| Wang Nan | bbb7d49 | 2015-11-16 12:10:14 +0000 | [diff] [blame] | 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 | #define FMODE_READ 0x1 |
| 14 | #define FMODE_WRITE 0x2 |
| 15 | |
| 16 | static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) = |
| 17 | (void *) 6; |
| 18 | |
| 19 | SEC("func=null_lseek file->f_mode offset orig") |
| 20 | int bpf_func__null_lseek(void *ctx, int err, unsigned long f_mode, |
| 21 | unsigned long offset, unsigned long orig) |
| 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_CODE; |