o Remove a cruft prevented libpthread sigaction(2) wrapper to

do its work for SIGINFO.  Always install libpthread signal handler
wrapper for SIGINFO even if user SIG_IGN's or SIG_DFL's it.

SIGINFO has a special meaning for libpthread: when LIBPTHREAD_DEBUG
enviroment variable defined it is used for dumping an information
about threads to /tmp/.

Reported by:	mi
Reviewed by:	deischen
MFC after:	2 weeks

3 files changed, 18 insertions, 7 deletions

diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h
index f839960..927e9d1 100644
--- a/lib/libpthread/thread/thr_private.h
+++ b/lib/libpthread/thread/thr_private.h
@@ -1317,4 +1317,11 @@ int 	__sys_poll(struct pollfd *, unsigned, int);
 int	__sys_msync(void *, size_t, int);
 #endif
 
+static __inline int
+_thr_dump_enabled(void)
+{
+
+	return ((_thr_debug_flags & DBG_INFO_DUMP) != 0);
+}
+
 #endif  /* !_THR_PRIVATE_H */
diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c
index f53b87f..116f9f6 100644
--- a/lib/libpthread/thread/thr_sig.c
+++ b/lib/libpthread/thread/thr_sig.c
@@ -98,12 +98,6 @@ 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.
  *
diff --git a/lib/libpthread/thread/thr_sigaction.c b/lib/libpthread/thread/thr_sigaction.c
index 7ee0ce6..bc54a86 100644
--- a/lib/libpthread/thread/thr_sigaction.c
+++ b/lib/libpthread/thread/thr_sigaction.c
@@ -75,7 +75,7 @@ _sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
 		 * Check if the kernel needs to be advised of a change
 		 * in signal action:
 		 */
-		if (act != NULL && sig != SIGINFO) {
+		if (act != NULL) {
 
 			newact.sa_flags |= SA_SIGINFO;
 
@@ -91,6 +91,16 @@ _sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
 				 */
 				newact.sa_handler = (void (*) ())_thr_sig_handler;
 			}
+			/*
+			 * Install libpthread signal handler wrapper
+			 * for SIGINFO signal if threads dump enabled
+			 * even if a user set the signal handler to
+			 * SIG_DFL or SIG_IGN.
+			 */
+			if (sig == SIGINFO && _thr_dump_enabled()) {
+				newact.sa_handler =
+				    (void (*) ())_thr_sig_handler;
+			}
 			/* Change the signal action in the kernel: */
 			if (__sys_sigaction(sig, &newact, NULL) != 0) {
 				_thread_sigact[sig - 1] = oldact;