Module Name: src
Committed By: kamil
Date: Thu May 14 19:21:35 UTC 2020
Modified Files:
src/tests/lib/libc/sys: t_ptrace_fork_wait.h
Log Message:
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.
Fixes PR lib/55241 by Andreas Gustafsson
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 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:1.2 src/tests/lib/libc/sys/t_ptrace_fork_wait.h:1.3
--- src/tests/lib/libc/sys/t_ptrace_fork_wait.h:1.2 Mon May 11 20:58:48 2020
+++ src/tests/lib/libc/sys/t_ptrace_fork_wait.h Thu May 14 19:21:35 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: t_ptrace_fork_wait.h,v 1.2 2020/05/11 20:58:48 kamil Exp $ */
+/* $NetBSD: t_ptrace_fork_wait.h,v 1.3 2020/05/14 19:21:35 kamil Exp $ */
/*-
* Copyright (c) 2016, 2017, 2018, 2020 The NetBSD Foundation, Inc.
@@ -38,6 +38,7 @@ fork_body(const char *fn, bool trackspaw
#if defined(TWAIT_HAVE_STATUS)
int status;
#endif
+ sigset_t set;
ptrace_state_t state;
const int slen = sizeof(state);
ptrace_event_t event;
@@ -98,6 +99,19 @@ fork_body(const char *fn, bool trackspaw
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);
@@ -207,16 +221,6 @@ fork_body(const char *fn, bool trackspaw
}
#endif
- 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);
