From c0e227a9fbb99cc9d437f8ac695c93c72c92e11b Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 26 Aug 2014 21:04:21 +0200
Subject: [PATCH] util: reset signals when we fork off agents

If we invoke agents, we should make sure we actually can kill them
again. I mean, it's probably not our job to cleanup the signals if our
tools are invoked in weird contexts, but at least we should make sure,
that the subprocesses we invoke and intend to control work as intended.

Also see:

http://lists.freedesktop.org/archives/systemd-devel/2014-August/022460.html

(cherry picked from commit 8a7c93d858c342744adf481565d8bb03b9713dcf)

Resolves: #1134818
---
 src/shared/util.c | 18 ++++++++++++++++++
 src/shared/util.h |  1 +
 2 files changed, 19 insertions(+)

diff --git a/src/shared/util.c b/src/shared/util.c
index 0fcc130..3620c0a 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -935,6 +935,18 @@ int reset_all_signal_handlers(void) {
         return 0;
 }
 
+int reset_signal_mask(void) {
+        sigset_t ss;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0)
+                return -errno;
+
+        return 0;
+}
+
 char *strstrip(char *s) {
         char *e;
 
@@ -5044,6 +5056,12 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa
         /* Don't leak fds to the agent */
         close_all_fds(except, n_except);
 
+        /* Make sure we actually can kill the agent, if we need to, in
+         * case somebody invoked us from a shell script that trapped
+         * SIGTERM or so... */
+        reset_all_signal_handlers();
+        reset_signal_mask();
+
         stdout_is_tty = isatty(STDOUT_FILENO);
         stderr_is_tty = isatty(STDERR_FILENO);
 
diff --git a/src/shared/util.h b/src/shared/util.h
index 3a4bc98..cf935ce 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -206,6 +206,7 @@ int readlink_and_make_absolute(const char *p, char **r);
 int readlink_and_canonicalize(const char *p, char **r);
 
 int reset_all_signal_handlers(void);
+int reset_signal_mask(void);
 
 char *strstrip(char *s);
 char *delete_chars(char *s, const char *bad);