On 8/6/19 4:42 PM, Daniel Xu wrote:
> ---
> tools/include/uapi/linux/perf_event.h | 23 ++++++++++
> .../selftests/bpf/prog_tests/attach_probe.c | 43 +++++++++++++++++++
Could you separate this into two patches?
one patch for uapi update tools/include/uapi/linux/perf_event.h
and the other for .../selftests/bpf/prog_tests/attach_probe.c
The reason is to help libbpf mirror sync'ing.
> 2 files changed, 66 insertions(+)
>
> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> index 7198ddd0c6b1..4a5e18606baf 100644
> --- a/tools/include/uapi/linux/perf_event.h
> +++ b/tools/include/uapi/linux/perf_event.h
> @@ -447,6 +447,28 @@ struct perf_event_query_bpf {
> __u32 ids[0];
> };
>
> +/*
> + * Structure used by below PERF_EVENT_IOC_QUERY_KPROE command
> + * to query information about the kprobe attached to the perf
> + * event.
> + */
> +struct perf_event_query_kprobe {
> + /*
> + * Size of structure for forward/backward compatibility
> + */
> + __u32 size;
> + /*
> + * Set by the kernel to indicate number of times this kprobe
> + * was temporarily disabled
> + */
> + __u64 nmissed;
> + /*
> + * Set by the kernel to indicate number of times this kprobe
> + * was hit
> + */
> + __u64 nhit;
> +};
> +
> /*
> * Ioctls that can be done on a perf event fd:
> */
> @@ -462,6 +484,7 @@ struct perf_event_query_bpf {
> #define PERF_EVENT_IOC_PAUSE_OUTPUT _IOW('$', 9, __u32)
> #define PERF_EVENT_IOC_QUERY_BPF _IOWR('$', 10, struct perf_event_query_bpf *)
> #define PERF_EVENT_IOC_MODIFY_ATTRIBUTES _IOW('$', 11, struct perf_event_attr *)
> +#define PERF_EVENT_IOC_QUERY_KPROBE _IOWR('$', 12, struct perf_event_query_kprobe *)
>
> enum perf_event_ioc_flags {
> PERF_IOC_FLAG_GROUP = 1U << 0,
> diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> index 5ecc267d98b0..5f118e9a1469 100644
> --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
> @@ -38,9 +38,12 @@ void test_attach_probe(void)
> struct bpf_link *kretprobe_link = NULL;
> struct bpf_link *uprobe_link = NULL;
> struct bpf_link *uretprobe_link = NULL;
> + int kprobe_fd, kretprobe_fd;
> int results_map_fd;
> size_t uprobe_offset;
> ssize_t base_addr;
> + struct perf_event_query_kprobe kprobe_query;
> + struct perf_event_query_kprobe kretprobe_query;
Since you are adding new fields, could you try to maintain reverse
Christmas coding style?
>
> base_addr = get_base_addr();
> if (CHECK(base_addr < 0, "get_base_addr",
> @@ -116,6 +119,46 @@ void test_attach_probe(void)
> /* trigger & validate kprobe && kretprobe */
> usleep(1);
>
> + kprobe_fd = bpf_link__get_perf_fd(kprobe_link);
> + if (CHECK(kprobe_fd < 0, "kprobe_get_perf_fd",
> + "failed to get perf fd from kprobe link\n"))
> + goto cleanup;
> +
> + kretprobe_fd = bpf_link__get_perf_fd(kretprobe_link);
> + if (CHECK(kprobe_fd < 0, "kprobe_get_perf_fd",
typo: kprobe_fd => kretprobe_fd, kretprobe_get_perf_fd?
> + "failed to get perf fd from kprobe link\n"))
kretprobe link?
> + goto cleanup;
> +
> + memset(&kprobe_query, 0, sizeof(kprobe_query));
> + kprobe_query.size = sizeof(kprobe_query);
> + err = ioctl(kprobe_fd, PERF_EVENT_IOC_QUERY_KPROBE, &kprobe_query);
> + if (CHECK(err, "get_kprobe_ioctl",
> + "failed to issue kprobe query ioctl\n"))
> + goto cleanup;
> + if (CHECK(kprobe_query.nmissed > 0, "get_kprobe_ioctl",
> + "read incorect nmissed from kprobe_ioctl: %llu\n",
> + kprobe_query.nmissed))
> + goto cleanup;
> + if (CHECK(kprobe_query.nhit <= 0, "get_kprobe_ioctl",
nhit is __u64, it cannot be less than 0.
> + "read incorect nhit from kprobe_ioctl: %llu\n",
> + kprobe_query.nhit))
> + goto cleanup;
> +
> + memset(&kretprobe_query, 0, sizeof(kretprobe_query));
> + kretprobe_query.size = sizeof(kretprobe_query);
> + err = ioctl(kretprobe_fd, PERF_EVENT_IOC_QUERY_KPROBE, &kretprobe_query);
> + if (CHECK(err, "get_kretprobe_ioctl",
> + "failed to issue kprobe query ioctl\n"))
> + goto cleanup;
> + if (CHECK(kretprobe_query.nmissed > 0, "get_kretprobe_ioctl",
> + "read incorect nmissed from kretprobe_ioctl: %llu\n",
> + kretprobe_query.nmissed))
> + goto cleanup;
> + if (CHECK(kretprobe_query.nhit <= 0, "get_kretprobe_ioctl",
<= 0 => == 0?
> + "read incorect nhit from kretprobe_ioctl: %llu\n",
> + kretprobe_query.nhit))
> + goto cleanup;
> +
> err = bpf_map_lookup_elem(results_map_fd, &kprobe_idx, &res);
> if (CHECK(err, "get_kprobe_res",
> "failed to get kprobe res: %d\n", err))
>
