Merge branch 'ti/glibc-stdio-mutex-from-signal-handler'

Allocation related functions and stdio are unsafe things to call
inside a signal handler, and indeed killing the pager can cause
glibc to deadlock waiting on allocation mutex as our signal handler
tries to free() some data structures in wait_for_pager().  Reduce
these unsafe calls.

* ti/glibc-stdio-mutex-from-signal-handler:
  pager: don't use unsafe functions in signal handlers

1 files changed, 16 insertions, 6 deletions

diff --git a/pager.c b/pager.c
index 27d4c8a17a..e425070528 100644
--- a/pager.c
+++ b/pager.c
@@ -14,19 +14,29 @@
 static const char *pager_argv[] = { NULL, NULL };
 static struct child_process pager_process = CHILD_PROCESS_INIT;
 
-static void wait_for_pager(void)
+static void wait_for_pager(int in_signal)
 {
-	fflush(stdout);
-	fflush(stderr);
+	if (!in_signal) {
+		fflush(stdout);
+		fflush(stderr);
+	}
 	/* signal EOF to pager */
 	close(1);
 	close(2);
-	finish_command(&pager_process);
+	if (in_signal)
+		finish_command_in_signal(&pager_process);
+	else
+		finish_command(&pager_process);
+}
+
+static void wait_for_pager_atexit(void)
+{
+	wait_for_pager(0);
 }
 
 static void wait_for_pager_signal(int signo)
 {
-	wait_for_pager();
+	wait_for_pager(1);
 	sigchain_pop(signo);
 	raise(signo);
 }
@@ -90,7 +100,7 @@ void setup_pager(void)
 
 	/* this makes sure that the parent terminates after the pager */
 	sigchain_push_common(wait_for_pager_signal);
-	atexit(wait_for_pager);
+	atexit(wait_for_pager_atexit);
 }
 
 int pager_in_use(void)