[asan] Interceptors for Fuchsia

Summary:
Fuchsia uses the "memintrinsics" interceptors, though not via any
generalized interception mechanism.  It doesn't use any other interceptors.

Submitted on behalf of Roland McGrath.

Reviewers: vitalybuka, alekseyshl, kcc

Reviewed By: vitalybuka

Subscribers: kubamracek, phosek, filcab, llvm-commits

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D36189

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@309798 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 40 insertions, 13 deletions

diff --git a/lib/asan/asan_interceptors.cc b/lib/asan/asan_interceptors.cc
index 999c799fe..1d68a2c0e 100644
--- a/lib/asan/asan_interceptors.cc
+++ b/lib/asan/asan_interceptors.cc
@@ -24,6 +24,11 @@
 #include "lsan/lsan_common.h"
 #include "sanitizer_common/sanitizer_libc.h"
 
+// There is no general interception at all on Fuchsia.
+// Only the functions in asan_interceptors_memintrinsics.cc are
+// really defined to replace libc functions.
+#if !SANITIZER_FUCHSIA
+
 #if SANITIZER_POSIX
 #include "sanitizer_common/sanitizer_posix.h"
 #endif
@@ -654,3 +659,5 @@ void InitializeAsanInterceptors() {
 }
 
 } // namespace __asan
+
+#endif  // !SANITIZER_FUCHSIA
diff --git a/lib/asan/asan_interceptors.h b/lib/asan/asan_interceptors.h
index 5bc621724..650e0869c 100644
--- a/lib/asan/asan_interceptors.h
+++ b/lib/asan/asan_interceptors.h
@@ -19,6 +19,26 @@
 #include "interception/interception.h"
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 
+namespace __asan {
+
+void InitializeAsanInterceptors();
+void InitializePlatformInterceptors();
+
+#define ENSURE_ASAN_INITED()      \
+  do {                            \
+    CHECK(!asan_init_is_running); \
+    if (UNLIKELY(!asan_inited)) { \
+      AsanInitFromRtl();          \
+    }                             \
+  } while (0)
+
+}  // namespace __asan
+
+// There is no general interception at all on Fuchsia.
+// Only the functions in asan_interceptors_memintrinsics.h are
+// really defined to replace libc functions.
+#if !SANITIZER_FUCHSIA
+
 // Use macro to describe if specific function should be
 // intercepted on a given platform.
 #if !SANITIZER_WINDOWS
@@ -112,18 +132,6 @@ DECLARE_REAL(int, sigaction, int signum, const struct sigaction *act,
 #define ASAN_INTERCEPT_FUNC(name)
 #endif  // SANITIZER_MAC
 
-namespace __asan {
-
-void InitializeAsanInterceptors();
-void InitializePlatformInterceptors();
-
-#define ENSURE_ASAN_INITED() do { \
-  CHECK(!asan_init_is_running); \
-  if (UNLIKELY(!asan_inited)) { \
-    AsanInitFromRtl(); \
-  } \
-} while (0)
-
-}  // namespace __asan
+#endif  // !SANITIZER_FUCHSIA
 
 #endif  // ASAN_INTERCEPTORS_H
diff --git a/lib/asan/asan_interceptors_memintrinsics.cc b/lib/asan/asan_interceptors_memintrinsics.cc
index 7a59e7c5f..c89cb0114 100644
--- a/lib/asan/asan_interceptors_memintrinsics.cc
+++ b/lib/asan/asan_interceptors_memintrinsics.cc
@@ -30,3 +30,15 @@ void *__asan_memset(void *block, int c, uptr size) {
 void *__asan_memmove(void *to, const void *from, uptr size) {
   ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
 }
+
+#if SANITIZER_FUCHSIA
+
+// Fuchsia doesn't use sanitizer_common_interceptors.inc, but the only
+// things there it wants are these three.  Just define them as aliases
+// here rather than repeating the contents.
+
+decltype(memcpy) memcpy[[gnu::alias("__asan_memcpy")]];
+decltype(memmove) memmove[[gnu::alias("__asan_memmove")]];
+decltype(memset) memset[[gnu::alias("__asan_memset")]];
+
+#endif  // SANITIZER_FUCHSIA