[PATCH/RFC] arm: Enable backtrace printing on oops when PC is corrupted

[PATCH/RFC] arm: Enable backtrace printing on oops when PC is corrupted

[Laurent Pinchart]

If PC points outside kernel text, start printing the backtrace at LR
instead.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 arch/arm/kernel/unwind.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 786ac2b..50292cd 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -359,7 +359,9 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk)
 		frame.fp = regs->ARM_fp;
 		frame.sp = regs->ARM_sp;
 		frame.lr = regs->ARM_lr;
-		frame.pc = regs->ARM_pc;
+		/* PC might be corrupted, use LR in that case. */
+		frame.pc = kernel_text_address(regs->ARM_pc)
+			 ? regs->ARM_pc : regs->ARM_lr;
 	} else if (tsk == current) {
 		frame.fp = (unsigned long)__builtin_frame_address(0);
 		frame.sp = current_sp;
-- 
1.6.4.4

[PATCH/RFC] arm: Enable backtrace printing on oops when PC iscorrupted

[Catalin Marinas]

On Thu, 2010-01-21 at 09:23 +0000, Laurent Pinchart wrote:
> If PC points outside kernel text, start printing the backtrace at LR
> instead.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

-- 
Catalin

[PATCH/RFC] arm: Enable backtrace printing on oops when PC iscorrupted

[Russell King - ARM Linux]

On Tue, Jan 26, 2010 at 05:41:01PM +0000, Catalin Marinas wrote:
> On Thu, 2010-01-21 at 09:23 +0000, Laurent Pinchart wrote:
> > If PC points outside kernel text, start printing the backtrace at LR
> > instead.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>

Has this been queued by someone?  If not, please send it to the patch
system.

[PATCH/RFC] arm: Enable backtrace printing on oops when PC iscorrupted

[Laurent Pinchart]

Hi Russell,

On Thursday 18 February 2010 18:07:50 Russell King - ARM Linux wrote:
> On Tue, Jan 26, 2010 at 05:41:01PM +0000, Catalin Marinas wrote:
> > On Thu, 2010-01-21 at 09:23 +0000, Laurent Pinchart wrote:
> > > If PC points outside kernel text, start printing the backtrace at LR
> > > instead.
> > > 
> > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> 
> Has this been queued by someone?  If not, please send it to the patch
> system.

As your mail was sent to Catalin I assumed he would take care of that. If the 
patch should still be sent to the patch system, could you tell me how to 
proceed ?

-- 
Regards,

Laurent Pinchart

[PATCH/RFC] arm: Enable backtrace printing on oops when PC iscorrupted

[Catalin Marinas]

On Thu, 2010-03-04 at 01:08 +0000, Laurent Pinchart wrote:
> On Thursday 18 February 2010 18:07:50 Russell King - ARM Linux wrote:
> > On Tue, Jan 26, 2010 at 05:41:01PM +0000, Catalin Marinas wrote:
> > > On Thu, 2010-01-21 at 09:23 +0000, Laurent Pinchart wrote:
> > > > If PC points outside kernel text, start printing the backtrace at LR
> > > > instead.
> > > >
> > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > >
> > > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> >
> > Has this been queued by someone?  If not, please send it to the patch
> > system.
> 
> As your mail was sent to Catalin I assumed he would take care of that. If the
> patch should still be sent to the patch system, could you tell me how to
> proceed ?

The patch system doesn't handle the patch authorship properly, it is
just assigning it to the person submitting it. That's why I haven't sent
your patch.

Have a look at http://www.arm.linux.org.uk/developer/patches/ and the
help.

If you don't want to subscribe, I can put the patch somewhere on a Git
tree and send Russell a pull request.


-- 
Catalin

[PATCH/RFC] arm: Enable backtrace printing on oops when PC iscorrupted

[Laurent Pinchart]

Hi Catalin,

On Thursday 04 March 2010 14:25:03 Catalin Marinas wrote:
> On Thu, 2010-03-04 at 01:08 +0000, Laurent Pinchart wrote:
> > On Thursday 18 February 2010 18:07:50 Russell King - ARM Linux wrote:
> > > On Tue, Jan 26, 2010 at 05:41:01PM +0000, Catalin Marinas wrote:
> > > > On Thu, 2010-01-21 at 09:23 +0000, Laurent Pinchart wrote:
> > > > > If PC points outside kernel text, start printing the backtrace at
> > > > > LR instead.
> > > > > 
> > > > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > 
> > > > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> > > 
> > > Has this been queued by someone?  If not, please send it to the patch
> > > system.
> > 
> > As your mail was sent to Catalin I assumed he would take care of that. If
> > the patch should still be sent to the patch system, could you tell me
> > how to proceed ?
> 
> The patch system doesn't handle the patch authorship properly, it is
> just assigning it to the person submitting it. That's why I haven't sent
> your patch.
> 
> Have a look at http://www.arm.linux.org.uk/developer/patches/ and the
> help.
> 
> If you don't want to subscribe, I can put the patch somewhere on a Git
> tree and send Russell a pull request.

Thanks for the information. I've submitted the patch 
(http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=5977/1)

-- 
Regards,

Laurent Pinchart