From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750863AbcEGPCt (ORCPT ); Sat, 7 May 2016 11:02:49 -0400 Received: from smtp39.i.mail.ru ([94.100.177.99]:34761 "EHLO smtp39.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750702AbcEGPCs (ORCPT ); Sat, 7 May 2016 11:02:48 -0400 X-Greylist: delayed 1477 seconds by postgrey-1.27 at vger.kernel.org; Sat, 07 May 2016 11:02:47 EDT Subject: Re: [PATCH 2/4] selftests/sigaltstack: Fix the sas test on old kernels To: Andy Lutomirski , x86@kernel.org References: Cc: linux-kernel@vger.kernel.org, Borislav Petkov , Al Viro , Andrew Morton , Andy Lutomirski , Brian Gerst , Denys Vlasenko , "H. Peter Anvin" , Linus Torvalds , Oleg Nesterov , Pavel Emelyanov , Peter Zijlstra , Shuah Khan , Thomas Gleixner , linux-api@vger.kernel.org From: Stas Sergeev Message-ID: Date: Sat, 7 May 2016 18:02:26 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-Mras: OK Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 03.05.2016 20:31, Andy Lutomirski пишет: > The handling for old kernels was wrong. Fix it. > > Reported-by: Ingo Molnar > Cc: Stas Sergeev > Cc: Al Viro > Cc: Andrew Morton > Cc: Andy Lutomirski > Cc: Borislav Petkov > Cc: Brian Gerst > Cc: Denys Vlasenko > Cc: H. Peter Anvin > Cc: Linus Torvalds > Cc: Oleg Nesterov > Cc: Pavel Emelyanov > Cc: Peter Zijlstra > Cc: Shuah Khan > Cc: Thomas Gleixner > Cc: linux-api@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Andy Lutomirski > --- > 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 > #include > #include > +#include > > #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 Unfortunalely, for Ingo it crashed... I am not sure why, I can't reproduce. :( So if you disable all the "old" tests, you can as well remove them, or... find the bug and re-enable. :)