[msan] Intercept fopencookie.

https://code.google.com/p/memory-sanitizer/issues/detail?id=86


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@240107 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 59 insertions, 0 deletions

diff --git a/test/msan/Linux/fopencookie.cc b/test/msan/Linux/fopencookie.cc
new file mode 100644
index 000000000..e9616d502
--- /dev/null
+++ b/test/msan/Linux/fopencookie.cc
@@ -0,0 +1,59 @@
+// Test fopencookie interceptor.
+// RUN: %clangxx_msan -std=c++11 -O0 %s -o %t && %run %t
+// RUN: %clangxx_msan -std=c++11 -fsanitize-memory-track-origins -O0 %s -o %t && %run %t
+
+#include <assert.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sanitizer/msan_interface.h>
+
+constexpr uintptr_t kMagicCookie = 0x12345678;
+
+static ssize_t cookie_read(void *cookie, char *buf, size_t size) {
+  assert((uintptr_t)cookie == kMagicCookie);
+  memset(buf, 0, size);
+  return 0;
+}
+
+static ssize_t cookie_write(void *cookie, const char *buf, size_t size) {
+  assert((uintptr_t)cookie == kMagicCookie);
+  __msan_check_mem_is_initialized(buf, size);
+  return 0;
+}
+
+static int cookie_seek(void *cookie, off64_t *offset, int whence) {
+  assert((uintptr_t)cookie == kMagicCookie);
+  __msan_check_mem_is_initialized(offset, sizeof(*offset));
+  return 0;
+}
+
+static int cookie_close(void *cookie) {
+  assert((uintptr_t)cookie == kMagicCookie);
+  return 0;
+}
+
+void PoisonStack() { char a[8192]; }
+
+void TestPoisonStack() {
+  // Verify that PoisonStack has poisoned the stack - otherwise this test is not
+  // testing anything.
+  char a;
+  assert(__msan_test_shadow(&a - 1000, 1) == 0);
+}
+
+int main() {
+  void *cookie = (void *)kMagicCookie;
+  FILE *f = fopencookie(cookie, "rw",
+                        {cookie_read, cookie_write, cookie_seek, cookie_close});
+  PoisonStack();
+  TestPoisonStack();
+  fseek(f, 100, SEEK_SET);
+  char buf[50];
+  fread(buf, 50, 1, f);
+  fwrite(buf, 50, 1, f);
+  fclose(f);
+}