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-rw-r--r--tools/perf/include/bpf/bpf.h70
1 files changed, 70 insertions, 0 deletions
diff --git a/tools/perf/include/bpf/bpf.h b/tools/perf/include/bpf/bpf.h
new file mode 100644
index 000000000..b422aeef5
--- /dev/null
+++ b/tools/perf/include/bpf/bpf.h
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _PERF_BPF_H
+#define _PERF_BPF_H
+
+#include <uapi/linux/bpf.h>
+
+/*
+ * A helper structure used by eBPF C program to describe map attributes to
+ * elf_bpf loader, taken from tools/testing/selftests/bpf/bpf_helpers.h:
+ */
+struct bpf_map {
+ unsigned int type;
+ unsigned int key_size;
+ unsigned int value_size;
+ unsigned int max_entries;
+ unsigned int map_flags;
+ unsigned int inner_map_idx;
+ unsigned int numa_node;
+};
+
+#define bpf_map(name, _type, type_key, type_val, _max_entries) \
+struct bpf_map SEC("maps") name = { \
+ .type = BPF_MAP_TYPE_##_type, \
+ .key_size = sizeof(type_key), \
+ .value_size = sizeof(type_val), \
+ .max_entries = _max_entries, \
+}; \
+struct ____btf_map_##name { \
+ type_key key; \
+ type_val value; \
+}; \
+struct ____btf_map_##name __attribute__((section(".maps." #name), used)) \
+ ____btf_map_##name = { }
+
+/*
+ * FIXME: this should receive .max_entries as a parameter, as careful
+ * tuning of these limits is needed to avoid hitting limits that
+ * prevents other BPF constructs, such as tracepoint handlers,
+ * to get installed, with cryptic messages from libbpf, etc.
+ * For the current need, 'perf trace --filter-pids', 64 should
+ * be good enough, but this surely needs to be revisited.
+ */
+#define pid_map(name, value_type) bpf_map(name, HASH, pid_t, value_type, 64)
+
+static int (*bpf_map_update_elem)(struct bpf_map *map, void *key, void *value, u64 flags) = (void *)BPF_FUNC_map_update_elem;
+static void *(*bpf_map_lookup_elem)(struct bpf_map *map, void *key) = (void *)BPF_FUNC_map_lookup_elem;
+
+static void (*bpf_tail_call)(void *ctx, void *map, int index) = (void *)BPF_FUNC_tail_call;
+
+#define SEC(NAME) __attribute__((section(NAME), used))
+
+#define probe(function, vars) \
+ SEC(#function "=" #function " " #vars) function
+
+#define syscall_enter(name) \
+ SEC("syscalls:sys_enter_" #name) syscall_enter_ ## name
+
+#define syscall_exit(name) \
+ SEC("syscalls:sys_exit_" #name) syscall_exit_ ## name
+
+#define license(name) \
+char _license[] SEC("license") = #name; \
+int _version SEC("version") = LINUX_VERSION_CODE;
+
+static int (*probe_read)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read;
+static int (*probe_read_str)(void *dst, int size, const void *unsafe_addr) = (void *)BPF_FUNC_probe_read_str;
+
+static int (*perf_event_output)(void *, struct bpf_map *, int, void *, unsigned long) = (void *)BPF_FUNC_perf_event_output;
+
+#endif /* _PERF_BPF_H */