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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-02-24 15:01:35 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-02-24 16:12:20 -0800 |
| commit | f03efe49bd16c017107ff5079d08ea428e390dde (patch) | |
| tree | 50cd6a079cead0ca2eb56fd805f860599238eaaf /kernel/trace | |
| parent | dbca151cad736c99f4817076daf9fd02ed0c2daa (diff) | |
| download | lwn-f03efe49bd16c017107ff5079d08ea428e390dde.tar.gz lwn-f03efe49bd16c017107ff5079d08ea428e390dde.zip | |
bpf/tracing: Remove redundant preempt_disable() in __bpf_trace_run()
__bpf_trace_run() disables preemption around the BPF_PROG_RUN() invocation.
This is redundant because __bpf_trace_run() is invoked from a trace point
via __DO_TRACE() which already disables preemption _before_ invoking any of
the functions which are attached to a trace point.
Remove it and add a cant_sleep() check.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145642.847220186@linutronix.de
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index b8661bd0d028..4d42a5d05ec9 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1516,10 +1516,9 @@ void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) static __always_inline void __bpf_trace_run(struct bpf_prog *prog, u64 *args) { + cant_sleep(); rcu_read_lock(); - preempt_disable(); (void) BPF_PROG_RUN(prog, args); - preempt_enable(); rcu_read_unlock(); } |