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| author |   Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2022-01-17 18:03:39 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2022-01-17 18:03:39 -0800 |
| commit | 87a0b2fafc09766d8c55461a18345a1cfb10a7fe (patch) | |
| tree | f2ecd87b34a4709e49b51470056f6b6e528fefca /kernel/livepatch/patch.c | |
| parent | Input: ti_am335x_tsc - fix a typo in a comment (diff) | |
| parent | Linux 5.16 (diff) | |
Merge tag 'v5.16' into next
Sync up with mainline to bring in the latest API changes.
Diffstat (limited to 'kernel/livepatch/patch.c')
| -rw-r--r-- | kernel/livepatch/patch.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index e8029aea67f1..fe316c021d73 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -49,14 +49,15 @@ static void notrace klp_ftrace_handler(unsigned long ip, ops = container_of(fops, struct klp_ops, fops); + /* + * The ftrace_test_recursion_trylock() will disable preemption, + * which is required for the variant of synchronize_rcu() that is + * used to allow patching functions where RCU is not watching. + * See klp_synchronize_transition() for more details. + */ bit = ftrace_test_recursion_trylock(ip, parent_ip); if (WARN_ON_ONCE(bit < 0)) return; - /* - * A variant of synchronize_rcu() is used to allow patching functions - * where RCU is not watching, see klp_synchronize_transition(). - */ - preempt_disable_notrace(); func = list_first_or_null_rcu(&ops->func_stack, struct klp_func, stack_node); @@ -120,7 +121,6 @@ static void notrace klp_ftrace_handler(unsigned long ip, klp_arch_set_pc(fregs, (unsigned long)func->new_func); unlock: - preempt_enable_notrace(); ftrace_test_recursion_unlock(bit); } |