tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
16static void (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
17 (void *) 6;
18
19SEC("func=null_lseek file->f_mode offset orig")
20int 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
34char _license[] SEC("license") = "GPL";
35int _version SEC("version") = LINUX_VERSION_CODE;