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authorWang Nan <wangnan0@huawei.com>2015-02-13 14:40:24 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-13 21:21:42 -0800
commit977ad481b66ca91e1f6492b3c5c4748c68fdee9c (patch)
tree2662accb1f4f5d238a56bff10d541b0797998302 /kernel/kprobes.c
parent5125991c9a9360fbdb717e22783c970bbd140660 (diff)
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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 <wangnan0@huawei.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c7
1 files changed, 6 insertions, 1 deletions
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: