Re: [PATCH 10/20] signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved.

Eric W. Biederman
2021-10-21T17:03:00Z

Kees Cook <keescook@chromium.org> writes:

> On Wed, Oct 20, 2021 at 12:43:56PM -0500, Eric W. Biederman wrote:
>> Instead of pretending to send SIGSEGV by calling do_exit(SIGSEGV)
>> call force_sigsegv(SIGSEGV) to force the process to take a SIGSEGV
>> and terminate.
>>
>> Update handle_signal to return immediately when save_v86_state fails
>> and kills the process. Returning immediately without doing anything
>> except killing the process with SIGSEGV is also what signal_setup_done
>> does when setup_rt_frame fails. Plus it is always ok to return
>> immediately without delivering a signal to a userspace handler when a
>> fatal signal has killed the current process.
>
> Do the tools/testing/selftests/x86 tests all pass after these changes? I
> know Andy has a bunch of weird corner cases in there.

That would require a 32bit userspace wouldn't it?

It is a good idea so I will see if I can dig such a box up, but I
unfortunately don't have an up-to-date 32bit box handy, or even
an up-to-date box with a 32bit userspace.

It has been about 20 years since I have done much with 32bit x86.

How hard is it to run the tests under tools/testing/selftests/...
Last time I tried it was a royal pain. I am hoping it is better this
round.

Eric