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| author |   Masami Hiramatsu <mhiramat@kernel.org> | 2020-07-28 16:34:00 +0900 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2020-07-28 13:19:05 +0200 |
| commit | 112a0e4171e111e963aada3fe790c71accf4d705 (patch) | |
| tree | d74254e8ac496dc145e75e3c355a4f8df2986ae9 /kernel/kprobes.c | |
| parent | Merge tag 'v5.8-rc7' into perf/core, to pick up fixes (diff) | |
| download | linux-dev-112a0e4171e111e963aada3fe790c71accf4d705.tar.xz linux-dev-112a0e4171e111e963aada3fe790c71accf4d705.zip | |
kprobes: Remove unnecessary module_mutex locking from kprobe_optimizer()
Since we already lock both kprobe_mutex and text_mutex in the optimizer,
text will not be changed and the module unloading will be stopped
inside kprobes_module_callback().
The mutex_lock() has originally been introduced to avoid conflict with text modification,
at that point we didn't hold text_mutex.
But after:
f1c6ece23729 ("kprobes: Fix potential deadlock in kprobe_optimizer()")
We started holding the text_mutex and don't need the modules mutex anyway.
So remove the module_mutex locking.
[ mingo: Amended the changelog. ]
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Link: https://lore.kernel.org/r/20200728163400.e00b09c594763349f99ce6cb@kernel.org
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 146c648eb943..e87679a48ba2 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -598,8 +598,6 @@ static void kprobe_optimizer(struct work_struct *work) mutex_lock(&kprobe_mutex); cpus_read_lock(); mutex_lock(&text_mutex); - /* Lock modules while optimizing kprobes */ - mutex_lock(&module_mutex); /* * Step 1: Unoptimize kprobes and collect cleaned (unused and disarmed) @@ -624,7 +622,6 @@ static void kprobe_optimizer(struct work_struct *work) /* Step 4: Free cleaned kprobes after quiesence period */ do_free_cleaned_kprobes(); - mutex_unlock(&module_mutex); mutex_unlock(&text_mutex); cpus_read_unlock(); |