core: check for return value from get_process_state

Fix for commit e10c9985bb.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/core/service.c b/src/core/service.c
index d9bc02181..c8dbbeff1 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -1429,11 +1429,17 @@ static int service_load_pid_file(Service *s, bool may_warn) {
                 return -ESRCH;
         }
 
-        if (get_process_state(pid) == 'Z') {
+        r = get_process_state(pid);
+        if (r < 0) {
+                if (may_warn)
+                        log_info_unit(UNIT(s)->id, "Failed to read /proc/%d/stat: %s",
+                                      pid, strerror(-r));
+                return r;
+        } else if (r == 'Z') {
                 if (may_warn)
                         log_info_unit(UNIT(s)->id,
-                                      "PID "PID_FMT" read from file %s is a zombie.",
-                                      pid, s->pid_file);
+                                      "PID %lu read from file %s is a zombie.",
+                                      (unsigned long) pid, s->pid_file);
                 return -ESRCH;
         }