Messages in this thread | | | From | Andy Lutomirski <> | Date | Sun, 8 May 2016 18:32:34 -0700 | Subject | Re: [PATCH 2/4] selftests/sigaltstack: Fix the sas test on old kernels |
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On May 7, 2016 8:02 AM, "Stas Sergeev" <stsp@list.ru> wrote: > > 03.05.2016 20:31, Andy Lutomirski пишет: > >> The handling for old kernels was wrong. Fix it. >> >> Reported-by: Ingo Molnar <mingo@kernel.org> >> Cc: Stas Sergeev <stsp@list.ru> >> Cc: Al Viro <viro@zeniv.linux.org.uk> >> Cc: Andrew Morton <akpm@linux-foundation.org> >> Cc: Andy Lutomirski <luto@amacapital.net> >> Cc: Borislav Petkov <bp@alien8.de> >> Cc: Brian Gerst <brgerst@gmail.com> >> Cc: Denys Vlasenko <dvlasenk@redhat.com> >> Cc: H. Peter Anvin <hpa@zytor.com> >> Cc: Linus Torvalds <torvalds@linux-foundation.org> >> Cc: Oleg Nesterov <oleg@redhat.com> >> Cc: Pavel Emelyanov <xemul@parallels.com> >> Cc: Peter Zijlstra <peterz@infradead.org> >> Cc: Shuah Khan <shuahkh@osg.samsung.com> >> Cc: Thomas Gleixner <tglx@linutronix.de> >> Cc: linux-api@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Andy Lutomirski <luto@kernel.org> >> --- >> tools/testing/selftests/sigaltstack/sas.c | 21 ++++++++++++++------- >> 1 file changed, 14 insertions(+), 7 deletions(-) >> >> diff --git a/tools/testing/selftests/sigaltstack/sas.c b/tools/testing/selftests/sigaltstack/sas.c >> index 57da8bfde60b..a98c3ef8141f 100644 >> --- a/tools/testing/selftests/sigaltstack/sas.c >> +++ b/tools/testing/selftests/sigaltstack/sas.c >> @@ -15,6 +15,7 @@ >> #include <alloca.h> >> #include <string.h> >> #include <assert.h> >> +#include <errno.h> >> #ifndef SS_AUTODISARM >> #define SS_AUTODISARM (1 << 4) >> @@ -117,13 +118,19 @@ int main(void) >> stk.ss_flags = SS_ONSTACK | SS_AUTODISARM; >> err = sigaltstack(&stk, NULL); >> if (err) { >> - perror("[FAIL]\tsigaltstack(SS_ONSTACK | SS_AUTODISARM)"); >> - stk.ss_flags = SS_ONSTACK; >> - } >> - err = sigaltstack(&stk, NULL); >> - if (err) { >> - perror("[FAIL]\tsigaltstack(SS_ONSTACK)"); >> - return EXIT_FAILURE; >> + if (errno == EINVAL) { >> + printf("[NOTE]\tThe running kernel doesn't support SS_AUTODISARM\n"); >> + /* >> + * If test cases for the !SS_AUTODISARM variant were >> + * added, we could still run them. We don't have any >> + * test cases like that yet, so just exit and report >> + * success. >> + */ > > But that was the point, please see how it handles the > old kernels: > > $ ./sas > [FAIL] sigaltstack(SS_ONSTACK | SS_AUTODISARM): Invalid argument > [RUN] signal USR1 > [FAIL] ss_flags=1, should be SS_DISABLE > [RUN] switched to user ctx > [RUN] signal USR2 > [FAIL] sigaltstack re-used > [FAIL] Stack corrupted > [RUN] Aborting
This is useful as a demonstration of why the feature is useful, but it doesn't indicate that anything is wrong with old kernels per she. That's why I changed it to simply report that the feature is missing.
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