linux/samples/bpf/syscall_tp_kern.c

63 lines
1.3 KiB
C

/* Copyright (c) 2017 Facebook
*
* 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 <uapi/linux/bpf.h>
#include "bpf_helpers.h"
struct syscalls_enter_open_args {
unsigned long long unused;
long syscall_nr;
long filename_ptr;
long flags;
long mode;
};
struct syscalls_exit_open_args {
unsigned long long unused;
long syscall_nr;
long ret;
};
struct bpf_map_def SEC("maps") enter_open_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u32),
.max_entries = 1,
};
struct bpf_map_def SEC("maps") exit_open_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(u32),
.value_size = sizeof(u32),
.max_entries = 1,
};
static __always_inline void count(void *map)
{
u32 key = 0;
u32 *value, init_val = 1;
value = bpf_map_lookup_elem(map, &key);
if (value)
*value += 1;
else
bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
}
SEC("tracepoint/syscalls/sys_enter_open")
int trace_enter_open(struct syscalls_enter_open_args *ctx)
{
count((void *)&enter_open_map);
return 0;
}
SEC("tracepoint/syscalls/sys_exit_open")
int trace_enter_exit(struct syscalls_exit_open_args *ctx)
{
count((void *)&exit_open_map);
return 0;
}