Created attachment 124137 [details] Suggested patch Specific use case bug found in SysRes VG_(do_sys_sigprocmask) coregrind/m_signals.c Fix for case when ,,set,, parameter is NULL. In this case ,,how,, parameter should be ignored because we are only requesting from kernel to put current signal mask into ,,oldset,,. But instead we determine the action based on ,,how,, parameter and therefore make the system call fail when it should pass. Taken from linux man pages (sigprocmask). Suggested patch provided in attachment.
Created attachment 124181 [details] Test example that fails for this bug This test passed successfully on x86 but failed with valgrind on x86. Expected behaviour: $ ./sigprocmask TEST PASSED $ ./vg-in-place --tool=none ./sigprocmask ==12634== Nulgrind, the minimal Valgrind tool ==12634== Copyright (C) 2002-2017, and GNU GPL'd, by Nicholas Nethercote. ==12634== Using Valgrind-3.16.0.GIT and LibVEX; rerun with -h for copyright info ==12634== Command: testovi/sigprocmask ==12634== --12634-- sigprocmask: unknown 'how' field 123 TEST FAILED ==12634==
the diff looks reasonable and seems to work, the test passes after applying the diff
Created attachment 124527 [details] patch Integrate the proposed test case to the testsuite
Thanks for the bug report, patch and integration of the testcase into the testsuite. I double checked that this is also specified by POSIX for sigprocmask, so it isn't linux specific. Pushed patches as: commit b70d208e97336fff617892f88d63afc97983d619 Author: Nikola Milutinovic <nikola.milutinovic@rt-rk.com> Date: Sun Dec 22 15:49:04 2019 +0100 sigprocmask should ignore HOW argument when SET is NULL. Specific use case bug found in SysRes VG_(do_sys_sigprocmask). Fix for case when ,,set,, parameter is NULL. In this case ,,how,, parameter should be ignored because we are only requesting from kernel to put current signal mask into ,,oldset,,. But instead we determine the action based on ,,how,, parameter and therefore make the system call fail when it should pass. Taken from linux man pages (sigprocmask). The same is specified for POSIX. https://bugs.kde.org/show_bug.cgi?id=414565 commit 2f729fdbd6a3e70fb61dcc5b77fd86ea23edf8ae (HEAD -> master) Author: Alexandra Hájková <ahajkova@redhat.com> Date: Mon Dec 16 15:58:26 2019 +0100 none/tests: Add test for bz414565. Integrate the test case written by Nikola Milutinovic to the testsuite. (https://bugs.kde.org/show_bug.cgi?id=414565)