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 <a...@kernel.org>
Signed-off-by: Yonghong Song <y...@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
