libsanitizer: merge from master

Merged revision: f58e0513dd95944b81ce7a6e7b49ba656de7d75f

1 files changed, 31 insertions, 10 deletions

diff --git a/libsanitizer/hwasan/hwasan_linux.cpp b/libsanitizer/hwasan/hwasan_linux.cpp
index e99926d355c..8ce0ff7da95 100644
--- a/libsanitizer/hwasan/hwasan_linux.cpp
+++ b/libsanitizer/hwasan/hwasan_linux.cpp
@@ -76,6 +76,8 @@ uptr kHighShadowEnd;
 uptr kHighMemStart;
 uptr kHighMemEnd;
 
+uptr kAliasRegionStart;  // Always 0 on non-x86.
+
 static void PrintRange(uptr start, uptr end, const char *name) {
   Printf("|| [%p, %p] || %.*s ||\n", (void *)start, (void *)end, 10, name);
 }
@@ -119,9 +121,11 @@ void InitPrctl() {
 #define PR_GET_TAGGED_ADDR_CTRL 56
 #define PR_TAGGED_ADDR_ENABLE (1UL << 0)
   // Check we're running on a kernel that can use the tagged address ABI.
-  if (internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0) == (uptr)-1 &&
-      errno == EINVAL) {
-#if SANITIZER_ANDROID
+  int local_errno = 0;
+  if (internal_iserror(internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0),
+                       &local_errno) &&
+      local_errno == EINVAL) {
+#if SANITIZER_ANDROID || defined(__x86_64__)
     // Some older Android kernels have the tagged pointer ABI on
     // unconditionally, and hence don't have the tagged-addr prctl while still
     // allow the ABI.
@@ -129,17 +133,20 @@ void InitPrctl() {
     // case.
     return;
 #else
-    Printf(
-        "FATAL: "
-        "HWAddressSanitizer requires a kernel with tagged address ABI.\n");
-    Die();
+    if (flags()->fail_without_syscall_abi) {
+      Printf(
+          "FATAL: "
+          "HWAddressSanitizer requires a kernel with tagged address ABI.\n");
+      Die();
+    }
 #endif
   }
 
   // Turn on the tagged address ABI.
-  if (internal_prctl(PR_SET_TAGGED_ADDR_CTRL, PR_TAGGED_ADDR_ENABLE, 0, 0, 0) ==
-          (uptr)-1 ||
-      !internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0)) {
+  if ((internal_iserror(internal_prctl(PR_SET_TAGGED_ADDR_CTRL,
+                                       PR_TAGGED_ADDR_ENABLE, 0, 0, 0)) ||
+       !internal_prctl(PR_GET_TAGGED_ADDR_CTRL, 0, 0, 0, 0)) &&
+      flags()->fail_without_syscall_abi) {
     Printf(
         "FATAL: HWAddressSanitizer failed to enable tagged address syscall "
         "ABI.\nSuggest check `sysctl abi.tagged_addr_disabled` "
@@ -174,6 +181,18 @@ bool InitShadow() {
   // High memory starts where allocated shadow allows.
   kHighMemStart = ShadowToMem(kHighShadowStart);
 
+#if defined(__x86_64__)
+  constexpr uptr kAliasRegionOffset = 1ULL << (kTaggableRegionCheckShift - 1);
+  kAliasRegionStart =
+      __hwasan_shadow_memory_dynamic_address + kAliasRegionOffset;
+
+  CHECK_EQ(kAliasRegionStart >> kTaggableRegionCheckShift,
+           __hwasan_shadow_memory_dynamic_address >> kTaggableRegionCheckShift);
+  CHECK_EQ(
+      (kAliasRegionStart + kAliasRegionOffset - 1) >> kTaggableRegionCheckShift,
+      __hwasan_shadow_memory_dynamic_address >> kTaggableRegionCheckShift);
+#endif
+
   // Check the sanity of the defined memory ranges (there might be gaps).
   CHECK_EQ(kHighMemStart % GetMmapGranularity(), 0);
   CHECK_GT(kHighMemStart, kHighShadowEnd);
@@ -217,7 +236,9 @@ void InitThreads() {
 }
 
 bool MemIsApp(uptr p) {
+#if !defined(__x86_64__)  // Memory outside the alias range has non-zero tags.
   CHECK(GetTagFromPointer(p) == 0);
+#endif
   return p >= kHighMemStart || (p >= kLowMemStart && p <= kLowMemEnd);
 }