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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /tools/testing/selftests/bpf/test_stacktrace_build_id.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/bpf/test_stacktrace_build_id.c')
-rw-r--r--tools/testing/selftests/bpf/test_stacktrace_build_id.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_stacktrace_build_id.c b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
new file mode 100644
index 000000000..d86c281e9
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_stacktrace_build_id.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Facebook
+
+#include <linux/bpf.h>
+#include "bpf_helpers.h"
+
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH 127
+#endif
+
+struct bpf_map_def SEC("maps") control_map = {
+ .type = BPF_MAP_TYPE_ARRAY,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(__u32),
+ .max_entries = 1,
+};
+
+struct bpf_map_def SEC("maps") stackid_hmap = {
+ .type = BPF_MAP_TYPE_HASH,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(__u32),
+ .max_entries = 16384,
+};
+
+struct bpf_map_def SEC("maps") stackmap = {
+ .type = BPF_MAP_TYPE_STACK_TRACE,
+ .key_size = sizeof(__u32),
+ .value_size = sizeof(struct bpf_stack_build_id)
+ * PERF_MAX_STACK_DEPTH,
+ .max_entries = 128,
+ .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;
+ int got_bits;
+ int pool_left;
+ int input_left;
+};
+
+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)
+ 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";
+__u32 _version SEC("version") = 1; /* ignored by tracepoints, required by libbpf.a */