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snsc: switch from force_sig to kill_proc

PATCH In review Christoph Hellwig 1 participant 1 message Jul 8, 2006 Char and misc drivers

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Christoph Hellwig

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PATCH 1/3 snsc: switch from force_sig to kill_proc

currently the snsc driver uses force_sig to send init a SIGPWR when the system overheats. This patch switches it to kill_proc instead which has the following advantages:

(1) gets rid of one of the last remaining tasklist_lock users in modular code
(2) simplifies the snsc code significantly

The downside is that an init implementation could in theory block SIGPWR and it would not get delivered. The sysvinit code used by all major distributions doesn't do this and blocking this signal in init would be a rather stupid thing to do.

Signed-off-by Christoph Hellwig <[email protected]>
drivers/char/snsc_event.c +1 -14
Index: linux-2.6/drivers/char/snsc_event.c
===================================================================
@@ -220,20 +220,7 @@
 			       " Sending SIGPWR to init...\n");
 
 		/* give a SIGPWR signal to init proc */
-
-		/* first find init's task */
-		read_lock(&tasklist_lock);
-		for_each_process(p) {
-			if (p->pid == 1)
-				break;
-		}
-		if (p) {
-			force_sig(SIGPWR, p);
-		} else {
-			printk(KERN_ERR "Failed to signal init!\n");
-			snsc_shutting_down = 0; /* so can try again (?) */
-		}
-		read_unlock(&tasklist_lock);
+		kill_proc(1, SIGPWR, 0);
 	} else {
 		/* print to system log */
 		printk("%s|$(0x%x)%s\n", severity, esp_code, desc);