[compiler-rt] r284901 - [sanitizers] support strict_string_checks for strncmp

[Kostya Serebryany via llvm-commits]

Author: kcc
Date: Fri Oct 21 18:52:26 2016
New Revision: 284901

URL: http://llvm.org/viewvc/llvm-project?rev=284901&view=rev
Log:
[sanitizers] support strict_string_checks for strncmp

Added:
    compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c
Modified:
    compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc

Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc?rev=284901&r1=284900&r2=284901&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common_interceptors.inc Fri Oct 21 18:52:26 2016
@@ -304,8 +304,8 @@ INTERCEPTOR(int, strncmp, const char *s1
     c2 = (unsigned char)s2[i];
     if (c1 != c2 || c1 == '\0') break;
   }
-  COMMON_INTERCEPTOR_READ_RANGE(ctx, s1, Min(i + 1, size));
-  COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, Min(i + 1, size));
+  COMMON_INTERCEPTOR_READ_STRING(ctx, s1, Min(i + 1, size));
+  COMMON_INTERCEPTOR_READ_STRING(ctx, s2, Min(i + 1, size));
   int result = CharCmpX(c1, c2);
   CALL_WEAK_INTERCEPTOR_HOOK(__sanitizer_weak_hook_strncmp, GET_CALLER_PC(), s1,
                              s2, size, result);

Added: compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c?rev=284901&view=auto
==============================================================================
--- compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c (added)
+++ compiler-rt/trunk/test/asan/TestCases/strncmp_strict.c Fri Oct 21 18:52:26 2016
@@ -0,0 +1,26 @@
+// Test strict_string_checks option in strncmp function
+// RUN: %clang_asan %s -o %t && %run %t 2>&1
+// RUN: %env_asan_opts=strict_string_checks=false %run %t 2>&1
+// RUN: %env_asan_opts=strict_string_checks=true not %run %t 2>&1 | FileCheck %s
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+int main(int argc, char **argv) {
+  size_t size = 100;
+  char fill = 'o';
+  char *s1 = (char*)malloc(size);
+  memset(s1, fill, size);
+  char *s2 = (char*)malloc(size);
+  memset(s2, fill, size);
+  s1[size - 1] = 'z';
+  s2[size - 1] = 'x';
+  int r = strncmp(s1, s2, size + 1);
+  // CHECK: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
+  // CHECK: READ of size 101
+  assert(r == 1);
+  free(s1);
+  free(s2);
+  return 0;
+}