pw_allocator/block.cc

// Copyright 2020 The Pigweed 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 "pw_allocator/block.h"

#include "pw_assert/check.h"

namespace pw::allocator {

#if defined(PW_ALLOCATOR_POISON_ENABLE) && PW_ALLOCATOR_POISON_ENABLE

void BaseBlock::Poison(void* block, size_t header_size, size_t outer_size) {
  auto* start = reinterpret_cast<std::byte*>(block);
  std::memcpy(
      start + header_size - kPoisonOffset, kPoisonPattern, kPoisonOffset);
  std::memcpy(
      start + outer_size - kPoisonOffset, kPoisonPattern, kPoisonOffset);
}

bool BaseBlock::CheckPoison(const void* block,
                            size_t header_size,
                            size_t outer_size) {
  const auto* start = reinterpret_cast<const std::byte*>(block);
  return std::memcmp(start + header_size - kPoisonOffset,
                     kPoisonPattern,
                     kPoisonOffset) == 0 &&
         std::memcmp(start + outer_size - kPoisonOffset,
                     kPoisonPattern,
                     kPoisonOffset) == 0;
}

#else  // PW_ALLOCATOR_POISON_ENABLE

void BaseBlock::Poison(void*, size_t, size_t) {}

bool BaseBlock::CheckPoison(const void*, size_t, size_t) { return true; }

#endif  // PW_ALLOCATOR_POISON_ENABLE

// TODO: b/234875269 - Add stack tracing to locate which call to the heap
// operation caused the corruption in the methods below.

void BaseBlock::CrashMisaligned(uintptr_t addr) {
  PW_DCHECK(false,
            "The block at address %p is not aligned.",
            reinterpret_cast<void*>(addr));
}

void BaseBlock::CrashNextMismatched(uintptr_t addr, uintptr_t next_prev) {
  PW_DCHECK(false,
            "The 'prev' field in the next block (%p) does not match the "
            "address of the current block (%p).",
            reinterpret_cast<void*>(next_prev),
            reinterpret_cast<void*>(addr));
}

void BaseBlock::CrashPrevMismatched(uintptr_t addr, uintptr_t prev_next) {
  PW_DCHECK(false,
            "The 'next' field in the previous block (%p) does not match "
            "the address of the current block (%p).",
            reinterpret_cast<void*>(prev_next),
            reinterpret_cast<void*>(addr));
}

void BaseBlock::CrashPoisonCorrupted(uintptr_t addr) {
  PW_DCHECK(false,
            "The poisoned pattern in the block at %p is corrupted.",
            reinterpret_cast<void*>(addr));
}

}  // namespace pw::allocator