From 9916aa2d95102a0c6816b3e3a4a1322bcb131a6e Mon Sep 17 00:00:00 2001
From: Alexey Samsonov <samsonov@google.com>
Date: Tue, 16 Jul 2013 12:51:53 +0000
Subject: [PATCH] [Sanitizer] move strcpy and strncpy to common interceptors

llvm-svn: 186408
---
 compiler-rt/lib/asan/asan_interceptors.cc          | 40 --------------------
 compiler-rt/lib/msan/tests/msan_test.cc            | 14 +++++++
 .../sanitizer_common_interceptors.inc              | 44 ++++++++++++++++++++++
 .../sanitizer_platform_interceptors.h              |  1 +
 compiler-rt/lib/tsan/rtl/tsan_interceptors.cc      | 26 -------------
 5 files changed, 59 insertions(+), 66 deletions(-)

diff --git a/compiler-rt/lib/asan/asan_interceptors.cc b/compiler-rt/lib/asan/asan_interceptors.cc
index 124bd3b..10b3778 100644
--- a/compiler-rt/lib/asan/asan_interceptors.cc
+++ b/compiler-rt/lib/asan/asan_interceptors.cc
@@ -432,24 +432,6 @@ INTERCEPTOR(char*, strncat, char *to, const char *from, uptr size) {
   return REAL(strncat)(to, from, size);
 }
 
-INTERCEPTOR(int, strcmp, const char *s1, const char *s2) {
-  if (!asan_inited) return internal_strcmp(s1, s2);
-  if (asan_init_is_running) {
-    return REAL(strcmp)(s1, s2);
-  }
-  ENSURE_ASAN_INITED();
-  unsigned char c1, c2;
-  uptr i;
-  for (i = 0; ; i++) {
-    c1 = (unsigned char)s1[i];
-    c2 = (unsigned char)s2[i];
-    if (c1 != c2 || c1 == '\0') break;
-  }
-  ASAN_READ_RANGE(s1, i + 1);
-  ASAN_READ_RANGE(s2, i + 1);
-  return CharCmp(c1, c2);
-}
-
 INTERCEPTOR(char*, strcpy, char *to, const char *from) {  // NOLINT
 #if SANITIZER_MAC
   if (!asan_inited) return REAL(strcpy)(to, from);  // NOLINT
@@ -499,26 +481,6 @@ INTERCEPTOR(uptr, strlen, const char *s) {
   return length;
 }
 
-INTERCEPTOR(int, strncmp, const char *s1, const char *s2, uptr size) {
-  if (!asan_inited) return internal_strncmp(s1, s2, size);
-  // strncmp is called from malloc_default_purgeable_zone()
-  // in __asan::ReplaceSystemAlloc() on Mac.
-  if (asan_init_is_running) {
-    return REAL(strncmp)(s1, s2, size);
-  }
-  ENSURE_ASAN_INITED();
-  unsigned char c1 = 0, c2 = 0;
-  uptr i;
-  for (i = 0; i < size; i++) {
-    c1 = (unsigned char)s1[i];
-    c2 = (unsigned char)s2[i];
-    if (c1 != c2 || c1 == '\0') break;
-  }
-  ASAN_READ_RANGE(s1, Min(i + 1, size));
-  ASAN_READ_RANGE(s2, Min(i + 1, size));
-  return CharCmp(c1, c2);
-}
-
 INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
   ENSURE_ASAN_INITED();
   if (flags()->replace_str) {
@@ -715,11 +677,9 @@ void InitializeAsanInterceptors() {
   // Intercept str* functions.
   ASAN_INTERCEPT_FUNC(strcat);  // NOLINT
   ASAN_INTERCEPT_FUNC(strchr);
-  ASAN_INTERCEPT_FUNC(strcmp);
   ASAN_INTERCEPT_FUNC(strcpy);  // NOLINT
   ASAN_INTERCEPT_FUNC(strlen);
   ASAN_INTERCEPT_FUNC(strncat);
-  ASAN_INTERCEPT_FUNC(strncmp);
   ASAN_INTERCEPT_FUNC(strncpy);
 #if ASAN_INTERCEPT_STRDUP
   ASAN_INTERCEPT_FUNC(strdup);
diff --git a/compiler-rt/lib/msan/tests/msan_test.cc b/compiler-rt/lib/msan/tests/msan_test.cc
index fe75d35..a13f05d 100644
--- a/compiler-rt/lib/msan/tests/msan_test.cc
+++ b/compiler-rt/lib/msan/tests/msan_test.cc
@@ -524,6 +524,20 @@ LargeStruct LargeRetTest() {
   return res;
 }
 
+TEST(MemorySanitizer, strcmp) {
+  char s1[10];
+  char s2[10];
+  strncpy(s1, "foo", 10);
+  s2[0] = 'f';
+  s2[1] = 'n';
+  EXPECT_GT(strcmp(s1, s2), 0);
+  s2[1] = 'o';
+  int res;
+  EXPECT_UMR(res = strcmp(s1, s2));
+  EXPECT_NOT_POISONED(res);
+  EXPECT_EQ(strncmp(s1, s2, 1), 0);
+}
+
 TEST(MemorySanitizer, LargeRet) {
   LargeStruct a = LargeRetTest();
   EXPECT_POISONED(a.x[0]);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index e63c2df..e48b392 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -28,6 +28,48 @@
 #define va_copy(dst, src) ((dst) = (src))
 #endif // _WIN32
 
+#if SANITIZER_INTERCEPT_STRCMP
+static inline int CharCmpX(unsigned char c1, unsigned char c2) {
+  return (c1 == c2) ? 0 : (c1 < c2) ? -1 : 1;
+}
+
+INTERCEPTOR(int, strcmp, const char *s1, const char *s2) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, strcmp, s1, s2);
+  unsigned char c1, c2;
+  uptr i;
+  for (i = 0; ; i++) {
+    c1 = (unsigned char)s1[i];
+    c2 = (unsigned char)s2[i];
+    if (c1 != c2 || c1 == '\0') break;
+  }
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s1, i + 1);
+  COMMON_INTERCEPTOR_READ_RANGE(ctx, s2, i + 1);
+  return CharCmpX(c1, c2);
+}
+
+INTERCEPTOR(int, strncmp, const char *s1, const char *s2, uptr size) {
+  void *ctx;
+  COMMON_INTERCEPTOR_ENTER(ctx, strncmp, s1, s2, size);
+  unsigned char c1 = 0, c2 = 0;
+  uptr i;
+  for (i = 0; i < size; i++) {
+    c1 = (unsigned char)s1[i];
+    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));
+  return CharCmpX(c1, c2);
+}
+
+#define INIT_STRCMP INTERCEPT_FUNCTION(strcmp)
+#define INIT_STRNCMP INTERCEPT_FUNCTION(strncmp)
+#else
+#define INIT_STRCMP
+#define INIT_STRNCMP
+#endif
+
 #if SANITIZER_INTERCEPT_STRCASECMP
 static inline int CharCaseCmp(unsigned char c1, unsigned char c2) {
   int c1_low = ToLower(c1);
@@ -1706,6 +1748,8 @@ INTERCEPTOR(char *, canonicalize_file_name, const char *path) {
 #endif
 
 #define SANITIZER_COMMON_INTERCEPTORS_INIT \
+  INIT_STRCMP;                             \
+  INIT_STRNCMP;                            \
   INIT_STRCASECMP;                         \
   INIT_STRNCASECMP;                        \
   INIT_READ;                               \
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 0b98d3a..e07a134 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -41,6 +41,7 @@
 # define SI_MAC 0
 #endif
 
+# define SANITIZER_INTERCEPT_STRCMP 1
 # define SANITIZER_INTERCEPT_STRCASECMP SI_NOT_WINDOWS
 
 # define SANITIZER_INTERCEPT_READ   SI_NOT_WINDOWS
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
index 92d8ae1..936a215 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors.cc
@@ -590,30 +590,6 @@ TSAN_INTERCEPTOR(int, memcmp, const void *s1, const void *s2, uptr n) {
   return res;
 }
 
-TSAN_INTERCEPTOR(int, strcmp, const char *s1, const char *s2) {
-  SCOPED_TSAN_INTERCEPTOR(strcmp, s1, s2);
-  uptr len = 0;
-  for (; s1[len] && s2[len]; len++) {
-    if (s1[len] != s2[len])
-      break;
-  }
-  MemoryAccessRange(thr, pc, (uptr)s1, len + 1, false);
-  MemoryAccessRange(thr, pc, (uptr)s2, len + 1, false);
-  return s1[len] - s2[len];
-}
-
-TSAN_INTERCEPTOR(int, strncmp, const char *s1, const char *s2, uptr n) {
-  SCOPED_TSAN_INTERCEPTOR(strncmp, s1, s2, n);
-  uptr len = 0;
-  for (; len < n && s1[len] && s2[len]; len++) {
-    if (s1[len] != s2[len])
-      break;
-  }
-  MemoryAccessRange(thr, pc, (uptr)s1, len < n ? len + 1 : n, false);
-  MemoryAccessRange(thr, pc, (uptr)s2, len < n ? len + 1 : n, false);
-  return len == n ? 0 : s1[len] - s2[len];
-}
-
 TSAN_INTERCEPTOR(void*, memchr, void *s, int c, uptr n) {
   SCOPED_TSAN_INTERCEPTOR(memchr, s, c, n);
   void *res = REAL(memchr)(s, c, n);
@@ -1957,7 +1933,6 @@ void InitializeInterceptors() {
   TSAN_INTERCEPT(strlen);
   TSAN_INTERCEPT(memset);
   TSAN_INTERCEPT(memcpy);
-  TSAN_INTERCEPT(strcmp);
   TSAN_INTERCEPT(memchr);
   TSAN_INTERCEPT(memrchr);
   TSAN_INTERCEPT(memmove);
@@ -1965,7 +1940,6 @@ void InitializeInterceptors() {
   TSAN_INTERCEPT(strchr);
   TSAN_INTERCEPT(strchrnul);
   TSAN_INTERCEPT(strrchr);
-  TSAN_INTERCEPT(strncmp);
   TSAN_INTERCEPT(strcpy);  // NOLINT
   TSAN_INTERCEPT(strncpy);
   TSAN_INTERCEPT(strstr);
-- 
2.7.4