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| author | Wang Nan <wangnan0@huawei.com> | 2015-02-13 14:40:24 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-13 21:21:42 -0800 |
| commit | 977ad481b66ca91e1f6492b3c5c4748c68fdee9c (patch) | |
| tree | 2662accb1f4f5d238a56bff10d541b0797998302 /kernel/kprobes.c | |
| parent | 5125991c9a9360fbdb717e22783c970bbd140660 (diff) | |
| download | lwn-977ad481b66ca91e1f6492b3c5c4748c68fdee9c.tar.gz lwn-977ad481b66ca91e1f6492b3c5c4748c68fdee9c.zip | |
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.c | 7 |
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: |