forked from Minki/linux
fe3300897c
Currently, open() is called from the user program and it calls the syscall
'sys_openat', not the 'sys_open'. This leads to an error of the program
of user side, due to the fact that the counter maps are zero since no
function such 'sys_open' is called.
This commit adds the kernel bpf program which are attached to the
tracepoint 'sys_enter_openat' and 'sys_enter_openat'.
Fixes: 1da236b6be ("bpf: add a test case for syscalls/sys_{enter|exit}_* tracepoints")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
74 lines
1.4 KiB
C
74 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/* Copyright (c) 2017 Facebook
|
|
*/
|
|
#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(&enter_open_map);
|
|
return 0;
|
|
}
|
|
|
|
SEC("tracepoint/syscalls/sys_enter_openat")
|
|
int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
|
|
{
|
|
count(&enter_open_map);
|
|
return 0;
|
|
}
|
|
|
|
SEC("tracepoint/syscalls/sys_exit_open")
|
|
int trace_enter_exit(struct syscalls_exit_open_args *ctx)
|
|
{
|
|
count(&exit_open_map);
|
|
return 0;
|
|
}
|
|
|
|
SEC("tracepoint/syscalls/sys_exit_openat")
|
|
int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
|
|
{
|
|
count(&exit_open_map);
|
|
return 0;
|
|
}
|