Re: [PATCH v5 3/6] perf: implement pmu perf_kprobe

From: Song Liu
Date: Wed Dec 20 2017 - 13:11:15 EST



> On Dec 20, 2017, at 2:14 AM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Wed, Dec 20, 2017 at 11:03:01AM +0100, Peter Zijlstra wrote:
>> On Wed, Dec 06, 2017 at 02:45:15PM -0800, Song Liu wrote:
>>> @@ -8537,7 +8620,7 @@ static int perf_event_set_filter(struct perf_event *event, void __user *arg)
>>> char *filter_str;
>>> int ret = -EINVAL;
>>>
>>> - if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
>>> + if ((!perf_event_is_tracing(event) ||
>>> !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
>>> !has_addr_filter(event))
>>> return -EINVAL;
>>
>> You actually missed an instance later in this same function... fixing
>> that.
>
>
> @@ -8518,23 +8601,19 @@ perf_event_set_addr_filter(struct perf_e
>
> static int perf_event_set_filter(struct perf_event *event, void __user *arg)
> {
> - char *filter_str;
> int ret = -EINVAL;
> -
> - if ((event->attr.type != PERF_TYPE_TRACEPOINT ||
> - !IS_ENABLED(CONFIG_EVENT_TRACING)) &&
> - !has_addr_filter(event))
> - return -EINVAL;
> + char *filter_str;
>
> filter_str = strndup_user(arg, PAGE_SIZE);
> if (IS_ERR(filter_str))
> return PTR_ERR(filter_str);
>
> - if (IS_ENABLED(CONFIG_EVENT_TRACING) &&
> - event->attr.type == PERF_TYPE_TRACEPOINT)
> - ret = ftrace_profile_set_filter(event, event->attr.config,
> - filter_str);
> - else if (has_addr_filter(event))
> +#ifdef CONFIG_EVENT_TRACING
> + if (perf_event_is_tracing(event))
> + ret = ftrace_profile_set_filter(event, event->attr.config, filter_str);
> + else
> +#endif
> + if (has_addr_filter(event))
> ret = perf_event_set_addr_filter(event, filter_str);
>
> kfree(filter_str);
>
>
>
> Is that right?

Yeah, this is right and neat. Thanks a lot for your help on this.

I think there is one more thing to change:

diff --git i/kernel/events/core.c w/kernel/events/core.c
index a906f30..516ff9b 100644
--- i/kernel/events/core.c
+++ w/kernel/events/core.c
@@ -8226,7 +8226,7 @@ static int perf_event_set_bpf_prog(struct perf_event *event, u32 prog_fd)

static void perf_event_free_bpf_prog(struct perf_event *event)
{
- if (event->attr.type != PERF_TYPE_TRACEPOINT) {
+ if (!perf_event_is_tracing(event)) {
perf_event_free_bpf_handler(event);
return;
}

Thanks,
Song