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 */