selftests/bpf: switch test_tcpnotify to perf_buffer API

Switch test_tcpnotify test to use libbpf's perf_buffer API instead of
re-implementing portion of it.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/tools/testing/selftests/bpf/test_tcpnotify_user.c b/tools/testing/selftests/bpf/test_tcpnotify_user.c
index 86152d9ae95b8f8bb87b4fff600c43d8d73709ee..f9765ddf07613ee26c108c93da57ebc44f9eb2ba 100644 (file)
--- a/tools/testing/selftests/bpf/test_tcpnotify_user.c
+++ b/tools/testing/selftests/bpf/test_tcpnotify_user.c
@@ -17,6 +17,7 @@
 #include <linux/rtnetlink.h>
 #include <signal.h>
 #include <linux/perf_event.h>
+#include <linux/err.h>
 
 #include "bpf_rlimit.h"
 #include "bpf_util.h"
@@ -30,28 +31,34 @@
 pthread_t tid;
 int rx_callbacks;
 
-static int dummyfn(void *data, int size)
+static void dummyfn(void *ctx, int cpu, void *data, __u32 size)
 {
        struct tcp_notifier *t = data;
 
        if (t->type != 0xde || t->subtype != 0xad ||
            t->source != 0xbe || t->hash != 0xef)
-               return 1;
+               return;
        rx_callbacks++;
-       return 0;
 }
 
-void tcp_notifier_poller(int fd)
+void tcp_notifier_poller(struct perf_buffer *pb)
 {
-       while (1)
-               perf_event_poller(fd, dummyfn);
+       int err;
+
+       while (1) {
+               err = perf_buffer__poll(pb, 100);
+               if (err < 0 && err != -EINTR) {
+                       printf("failed perf_buffer__poll: %d\n", err);
+                       return;
+               }
+       }
 }
 
 static void *poller_thread(void *arg)
 {
-       int fd = *(int *)arg;
+       struct perf_buffer *pb = arg;
 
-       tcp_notifier_poller(fd);
+       tcp_notifier_poller(pb);
        return arg;
 }
 
@@ -60,52 +67,20 @@ int verify_result(const struct tcpnotify_globals *result)
        return (result->ncalls > 0 && result->ncalls == rx_callbacks ? 0 : 1);
 }
 
-static int bpf_find_map(const char *test, struct bpf_object *obj,
-                       const char *name)
-{
-       struct bpf_map *map;
-
-       map = bpf_object__find_map_by_name(obj, name);
-       if (!map) {
-               printf("%s:FAIL:map '%s' not found\n", test, name);
-               return -1;
-       }
-       return bpf_map__fd(map);
-}
-
-static int setup_bpf_perf_event(int mapfd)
-{
-       struct perf_event_attr attr = {
-               .sample_type = PERF_SAMPLE_RAW,
-               .type = PERF_TYPE_SOFTWARE,
-               .config = PERF_COUNT_SW_BPF_OUTPUT,
-       };
-       int key = 0;
-       int pmu_fd;
-
-       pmu_fd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, 0);
-       if (pmu_fd < 0)
-               return pmu_fd;
-       bpf_map_update_elem(mapfd, &key, &pmu_fd, BPF_ANY);
-
-       ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0);
-       return pmu_fd;
-}
-
 int main(int argc, char **argv)
 {
        const char *file = "test_tcpnotify_kern.o";
-       int prog_fd, map_fd, perf_event_fd;
+       struct bpf_map *perf_map, *global_map;
+       struct perf_buffer_opts pb_opts = {};
        struct tcpnotify_globals g = {0};
+       struct perf_buffer *pb = NULL;
        const char *cg_path = "/foo";
+       int prog_fd, rv, cg_fd = -1;
        int error = EXIT_FAILURE;
        struct bpf_object *obj;
-       int cg_fd = -1;
-       __u32 key = 0;
-       int rv;
        char test_script[80];
-       int pmu_fd;
        cpu_set_t cpuset;
+       __u32 key = 0;
 
        CPU_ZERO(&cpuset);
        CPU_SET(0, &cpuset);
@@ -133,19 +108,24 @@ int main(int argc, char **argv)
                goto err;
        }
 
-       perf_event_fd = bpf_find_map(__func__, obj, "perf_event_map");
-       if (perf_event_fd < 0)
+       perf_map = bpf_object__find_map_by_name(obj, "perf_event_map");
+       if (!perf_map) {
+               printf("FAIL:map '%s' not found\n", "perf_event_map");
                goto err;
+       }
 
-       map_fd = bpf_find_map(__func__, obj, "global_map");
-       if (map_fd < 0)
-               goto err;
+       global_map = bpf_object__find_map_by_name(obj, "global_map");
+       if (!global_map) {
+               printf("FAIL:map '%s' not found\n", "global_map");
+               return -1;
+       }
 
-       pmu_fd = setup_bpf_perf_event(perf_event_fd);
-       if (pmu_fd < 0 || perf_event_mmap(pmu_fd) < 0)
+       pb_opts.sample_cb = dummyfn;
+       pb = perf_buffer__new(bpf_map__fd(perf_map), 8, &pb_opts);
+       if (IS_ERR(pb))
                goto err;
 
-       pthread_create(&tid, NULL, poller_thread, (void *)&pmu_fd);
+       pthread_create(&tid, NULL, poller_thread, pb);
 
        sprintf(test_script,
                "iptables -A INPUT -p tcp --dport %d -j DROP",
@@ -162,7 +142,7 @@ int main(int argc, char **argv)
                TESTPORT);
        system(test_script);
 
-       rv = bpf_map_lookup_elem(map_fd, &key, &g);
+       rv = bpf_map_lookup_elem(bpf_map__fd(global_map), &key, &g);
        if (rv != 0) {
                printf("FAILED: bpf_map_lookup_elem returns %d\n", rv);
                goto err;
@@ -182,5 +162,7 @@ err:
        bpf_prog_detach(cg_fd, BPF_CGROUP_SOCK_OPS);
        close(cg_fd);
        cleanup_cgroup_environment();
+       if (!IS_ERR_OR_NULL(pb))
+               perf_buffer__free(pb);
        return error;
 }