From 0134dc1b56e8c7c19f655e583ff3f3ba0d6cae4e Mon Sep 17 00:00:00 2001
From: Daniel Drake <drake@endlessm.com>
Date: Wed, 20 May 2015 13:16:12 -0600
Subject: [PATCH] Keep SIGALRM restart flag after Popen

Commit 94ab7455 added SA_RESTART to the SIGALRM handler.  However, the
Popen code tears down and recreates the SIGALRM handler via OsSignal(),
and this flag is dropped at this time.

Clean the code to use just a single codepath for creating this signal
handler, always applying SA_RESTART.

[ajax: Fixed commit id]

Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
(cherry picked from commit 1f915e8b524dd02011158aa038935970684c7630)
---
 os/utils.c | 49 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 38 insertions(+), 11 deletions(-)

diff --git a/os/utils.c b/os/utils.c
index 881d173e3..2b23430a4 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1208,14 +1208,15 @@ SmartScheduleTimer(int sig)
     SmartScheduleTime += SmartScheduleInterval;
 }
 
-void
-SmartScheduleInit(void)
+static int
+SmartScheduleEnable(void)
 {
+    int ret = 0;
 #ifdef SMART_SCHEDULE_POSSIBLE
     struct sigaction act;
 
     if (SmartScheduleDisable)
-        return;
+        return 0;
 
     memset((char *) &act, 0, sizeof(struct sigaction));
 
@@ -1224,11 +1225,40 @@ SmartScheduleInit(void)
     act.sa_handler = SmartScheduleTimer;
     sigemptyset(&act.sa_mask);
     sigaddset(&act.sa_mask, SIGALRM);
-    if (sigaction(SIGALRM, &act, 0) < 0) {
+    ret = sigaction(SIGALRM, &act, 0);
+#endif
+    return ret;
+}
+
+static int
+SmartSchedulePause(void)
+{
+    int ret = 0;
+#ifdef SMART_SCHEDULE_POSSIBLE
+    struct sigaction act;
+
+    if (SmartScheduleDisable)
+        return 0;
+
+    memset((char *) &act, 0, sizeof(struct sigaction));
+
+    act.sa_handler = SIG_IGN;
+    sigemptyset(&act.sa_mask);
+    ret = sigaction(SIGALRM, &act, 0);
+#endif
+    return ret;
+}
+
+void
+SmartScheduleInit(void)
+{
+    if (SmartScheduleDisable)
+        return;
+
+    if (SmartScheduleEnable() < 0) {
         perror("sigaction for smart scheduler");
         SmartScheduleDisable = TRUE;
     }
-#endif
 }
 
 #ifdef SIG_BLOCK
@@ -1403,8 +1433,6 @@ static struct pid {
     int pid;
 } *pidlist;
 
-OsSigHandlerPtr old_alarm = NULL;       /* XXX horrible awful hack */
-
 void *
 Popen(const char *command, const char *type)
 {
@@ -1427,8 +1455,7 @@ Popen(const char *command, const char *type)
     }
 
     /* Ignore the smart scheduler while this is going on */
-    old_alarm = OsSignal(SIGALRM, SIG_IGN);
-    if (old_alarm == SIG_ERR) {
+    if (SmartSchedulePause() < 0) {
         close(pdes[0]);
         close(pdes[1]);
         free(cur);
@@ -1441,7 +1468,7 @@ Popen(const char *command, const char *type)
         close(pdes[0]);
         close(pdes[1]);
         free(cur);
-        if (OsSignal(SIGALRM, old_alarm) == SIG_ERR)
+        if (SmartScheduleEnable() < 0)
             perror("signal");
         return NULL;
     case 0:                    /* child */
@@ -1616,7 +1643,7 @@ Pclose(void *iop)
     /* allow EINTR again */
     OsReleaseSignals();
 
-    if (old_alarm && OsSignal(SIGALRM, old_alarm) == SIG_ERR) {
+    if (SmartScheduleEnable() < 0) {
         perror("signal");
         return -1;
     }