Author: labath Date: Wed Aug 19 08:47:57 2015 New Revision: 245436 URL: http://llvm.org/viewvc/llvm-project?rev=245436&view=rev Log: On Linux, clear the signal mask of the launched inferior
Summary: Due to fork()/execve(), the launched inferior inherits the signal mask of its parent (lldb-server). But because lldb-server modifies its signal mask (It blocks SIGCHLD, for example), the inferior starts with some signals being initially blocked. One consequence is that TestCallThatRestarts.ExprCommandThatRestartsTestCase (test/expression_command/call-restarts) fails because sigchld_handler() in lotta-signals.c is not called, due to the SIGCHLD signal being blocked. To prevent the signal masking done by lldb-server from affecting the created inferior, the signal mask of the inferior is now cleared before the execve(). Patch by: Yacine Belkadi Reviewers: ovyalov, labath Subscribers: lldb-commits Differential Revision: http://reviews.llvm.org/D12138 Modified: lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp lldb/trunk/test/expression_command/call-restarts/TestCallThatRestarts.py Modified: lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp?rev=245436&r1=245435&r2=245436&view=diff ============================================================================== --- lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp (original) +++ lldb/trunk/source/Plugins/Process/Linux/NativeProcessLinux.cpp Wed Aug 19 08:47:57 2015 @@ -554,7 +554,8 @@ NativeProcessLinux::Launch(LaunchArgs *a eDupStderrFailed, eChdirFailed, eExecFailed, - eSetGidFailed + eSetGidFailed, + eSetSigMaskFailed }; // Child process. @@ -632,6 +633,12 @@ NativeProcessLinux::Launch(LaunchArgs *a } } + // Clear the signal mask to prevent the child from being affected by + // any masking done by the parent. + sigset_t set; + if (sigemptyset(&set) != 0 || pthread_sigmask(SIG_SETMASK, &set, nullptr) != 0) + exit(eSetSigMaskFailed); + // Execute. We should never return... execve(argv[0], const_cast<char *const *>(argv), @@ -689,6 +696,9 @@ NativeProcessLinux::Launch(LaunchArgs *a case eSetGidFailed: error.SetErrorString("Child setgid failed."); break; + case eSetSigMaskFailed: + error.SetErrorString("Child failed to set signal mask."); + break; default: error.SetErrorString("Child returned unknown exit status."); break; Modified: lldb/trunk/test/expression_command/call-restarts/TestCallThatRestarts.py URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/test/expression_command/call-restarts/TestCallThatRestarts.py?rev=245436&r1=245435&r2=245436&view=diff ============================================================================== --- lldb/trunk/test/expression_command/call-restarts/TestCallThatRestarts.py (original) +++ lldb/trunk/test/expression_command/call-restarts/TestCallThatRestarts.py Wed Aug 19 08:47:57 2015 @@ -29,7 +29,6 @@ class ExprCommandThatRestartsTestCase(Te @dwarf_test @skipIfFreeBSD # llvm.org/pr19246: intermittent failure - @expectedFailureLinux("llvm.org/pr19246") @skipIfDarwin # llvm.org/pr19246: intermittent failure @skipIfWindows # Test relies on signals, unsupported on Windows def test_with_dwarf(self): _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
