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| author | Andrii Nakryiko <andrii@kernel.org> | 2024-04-18 12:09:09 -0700 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2024-05-01 23:18:48 +0900 |
| commit | e03c05ac9813410d15c9c39ccf02c84efe563533 (patch) | |
| tree | 87dc83a0f32ca2fd563cebeec0a164f8b7ae6ba1 | |
| parent | b0e28a4b5becea84ae6fca5cbd8a6b80a134e223 (diff) | |
rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get()
Take into account CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING when validating
that RCU is watching when trying to setup rethooko on a function entry.
One notable exception when we force rcu_is_watching() check is
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y case, in which case kretprobes will use
old-style int3-based workflow instead of relying on ftrace, making RCU
watching check important to validate.
This further (in addition to improvements in the previous patch)
improves BPF multi-kretprobe (which rely on rethook) runtime throughput
by 2.3%, according to BPF benchmarks ([0]).
[0] https://lore.kernel.org/bpf/CAEf4BzauQ2WKMjZdc9s0rBWa01BYbgwHN6aNDXQSHYia47pQ-w@mail.gmail.com/
Link: https://lore.kernel.org/all/20240418190909.704286-2-andrii@kernel.org/
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
| -rw-r--r-- | kernel/trace/rethook.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index 4297a132a7ae..30d224946881 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -166,6 +166,7 @@ struct rethook_node *rethook_try_get(struct rethook *rh) if (unlikely(!handler)) return NULL; +#if defined(CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING) || defined(CONFIG_KPROBE_EVENTS_ON_NOTRACE) /* * This expects the caller will set up a rethook on a function entry. * When the function returns, the rethook will eventually be reclaimed @@ -174,6 +175,7 @@ struct rethook_node *rethook_try_get(struct rethook *rh) */ if (unlikely(!rcu_is_watching())) return NULL; +#endif return (struct rethook_node *)objpool_pop(&rh->pool); } |