LXR linux/tools/perf/tests/bpf-script-test-prologue.c

   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;
  48