Only catch SIGINFO (for dumping thread states) when LIBPTHREAD_DEBUG

is defined in the environment.

Requested by:	jmg & a few others

3 files changed, 28 insertions, 16 deletions

diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c
index 7945ed9..ac04336 100644
--- a/lib/libpthread/thread/thr_init.c
+++ b/lib/libpthread/thread/thr_init.c
@@ -518,6 +518,8 @@ init_private(void)
 	else if (getenv("LIBPTHREAD_PROCESS_SCOPE") != NULL)
 		_thread_scope_system = -1;
 #endif
+	if (getenv("LIBPTHREAD_DEBUG") != NULL)
+		_thr_debug_flags |= DBG_INFO_DUMP;
 
 	/*
 	 * _thread_list_lock and _kse_count are initialized
diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h
index e2055bc..9d8ee63 100644
--- a/lib/libpthread/thread/thr_private.h
+++ b/lib/libpthread/thread/thr_private.h
@@ -82,6 +82,7 @@
 
 #define	DBG_MUTEX	0x0001
 #define	DBG_SIG		0x0002
+#define	DBG_INFO_DUMP	0x0004
 
 #ifdef _PTHREADS_INVARIANTS
 #define THR_ASSERT(cond, msg) do {	\
diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c
index ec6ebd5..f53b87f 100644
--- a/lib/libpthread/thread/thr_sig.c
+++ b/lib/libpthread/thread/thr_sig.c
@@ -98,6 +98,12 @@ static int sigproptbl[NSIG] = {
 #define DBG_MSG(x...)
 #endif
 
+static __inline int
+_thr_dump_enabled(void)
+{
+	return ((_thr_debug_flags & DBG_INFO_DUMP) != 0);
+}
+
 /*
  * Signal setup and delivery.
  *
@@ -253,7 +259,7 @@ _thr_sig_dispatch(struct kse *curkse, int sig, siginfo_t *info)
 	DBG_MSG(">>> _thr_sig_dispatch(%d)\n", sig);
 
 	/* Check if the signal requires a dump of thread information: */
-	if (sig == SIGINFO) {
+	if (_thr_dump_enabled() && (sig == SIGINFO)) {
 		/* Dump thread information to file: */
 		_thread_dump_info();
 	}
@@ -347,7 +353,7 @@ _thr_sig_handler(int sig, siginfo_t *info, ucontext_t *ucp)
 	}
 
 	/* Check if the signal requires a dump of thread information: */
-	if (sig == SIGINFO) {
+	if (_thr_dump_enabled() && (sig == SIGINFO)) {
 		/* Dump thread information to file: */
 		_thread_dump_info();
 	}
@@ -521,7 +527,7 @@ handle_signal(struct pthread *curthread, struct sighandle_info *shi)
 	_kse_critical_leave(&curthread->tcb->tcb_tmbx);
 
 	/* Check if the signal requires a dump of thread information: */
-	if (shi->sig == SIGINFO) {
+	if (_thr_dump_enabled() && (shi->sig == SIGINFO)) {
 		/* Dump thread information to file: */
 		_thread_dump_info();
 	}
@@ -1200,21 +1206,24 @@ _thr_signal_init(void)
 			__sys_sigaction(i, &act, NULL);
 		}
 	}
-	/*
-	 * Install the signal handler for SIGINFO.  It isn't
-	 * really needed, but it is nice to have for debugging
-	 * purposes.
-	 */
-	_thread_sigact[SIGINFO - 1].sa_flags = SA_SIGINFO | SA_RESTART;
-	SIGEMPTYSET(act.sa_mask);
-	act.sa_flags = SA_SIGINFO | SA_RESTART;
-	act.sa_sigaction = (__siginfohandler_t *)&_thr_sig_handler;
-	if (__sys_sigaction(SIGINFO, &act, NULL) != 0) {
-		__sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask, NULL);
+	if (_thr_dump_enabled()) {
 		/*
-		 * Abort this process if signal initialisation fails:
+		 * Install the signal handler for SIGINFO.  It isn't
+		 * really needed, but it is nice to have for debugging
+		 * purposes.
 		 */
-		PANIC("Cannot initialize signal handler");
+		_thread_sigact[SIGINFO - 1].sa_flags = SA_SIGINFO | SA_RESTART;
+		SIGEMPTYSET(act.sa_mask);
+		act.sa_flags = SA_SIGINFO | SA_RESTART;
+		act.sa_sigaction = (__siginfohandler_t *)&_thr_sig_handler;
+		if (__sys_sigaction(SIGINFO, &act, NULL) != 0) {
+			__sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask,
+			    NULL);
+			/*
+			 * Abort this process if signal initialisation fails:
+			 */
+			PANIC("Cannot initialize signal handler");
+		}
 	}
 	__sys_sigprocmask(SIG_SETMASK, &_thr_initial->sigmask, NULL);
 	__sys_sigaltstack(NULL, &_thr_initial->sigstk);