1 /* 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-op
8 #endif
9 #define SEC(NAME) __attribute__((section(NAME)
10
11 #include <uapi/linux/fs.h>
12
13 #define FMODE_READ 0x1
14 #define FMODE_WRITE 0x2
15
16 static void (*bpf_trace_printk)(const char *fm
17 (void *) 6;
18
19 SEC("func=null_lseek file->f_mode offset orig"
20 int bpf_func__null_lseek(void *ctx, int err, u
21 unsigned long offset,
22 {
23 if (err)
24 return 0;
25 if (f_mode & FMODE_WRITE)
26 return 0;
27 if (offset & 1)
28 return 0;
29 if (orig == SEEK_CUR)
30 return 0;
31 return 1;
32 }
33
34 char _license[] SEC("license") = "GPL";
35 int _version SEC("version") = LINUX_VERSION_CO
36
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.