linux/samples/bpf/tracex2_kern.c
Toke Høiland-Jørgensen 7cf245a37e samples/bpf: Use consistent include paths for libbpf
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 16:37:45 -08:00

102 lines
2.3 KiB
C

/* Copyright (c) 2013-2015 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/skbuff.h>
#include <linux/netdevice.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
struct bpf_map_def SEC("maps") my_map = {
.type = BPF_MAP_TYPE_HASH,
.key_size = sizeof(long),
.value_size = sizeof(long),
.max_entries = 1024,
};
/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
* example will no longer be meaningful
*/
SEC("kprobe/kfree_skb")
int bpf_prog2(struct pt_regs *ctx)
{
long loc = 0;
long init_val = 1;
long *value;
/* read ip of kfree_skb caller.
* non-portable version of __builtin_return_address(0)
*/
BPF_KPROBE_READ_RET_IP(loc, ctx);
value = bpf_map_lookup_elem(&my_map, &loc);
if (value)
*value += 1;
else
bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
return 0;
}
static unsigned int log2(unsigned int v)
{
unsigned int r;
unsigned int shift;
r = (v > 0xFFFF) << 4; v >>= r;
shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
shift = (v > 0xF) << 2; v >>= shift; r |= shift;
shift = (v > 0x3) << 1; v >>= shift; r |= shift;
r |= (v >> 1);
return r;
}
static unsigned int log2l(unsigned long v)
{
unsigned int hi = v >> 32;
if (hi)
return log2(hi) + 32;
else
return log2(v);
}
struct hist_key {
char comm[16];
u64 pid_tgid;
u64 uid_gid;
u64 index;
};
struct bpf_map_def SEC("maps") my_hist_map = {
.type = BPF_MAP_TYPE_PERCPU_HASH,
.key_size = sizeof(struct hist_key),
.value_size = sizeof(long),
.max_entries = 1024,
};
SEC("kprobe/sys_write")
int bpf_prog3(struct pt_regs *ctx)
{
long write_size = PT_REGS_PARM3(ctx);
long init_val = 1;
long *value;
struct hist_key key;
key.index = log2l(write_size);
key.pid_tgid = bpf_get_current_pid_tgid();
key.uid_gid = bpf_get_current_uid_gid();
bpf_get_current_comm(&key.comm, sizeof(key.comm));
value = bpf_map_lookup_elem(&my_hist_map, &key);
if (value)
__sync_fetch_and_add(value, 1);
else
bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
return 0;
}
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;