From 57f04ad892729f798da520a80394cf25afe085e8 Mon Sep 17 00:00:00 2001
From: Derek Mauro <dmauro@google.com>
Date: Mon, 1 Jul 2024 08:25:45 -0700
Subject: Rollback new poisoned pointer API

This breaks Chromium due to global constructor and incorrectly
assumes page size.
https://github.com/abseil/abseil-cpp/pull/1697

PiperOrigin-RevId: 648377066
Change-Id: I19f8b2655971a0c314091e26e62e10a5a9c46e94
---
 absl/base/internal/poison.cc | 79 --------------------------------------------
 1 file changed, 79 deletions(-)
 delete mode 100644 absl/base/internal/poison.cc

(limited to 'absl/base/internal/poison.cc')

diff --git a/absl/base/internal/poison.cc b/absl/base/internal/poison.cc
deleted file mode 100644
index 721d9144..00000000
--- a/absl/base/internal/poison.cc
+++ /dev/null
@@ -1,79 +0,0 @@
-// Copyright 2024 The Abseil Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     https://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "absl/base/internal/poison.h"
-
-#include <atomic>
-#include <cstdint>  // NOLINT - used in ifdef
-#include <cstdlib>
-
-#include "absl/base/attributes.h"
-#include "absl/base/config.h"
-
-#if defined(ABSL_HAVE_ADDRESS_SANITIZER)
-#include <sanitizer/asan_interface.h>
-#elif defined(ABSL_HAVE_MEMORY_SANITIZER)
-#include <sanitizer/msan_interface.h>
-#elif defined(ABSL_HAVE_MMAP)
-#include <sys/mman.h>
-#elif defined(_MSC_VER)
-#include <windows.h>
-#endif
-
-namespace absl {
-ABSL_NAMESPACE_BEGIN
-namespace base_internal {
-namespace {
-constexpr size_t kPageSize = 1 << 12;
-alignas(kPageSize) static char poison_page[kPageSize];
-}  // namespace
-
-std::atomic<void*> poison_data = {&poison_page};
-
-namespace {
-
-#if defined(ABSL_HAVE_ADDRESS_SANITIZER)
-void PoisonBlock(void* data) { ASAN_POISON_MEMORY_REGION(data, kPageSize); }
-#elif defined(ABSL_HAVE_MEMORY_SANITIZER)
-void PoisonBlock(void* data) { __msan_poison(data, kPageSize); }
-#elif defined(ABSL_HAVE_MMAP)
-void PoisonBlock(void* data) { mprotect(data, kPageSize, PROT_NONE); }
-#elif defined(_MSC_VER)
-void PoisonBlock(void* data) {
-  DWORD old_mode = 0;
-  VirtualProtect(data, kPageSize, PAGE_NOACCESS, &old_mode);
-}
-#else
-void PoisonBlock(void* data) {
-  // We can't make poisoned memory, so just use a likely bad pointer.
-  // Pointers are required to have high bits that are all zero or all one for
-  // certain 64-bit CPUs. This pointer value will hopefully cause a crash on
-  // dereference and also be clearly recognizable as invalid.
-  constexpr uint64_t kBadPtr = 0xBAD0BAD0BAD0BAD0;
-  poison_data = reinterpret_cast<void*>(static_cast<uintptr_t>(kBadPtr));
-}
-#endif
-
-void* InitializePoisonedPointer() {
-  PoisonBlock(&poison_page);
-  return &poison_page;
-}
-
-}  // namespace
-
-ABSL_ATTRIBUTE_UNUSED void* force_initialize = InitializePoisonedPointer();
-
-}  // namespace base_internal
-ABSL_NAMESPACE_END
-}  // namespace absl
-- 
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