Re: [PATCH v3 perf, bpf-next 1/4] perf, bpf: Introduce PERF_RECORD_BPF_EVENT

From: Peter Zijlstra
Date: Wed Dec 12 2018 - 07:06:44 EST


On Tue, Dec 11, 2018 at 03:33:47PM -0800, Song Liu wrote:
> +static void perf_event_bpf_output(struct perf_event *event,
> + void *data)
> +{
> + struct perf_bpf_event *bpf_event = data;
> + struct perf_output_handle handle;
> + struct perf_sample_data sample;
> + char name[KSYM_NAME_LEN];
> + int name_len;
> + int ret;
> +
> + if (!perf_event_bpf_match(event))
> + return;
> +
> + /* get prog name and round up to 64 bit aligned */
> + bpf_get_prog_name(bpf_event->prog, name);
> + name_len = strlen(name) + 1;
> + while (!IS_ALIGNED(name_len, sizeof(u64)))
> + name[name_len++] = '\0';

Does this not require something like:

BUILD_BUG_ON(KSYM_NAME_LEN % sizeof(u64));