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// 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 */
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