Re: [PATCH v2] x86/asm/entry/32, selftests: Add test_syscall_vdso test

Denys Vlasenko
2015-06-14T12:50:14Z

On 06/13/2015 08:39 AM, Ingo Molnar wrote:
>
> * Denys Vlasenko <dvlasenk@redhat.com> wrote:
>
>> The test is fairly simplistic: it checks that all registers
>> are preserved across 32-bit syscall via VDSO.
>>
>> Run-tested:
>>
>> $ ./test_syscall_vdso_32
>> [RUN] Executing 6-argument 32-bit syscall via VDSO
>> [Ok] Arguments are preserved across syscall
>> [RUN] Executing 6-argument 32-bit syscall via INT 80
>> [Ok] Arguments are preserved across syscall
>> [RUN] Running tests under ptrace
>> [RUN] Executing 6-argument 32-bit syscall via VDSO
>> [Ok] Arguments are preserved across syscall
>> [RUN] Executing 6-argument 32-bit syscall via INT 80
>> [Ok] Arguments are preserved across syscall
>
> Just curious: is there a kernel sha1 where this test would fail? Or did you try to
> provoke an information leak perhaps?

I did see failures, more than once, when testing my own patches.

I'm not aware of released kernels which are buggy wrt this test.