init: improve log message when a process exits: show exit code

function                                             old     new   delta
.rodata                                           105649  105680     +31
init_main                                            776     804     +28
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 59/0)               Total: 59 bytes

Signed-off-by: Sébastien Parisot <sparisot@free-mobile.fr>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/init/init.c b/init/init.c
index 2ee1e4cde..797e0a0eb 100644
--- a/init/init.c
+++ b/init/init.c
@@ -1198,17 +1198,29 @@ int init_main(int argc UNUSED_PARAM, char **argv)
                 /* Wait for any child process(es) to exit */
                 while (1) {
                         pid_t wpid;
+                        int status;
                         struct init_action *a;
 
-                        wpid = waitpid(-1, NULL, WNOHANG);
+                        wpid = waitpid(-1, &status, WNOHANG);
                         if (wpid <= 0)
                                 break;
 
                         a = mark_terminated(wpid);
                         if (a) {
-                                message(L_LOG, "process '%s' (pid %u) exited. "
+                                const char *s = "killed, signal";
+                                int ex = WTERMSIG(status);
+                                /* "if (!WIFSIGNALED(status))" generates more code:
+                                 * on linux, WIFEXITED(status) is "WTERMSIG(status) == 0"
+                                 * and WTERMSIG(status) is known, so compiler optimizes.
+                                 */
+                                if (WIFEXITED(status)) {
+                                        s = "exited, exitcode";
+                                        ex = WEXITSTATUS(status);
+                                }
+                                message(L_LOG, "process '%s' (pid %u) %s:%d. "
                                                 "Scheduling for restart.",
-                                                a->command, (unsigned)wpid);
+                                                a->command, (unsigned)wpid,
+                                                s, ex);
                         }
                 }