Messages in this thread Patch in this message | | | Date | Mon, 24 Feb 2020 15:01:35 +0100 | From | Thomas Gleixner <> | Subject | [patch V3 04/22] bpf/tracing: Remove redundant preempt_disable() in __bpf_trace_run() |
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__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> --- V3: Add a cant_sleep() check. --- kernel/trace/bpf_trace.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1516,10 +1516,9 @@ void bpf_put_raw_tracepoint(struct bpf_r 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(); }
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