From 977ad481b66ca91e1f6492b3c5c4748c68fdee9c Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Fri, 13 Feb 2015 14:40:24 -0800 Subject: kprobes: set kprobes_all_disarmed earlier to enable re-optimization. In original code, the probed instruction doesn't get optimized after echo 0 > /sys/kernel/debug/kprobes/enabled echo 1 > /sys/kernel/debug/kprobes/enabled This is because original code checks kprobes_all_disarmed in optimize_kprobe(), but this flag is turned off after calling that function. Therefore, optimize_kprobe() will see kprobes_all_disarmed == true and doesn't do the optimization. This patch simply turns off kprobes_all_disarmed earlier to enable optimization. Signed-off-by: Wang Nan Signed-off-by: Masami Hiramatsu Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kprobes.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel/kprobes.c') diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 2ca272f8f62e..c39790001854 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2320,6 +2320,12 @@ static void arm_all_kprobes(void) if (!kprobes_all_disarmed) goto already_enabled; + /* + * optimize_kprobe() called by arm_kprobe() checks + * kprobes_all_disarmed, so set kprobes_all_disarmed before + * arm_kprobe. + */ + kprobes_all_disarmed = false; /* Arming kprobes doesn't optimize kprobe itself */ for (i = 0; i < KPROBE_TABLE_SIZE; i++) { head = &kprobe_table[i]; @@ -2328,7 +2334,6 @@ static void arm_all_kprobes(void) arm_kprobe(p); } - kprobes_all_disarmed = false; printk(KERN_INFO "Kprobes globally enabled\n"); already_enabled: -- cgit v1.2.3-59-g8ed1b