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Diffstat (limited to 'pthread_stop_world.c')
-rw-r--r--pthread_stop_world.c58
1 files changed, 38 insertions, 20 deletions
diff --git a/pthread_stop_world.c b/pthread_stop_world.c
index 1cdda21..832c49c 100644
--- a/pthread_stop_world.c
+++ b/pthread_stop_world.c
@@ -39,6 +39,34 @@ void GC_print_sig_mask()
#endif
+/* Remove the signals that we want to allow in thread stopping */
+/* handler from a set. */
+void GC_remove_allowed_signals(sigset_t *set)
+{
+# ifdef NO_SIGNALS
+ if (sigdelset(set, SIGINT) != 0
+ || sigdelset(set, SIGQUIT) != 0
+ || sigdelset(set, SIGABRT) != 0
+ || sigdelset(set, SIGTERM) != 0) {
+ ABORT("sigdelset() failed");
+ }
+# endif
+
+# ifdef MPROTECT_VDB
+ /* Handlers write to the thread structure, which is in the heap, */
+ /* and hence can trigger a protection fault. */
+ if (sigdelset(set, SIGSEGV) != 0
+# ifdef SIGBUS
+ || sigdelset(set, SIGBUS) != 0
+# endif
+ ) {
+ ABORT("sigdelset() failed");
+ }
+# endif
+}
+
+static sigset_t suspend_handler_mask;
+
word GC_stop_count; /* Incremented at the beginning of GC_stop_world. */
#ifdef GC_OSF1_THREADS
@@ -78,7 +106,6 @@ void GC_suspend_handler(int sig)
int dummy;
pthread_t my_thread = pthread_self();
GC_thread me;
- sigset_t mask;
# ifdef PARALLEL_MARK
word my_mark_no = GC_mark_no;
/* Marker can't proceed until we acknowledge. Thus this is */
@@ -125,17 +152,9 @@ void GC_suspend_handler(int sig)
/* this thread a SIG_THR_RESTART signal. */
/* SIG_THR_RESTART should be masked at this point. Thus there */
/* is no race. */
- if (sigfillset(&mask) != 0) ABORT("sigfillset() failed");
- if (sigdelset(&mask, SIG_THR_RESTART) != 0) ABORT("sigdelset() failed");
-# ifdef NO_SIGNALS
- if (sigdelset(&mask, SIGINT) != 0) ABORT("sigdelset() failed");
- if (sigdelset(&mask, SIGQUIT) != 0) ABORT("sigdelset() failed");
- if (sigdelset(&mask, SIGTERM) != 0) ABORT("sigdelset() failed");
- if (sigdelset(&mask, SIGABRT) != 0) ABORT("sigdelset() failed");
-# endif
do {
me->stop_info.signal = 0;
- sigsuspend(&mask); /* Wait for signal */
+ sigsuspend(&suspend_handler_mask); /* Wait for signal */
} while (me->stop_info.signal != SIG_THR_RESTART);
/* If the RESTART signal gets lost, we can still lose. That should be */
/* less likely than losing the SUSPEND signal, since we don't do much */
@@ -417,16 +436,9 @@ void GC_stop_init() {
if (sigfillset(&act.sa_mask) != 0) {
ABORT("sigfillset() failed");
}
-# ifdef NO_SIGNALS
- if (sigdelset(&act.sa_mask, SIGINT) != 0
- || sigdelset(&act.sa_mask, SIGQUIT != 0)
- || sigdelset(&act.sa_mask, SIGABRT != 0)
- || sigdelset(&act.sa_mask, SIGTERM != 0)) {
- ABORT("sigdelset() failed");
- }
-# endif
-
- /* SIG_THR_RESTART is unmasked by the handler when necessary. */
+ GC_remove_allowed_signals(&act.sa_mask);
+ /* SIG_THR_RESTART is set in the resulting mask. */
+ /* It is unmasked by the handler when necessary. */
act.sa_handler = GC_suspend_handler;
if (sigaction(SIG_SUSPEND, &act, NULL) != 0) {
ABORT("Cannot set SIG_SUSPEND handler");
@@ -437,6 +449,12 @@ void GC_stop_init() {
ABORT("Cannot set SIG_THR_RESTART handler");
}
+ /* Inititialize suspend_handler_mask. It excludes SIG_THR_RESTART. */
+ if (sigfillset(&suspend_handler_mask) != 0) ABORT("sigfillset() failed");
+ GC_remove_allowed_signals(&suspend_handler_mask);
+ if (sigdelset(&suspend_handler_mask, SIG_THR_RESTART) != 0)
+ ABORT("sigdelset() failed");
+
/* Check for GC_RETRY_SIGNALS. */
if (0 != GETENV("GC_RETRY_SIGNALS")) {
GC_retry_signals = TRUE;