1 files changed, 64 insertions, 15 deletions

diff --git a/lib/asan/asan_globals.cc b/lib/asan/asan_globals.cc
index f185761809c7a..b7233067358c3 100644
--- a/lib/asan/asan_globals.cc
+++ b/lib/asan/asan_globals.cc
@@ -25,6 +25,7 @@
 #include "sanitizer_common/sanitizer_mutex.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
+#include "sanitizer_common/sanitizer_symbolizer.h"
 
 namespace __asan {
 
@@ -123,18 +124,6 @@ int GetGlobalsForAddress(uptr addr, Global *globals, u32 *reg_sites,
   return res;
 }
 
-bool GetInfoForAddressIfGlobal(uptr addr, AddressDescription *descr) {
-  Global g = {};
-  if (GetGlobalsForAddress(addr, &g, nullptr, 1)) {
-    internal_strncpy(descr->name, g.name, descr->name_size);
-    descr->region_address = g.beg;
-    descr->region_size = g.size;
-    descr->region_kind = "global";
-    return true;
-  }
-  return false;
-}
-
 enum GlobalSymbolState {
   UNREGISTERED = 0,
   REGISTERED = 1
@@ -279,6 +268,46 @@ void StopInitOrderChecking() {
   }
 }
 
+static bool IsASCII(unsigned char c) { return /*0x00 <= c &&*/ c <= 0x7F; }
+
+const char *MaybeDemangleGlobalName(const char *name) {
+  // We can spoil names of globals with C linkage, so use an heuristic
+  // approach to check if the name should be demangled.
+  bool should_demangle = false;
+  if (name[0] == '_' && name[1] == 'Z')
+    should_demangle = true;
+  else if (SANITIZER_WINDOWS && name[0] == '\01' && name[1] == '?')
+    should_demangle = true;
+
+  return should_demangle ? Symbolizer::GetOrInit()->Demangle(name) : name;
+}
+
+// Check if the global is a zero-terminated ASCII string. If so, print it.
+void PrintGlobalNameIfASCII(InternalScopedString *str, const __asan_global &g) {
+  for (uptr p = g.beg; p < g.beg + g.size - 1; p++) {
+    unsigned char c = *(unsigned char *)p;
+    if (c == '\0' || !IsASCII(c)) return;
+  }
+  if (*(char *)(g.beg + g.size - 1) != '\0') return;
+  str->append("  '%s' is ascii string '%s'\n", MaybeDemangleGlobalName(g.name),
+              (char *)g.beg);
+}
+
+static const char *GlobalFilename(const __asan_global &g) {
+  const char *res = g.module_name;
+  // Prefer the filename from source location, if is available.
+  if (g.location) res = g.location->filename;
+  CHECK(res);
+  return res;
+}
+
+void PrintGlobalLocation(InternalScopedString *str, const __asan_global &g) {
+  str->append("%s", GlobalFilename(g));
+  if (!g.location) return;
+  if (g.location->line_no) str->append(":%d", g.location->line_no);
+  if (g.location->column_no) str->append(":%d", g.location->column_no);
+}
+
 } // namespace __asan
 
 // ---------------------- Interface ---------------- {{{1
@@ -319,6 +348,20 @@ void __asan_register_globals(__asan_global *globals, uptr n) {
     Printf("=== ID %d; %p %p\n", stack_id, &globals[0], &globals[n - 1]);
   }
   for (uptr i = 0; i < n; i++) {
+    if (SANITIZER_WINDOWS && globals[i].beg == 0) {
+      // The MSVC incremental linker may pad globals out to 256 bytes. As long
+      // as __asan_global is less than 256 bytes large and its size is a power
+      // of two, we can skip over the padding.
+      static_assert(
+          sizeof(__asan_global) < 256 &&
+              (sizeof(__asan_global) & (sizeof(__asan_global) - 1)) == 0,
+          "sizeof(__asan_global) incompatible with incremental linker padding");
+      // If these are padding bytes, the rest of the global should be zero.
+      CHECK(globals[i].size == 0 && globals[i].size_with_redzone == 0 &&
+            globals[i].name == nullptr && globals[i].module_name == nullptr &&
+            globals[i].odr_indicator == 0);
+      continue;
+    }
     RegisterGlobal(&globals[i]);
   }
 }
@@ -329,6 +372,11 @@ void __asan_unregister_globals(__asan_global *globals, uptr n) {
   if (!flags()->report_globals) return;
   BlockingMutexLock lock(&mu_for_globals);
   for (uptr i = 0; i < n; i++) {
+    if (SANITIZER_WINDOWS && globals[i].beg == 0) {
+      // Skip globals that look like padding from the MSVC incremental linker.
+      // See comment in __asan_register_globals.
+      continue;
+    }
     UnregisterGlobal(&globals[i]);
   }
 }
@@ -339,10 +387,10 @@ void __asan_unregister_globals(__asan_global *globals, uptr n) {
 // initializer can only touch global variables in the same TU.
 void __asan_before_dynamic_init(const char *module_name) {
   if (!flags()->check_initialization_order ||
-      !CanPoisonMemory())
+      !CanPoisonMemory() ||
+      !dynamic_init_globals)
     return;
   bool strict_init_order = flags()->strict_init_order;
-  CHECK(dynamic_init_globals);
   CHECK(module_name);
   CHECK(asan_inited);
   BlockingMutexLock lock(&mu_for_globals);
@@ -365,7 +413,8 @@ void __asan_before_dynamic_init(const char *module_name) {
 // TU are poisoned.  It simply unpoisons all dynamically initialized globals.
 void __asan_after_dynamic_init() {
   if (!flags()->check_initialization_order ||
-      !CanPoisonMemory())
+      !CanPoisonMemory() ||
+      !dynamic_init_globals)
     return;
   CHECK(asan_inited);
   BlockingMutexLock lock(&mu_for_globals);