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* [PATCH] tracing/trace_stack: Fix stack trace on ppc64
@ 2010-08-25  1:32 Anton Blanchard
  2010-08-25 12:58 ` [tip:perf/urgent] " tip-bot for Anton Blanchard
  2010-08-31  1:31 ` [PATCH] " Steven Rostedt
  0 siblings, 2 replies; 7+ messages in thread
From: Anton Blanchard @ 2010-08-25  1:32 UTC (permalink / raw)
  To: rostedt, fweisbec, mingo; +Cc: linux-kernel


save_stack_trace() stores the instruction pointer, not the function
descriptor. On ppc64 the trace stack code currently dereferences the
instruction pointer and shows 8 bytes of instructions in our backtraces:

# cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   0x6000000048000004
  1)     5312     160   0x60000000ebad01b0
  2)     5152     160   0x2c23000041c20030
  3)     4992     240   0x600000007c781b79
  4)     4752     160   0xe84100284800000c
  5)     4592     192   0x600000002fa30000
  6)     4400     256   0x7f1800347b7407e0
  7)     4144     208   0xe89f0108f87f0070
  8)     3936     272   0xe84100282fa30000

Since we aren't dealing with function descriptors, use %pS instead of %pF
to fix it:

# cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   ftrace_call+0x4/0x8
  1)     5312     160   .current_io_context+0x28/0x74
  2)     5152     160   .get_io_context+0x48/0xa0
  3)     4992     240   .cfq_set_request+0x94/0x4c4
  4)     4752     160   .elv_set_request+0x60/0x84
  5)     4592     192   .get_request+0x2d4/0x468
  6)     4400     256   .get_request_wait+0x7c/0x258
  7)     4144     208   .__make_request+0x49c/0x610
  8)     3936     272   .generic_make_request+0x390/0x434

Signed-off-by: Anton Blanchard <anton@samba.org>
---

Index: powerpc.git/kernel/trace/trace_stack.c
===================================================================
--- powerpc.git.orig/kernel/trace/trace_stack.c	2010-08-25 11:03:52.337982567 +1000
+++ powerpc.git/kernel/trace/trace_stack.c	2010-08-25 11:03:55.018371055 +1000
@@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq
 {
 	unsigned long addr = stack_dump_trace[i];
 
-	return seq_printf(m, "%pF\n", (void *)addr);
+	return seq_printf(m, "%pS\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [tip:perf/urgent] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-25  1:32 [PATCH] tracing/trace_stack: Fix stack trace on ppc64 Anton Blanchard
@ 2010-08-25 12:58 ` tip-bot for Anton Blanchard
  2010-08-31  1:31 ` [PATCH] " Steven Rostedt
  1 sibling, 0 replies; 7+ messages in thread
From: tip-bot for Anton Blanchard @ 2010-08-25 12:58 UTC (permalink / raw)
  To: linux-tip-commits; +Cc: linux-kernel, anton, hpa, mingo, tglx, mingo

Commit-ID:  151772dbfad4dbe81721e40f9b3d588ea77bb7aa
Gitweb:     http://git.kernel.org/tip/151772dbfad4dbe81721e40f9b3d588ea77bb7aa
Author:     Anton Blanchard <anton@samba.org>
AuthorDate: Wed, 25 Aug 2010 11:32:38 +1000
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 25 Aug 2010 13:08:48 +0200

tracing/trace_stack: Fix stack trace on ppc64

save_stack_trace() stores the instruction pointer, not the
function descriptor. On ppc64 the trace stack code currently
dereferences the instruction pointer and shows 8 bytes of
instructions in our backtraces:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   0x6000000048000004
  1)     5312     160   0x60000000ebad01b0
  2)     5152     160   0x2c23000041c20030
  3)     4992     240   0x600000007c781b79
  4)     4752     160   0xe84100284800000c
  5)     4592     192   0x600000002fa30000
  6)     4400     256   0x7f1800347b7407e0
  7)     4144     208   0xe89f0108f87f0070
  8)     3936     272   0xe84100282fa30000

Since we aren't dealing with function descriptors, use %pS
instead of %pF to fix it:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   ftrace_call+0x4/0x8
  1)     5312     160   .current_io_context+0x28/0x74
  2)     5152     160   .get_io_context+0x48/0xa0
  3)     4992     240   .cfq_set_request+0x94/0x4c4
  4)     4752     160   .elv_set_request+0x60/0x84
  5)     4592     192   .get_request+0x2d4/0x468
  6)     4400     256   .get_request_wait+0x7c/0x258
  7)     4144     208   .__make_request+0x49c/0x610
  8)     3936     272   .generic_make_request+0x390/0x434

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
LKML-Reference: <20100825013238.GE28360@kryten>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_stack.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 056468e..a6b7e0e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 {
 	unsigned long addr = stack_dump_trace[i];
 
-	return seq_printf(m, "%pF\n", (void *)addr);
+	return seq_printf(m, "%pS\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)

^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-25  1:32 [PATCH] tracing/trace_stack: Fix stack trace on ppc64 Anton Blanchard
  2010-08-25 12:58 ` [tip:perf/urgent] " tip-bot for Anton Blanchard
@ 2010-08-31  1:31 ` Steven Rostedt
  2010-08-31 14:21   ` Frederic Weisbecker
  1 sibling, 1 reply; 7+ messages in thread
From: Steven Rostedt @ 2010-08-31  1:31 UTC (permalink / raw)
  To: Anton Blanchard; +Cc: fweisbec, mingo, linux-kernel

On Wed, 2010-08-25 at 11:32 +1000, Anton Blanchard wrote:
> save_stack_trace() stores the instruction pointer, not the function
> descriptor. On ppc64 the trace stack code currently dereferences the
> instruction pointer and shows 8 bytes of instructions in our backtraces:
> 
> # cat /sys/kernel/debug/tracing/stack_trace
>         Depth    Size   Location    (26 entries)
>         -----    ----   --------
>   0)     5424     112   0x6000000048000004
>   1)     5312     160   0x60000000ebad01b0
>   2)     5152     160   0x2c23000041c20030
>   3)     4992     240   0x600000007c781b79
>   4)     4752     160   0xe84100284800000c
>   5)     4592     192   0x600000002fa30000
>   6)     4400     256   0x7f1800347b7407e0
>   7)     4144     208   0xe89f0108f87f0070
>   8)     3936     272   0xe84100282fa30000
> 
> Since we aren't dealing with function descriptors, use %pS instead of %pF
> to fix it:
> 
> # cat /sys/kernel/debug/tracing/stack_trace
>         Depth    Size   Location    (26 entries)
>         -----    ----   --------
>   0)     5424     112   ftrace_call+0x4/0x8
>   1)     5312     160   .current_io_context+0x28/0x74
>   2)     5152     160   .get_io_context+0x48/0xa0
>   3)     4992     240   .cfq_set_request+0x94/0x4c4
>   4)     4752     160   .elv_set_request+0x60/0x84
>   5)     4592     192   .get_request+0x2d4/0x468
>   6)     4400     256   .get_request_wait+0x7c/0x258
>   7)     4144     208   .__make_request+0x49c/0x610
>   8)     3936     272   .generic_make_request+0x390/0x434
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>

Thanks, I'll test this to make sure it doesn't break x86, and then push
it into a stable/-rc patch queue.

-- Steve

> ---
> 
> Index: powerpc.git/kernel/trace/trace_stack.c
> ===================================================================
> --- powerpc.git.orig/kernel/trace/trace_stack.c	2010-08-25 11:03:52.337982567 +1000
> +++ powerpc.git/kernel/trace/trace_stack.c	2010-08-25 11:03:55.018371055 +1000
> @@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq
>  {
>  	unsigned long addr = stack_dump_trace[i];
>  
> -	return seq_printf(m, "%pF\n", (void *)addr);
> +	return seq_printf(m, "%pS\n", (void *)addr);
>  }
>  
>  static void print_disabled(struct seq_file *m)



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-31  1:31 ` [PATCH] " Steven Rostedt
@ 2010-08-31 14:21   ` Frederic Weisbecker
  2010-08-31 14:58     ` Steven Rostedt
  0 siblings, 1 reply; 7+ messages in thread
From: Frederic Weisbecker @ 2010-08-31 14:21 UTC (permalink / raw)
  To: Steven Rostedt; +Cc: Anton Blanchard, mingo, linux-kernel

On Mon, Aug 30, 2010 at 09:31:50PM -0400, Steven Rostedt wrote:
> On Wed, 2010-08-25 at 11:32 +1000, Anton Blanchard wrote:
> > save_stack_trace() stores the instruction pointer, not the function
> > descriptor. On ppc64 the trace stack code currently dereferences the
> > instruction pointer and shows 8 bytes of instructions in our backtraces:
> > 
> > # cat /sys/kernel/debug/tracing/stack_trace
> >         Depth    Size   Location    (26 entries)
> >         -----    ----   --------
> >   0)     5424     112   0x6000000048000004
> >   1)     5312     160   0x60000000ebad01b0
> >   2)     5152     160   0x2c23000041c20030
> >   3)     4992     240   0x600000007c781b79
> >   4)     4752     160   0xe84100284800000c
> >   5)     4592     192   0x600000002fa30000
> >   6)     4400     256   0x7f1800347b7407e0
> >   7)     4144     208   0xe89f0108f87f0070
> >   8)     3936     272   0xe84100282fa30000
> > 
> > Since we aren't dealing with function descriptors, use %pS instead of %pF
> > to fix it:
> > 
> > # cat /sys/kernel/debug/tracing/stack_trace
> >         Depth    Size   Location    (26 entries)
> >         -----    ----   --------
> >   0)     5424     112   ftrace_call+0x4/0x8
> >   1)     5312     160   .current_io_context+0x28/0x74
> >   2)     5152     160   .get_io_context+0x48/0xa0
> >   3)     4992     240   .cfq_set_request+0x94/0x4c4
> >   4)     4752     160   .elv_set_request+0x60/0x84
> >   5)     4592     192   .get_request+0x2d4/0x468
> >   6)     4400     256   .get_request_wait+0x7c/0x258
> >   7)     4144     208   .__make_request+0x49c/0x610
> >   8)     3936     272   .generic_make_request+0x390/0x434
> > 
> > Signed-off-by: Anton Blanchard <anton@samba.org>
> 
> Thanks, I'll test this to make sure it doesn't break x86, and then push
> it into a stable/-rc patch queue.
> 
> -- Steve


Ingo has applied it already in perf/urgent.

Thanks.


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-31 14:21   ` Frederic Weisbecker
@ 2010-08-31 14:58     ` Steven Rostedt
  2010-08-31 15:14       ` Frederic Weisbecker
  0 siblings, 1 reply; 7+ messages in thread
From: Steven Rostedt @ 2010-08-31 14:58 UTC (permalink / raw)
  To: Frederic Weisbecker; +Cc: Anton Blanchard, mingo, linux-kernel

On Tue, 2010-08-31 at 16:21 +0200, Frederic Weisbecker wrote:
> On Mon, Aug 30, 2010 at 09:31:50PM -0400, Steven Rostedt wrote:
> > On Wed, 2010-08-25 at 11:32 +1000, Anton Blanchard wrote:
> > > save_stack_trace() stores the instruction pointer, not the function
> > > descriptor. On ppc64 the trace stack code currently dereferences the
> > > instruction pointer and shows 8 bytes of instructions in our backtraces:
> > > 
> > > # cat /sys/kernel/debug/tracing/stack_trace
> > >         Depth    Size   Location    (26 entries)
> > >         -----    ----   --------
> > >   0)     5424     112   0x6000000048000004
> > >   1)     5312     160   0x60000000ebad01b0
> > >   2)     5152     160   0x2c23000041c20030
> > >   3)     4992     240   0x600000007c781b79
> > >   4)     4752     160   0xe84100284800000c
> > >   5)     4592     192   0x600000002fa30000
> > >   6)     4400     256   0x7f1800347b7407e0
> > >   7)     4144     208   0xe89f0108f87f0070
> > >   8)     3936     272   0xe84100282fa30000
> > > 
> > > Since we aren't dealing with function descriptors, use %pS instead of %pF
> > > to fix it:
> > > 
> > > # cat /sys/kernel/debug/tracing/stack_trace
> > >         Depth    Size   Location    (26 entries)
> > >         -----    ----   --------
> > >   0)     5424     112   ftrace_call+0x4/0x8
> > >   1)     5312     160   .current_io_context+0x28/0x74
> > >   2)     5152     160   .get_io_context+0x48/0xa0
> > >   3)     4992     240   .cfq_set_request+0x94/0x4c4
> > >   4)     4752     160   .elv_set_request+0x60/0x84
> > >   5)     4592     192   .get_request+0x2d4/0x468
> > >   6)     4400     256   .get_request_wait+0x7c/0x258
> > >   7)     4144     208   .__make_request+0x49c/0x610
> > >   8)     3936     272   .generic_make_request+0x390/0x434
> > > 
> > > Signed-off-by: Anton Blanchard <anton@samba.org>
> > 
> > Thanks, I'll test this to make sure it doesn't break x86, and then push
> > it into a stable/-rc patch queue.
> > 
> > -- Steve
> 
> 
> Ingo has applied it already in perf/urgent.

Hmm, I never saw the tip-bot reply :-(

I guess it only sends to the Cc tags.

-- Steve



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-31 14:58     ` Steven Rostedt
@ 2010-08-31 15:14       ` Frederic Weisbecker
  2010-08-31 17:36         ` Ingo Molnar
  0 siblings, 1 reply; 7+ messages in thread
From: Frederic Weisbecker @ 2010-08-31 15:14 UTC (permalink / raw)
  To: Steven Rostedt; +Cc: Anton Blanchard, mingo, linux-kernel

On Tue, Aug 31, 2010 at 10:58:42AM -0400, Steven Rostedt wrote:
> Hmm, I never saw the tip-bot reply :-(
> 
> I guess it only sends to the Cc tags.
> 
> -- Steve
> 
> 


We were in the commit Cc tags but somehow they didn't make it in the email
tags.

Here is the tip-bot email:

---
Commit-ID:  151772dbfad4dbe81721e40f9b3d588ea77bb7aa
Gitweb:     http://git.kernel.org/tip/151772dbfad4dbe81721e40f9b3d588ea77bb7aa
Author:     Anton Blanchard <anton@samba.org>
AuthorDate: Wed, 25 Aug 2010 11:32:38 +1000
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 25 Aug 2010 13:08:48 +0200

tracing/trace_stack: Fix stack trace on ppc64

save_stack_trace() stores the instruction pointer, not the
function descriptor. On ppc64 the trace stack code currently
dereferences the instruction pointer and shows 8 bytes of
instructions in our backtraces:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   0x6000000048000004
  1)     5312     160   0x60000000ebad01b0
  2)     5152     160   0x2c23000041c20030
  3)     4992     240   0x600000007c781b79
  4)     4752     160   0xe84100284800000c
  5)     4592     192   0x600000002fa30000
  6)     4400     256   0x7f1800347b7407e0
  7)     4144     208   0xe89f0108f87f0070
  8)     3936     272   0xe84100282fa30000

Since we aren't dealing with function descriptors, use %pS
instead of %pF to fix it:

 # cat /sys/kernel/debug/tracing/stack_trace
        Depth    Size   Location    (26 entries)
        -----    ----   --------
  0)     5424     112   ftrace_call+0x4/0x8
  1)     5312     160   .current_io_context+0x28/0x74
  2)     5152     160   .get_io_context+0x48/0xa0
  3)     4992     240   .cfq_set_request+0x94/0x4c4
  4)     4752     160   .elv_set_request+0x60/0x84
  5)     4592     192   .get_request+0x2d4/0x468
  6)     4400     256   .get_request_wait+0x7c/0x258
  7)     4144     208   .__make_request+0x49c/0x610
  8)     3936     272   .generic_make_request+0x390/0x434

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: rostedt@goodmis.org
Cc: fweisbec@gmail.com
LKML-Reference: <20100825013238.GE28360@kryten>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_stack.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 056468e..a6b7e0e 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -249,7 +249,7 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 {
 	unsigned long addr = stack_dump_trace[i];
 
-	return seq_printf(m, "%pF\n", (void *)addr);
+	return seq_printf(m, "%pS\n", (void *)addr);
 }
 
 static void print_disabled(struct seq_file *m)
--
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^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] tracing/trace_stack: Fix stack trace on ppc64
  2010-08-31 15:14       ` Frederic Weisbecker
@ 2010-08-31 17:36         ` Ingo Molnar
  0 siblings, 0 replies; 7+ messages in thread
From: Ingo Molnar @ 2010-08-31 17:36 UTC (permalink / raw)
  To: Frederic Weisbecker; +Cc: Steven Rostedt, Anton Blanchard, mingo, linux-kernel


* Frederic Weisbecker <fweisbec@gmail.com> wrote:

> On Tue, Aug 31, 2010 at 10:58:42AM -0400, Steven Rostedt wrote:
> > Hmm, I never saw the tip-bot reply :-(
> > 
> > I guess it only sends to the Cc tags.
> > 
> > -- Steve
> > 
> > 
> 
> 
> We were in the commit Cc tags but somehow they didn't make it in the email
> tags.

indeed - i forwarded this to hpa.

	Ingo

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2010-08-31 17:37 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-08-25  1:32 [PATCH] tracing/trace_stack: Fix stack trace on ppc64 Anton Blanchard
2010-08-25 12:58 ` [tip:perf/urgent] " tip-bot for Anton Blanchard
2010-08-31  1:31 ` [PATCH] " Steven Rostedt
2010-08-31 14:21   ` Frederic Weisbecker
2010-08-31 14:58     ` Steven Rostedt
2010-08-31 15:14       ` Frederic Weisbecker
2010-08-31 17:36         ` Ingo Molnar

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