1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * bpf-script-test-prologue.c
 4 * Test BPF prologue
 5 */
 6#ifndef LINUX_VERSION_CODE
 7# error Need LINUX_VERSION_CODE
 8# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
 9#endif
10#define SEC(NAME) __attribute__((section(NAME), used))
11
12#include <uapi/linux/fs.h>
13
14/*
15 * If CONFIG_PROFILE_ALL_BRANCHES is selected,
16 * 'if' is redefined after include kernel header.
17 * Recover 'if' for BPF object code.
18 */
19#ifdef if
20# undef if
21#endif
22
23#define FMODE_READ		0x1
24#define FMODE_WRITE		0x2
25
26static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
27	(void *) 6;
28
29SEC("func=null_lseek file->f_mode offset orig")
30int bpf_func__null_lseek(void *ctx, int err, unsigned long _f_mode,
31			 unsigned long offset, unsigned long orig)
32{
33	fmode_t f_mode = (fmode_t)_f_mode;
34
35	if (err)
36		return 0;
37	if (f_mode & FMODE_WRITE)
38		return 0;
39	if (offset & 1)
40		return 0;
41	if (orig == SEEK_CUR)
42		return 0;
43	return 1;
44}
45
46char _license[] SEC("license") = "GPL";
47int _version SEC("version") = LINUX_VERSION_CODE;

 
 1/*
 2 * bpf-script-test-prologue.c
 3 * Test BPF prologue
 4 */
 5#ifndef LINUX_VERSION_CODE
 6# error Need LINUX_VERSION_CODE
 7# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
 8#endif
 9#define SEC(NAME) __attribute__((section(NAME), used))
10
11#include <uapi/linux/fs.h>
12
13/*
14 * If CONFIG_PROFILE_ALL_BRANCHES is selected,
15 * 'if' is redefined after include kernel header.
16 * Recover 'if' for BPF object code.
17 */
18#ifdef if
19# undef if
20#endif
21
22#define FMODE_READ		0x1
23#define FMODE_WRITE		0x2
24
25static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
26	(void *) 6;
27
28SEC("func=null_lseek file->f_mode offset orig")
29int bpf_func__null_lseek(void *ctx, int err, unsigned long _f_mode,
30			 unsigned long offset, unsigned long orig)
31{
32	fmode_t f_mode = (fmode_t)_f_mode;
33
34	if (err)
35		return 0;
36	if (f_mode & FMODE_WRITE)
37		return 0;
38	if (offset & 1)
39		return 0;
40	if (orig == SEEK_CUR)
41		return 0;
42	return 1;
43}
44
45char _license[] SEC("license") = "GPL";
46int _version SEC("version") = LINUX_VERSION_CODE;