[sanitizers] support strict_string_checks for strncmp

llvm-svn: 284901

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index d090fc2..b24498b 100644 (file)
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -304,8 +304,8 @@ INTERCEPTOR(int, strncmp, const char *s1, const char *s2, uptr size) {
     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);

diff --git a/compiler-rt/test/asan/TestCases/strncmp_strict.c b/compiler-rt/test/asan/TestCases/strncmp_strict.c
new file mode 100644 (file)
index 0000000..0462da0
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/strncmp_strict.c
@@ -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;
+}