[asan] Add strndup/__strndup interceptors.

Recommit of r302781 with Vitaly Buka's fix for non zero terminated strings.

Differential Revision: https://reviews.llvm.org/D31457


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@304399 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 0 deletions

diff --git a/test/msan/strndup.cc b/test/msan/strndup.cc
new file mode 100644
index 000000000..d4b9af1a9
--- /dev/null
+++ b/test/msan/strndup.cc
@@ -0,0 +1,28 @@
+// RUN: %clangxx_msan %s -o %t && not %run %t 2>&1 | FileCheck --check-prefix=ON %s
+// RUN: %clangxx_msan %s -o %t && MSAN_OPTIONS=intercept_strndup=0 %run %t 2>&1 | FileCheck --check-prefix=OFF --allow-empty %s
+
+// When built as C on Linux, strndup is transformed to __strndup.
+// RUN: %clangxx_msan -O3 -xc %s -o %t && not %run %t 2>&1 | FileCheck --check-prefix=ON %s
+
+// UNSUPPORTED: win32
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sanitizer/msan_interface.h>
+
+int main(int argc, char **argv) {
+  char kString[4] = "abc";
+  __msan_poison(kString + 2, 1);
+  char *copy = strndup(kString, 4); // BOOM
+  assert(__msan_test_shadow(copy, 4) == 2); // Poisoning is preserved.
+  free(copy);
+  return 0;
+  // ON: Uninitialized bytes in __interceptor_{{(__)?}}strndup at offset 2 inside [{{.*}}, 4)
+  // ON: MemorySanitizer: use-of-uninitialized-value
+  // ON: #0 {{.*}}main {{.*}}strndup.cc:[[@LINE-6]]
+  // ON-LABEL: SUMMARY
+  // ON: {{.*}}strndup.cc:[[@LINE-8]]
+  // OFF-NOT: MemorySanitizer
+}
+