[git commit] init: don't srop unterminated processes' entries during inittab reload

[Denys Vlasenko]

commit: http://git.busybox.net/busybox/commit/?id=9f07af6156267f1e3064c14f2bee96560f7ed69d
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

This feature was removed in 72c99af

It is useful when process is removed from inittab and later added
back, but never terminated. It prevents init from spawning duplicate.

function                                             old     new   delta
check_delayed_sigs                                   176     182      +6

Signed-off-by: Paulius Zaleckas <paulius.zaleckas at gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 init/init.c |   13 ++++++++++---
 1 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/init/init.c b/init/init.c
index 05ed4f7..edb5be6 100644
--- a/init/init.c
+++ b/init/init.c
@@ -638,7 +638,7 @@ static void new_init_action(uint8_t action_type, const char *command, const char
 	a->action_type = action_type;
 	strcpy(a->command, command);
 	safe_strncpy(a->terminal, cons, sizeof(a->terminal));
-	dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n",
+	dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%x tty='%s'\n",
 		a->command, a->action_type, a->terminal);
 }
 
@@ -934,10 +934,17 @@ static void reload_inittab(void)
 
 	/* Remove stale entries and SYSINIT entries.
 	 * We never rerun SYSINIT entries anyway,
-	 * removing them too saves a few bytes */
+	 * removing them too saves a few bytes
+	 */
 	nextp = &init_action_list;
 	while ((a = *nextp) != NULL) {
-		if ((a->action_type & ~SYSINIT) == 0) {
+		/*
+		 * Why pid == 0 check?
+		 * Process can be removed from inittab and added *later*.
+		 * If we delete its entry but process still runs,
+		 * duplicate is spawned when the entry is re-added.
+		 */
+		if ((a->action_type & ~SYSINIT) == 0 && a->pid == 0) {
 			*nextp = a->next;
 			free(a);
 		} else {