diff options
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c new file mode 100644 index 000000000..0c4426592 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_stacktrace_build_id.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018 Facebook + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +#ifndef PERF_MAX_STACK_DEPTH +#define PERF_MAX_STACK_DEPTH 127 +#endif + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} control_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, 16384); + __type(key, __u32); + __type(value, __u32); +} stackid_hmap SEC(".maps"); + +typedef struct bpf_stack_build_id stack_trace_t[PERF_MAX_STACK_DEPTH]; + +struct { + __uint(type, BPF_MAP_TYPE_STACK_TRACE); + __uint(max_entries, 128); + __uint(map_flags, BPF_F_STACK_BUILD_ID); + __type(key, __u32); + __type(value, stack_trace_t); +} stackmap SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 128); + __type(key, __u32); + __type(value, stack_trace_t); +} stack_amap SEC(".maps"); + +SEC("kprobe/urandom_read_iter") +int oncpu(struct pt_regs *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) + return 0; /* skip if non-zero *value_p */ + + /* 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) { + 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; +} + +char _license[] SEC("license") = "GPL"; |