Commit 4a2bb6fc authored Jun 30, 2009 by Masami Hiramatsu Committed by Ingo Molnar Jul 01, 2009

kprobes: No need to unlock kprobe_insn_mutex



Remove needless kprobe_insn_mutex unlocking during safety check
in garbage collection, because if someone releases a dirty slot
during safety check (which ensures other cpus doesn't execute
all dirty slots), the safety check must be fail. So, we need to
hold the mutex while checking safety.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20090630210809.17851.28781.stgit@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 238a24f6

kernel/kprobes.c

+1 −5

Original line number	Original line	Diff line number	Diff line
	@@ -237,13 +237,9 @@ static int __kprobes collect_garbage_slots(void)
	{		{
	struct kprobe_insn_page *kip;		struct kprobe_insn_page *kip;
	struct hlist_node pos, next;		struct hlist_node pos, next;
	int safety;

	/* Ensure no-one is preepmted on the garbages */		/* Ensure no-one is preepmted on the garbages */
	mutex_unlock(&kprobe_insn_mutex);		if (check_safety())
	safety = check_safety();
	mutex_lock(&kprobe_insn_mutex);
	if (safety != 0)
	return -EAGAIN;		return -EAGAIN;

	hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {		hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {