From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yonghong Song Subject: [PATCH bpf-next v8 10/10] tools/bpf: add a test for bpf_get_stack with tracepoint prog Date: Sat, 28 Apr 2018 00:02:05 -0700 Message-ID: <20180428070205.1059628-11-yhs@fb.com> References: <20180428070205.1059628-1-yhs@fb.com> Mime-Version: 1.0 Content-Type: text/plain Cc: To: , , Return-path: Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:60604 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752967AbeD1HCH (ORCPT ); Sat, 28 Apr 2018 03:02:07 -0400 Received: from pps.filterd (m0044010.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3S70Xbk005276 for ; Sat, 28 Apr 2018 00:02:07 -0700 Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2hmh2s0780-2 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Sat, 28 Apr 2018 00:02:07 -0700 In-Reply-To: <20180428070205.1059628-1-yhs@fb.com> Sender: netdev-owner@vger.kernel.org List-ID: The test_stacktrace_map and test_stacktrace_build_id are enhanced to call bpf_get_stack in the helper to get the stack trace as well. The stack traces from bpf_get_stack and bpf_get_stackid are compared to ensure that for the same stack as represented as the same hash, their ip addresses or build id's must be the same. Acked-by: Alexei Starovoitov Signed-off-by: Yonghong Song --- tools/testing/selftests/bpf/test_progs.c | 70 ++++++++++++++++++++-- .../selftests/bpf/test_stacktrace_build_id.c | 20 ++++++- tools/testing/selftests/bpf/test_stacktrace_map.c | 19 +++++- 3 files changed, 98 insertions(+), 11 deletions(-) diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index c148a55..664db67 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -897,11 +897,47 @@ static int compare_map_keys(int map1_fd, int map2_fd) return 0; } +static int compare_stack_ips(int smap_fd, int amap_fd, int stack_trace_len) +{ + __u32 key, next_key, *cur_key_p, *next_key_p; + char *val_buf1, *val_buf2; + int i, err = 0; + + val_buf1 = malloc(stack_trace_len); + val_buf2 = malloc(stack_trace_len); + cur_key_p = NULL; + next_key_p = &key; + while (bpf_map_get_next_key(smap_fd, cur_key_p, next_key_p) == 0) { + err = bpf_map_lookup_elem(smap_fd, next_key_p, val_buf1); + if (err) + goto out; + err = bpf_map_lookup_elem(amap_fd, next_key_p, val_buf2); + if (err) + goto out; + for (i = 0; i < stack_trace_len; i++) { + if (val_buf1[i] != val_buf2[i]) { + err = -1; + goto out; + } + } + key = *next_key_p; + cur_key_p = &key; + next_key_p = &next_key; + } + if (errno != ENOENT) + err = -1; + +out: + free(val_buf1); + free(val_buf2); + return err; +} + static void test_stacktrace_map() { - int control_map_fd, stackid_hmap_fd, stackmap_fd; + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; const char *file = "./test_stacktrace_map.o"; - int bytes, efd, err, pmu_fd, prog_fd; + int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len; struct perf_event_attr attr = {}; __u32 key, val, duration = 0; struct bpf_object *obj; @@ -957,6 +993,10 @@ static void test_stacktrace_map() if (stackmap_fd < 0) goto disable_pmu; + stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); + if (stack_amap_fd < 0) + goto disable_pmu; + /* give some time for bpf program run */ sleep(1); @@ -978,6 +1018,12 @@ static void test_stacktrace_map() "err %d errno %d\n", err, errno)) goto disable_pmu_noerr; + stack_trace_len = PERF_MAX_STACK_DEPTH * sizeof(__u64); + err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); + if (CHECK(err, "compare_stack_ips stackmap vs. stack_amap", + "err %d errno %d\n", err, errno)) + goto disable_pmu_noerr; + goto disable_pmu_noerr; disable_pmu: error_cnt++; @@ -1071,9 +1117,9 @@ static int extract_build_id(char *build_id, size_t size) static void test_stacktrace_build_id(void) { - int control_map_fd, stackid_hmap_fd, stackmap_fd; + int control_map_fd, stackid_hmap_fd, stackmap_fd, stack_amap_fd; const char *file = "./test_stacktrace_build_id.o"; - int bytes, efd, err, pmu_fd, prog_fd; + int bytes, efd, err, pmu_fd, prog_fd, stack_trace_len; struct perf_event_attr attr = {}; __u32 key, previous_key, val, duration = 0; struct bpf_object *obj; @@ -1138,6 +1184,11 @@ static void test_stacktrace_build_id(void) err, errno)) goto disable_pmu; + stack_amap_fd = bpf_find_map(__func__, obj, "stack_amap"); + if (CHECK(stack_amap_fd < 0, "bpf_find_map stack_amap", + "err %d errno %d\n", err, errno)) + goto disable_pmu; + assert(system("dd if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0); assert(system("./urandom_read if=/dev/urandom of=/dev/zero count=4 2> /dev/null") == 0); @@ -1189,8 +1240,15 @@ static void test_stacktrace_build_id(void) previous_key = key; } while (bpf_map_get_next_key(stackmap_fd, &previous_key, &key) == 0); - CHECK(build_id_matches < 1, "build id match", - "Didn't find expected build ID from the map"); + if (CHECK(build_id_matches < 1, "build id match", + "Didn't find expected build ID from the map")) + goto disable_pmu; + + stack_trace_len = PERF_MAX_STACK_DEPTH + * sizeof(struct bpf_stack_build_id); + err = compare_stack_ips(stackmap_fd, stack_amap_fd, stack_trace_len); + CHECK(err, "compare_stack_ips stackmap vs. stack_amap", + "err %d errno %d\n", err, errno); disable_pmu: ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE); diff --git a/tools/testing/selftests/bpf/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/test_stacktrace_build_id.c index b755bd7..d86c281 100644 --- a/tools/testing/selftests/bpf/test_stacktrace_build_id.c +++ b/tools/testing/selftests/bpf/test_stacktrace_build_id.c @@ -19,7 +19,7 @@ struct bpf_map_def SEC("maps") stackid_hmap = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(__u32), .value_size = sizeof(__u32), - .max_entries = 10000, + .max_entries = 16384, }; struct bpf_map_def SEC("maps") stackmap = { @@ -31,6 +31,14 @@ struct bpf_map_def SEC("maps") stackmap = { .map_flags = BPF_F_STACK_BUILD_ID, }; +struct bpf_map_def SEC("maps") stack_amap = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(struct bpf_stack_build_id) + * PERF_MAX_STACK_DEPTH, + .max_entries = 128, +}; + /* taken from /sys/kernel/debug/tracing/events/random/urandom_read/format */ struct random_urandom_args { unsigned long long pad; @@ -42,7 +50,10 @@ struct random_urandom_args { SEC("tracepoint/random/urandom_read") int oncpu(struct random_urandom_args *args) { + __u32 max_len = sizeof(struct bpf_stack_build_id) + * PERF_MAX_STACK_DEPTH; __u32 key = 0, val = 0, *value_p; + void *stack_p; value_p = bpf_map_lookup_elem(&control_map, &key); if (value_p && *value_p) @@ -50,8 +61,13 @@ int oncpu(struct random_urandom_args *args) /* The size of stackmap and stackid_hmap should be the same */ key = bpf_get_stackid(args, &stackmap, BPF_F_USER_STACK); - if ((int)key >= 0) + if ((int)key >= 0) { bpf_map_update_elem(&stackid_hmap, &key, &val, 0); + stack_p = bpf_map_lookup_elem(&stack_amap, &key); + if (stack_p) + bpf_get_stack(args, stack_p, max_len, + BPF_F_USER_STACK | BPF_F_USER_BUILD_ID); + } return 0; } diff --git a/tools/testing/selftests/bpf/test_stacktrace_map.c b/tools/testing/selftests/bpf/test_stacktrace_map.c index 76d85c5d..af111af 100644 --- a/tools/testing/selftests/bpf/test_stacktrace_map.c +++ b/tools/testing/selftests/bpf/test_stacktrace_map.c @@ -19,14 +19,21 @@ struct bpf_map_def SEC("maps") stackid_hmap = { .type = BPF_MAP_TYPE_HASH, .key_size = sizeof(__u32), .value_size = sizeof(__u32), - .max_entries = 10000, + .max_entries = 16384, }; struct bpf_map_def SEC("maps") stackmap = { .type = BPF_MAP_TYPE_STACK_TRACE, .key_size = sizeof(__u32), .value_size = sizeof(__u64) * PERF_MAX_STACK_DEPTH, - .max_entries = 10000, + .max_entries = 16384, +}; + +struct bpf_map_def SEC("maps") stack_amap = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(__u64) * PERF_MAX_STACK_DEPTH, + .max_entries = 16384, }; /* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */ @@ -44,7 +51,9 @@ struct sched_switch_args { SEC("tracepoint/sched/sched_switch") int oncpu(struct sched_switch_args *ctx) { + __u32 max_len = PERF_MAX_STACK_DEPTH * sizeof(__u64); __u32 key = 0, val = 0, *value_p; + void *stack_p; value_p = bpf_map_lookup_elem(&control_map, &key); if (value_p && *value_p) @@ -52,8 +61,12 @@ int oncpu(struct sched_switch_args *ctx) /* The size of stackmap and stackid_hmap should be the same */ key = bpf_get_stackid(ctx, &stackmap, 0); - if ((int)key >= 0) + if ((int)key >= 0) { bpf_map_update_elem(&stackid_hmap, &key, &val, 0); + stack_p = bpf_map_lookup_elem(&stack_amap, &key); + if (stack_p) + bpf_get_stack(ctx, stack_p, max_len, 0); + } return 0; } -- 2.9.5