CFI: Add diagnostic information to likely CFI violation stack traces.

CFI: Add diagnostic information to likely CFI violation stack traces.

If CFI enforcement is enabled and we receive a SIGILL, it is most likely
that a CFI check failed. Add a reference to the CFI documentation to the
stack trace to make it easier to identify and investigate CFI violations.

Also add an end marker to stack traces to make it easier for automated
tools to extract stack traces.

BUG=464797
R=thakis@chromium.org

Committed: https://crrev.com/ff550411a2f2701746c93b32e9675e4047be167f
Cr-Commit-Position: refs/heads/master@{#342246}

[Avi (use Gerrit), 2015-08-05 15:19:35]

https://codereview.chromium.org/1267423002/diff/1/base/debug/stack_trace_posi...
File base/debug/stack_trace_posix.cc (right):

https://codereview.chromium.org/1267423002/diff/1/base/debug/stack_trace_posi...
base/debug/stack_trace_posix.cc:291: "control-flow-integrity\n");
FYI, rather than the sites page URL, use

https://www.chromium.org/developers/testing/control-flow-integrity

instead.

[pcc1, 2015-08-05 19:58:15]

https://codereview.chromium.org/1267423002/diff/1/base/debug/stack_trace_posi...
File base/debug/stack_trace_posix.cc (right):

https://codereview.chromium.org/1267423002/diff/1/base/debug/stack_trace_posi...
base/debug/stack_trace_posix.cc:291: "control-flow-integrity\n");
On 2015/08/05 15:19:35, Avi wrote:
> FYI, rather than the sites page URL, use
> 
> https://www.chromium.org/developers/testing/control-flow-integrity
> 
> instead.

Done.

[Nico, 2015-08-05 20:59:07]

https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
File base/debug/stack_trace_posix.cc (right):

https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
base/debug/stack_trace_posix.cc:413: #endif
this block seems to not add anything useful

[pcc1, 2015-08-05 21:00:30]

https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
File base/debug/stack_trace_posix.cc (right):

https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
base/debug/stack_trace_posix.cc:413: #endif
On 2015/08/05 20:59:07, Nico (hiding) wrote:
> this block seems to not add anything useful

It acts as an end marker for the problem report. ClusterFuzz folks in particular
have indicated that this would be useful for them.

[Nico, 2015-08-05 21:03:29]

On 2015/08/05 21:00:30, pcc1 wrote:
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> File base/debug/stack_trace_posix.cc (right):
> 
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> base/debug/stack_trace_posix.cc:413: #endif
> On 2015/08/05 20:59:07, Nico (hiding) wrote:
> > this block seems to not add anything useful
> 
> It acts as an end marker for the problem report. ClusterFuzz folks in
particular
> have indicated that this would be useful for them.

Why would it be useful for CFI but not for other configs?

[pcc1, 2015-08-05 21:11:16]

On 2015/08/05 21:03:29, Nico (hiding) wrote:
> On 2015/08/05 21:00:30, pcc1 wrote:
> >
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> > File base/debug/stack_trace_posix.cc (right):
> > 
> >
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> > base/debug/stack_trace_posix.cc:413: #endif
> > On 2015/08/05 20:59:07, Nico (hiding) wrote:
> > > this block seems to not add anything useful
> > 
> > It acts as an end marker for the problem report. ClusterFuzz folks in
> particular
> > have indicated that this would be useful for them.
> 
> Why would it be useful for CFI but not for other configs?

Yes, good point. We could have a generic "[end of stack trace]" message here
instead, perhaps. I'll see what CF folks think.

[pcc1, 2015-08-06 22:14:29]

On 2015/08/05 21:11:16, pcc1 wrote:
> On 2015/08/05 21:03:29, Nico (hiding) wrote:
> > On 2015/08/05 21:00:30, pcc1 wrote:
> > >
> >
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> > > File base/debug/stack_trace_posix.cc (right):
> > > 
> > >
> >
>
https://codereview.chromium.org/1267423002/diff/20001/base/debug/stack_trace_...
> > > base/debug/stack_trace_posix.cc:413: #endif
> > > On 2015/08/05 20:59:07, Nico (hiding) wrote:
> > > > this block seems to not add anything useful
> > > 
> > > It acts as an end marker for the problem report. ClusterFuzz folks in
> > particular
> > > have indicated that this would be useful for them.
> > 
> > Why would it be useful for CFI but not for other configs?
> 
> Yes, good point. We could have a generic "[end of stack trace]" message here
> instead, perhaps. I'll see what CF folks think.

This works for CF, so this is now done.

[Nico, 2015-08-06 22:21:25]

lgtm, thanks!

[pcc1, 2015-08-06 22:22:29]

The CQ bit was checked by pcc@chromium.org

[commit-bot: I haz the power, 2015-08-06 22:23:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1267423002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1267423002/40001

[commit-bot: I haz the power, 2015-08-07 00:50:43]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-08-07 00:52:24]

Patchset 3 (id:??) landed as
https://crrev.com/ff550411a2f2701746c93b32e9675e4047be167f
Cr-Commit-Position: refs/heads/master@{#342246}