You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
systemd/SOURCES/0231-process-util-introduce...

115 lines
3.5 KiB

From f057aa6bb604845fa10ad569bca306e5e1e8fe0d Mon Sep 17 00:00:00 2001
From: Franck Bui <fbui@suse.com>
Date: Mon, 18 Mar 2019 11:48:34 +0100
Subject: [PATCH] process-util: introduce pid_is_my_child() helper
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
No functional changes.
Thanks Renaud Métrich for backporting this to RHEL.
Resolves: #1744972
---
src/basic/process-util.c | 14 ++++++++++++++
src/basic/process-util.h | 1 +
src/core/cgroup.c | 7 ++-----
src/core/service.c | 8 ++------
4 files changed, 19 insertions(+), 11 deletions(-)
diff --git a/src/basic/process-util.c b/src/basic/process-util.c
index aa3eff779a..6dbeee9dda 100644
--- a/src/basic/process-util.c
+++ b/src/basic/process-util.c
@@ -903,6 +903,20 @@ int getenv_for_pid(pid_t pid, const char *field, char **ret) {
return 0;
}
+int pid_is_my_child(pid_t pid) {
+ pid_t ppid;
+ int r;
+
+ if (pid <= 1)
+ return false;
+
+ r = get_process_ppid(pid, &ppid);
+ if (r < 0)
+ return r;
+
+ return ppid == getpid_cached();
+}
+
bool pid_is_unwaited(pid_t pid) {
/* Checks whether a PID is still valid at all, including a zombie */
diff --git a/src/basic/process-util.h b/src/basic/process-util.h
index a5bb072b25..a3bd2851b4 100644
--- a/src/basic/process-util.h
+++ b/src/basic/process-util.h
@@ -68,6 +68,7 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value);
bool pid_is_alive(pid_t pid);
bool pid_is_unwaited(pid_t pid);
+int pid_is_my_child(pid_t pid);
int pid_from_same_root_fs(pid_t pid);
bool is_main_thread(void);
diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 62ab41a288..b7ed07e65b 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -1876,7 +1876,7 @@ void unit_prune_cgroup(Unit *u) {
int unit_search_main_pid(Unit *u, pid_t *ret) {
_cleanup_fclose_ FILE *f = NULL;
- pid_t pid = 0, npid, mypid;
+ pid_t pid = 0, npid;
int r;
assert(u);
@@ -1889,15 +1889,12 @@ int unit_search_main_pid(Unit *u, pid_t *ret) {
if (r < 0)
return r;
- mypid = getpid_cached();
while (cg_read_pid(f, &npid) > 0) {
- pid_t ppid;
if (npid == pid)
continue;
- /* Ignore processes that aren't our kids */
- if (get_process_ppid(npid, &ppid) >= 0 && ppid != mypid)
+ if (pid_is_my_child(npid) == 0)
continue;
if (pid != 0)
diff --git a/src/core/service.c b/src/core/service.c
index 24f167572a..614ba05d89 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -139,8 +139,6 @@ static void service_unwatch_pid_file(Service *s) {
}
static int service_set_main_pid(Service *s, pid_t pid) {
- pid_t ppid;
-
assert(s);
if (pid <= 1)
@@ -159,12 +157,10 @@ static int service_set_main_pid(Service *s, pid_t pid) {
s->main_pid = pid;
s->main_pid_known = true;
+ s->main_pid_alien = pid_is_my_child(pid) == 0;
- if (get_process_ppid(pid, &ppid) >= 0 && ppid != getpid_cached()) {
+ if (s->main_pid_alien)
log_unit_warning(UNIT(s), "Supervising process "PID_FMT" which is not our child. We'll most likely not notice when it exits.", pid);
- s->main_pid_alien = true;
- } else
- s->main_pid_alien = false;
return 0;
}