compiler-rt/test/msan/Linux/fopencookie.cpp

   1 // Test fopencookie interceptor.
   2 // RUN: %clangxx_msan -std=c++11 -O0 %s -o %t && %run %t
   3 // RUN: %clangxx_msan -std=c++11 -fsanitize-memory-track-origins -O0 %s -o %t && %run %t
   4
   5 #include <assert.h>
   6 #include <pthread.h>
   7 #include <stdint.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11
  12 #include <sanitizer/msan_interface.h>
  13
  14 constexpr uintptr_t kMagicCookie = 0x12345678;
  15
  16 static ssize_t cookie_read(void *cookie, char *buf, size_t size) {
  17   assert((uintptr_t)cookie == kMagicCookie);
  18   memset(buf, 0, size);
  19   return 0;
  20 }
  21
  22 static ssize_t cookie_write(void *cookie, const char *buf, size_t size) {
  23   assert((uintptr_t)cookie == kMagicCookie);
  24   __msan_check_mem_is_initialized(buf, size);
  25   return 0;
  26 }
  27
  28 static int cookie_seek(void *cookie, off64_t *offset, int whence) {
  29   assert((uintptr_t)cookie == kMagicCookie);
  30   __msan_check_mem_is_initialized(offset, sizeof(*offset));
  31   return 0;
  32 }
  33
  34 static int cookie_close(void *cookie) {
  35   assert((uintptr_t)cookie == kMagicCookie);
  36   return 0;
  37 }
  38
  39 void PoisonStack() { char a[8192]; }
  40
  41 void TestPoisonStack() {
  42   // Verify that PoisonStack has poisoned the stack - otherwise this test is not
  43   // testing anything.
  44   char a;
  45   assert(__msan_test_shadow(&a - 1000, 1) == 0);
  46 }
  47
  48 int main() {
  49   void *cookie = (void *)kMagicCookie;
  50   FILE *f = fopencookie(cookie, "rw",
  51                         {cookie_read, cookie_write, cookie_seek, cookie_close});
  52   PoisonStack();
  53   TestPoisonStack();
  54   fseek(f, 100, SEEK_SET);
  55   char buf[50];
  56   fread(buf, 50, 1, f);
  57   fwrite(buf, 50, 1, f);
  58   fclose(f);
  59
  60   f = fopencookie(cookie, "rw", {nullptr, nullptr, nullptr, nullptr});
  61   fseek(f, 100, SEEK_SET);
  62   fread(buf, 50, 1, f);
  63   fwrite(buf, 50, 1, f);
  64   fclose(f);
  65 }