS:  %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
+	printk(KERN_DEFAULT "CS:  %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
 			es, cr0);
-	printk(KERN_INFO "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
+	printk(KERN_DEFAULT "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
 			cr4);
 
 	get_debugreg(d0, 0);
 	get_debugreg(d1, 1);
 	get_debugreg(d2, 2);
-	printk(KERN_INFO "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
+	printk(KERN_DEFAULT "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
 	get_debugreg(d3, 3);
 	get_debugreg(d6, 6);
 	get_debugreg(d7, 7);
-	printk(KERN_INFO "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
+	printk(KERN_DEFAULT "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
 }
 
 void show_regs(struct pt_regs *regs)

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs()
  2009-12-28  8:26 [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs() Pekka Enberg
  2009-12-28 10:07 ` [tip:x86/urgent] " tip-bot for Pekka Enberg
@ 2009-12-28 19:47 ` Joe Perches
  2009-12-29  7:08   ` Pekka Enberg
  1 sibling, 1 reply; 5+ messages in thread
From: Joe Perches @ 2009-12-28 19:47 UTC (permalink / raw)
  To: Pekka Enberg; +Cc: mingo, vegard.nossum, akpm, x86, linux-kernel

On Mon, 2009-12-28 at 10:26 +0200, Pekka Enberg wrote:
> From: Pekka Enberg <penberg@cs.helsinki.fi>
> 
> Andrew Morton reported a strange looking kmemcheck warning:
> 
>   WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20)
>   0000000000000000310000000000000000000000000000002413000000c9ffff
>    u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u
> 
>    [<ffffffff810af3aa>] kmemleak_scan+0x25a/0x540
>    [<ffffffff810afbcb>] kmemleak_scan_thread+0x5b/0xe0
>    [<ffffffff8104d0fe>] kthread+0x9e/0xb0
>    [<ffffffff81003074>] kernel_thread_helper+0x4/0x10
>    [<ffffffffffffffff>] 0xffffffffffffffff
> 
> The above printout is missing register dump completely. The problem here is
> that the output comes from syslog which doesn't show KERN_INFO log-level
> messages. We didn't see this before because both of us were testing on 32-bit
> kernels which use the _default_ log-level.
> 
> Fix that up by explicitly using KERN_DEFAULT log-level for __show_regs()
> printks.
> 
> Cc: Vegard Nossum <vegard.nossum@gmail.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
> ---
>  arch/x86/kernel/process.c    |    4 ++--
>  arch/x86/kernel/process_32.c |   14 +++++++-------
>  arch/x86/kernel/process_64.c |   24 ++++++++++++------------
>  3 files changed, 21 insertions(+), 21 deletions(-)
> 
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index 98c2cde..c6ee241 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -103,8 +103,8 @@ void show_regs_common(void)
>  	if (!product)
>  		product = "";
>  
> -	printk("\n");
> -	printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
> +	printk(KERN_CONT "\n");
> +	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",

What is the reason to convert KERN_INFO to KERN_DEFAULT here?

The original commit for KERN_DEFAULT said:

    This adds a KERN_DEFAULT loglevel marker, for when you cannot decide
    which loglevel you want, and just want to keep an existing printk
    with the default loglevel.
    
    The difference between having KERN_DEFAULT and having no log-level
    marker at all is two-fold:
    
     - having the log-level marker will now force a new-line if the
       previous printout had not added one (perhaps because it forgot,
       but perhaps because it expected a continuation)
    
     - having a log-level marker is required if you are printing out a
       message that otherwise itself could perhaps otherwise be mistaken
       for a log-level.



^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs()
  2009-12-28 19:47 ` [RFC/PATCH] " Joe Perches
@ 2009-12-29  7:08   ` Pekka Enberg
       [not found]     ` <1262072421.1888.57.camel@Joe-Laptop.home>
  0 siblings, 1 reply; 5+ messages in thread
From: Pekka Enberg @ 2009-12-29  7:08 UTC (permalink / raw)
  To: Joe Perches; +Cc: mingo, vegard.nossum, akpm, x86, linux-kernel

Joe Perches kirjoitti:
> On Mon, 2009-12-28 at 10:26 +0200, Pekka Enberg wrote:
>> From: Pekka Enberg <penberg@cs.helsinki.fi>
>>
>> Andrew Morton reported a strange looking kmemcheck warning:
>>
>>   WARNING: kmemcheck: Caught 32-bit read from uninitialized memory (ffff88004fba6c20)
>>   0000000000000000310000000000000000000000000000002413000000c9ffff
>>    u u u u u u u u u u u u u u u u i i i i i i i i u u u u u u u u
>>
>>    [<ffffffff810af3aa>] kmemleak_scan+0x25a/0x540
>>    [<ffffffff810afbcb>] kmemleak_scan_thread+0x5b/0xe0
>>    [<ffffffff8104d0fe>] kthread+0x9e/0xb0
>>    [<ffffffff81003074>] kernel_thread_helper+0x4/0x10
>>    [<ffffffffffffffff>] 0xffffffffffffffff
>>
>> The above printout is missing register dump completely. The problem here is
>> that the output comes from syslog which doesn't show KERN_INFO log-level
>> messages. We didn't see this before because both of us were testing on 32-bit
>> kernels which use the _default_ log-level.
>>
>> Fix that up by explicitly using KERN_DEFAULT log-level for __show_regs()
>> printks.
>>
>> Cc: Vegard Nossum <vegard.nossum@gmail.com>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
>> ---
>>  arch/x86/kernel/process.c    |    4 ++--
>>  arch/x86/kernel/process_32.c |   14 +++++++-------
>>  arch/x86/kernel/process_64.c |   24 ++++++++++++------------
>>  3 files changed, 21 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
>> index 98c2cde..c6ee241 100644
>> --- a/arch/x86/kernel/process.c
>> +++ b/arch/x86/kernel/process.c
>> @@ -103,8 +103,8 @@ void show_regs_common(void)
>>  	if (!product)
>>  		product = "";
>>  
>> -	printk("\n");
>> -	printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
>> +	printk(KERN_CONT "\n");
>> +	printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
> 
> What is the reason to convert KERN_INFO to KERN_DEFAULT here?

To be consistent with rest of __show_regs() log-levels.

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs()
       [not found]     ` <1262072421.1888.57.camel@Joe-Laptop.home>
@ 2009-12-29  7:47       ` Pekka Enberg
  0 siblings, 0 replies; 5+ messages in thread
From: Pekka Enberg @ 2009-12-29  7:47 UTC (permalink / raw)
  To: Joe Perches, Ingo Molnar, Vegard Nossum, LKML, x86, Andrew Morton

Hi Joe,

[ I'm restoring CC, dunno if I broke accidentally. ]

Joe Perches kirjoitti:
> On Tue, 2009-12-29 at 09:08 +0200, Pekka Enberg wrote:
>> Joe Perches kirjoitti:
>>> What is the reason to convert KERN_INFO to KERN_DEFAULT here?
>> To be consistent with rest of __show_regs() log-levels.
> 
> What log level is DEFAULT?
> 
> It's default 4 or WARNING, but I'd guess you had to
> look to find it.
> 
> Does anyone override it?
> 
> Why not simply specify KERN_WARNING for all of them?

For the reasons outlined here:

> from:
> $ git log -1 e28d713704117bca0820c732210df6075b09f13b
> This adds a KERN_DEFAULT loglevel marker, for when you cannot decide
> which loglevel you want, and just want to keep an existing printk
> with the default loglevel.

The whole point of the patch is to unify 32-bit and 64-bit wrt 
log-levels. The 32-bit version _is_ using KERN_DEFAULT implicitly and 
KERN_INFO is arguably wrong which is why I decided to go with the 
former. That way I don't need to go and audit all the callers of 
__show_regs() to see if KERN_WARN or some other level makes sense for them.

			Pekka

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2009-12-29  7:47 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-12-28  8:26 [RFC/PATCH] x86: Use KERN_DEFAULT log-level in __show_regs() Pekka Enberg
2009-12-28 10:07 ` [tip:x86/urgent] " tip-bot for Pekka Enberg
2009-12-28 19:47 ` [RFC/PATCH] " Joe Perches
2009-12-29  7:08   ` Pekka Enberg
     [not found]     ` <1262072421.1888.57.camel@Joe-Laptop.home>
2009-12-29  7:47       ` Pekka Enberg

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