code review 48650043: runtime: handle gdb breakpoint in x86 traceback

runtime: handle gdb breakpoint in x86 traceback

This lets stack splits work correctly when running under gdb
when gdb has inserted a breakpoint somewhere on the call
stack.

Fixes issue 6834.

[iant, 2014-01-07 21:57:08]

Hello golang-codereviews@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[minux1, 2014-01-07 23:36:30]

we also check the instruction at pc in sys_arm.c, do we need to
do the same there?

[iant, 2014-01-08 00:06:07]

On 2014/01/07 23:36:30, minux wrote:
> we also check the instruction at pc in sys_arm.c, do we need to
> do the same there?

I don't know.  It's certainly possible, but it depends on what gdb does on ARM. 
Try playing around with the test case in http://golang.org/issue/6834 on ARM and
see.

[minux1, 2014-01-08 05:12:24]

On Tue, Jan 7, 2014 at 7:06 PM, <iant@golang.org> wrote:

> On 2014/01/07 23:36:30, minux wrote:
>
>> we also check the instruction at pc in sys_arm.c, do we need to
>> do the same there?
>>
>
> I don't know.  It's certainly possible, but it depends on what gdb does
> on ARM.  Try playing around with the test case in
> http://golang.org/issue/6834 on ARM and see.
>
I saw no crash on ARM when debugging in gdb. (perhaps gdb placed breakpoint
instruction
in some other place)

This change LGTM.

[iant, 2014-01-08 20:36:33]

*** Submitted as https://code.google.com/p/go/source/detail?r=f7453c243cb9 ***

runtime: handle gdb breakpoint in x86 traceback

This lets stack splits work correctly when running under gdb
when gdb has inserted a breakpoint somewhere on the call
stack.

Fixes issue 6834.

R=golang-codereviews, minux.ma
CC=golang-codereviews
https://codereview.appspot.com/48650043