Allow SIGABRT to abort the program.

Allow SIGABRT to abort the program.

SIGABRT can be generated internally, usually by calling abort(),
or externally by another process.  When the signal is generated
by the kernel, info->si_pid is 0 and the signal is treated in the
same way as an exception (SIGSEGV, etc.), but the assumption
that the exception happens again upon return from the handler
is wrong, so we must have a special case for this.

BUG=crbug.com/303075
TEST=tested with Alt-VolumeUp-X on Chrome OS

[semenzato]

I don't know who the good reviewers might be, so please add yourself.  Thank you
in advance!

[semenzato]

I should add:

I have examined all uses of SIGABRT/SIGIOT in the kernel for various
architectures.  I was skipping a little, but I found that, consistently with its
definition, SIGABRT does not seem to be sent to user processes as the result of
some exception.  In fact I did not find any case in which the kernel sends that
signal to a user process, except for the Chrome OS SysRQ request
(Alt-VolumeUp-X).

So, given that 1. there is no evidence that SIGABRT is used inconsistently with
its definition; and 2. it's possible that Alt-VolumeUp-X never worked correctly;
then I am comfortable with proposing this change.

Unless you folks know of some SIGABRT use which invalidates my conjectures.

[markus]

LGTM, but I am not sure I am the best reviewer for breakpad code.

[semenzato]

Thank you!  Can you suggest another reviewer?

On Thu, Nov 7, 2013 at 11:21 AM,  <markus@chromium.org> wrote:
> LGTM, but I am not sure I am the best reviewer for breakpad code.
>
> https://breakpad.appspot.com/734002/

[markus]

I usually defer to thestig for anything related to breakpad

[Lei Zhang (chromium)]

lgtm

[semenzato]

On 2013/11/07 21:39:47, thestig wrote:
> lgtm

Thank you!

Do I have permissions to commit, and how would I do that?  I tried "gcl commit
<name>" but:

svn: Commit failed (details follow):
svn: Server sent unexpected return value (405 Method Not Allowed) in response to
MKACTIVITY request for '/svn/!svn/act/f282c9b9-ce45-4314-8ebb-4fb6e51c946d'