From 79b45350131057250236e162ce7b3c0b291dc0a4 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 28 Apr 2018 22:28:16 -0700 Subject: 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 Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov --- .../testing/selftests/bpf/test_stacktrace_build_id.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'tools/testing/selftests/bpf/test_stacktrace_build_id.c') 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; } -- cgit v1.2.3-59-g8ed1b