[sanitizer] Lift AsanDoesNotSupportStaticLinkage to sanitizer_common.…

…h. NFC (#80948) The `_DYNAMIC` reference from `AsanDoesNotSupportStaticLinkage` ensures that `clang++ -fsanitize=address -static` gets a linker error. `MemprofDoesNotSupportStaticLinkage` is similar for `-fmemory-profile`. Move the functions to sanitizer_common.h to be used by more sanitizers on ELF platforms. Fuchsia does not use interposition and opts out the check (its `AsanDoesNotSupportStaticLinkage` is a no-op).
llvm · Feb 17, 2024 · 8443ce5 · 8443ce5
1 parent db836f6
commit 8443ce5
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Showing 10 changed files with 15 additions and 30 deletions.
diff --git a/compiler-rt/lib/asan/asan_fuchsia.cpp b/compiler-rt/lib/asan/asan_fuchsia.cpp
@@ -57,8 +57,6 @@ void AsanCheckDynamicRTPrereqs() {}
 void AsanCheckIncompatibleRT() {}
 void InitializeAsanInterceptors() {}
 
-void *AsanDoesNotSupportStaticLinkage() { return nullptr; }
-
 void InitializePlatformExceptionHandlers() {}
 void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   UNIMPLEMENTED();

diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
@@ -80,7 +80,6 @@ void ReplaceSystemMalloc();
 
 // asan_linux.cpp / asan_mac.cpp / asan_win.cpp
 uptr FindDynamicShadowStart();
-void *AsanDoesNotSupportStaticLinkage();
 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 

diff --git a/compiler-rt/lib/asan/asan_linux.cpp b/compiler-rt/lib/asan/asan_linux.cpp
@@ -47,15 +47,12 @@
 
 #  if SANITIZER_ANDROID || SANITIZER_FREEBSD || SANITIZER_SOLARIS
 #    include <ucontext.h>
-extern "C" void *_DYNAMIC;
 #  elif SANITIZER_NETBSD
 #    include <link_elf.h>
 #    include <ucontext.h>
-extern Elf_Dyn _DYNAMIC;
 #  else
 #    include <link.h>
 #    include <sys/ucontext.h>
-extern ElfW(Dyn) _DYNAMIC[];
 #  endif
 
 typedef enum {
@@ -76,11 +73,6 @@ void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 bool IsSystemHeapAddress(uptr addr) { return false; }
 
-void *AsanDoesNotSupportStaticLinkage() {
-  // This will fail to link with -static.
-  return &_DYNAMIC;
-}
-
 #  if ASAN_PREMAP_SHADOW
 uptr FindPremappedShadowStart(uptr shadow_size_bytes) {
   uptr granularity = GetMmapGranularity();

diff --git a/compiler-rt/lib/asan/asan_mac.cpp b/compiler-rt/lib/asan/asan_mac.cpp
@@ -49,11 +49,6 @@ void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 bool IsSystemHeapAddress (uptr addr) { return false; }
 
-// No-op. Mac does not support static linkage anyway.
-void *AsanDoesNotSupportStaticLinkage() {
-  return 0;
-}
-
 uptr FindDynamicShadowStart() {
   return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,
                           /*min_shadow_base_alignment*/ 0, kHighMemEnd);

diff --git a/compiler-rt/lib/asan/asan_rtl.cpp b/compiler-rt/lib/asan/asan_rtl.cpp
@@ -410,6 +410,8 @@ static bool AsanInitInternal() {
     return false;
   }
 
+  // Make sure we are not statically linked.
+  __interception::DoesNotSupportStaticLinking();
   AsanCheckIncompatibleRT();
   AsanCheckDynamicRTPrereqs();
   AvoidCVE_2016_2143();
@@ -421,9 +423,6 @@ static bool AsanInitInternal() {
 
   InitializeHighMemEnd();
 
-  // Make sure we are not statically linked.
-  AsanDoesNotSupportStaticLinkage();
-
   // Install tool-specific callbacks in sanitizer_common.
   AddDieCallback(AsanDie);
   SetCheckUnwindCallback(CheckUnwind);

diff --git a/compiler-rt/lib/asan/asan_win.cpp b/compiler-rt/lib/asan/asan_win.cpp
@@ -266,8 +266,6 @@ void PlatformTSDDtor(void *tsd) { AsanThread::TSDDtor(tsd); }
 // }}}
 
 // ---------------------- Various stuff ---------------- {{{
-void *AsanDoesNotSupportStaticLinkage() { return 0; }
-
 uptr FindDynamicShadowStart() {
   return MapDynamicShadow(MemToShadowSize(kHighMemEnd), ASAN_SHADOW_SCALE,
                           /*min_shadow_base_alignment*/ 0, kHighMemEnd);

diff --git a/compiler-rt/lib/interception/interception.h b/compiler-rt/lib/interception/interception.h
@@ -348,6 +348,18 @@ typedef unsigned long long uptr;
 #else
 typedef unsigned long uptr;
 #endif  // _WIN64
+
+#if defined(__ELF__) && !SANITIZER_FUCHSIA
+// The use of interceptors makes many sanitizers unusable for static linking.
+// Define a function, if called, will cause a linker error (undefined _DYNAMIC).
+// However, -static-pie (which is not common) cannot be detected at link time.
+extern uptr kDynamic[] asm("_DYNAMIC");
+inline void DoesNotSupportStaticLinking() {
+  [[maybe_unused]] volatile auto x = &kDynamic;
+}
+#else
+inline void DoesNotSupportStaticLinking() {}
+#endif
 }  // namespace __interception
 
 #define INCLUDED_FROM_INTERCEPTION_LIB

diff --git a/compiler-rt/lib/memprof/memprof_internal.h b/compiler-rt/lib/memprof/memprof_internal.h
@@ -57,7 +57,6 @@ void ReplaceSystemMalloc();
 
 // memprof_linux.cpp
 uptr FindDynamicShadowStart();
-void *MemprofDoesNotSupportStaticLinkage();
 
 // memprof_thread.cpp
 MemprofThread *CreateMainThread();

diff --git a/compiler-rt/lib/memprof/memprof_linux.cpp b/compiler-rt/lib/memprof/memprof_linux.cpp
@@ -38,8 +38,6 @@
 #include <unistd.h>
 #include <unwind.h>
 
-extern ElfW(Dyn) _DYNAMIC[];
-
 typedef enum {
   MEMPROF_RT_VERSION_UNDEFINED = 0,
   MEMPROF_RT_VERSION_DYNAMIC,
@@ -57,11 +55,6 @@ namespace __memprof {
 void InitializePlatformInterceptors() {}
 void InitializePlatformExceptionHandlers() {}
 
-void *MemprofDoesNotSupportStaticLinkage() {
-  // This will fail to link with -static.
-  return &_DYNAMIC;
-}
-
 uptr FindDynamicShadowStart() {
   uptr shadow_size_bytes = MemToShadowSize(kHighMemEnd);
   return MapDynamicShadow(shadow_size_bytes, SHADOW_SCALE,

diff --git a/compiler-rt/lib/memprof/memprof_rtl.cpp b/compiler-rt/lib/memprof/memprof_rtl.cpp
@@ -162,7 +162,7 @@ static void MemprofInitInternal() {
   InitializeHighMemEnd();
 
   // Make sure we are not statically linked.
-  MemprofDoesNotSupportStaticLinkage();
+  __interception::DoesNotSupportStaticLinking();
 
   // Install tool-specific callbacks in sanitizer_common.
   AddDieCallback(MemprofDie);