| From: Thomas Gleixner <tglx@linutronix.de> |
| Date: Mon, 24 Feb 2020 15:01:37 +0100 |
| Subject: [PATCH 06/22] bpf/trace: Remove redundant preempt_disable from |
| trace_call_bpf() |
| |
| Similar to __bpf_trace_run 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: Sebastian Andrzej Siewior <bigeasy@linutronix.de> |
| --- |
| 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 |
| @@ -83,7 +83,7 @@ unsigned int trace_call_bpf(struct trace |
| if (in_nmi()) /* not supported yet */ |
| return 1; |
| |
| - preempt_disable(); |
| + cant_sleep(); |
| |
| if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { |
| /* |
| @@ -115,7 +115,6 @@ unsigned int trace_call_bpf(struct trace |
| |
| out: |
| __this_cpu_dec(bpf_prog_active); |
| - preempt_enable(); |
| |
| return ret; |
| } |
