зеркало из https://github.com/mozilla/gecko-dev.git
103 строки
3.2 KiB
C++
103 строки
3.2 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* vim: set ts=2 et sw=2 tw=80: */
|
|
/* This Source Code Form is subject to the terms of the Mozilla Public
|
|
* License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
|
|
|
|
#ifndef PHC_h
|
|
#define PHC_h
|
|
|
|
#include "mozilla/Assertions.h"
|
|
#include "mozilla/Maybe.h"
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
|
|
namespace mozilla {
|
|
namespace phc {
|
|
|
|
// Note: a stack trace may have no frames due to a collection problem.
|
|
//
|
|
// Also note: a more compact stack trace representation could be achieved with
|
|
// some effort.
|
|
struct StackTrace {
|
|
public:
|
|
static const size_t kMaxFrames = 16;
|
|
|
|
// The number of PCs in the stack trace.
|
|
size_t mLength;
|
|
|
|
// The PCs in the stack trace. Only the first mLength are initialized.
|
|
const void* mPcs[kMaxFrames];
|
|
|
|
public:
|
|
StackTrace() : mLength(0) {}
|
|
};
|
|
|
|
// Info from PHC about an address in memory.
|
|
class AddrInfo {
|
|
public:
|
|
enum class Kind {
|
|
// The address is not in PHC-managed memory.
|
|
Unknown = 0,
|
|
|
|
// The address is within a PHC page that has never been allocated. A crash
|
|
// involving such an address is unlikely in practice, because it would
|
|
// require the crash to happen quite early.
|
|
NeverAllocatedPage = 1,
|
|
|
|
// The address is within a PHC page that is in use.
|
|
InUsePage = 2,
|
|
|
|
// The address is within a PHC page that has been allocated and then freed.
|
|
// A crash involving such an address most likely indicates a
|
|
// use-after-free. (A sufficiently wild write -- e.g. a large buffer
|
|
// overflow -- could also trigger it, but this is less likely.)
|
|
FreedPage = 3,
|
|
|
|
// The address is within a PHC guard page. A crash involving such an
|
|
// address most likely indicates a buffer overflow. (Again, a sufficiently
|
|
// wild write could unluckily trigger it, but this is less likely.)
|
|
GuardPage = 4,
|
|
};
|
|
|
|
// The page kind.
|
|
Kind mKind;
|
|
|
|
// The starting address of the allocation.
|
|
// - Unknown | NeverAllocatedPage: nullptr.
|
|
// - InUsePage | FreedPage: the address of the allocation within the page.
|
|
// - GuardPage: the mBaseAddr value from the preceding allocation page.
|
|
const void* mBaseAddr;
|
|
|
|
// The usable size, which could be bigger than the requested size.
|
|
// - Unknown | NeverAllocatePage: 0.
|
|
// - InUsePage | FreedPage: the usable size of the allocation within the page.
|
|
// - GuardPage: the mUsableSize value from the preceding allocation page.
|
|
size_t mUsableSize;
|
|
|
|
// The allocation stack.
|
|
// - Unknown | NeverAllocatedPage: Nothing.
|
|
// - InUsePage | FreedPage: Some.
|
|
// - GuardPage: the mAllocStack value from the preceding allocation page.
|
|
mozilla::Maybe<StackTrace> mAllocStack;
|
|
|
|
// The free stack.
|
|
// - Unknown | NeverAllocatedPage | InUsePage: Nothing.
|
|
// - FreedPage: Some.
|
|
// - GuardPage: the mFreeStack value from the preceding allocation page.
|
|
mozilla::Maybe<StackTrace> mFreeStack;
|
|
|
|
// Default to no PHC info.
|
|
AddrInfo()
|
|
: mKind(Kind::Unknown),
|
|
mBaseAddr(nullptr),
|
|
mUsableSize(0),
|
|
mAllocStack(),
|
|
mFreeStack() {}
|
|
};
|
|
|
|
} // namespace phc
|
|
} // namespace mozilla
|
|
|
|
#endif /* PHC_h */
|