On Thu, Oct 21, 2021 at 12:02:49PM -0500, Eric W. Biederman wrote: > Kees Cook <keescook@xxxxxxxxxxxx> 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. I've done recent ia32 testing just under qemu with a 32bit x86 image. Since I've got this set up already, I'll give it a spin... > 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. It _is_ a little weird. :P I do it like this, pulled from the larger docs[1]: # Build host $ make -C tools/testing/selftests gen_tar TARGETS="x86" FORMAT=.xz $ scp $(find tools/testing/selftests -name kselftests.tar.xz) target: # Target host $ mkdir kselftests && cd kselftests $ tar -xaf ../kselftests.tar.xz $ ./run_kselftest.sh [1] https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html -- Kees Cook
