[HWASAN/compiler-rt] Instrument globals

[evgeny777]

Summary

This is compiler-rt part of D56672
It also depends on D56603

[evgeny777]

Rebased

lib/hwasan/hwasan.cc

 void __hwasan_tag_memory(uptr p, u8 tag, uptr sz) {
   TagMemoryAligned(p, sz, tag);
 }
 
 uptr __hwasan_tag_pointer(uptr p, u8 tag) {
   return AddTagToPointer(p, tag);
 }
 
+struct GlobalInfo {
+  uptr addr;
+  uptr size;
+  uptr tag;
+};
+
+void __hwasan_register_globals(void *globals, uptr count) {
+  GlobalInfo *gi = static_cast<GlobalInfo *>(globals);
+  for (uptr i = 0; i < count; ++i)
+    TagMemoryAligned(gi[i].addr, gi[i].size, gi[i].tag);
+}
+
+void __hwasan_unregister_globals(void *globals, uptr count) {
+  GlobalInfo *gi = static_cast<GlobalInfo *>(globals);
+  for (uptr i = 0; i < count; ++i) TagMemoryAligned(gi[i].addr, gi[i].size, 0);
+}
+
 void __hwasan_handle_longjmp(const void *sp_dst) {
   uptr dst = (uptr)sp_dst;
   // HWASan does not support tagged SP.
   CHECK(GetTagFromPointer(dst) == 0);
 
   uptr sp = (uptr)__builtin_frame_address(0);
   static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
   if (dst < sp || dst - sp > kMaxExpectedCleanupSize) {

lib/hwasan/hwasan_interface_internal.h

 void * __sanitizer_malloc(uptr size);
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__hwasan_memcpy(void *dst, const void *src, uptr size);
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__hwasan_memset(void *s, int c, uptr n);
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__hwasan_memmove(void *dest, const void *src, uptr n);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __hwasan_register_globals(void *globals, uptr count);
+SANITIZER_INTERFACE_ATTRIBUTE
+void __hwasan_unregister_globals(void *globals, uptr count);
 }  // extern "C"
 
 #endif  // HWASAN_INTERFACE_INTERNAL_H

test/hwasan/TestCases/globals.c

+// RUN: %clang_hwasan %s -mllvm -hwasan-instrument-globals -o %t && not %run %t 2>&1 | FileCheck %s
+// REQUIRES: stable-runtime
+
+#include <string.h>
+long Q = 42;
+
+int main() {
+  memset(&Q, 0, 32);
+  // CHECK: ERROR: HWAddressSanitizer: tag-mismatch on address
+  // CHECK: WRITE of size 32 at {{.*}} tags: [[PTR_TAG:..]]/[[MEM_TAG:..]] (ptr/mem)
+  // CHECK: Offset to first bad byte is in range [16, 32)
+  // CHECK: Memory tags around the buggy address (one tag corresponds to 16 bytes):
+  // CHECK: =>{{.*}}[[PTR_TAG]]{{[[:space:]]\[}}[[MEM_TAG]]
+  return 0;
+}