On Wed, Aug 31, 2016 at 02:50:41PM -0700, Alexei Starovoitov wrote:
> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
> index 97bfe62f30d7..dcaaaf3ec8e6 100644
> --- a/include/linux/perf_event.h
> +++ b/include/linux/perf_event.h
> @@ -679,6 +679,8 @@ struct perf_event {
> u64 (*clock)(void);
> perf_overflow_handler_t overflow_handler;
> void *overflow_handler_context;
> + perf_overflow_handler_t orig_overflow_handler;
> + struct bpf_prog *prog;
Should we put that under CONFIG_BPF_SYSCALL too?
> diff --git a/kernel/events/core.c b/kernel/events/core.c
> index 3cfabdf7b942..305433ab2447 100644
> --- a/kernel/events/core.c
> +++ b/kernel/events/core.c
> @@ -7637,11 +7637,75 @@ static void perf_event_free_filter(struct perf_event
> *event)
> ftrace_profile_free_filter(event);
> }
>
> +static void bpf_overflow_handler(struct perf_event *event,
> + struct perf_sample_data *data,
> + struct pt_regs *regs)
> +{
> + struct bpf_perf_event_data_kern ctx = {
> + .data = data,
> + .regs = regs,
> + };
> + int ret = 0;
> +
> +#ifdef CONFIG_BPF_SYSCALL
> + preempt_disable();
> + if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1))
> + goto out;
> + rcu_read_lock();
> + ret = BPF_PROG_RUN(event->prog, (void *)&ctx);
> + rcu_read_unlock();
> + out:
Please, no leading space before labels. Use something like:
[diff "default"]
xfuncname = "^[[:alpha:]$_].*[^:]$"
In your .gitconfig if you want to keep diff output 'sane'.
> + __this_cpu_dec(bpf_prog_active);
> + preempt_enable();
> +#endif
> + if (!ret)
> + return;
> +
> + event->orig_overflow_handler(event, data, regs);
> +}
Other than that, ACK.
