vendor/llvm-project/llvmorg-11-init-20887-g2e10b7a39b9vendor/llvm-project/master

9 files changed, 105 insertions, 28 deletions

diff --git a/compiler-rt/lib/asan/asan_allocator.cpp b/compiler-rt/lib/asan/asan_allocator.cpp
index 65c51fbafdd0..126d26d0823b 100644
--- a/compiler-rt/lib/asan/asan_allocator.cpp
+++ b/compiler-rt/lib/asan/asan_allocator.cpp
@@ -1037,8 +1037,19 @@ uptr PointsIntoChunk(void* p) {
   return 0;
 }
 
+// Debug code. Delete once issue #1193 is chased down.
+extern "C" SANITIZER_WEAK_ATTRIBUTE const char *__lsan_current_stage;
+
 uptr GetUserBegin(uptr chunk) {
   __asan::AsanChunk *m = __asan::instance.GetAsanChunkByAddrFastLocked(chunk);
+  if (!m)
+    Printf(
+        "ASAN is about to crash with a CHECK failure.\n"
+        "The ASAN developers are trying to chase down this bug,\n"
+        "so if you've encountered this bug please let us know.\n"
+        "See also: https://github.com/google/sanitizers/issues/1193\n"
+        "chunk: %p caller %p __lsan_current_stage %s\n",
+        chunk, GET_CALLER_PC(), __lsan_current_stage);
   CHECK(m);
   return m->Beg();
 }
diff --git a/compiler-rt/lib/asan/asan_fuchsia.cpp b/compiler-rt/lib/asan/asan_fuchsia.cpp
index f8b2d5f26979..64f6dcbcefeb 100644
--- a/compiler-rt/lib/asan/asan_fuchsia.cpp
+++ b/compiler-rt/lib/asan/asan_fuchsia.cpp
@@ -62,6 +62,8 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   UNIMPLEMENTED();
 }
 
+bool PlatformUnpoisonStacks() { return false; }
+
 // We can use a plain thread_local variable for TSD.
 static thread_local void *per_thread;
 
diff --git a/compiler-rt/lib/asan/asan_internal.h b/compiler-rt/lib/asan/asan_internal.h
index 72a4c3f22ff1..d4bfe996b664 100644
--- a/compiler-rt/lib/asan/asan_internal.h
+++ b/compiler-rt/lib/asan/asan_internal.h
@@ -83,6 +83,16 @@ void *AsanDoesNotSupportStaticLinkage();
 void AsanCheckDynamicRTPrereqs();
 void AsanCheckIncompatibleRT();
 
+// Unpoisons platform-specific stacks.
+// Returns true if all stacks have been unpoisoned.
+bool PlatformUnpoisonStacks();
+
+// asan_rtl.cpp
+// Unpoison a region containing a stack.
+// Performs a sanity check and warns if the bounds don't look right.
+// The warning contains the type string to identify the stack type.
+void UnpoisonStack(uptr bottom, uptr top, const char *type);
+
 // asan_thread.cpp
 AsanThread *CreateMainThread();
 
diff --git a/compiler-rt/lib/asan/asan_posix.cpp b/compiler-rt/lib/asan/asan_posix.cpp
index 920d216624a3..d7f19d846544 100644
--- a/compiler-rt/lib/asan/asan_posix.cpp
+++ b/compiler-rt/lib/asan/asan_posix.cpp
@@ -17,6 +17,7 @@
 #include "asan_internal.h"
 #include "asan_interceptors.h"
 #include "asan_mapping.h"
+#include "asan_poisoning.h"
 #include "asan_report.h"
 #include "asan_stack.h"
 #include "sanitizer_common/sanitizer_libc.h"
@@ -24,6 +25,7 @@
 #include "sanitizer_common/sanitizer_procmaps.h"
 
 #include <pthread.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <sys/time.h>
 #include <sys/resource.h>
@@ -37,6 +39,32 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   ReportDeadlySignal(sig);
 }
 
+bool PlatformUnpoisonStacks() {
+  stack_t signal_stack;
+  CHECK_EQ(0, sigaltstack(nullptr, &signal_stack));
+  uptr sigalt_bottom = (uptr)signal_stack.ss_sp;
+  uptr sigalt_top = (uptr)((char *)signal_stack.ss_sp + signal_stack.ss_size);
+  // If we're executing on the signal alternate stack AND the Linux flag
+  // SS_AUTODISARM was used, then we cannot get the signal alternate stack
+  // bounds from sigaltstack -- sigaltstack's output looks just as if no
+  // alternate stack has ever been set up.
+  // We're always unpoisoning the signal alternate stack to support jumping
+  // between the default stack and signal alternate stack.
+  if (signal_stack.ss_flags != SS_DISABLE)
+    UnpoisonStack(sigalt_bottom, sigalt_top, "sigalt");
+
+  if (signal_stack.ss_flags != SS_ONSTACK)
+    return false;
+
+  // Since we're on the signal altnerate stack, we cannot find the DEFAULT
+  // stack bottom using a local variable.
+  uptr default_bottom, tls_addr, tls_size, stack_size;
+  GetThreadStackAndTls(/*main=*/false, &default_bottom, &stack_size, &tls_addr,
+                       &tls_size);
+  UnpoisonStack(default_bottom, default_bottom + stack_size, "default");
+  return true;
+}
+
 // ---------------------- TSD ---------------- {{{1
 
 #if SANITIZER_NETBSD && !ASAN_DYNAMIC
diff --git a/compiler-rt/lib/asan/asan_report.cpp b/compiler-rt/lib/asan/asan_report.cpp
index 2e6ce436d030..99e8678aa785 100644
--- a/compiler-rt/lib/asan/asan_report.cpp
+++ b/compiler-rt/lib/asan/asan_report.cpp
@@ -160,6 +160,9 @@ class ScopedInErrorReport {
       BlockingMutexLock l(&error_message_buf_mutex);
       internal_memcpy(buffer_copy.data(),
                       error_message_buffer, kErrorMessageBufferSize);
+      // Clear error_message_buffer so that if we find other errors
+      // we don't re-log this error.
+      error_message_buffer_pos = 0;
     }
 
     LogFullErrorReport(buffer_copy.data());
diff --git a/compiler-rt/lib/asan/asan_rtems.cpp b/compiler-rt/lib/asan/asan_rtems.cpp
index ecd568c5981b..2e5b2f0a3b21 100644
--- a/compiler-rt/lib/asan/asan_rtems.cpp
+++ b/compiler-rt/lib/asan/asan_rtems.cpp
@@ -64,6 +64,8 @@ void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
   UNIMPLEMENTED();
 }
 
+bool PlatformUnpoisonStacks() { return false; }
+
 void EarlyInit() {
   // Provide early initialization of shadow memory so that
   // instrumented code running before full initialzation will not
diff --git a/compiler-rt/lib/asan/asan_rtl.cpp b/compiler-rt/lib/asan/asan_rtl.cpp
index 594d7752eea6..463bfa02f9f1 100644
--- a/compiler-rt/lib/asan/asan_rtl.cpp
+++ b/compiler-rt/lib/asan/asan_rtl.cpp
@@ -551,22 +551,33 @@ class AsanInitializer {
 static AsanInitializer asan_initializer;
 #endif  // ASAN_DYNAMIC
 
-} // namespace __asan
-
-// ---------------------- Interface ---------------- {{{1
-using namespace __asan;
-
-void NOINLINE __asan_handle_no_return() {
-  if (asan_init_is_running)
+void UnpoisonStack(uptr bottom, uptr top, const char *type) {
+  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
+  if (top - bottom > kMaxExpectedCleanupSize) {
+    static bool reported_warning = false;
+    if (reported_warning)
+      return;
+    reported_warning = true;
+    Report(
+        "WARNING: ASan is ignoring requested __asan_handle_no_return: "
+        "stack type: %s top: %p; bottom %p; size: %p (%zd)\n"
+        "False positive error reports may follow\n"
+        "For details see "
+        "https://github.com/google/sanitizers/issues/189\n",
+        type, top, bottom, top - bottom, top - bottom);
     return;
+  }
+  PoisonShadow(bottom, top - bottom, 0);
+}
 
-  int local_stack;
-  AsanThread *curr_thread = GetCurrentThread();
-  uptr PageSize = GetPageSizeCached();
-  uptr top, bottom;
-  if (curr_thread) {
+static void UnpoisonDefaultStack() {
+  uptr bottom, top;
+
+  if (AsanThread *curr_thread = GetCurrentThread()) {
+    int local_stack;
+    const uptr page_size = GetPageSizeCached();
     top = curr_thread->stack_top();
-    bottom = ((uptr)&local_stack - PageSize) & ~(PageSize - 1);
+    bottom = ((uptr)&local_stack - page_size) & ~(page_size - 1);
   } else if (SANITIZER_RTEMS) {
     // Give up On RTEMS.
     return;
@@ -578,25 +589,31 @@ void NOINLINE __asan_handle_no_return() {
                          &tls_size);
     top = bottom + stack_size;
   }
-  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
-  if (top - bottom > kMaxExpectedCleanupSize) {
-    static bool reported_warning = false;
-    if (reported_warning)
-      return;
-    reported_warning = true;
-    Report("WARNING: ASan is ignoring requested __asan_handle_no_return: "
-           "stack top: %p; bottom %p; size: %p (%zd)\n"
-           "False positive error reports may follow\n"
-           "For details see "
-           "https://github.com/google/sanitizers/issues/189\n",
-           top, bottom, top - bottom, top - bottom);
-    return;
-  }
-  PoisonShadow(bottom, top - bottom, 0);
+
+  UnpoisonStack(bottom, top, "default");
+}
+
+static void UnpoisonFakeStack() {
+  AsanThread *curr_thread = GetCurrentThread();
   if (curr_thread && curr_thread->has_fake_stack())
     curr_thread->fake_stack()->HandleNoReturn();
 }
 
+}  // namespace __asan
+
+// ---------------------- Interface ---------------- {{{1
+using namespace __asan;
+
+void NOINLINE __asan_handle_no_return() {
+  if (asan_init_is_running)
+    return;
+
+  if (!PlatformUnpoisonStacks())
+    UnpoisonDefaultStack();
+
+  UnpoisonFakeStack();
+}
+
 extern "C" void *__asan_extra_spill_area() {
   AsanThread *t = GetCurrentThread();
   CHECK(t);
diff --git a/compiler-rt/lib/asan/asan_thread.cpp b/compiler-rt/lib/asan/asan_thread.cpp
index 6734d9a1668c..f0df8bd4b374 100644
--- a/compiler-rt/lib/asan/asan_thread.cpp
+++ b/compiler-rt/lib/asan/asan_thread.cpp
@@ -480,6 +480,8 @@ bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
   return true;
 }
 
+void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {}
+
 void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
                             void *arg) {
   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
diff --git a/compiler-rt/lib/asan/asan_win.cpp b/compiler-rt/lib/asan/asan_win.cpp
index 417892aaedd8..03feddbe86b4 100644
--- a/compiler-rt/lib/asan/asan_win.cpp
+++ b/compiler-rt/lib/asan/asan_win.cpp
@@ -268,6 +268,8 @@ void ReadContextStack(void *context, uptr *stack, uptr *ssize) {
 
 void AsanOnDeadlySignal(int, void *siginfo, void *context) { UNIMPLEMENTED(); }
 
+bool PlatformUnpoisonStacks() { return false; }
+
 #if SANITIZER_WINDOWS64
 // Exception handler for dealing with shadow memory.
 static LONG CALLBACK