linux/samples/bpf/tracex4_kern.c
Andrii Nakryiko 3ac4dbe3dd selftests/bpf: Split off tracing-only helpers into bpf_tracing.h
Split-off PT_REGS-related helpers into bpf_tracing.h header. Adjust
selftests and samples to include it where necessary.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-5-andriin@fb.com
2019-10-08 23:16:03 +02:00

56 lines
1.3 KiB
C

/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"
#include "bpf_tracing.h"
struct pair {
u64 val;
u64 ip;
};
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(long),
.value_size = sizeof(struct pair),
.max_entries = 1000000,
};
/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
* example will no longer be meaningful
*/
SEC("kprobe/kmem_cache_free")
int bpf_prog1(struct pt_regs *ctx)
{
long ptr = PT_REGS_PARM2(ctx);
bpf_map_delete_elem(&my_map, &ptr);
return 0;
}
SEC("kretprobe/kmem_cache_alloc_node")
int bpf_prog2(struct pt_regs *ctx)
{
long ptr = PT_REGS_RC(ctx);
long ip = 0;
/* get ip address of kmem_cache_alloc_node() caller */
BPF_KRETPROBE_READ_RET_IP(ip, ctx);
struct pair v = {
.val = bpf_ktime_get_ns(),
.ip = ip,
};
bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;