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From: Yonghong Song <yhs@fb.com>
To: <ast@fb.com>, <daniel@iogearbox.net>, <netdev@vger.kernel.org>
Cc: <kernel-team@fb.com>
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	[thread overview]
Message-ID: <20180428070205.1059628-11-yhs@fb.com> (raw)
In-Reply-To: <20180428070205.1059628-1-yhs@fb.com>

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 <ast@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
 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

      parent reply	other threads:[~2018-04-28  7:02 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-28  7:01 [PATCH bpf-next v8 00/10] bpf: add bpf_get_stack helper Yonghong Song
2018-04-28  7:01 ` [PATCH bpf-next v8 01/10] bpf: change prototype for stack_map_get_build_id_offset Yonghong Song
2018-04-28  7:01 ` [PATCH bpf-next v8 02/10] bpf: add bpf_get_stack helper Yonghong Song
2018-04-28  7:01 ` [PATCH bpf-next v8 03/10] bpf/verifier: refine retval R0 state for " Yonghong Song
2018-04-28  7:01 ` [PATCH bpf-next v8 04/10] bpf: remove never-hit branches in verifier adjust_scalar_min_max_vals Yonghong Song
2018-04-28  7:02 ` [PATCH bpf-next v8 05/10] bpf/verifier: improve register value range tracking with ARSH Yonghong Song
2018-04-28 16:52   ` Alexei Starovoitov
2018-04-28  7:02 ` [PATCH bpf-next v8 06/10] tools/bpf: add bpf_get_stack helper to tools headers Yonghong Song
2018-04-28  7:02 ` [PATCH bpf-next v8 07/10] samples/bpf: move common-purpose trace functions to selftests Yonghong Song
2018-04-28  7:02 ` [PATCH bpf-next v8 08/10] tools/bpf: add a verifier test case for bpf_get_stack helper and ARSH Yonghong Song
2018-04-28  7:02 ` [PATCH bpf-next v8 09/10] tools/bpf: add a test for bpf_get_stack with raw tracepoint prog Yonghong Song
2018-04-28 16:56   ` Alexei Starovoitov
2018-04-28 18:17     ` Y Song
2018-04-28 19:06       ` Alexei Starovoitov
2018-04-28 20:02         ` Yonghong Song
2018-04-28  7:02 ` Yonghong Song [this message]

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