syscalls/remap_file_pages.c

   1 /*
   2  * SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
   3          unsigned long, prot, unsigned long, pgoff, unsigned long, flags)
   4  */
   5 #include <stdlib.h>
   6 #include <asm/mman.h>
   7 #include "arch.h"
   8 #include "maps.h"
   9 #include "random.h"
  10 #include "sanitise.h"
  11 #include "shm.h"
  12
  13 static void sanitise_remap_file_pages(int childno)
  14 {
  15         struct map *map;
  16         size_t size;
  17
  18         map = common_set_mmap_ptr_len(childno);
  19
  20         /* We just want to remap a part of the mapping. */
  21         size = rand() % map->size;
  22         shm->syscall[childno].a2 = size;
  23
  24         /* "The prot argument must be specified as 0" */
  25         shm->syscall[childno].a3 = 0;
  26
  27         /* Pick a random pgoff. */
  28         shm->syscall[childno].a4 = rand() & (size / page_size);
  29 }
  30
  31 struct syscallentry syscall_remap_file_pages = {
  32         .name = "remap_file_pages",
  33         .num_args = 5,
  34         .arg1name = "start",
  35         .arg1type = ARG_MMAP,
  36         .arg2name = "size",
  37         .arg3name = "prot",
  38         .arg4name = "pgoff",
  39         .arg5name = "flags",
  40         .arg5type = ARG_LIST,
  41         .arg5list = {
  42                 .num = 1,
  43                 .values = { MAP_NONBLOCK },
  44         },
  45         .group = GROUP_VM,
  46         .sanitise = sanitise_remap_file_pages,
  47 };