Module Name: src
Committed By: kamil
Date: Sat May 16 19:08:20 UTC 2020
Modified Files:
src/tests/lib/libc/sys: t_ptrace_fork_wait.h
Log Message:
Ignore interception of SIGCHLD signals in the debugger
Set SIGPASS for SIGCHLD for the traced child in the following tests:
- posix_spawn_singalmasked
- posix_spawn_singalignored
- fork_singalmasked
- fork_singalignored
- vfork_singalmasked
- vfork_singalignored
- vforkdone_singalmasked
- vforkdone_singalignored
There is a race that SIGCHLD might be blocked during forking and dropped.
PR/55241 by Andreas Gustafsson
To generate a diff of this commit:
cvs rdiff -u -r1.3 -r1.4 src/tests/lib/libc/sys/t_ptrace_fork_wait.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/tests/lib/libc/sys/t_ptrace_fork_wait.h
diff -u src/tests/lib/libc/sys/t_ptrace_fork_wait.h:1.3 src/tests/lib/libc/sys/t_ptrace_fork_wait.h:1.4
--- src/tests/lib/libc/sys/t_ptrace_fork_wait.h:1.3 Thu May 14 19:21:35 2020
+++ src/tests/lib/libc/sys/t_ptrace_fork_wait.h Sat May 16 19:08:20 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: t_ptrace_fork_wait.h,v 1.3 2020/05/14 19:21:35 kamil Exp $ */
+/* $NetBSD: t_ptrace_fork_wait.h,v 1.4 2020/05/16 19:08:20 kamil Exp $ */
/*-
* Copyright (c) 2016, 2017, 2018, 2020 The NetBSD Foundation, Inc.
@@ -1250,6 +1250,7 @@ fork2_body(const char *fn, bool masked,
int name[6];
const size_t namelen = __arraycount(name);
+ sigset_t set;
ki_sigset_t kp_sigmask;
ki_sigset_t kp_sigignore;
@@ -1341,6 +1342,19 @@ fork2_body(const char *fn, bool masked,
event.pe_set_event |= PTRACE_VFORK_DONE;
SYSCALL_REQUIRE(ptrace(PT_SET_EVENT_MASK, child, &event, elen) != -1);
+ /*
+ * Ignore interception of the SIGCHLD signals.
+ *
+ * SIGCHLD once blocked is discarded by the kernel as it has the
+ * SA_IGNORE property. During the fork(2) operation all signals can be
+ * shortly blocked and missed (unless there is a registered signal
+ * handler in the traced child). This leads to a race in this test if
+ * there would be an intention to catch SIGCHLD.
+ */
+ sigemptyset(&set);
+ sigaddset(&set, SIGCHLD);
+ SYSCALL_REQUIRE(ptrace(PT_SET_SIGPASS, child, &set, sizeof(set)) != -1);
+
DPRINTF("Before resuming the child process where it left off and "
"without signal to be sent\n");
SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);
@@ -1560,16 +1574,6 @@ fork2_body(const char *fn, bool masked,
wpid = TWAIT_GENERIC(child2, &status, 0));
}
- DPRINTF("Before calling %s() for the child - expected stopped "
- "SIGCHLD\n", TWAIT_FNAME);
- TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);
-
- validate_status_stopped(status, SIGCHLD);
-
- DPRINTF("Before resuming the child process where it left off and "
- "without signal to be sent\n");
- SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);
-
DPRINTF("Before calling %s() for the child - expected exited\n",
TWAIT_FNAME);
TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);
