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authorYonghong Song <yhs@fb.com>2018-04-28 22:28:16 -0700
committerAlexei Starovoitov <ast@kernel.org>2018-04-29 08:45:54 -0700
commit79b45350131057250236e162ce7b3c0b291dc0a4 (patch)
tree6aeacaea9a6182914c6e79e073e9f279f57d7cf2 /tools/testing/selftests/bpf/test_stacktrace_build_id.c
parent173965fbfba596c02fa128966c2a33cb88afcd7f (diff)
tools/bpf: add a test for bpf_get_stack with tracepoint prog
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> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/test_stacktrace_build_id.c')
-rw-r--r--tools/testing/selftests/bpf/test_stacktrace_build_id.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/tools/testing/selftests/bpf/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
index b755bd783ce5..d86c281e957f 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;
}