diff options
Diffstat (limited to 'mfbt/TaggedAnonymousMemory.cpp')
-rw-r--r-- | mfbt/TaggedAnonymousMemory.cpp | 105 |
1 files changed, 0 insertions, 105 deletions
diff --git a/mfbt/TaggedAnonymousMemory.cpp b/mfbt/TaggedAnonymousMemory.cpp deleted file mode 100644 index a2ba9ee4b..000000000 --- a/mfbt/TaggedAnonymousMemory.cpp +++ /dev/null @@ -1,105 +0,0 @@ -/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ -/* vim: set ts=8 sts=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/. */ - -#ifdef ANDROID - -#include "mozilla/TaggedAnonymousMemory.h" - -#include <sys/types.h> -#include <sys/mman.h> -#include <sys/prctl.h> -#include <sys/syscall.h> -#include <unistd.h> - -#include "mozilla/Assertions.h" - -// These constants are copied from <sys/prctl.h>, because the headers -// used for building may not have them even though the running kernel -// supports them. -#ifndef PR_SET_VMA -#define PR_SET_VMA 0x53564d41 -#endif -#ifndef PR_SET_VMA_ANON_NAME -#define PR_SET_VMA_ANON_NAME 0 -#endif - -namespace mozilla { - -// Returns 0 for success and -1 (with errno) for error. -static int -TagAnonymousMemoryAligned(const void* aPtr, size_t aLength, const char* aTag) -{ - return prctl(PR_SET_VMA, - PR_SET_VMA_ANON_NAME, - reinterpret_cast<unsigned long>(aPtr), - aLength, - reinterpret_cast<unsigned long>(aTag)); -} - -// On some architectures, it's possible for the page size to be larger -// than the PAGE_SIZE we were compiled with. This computes the -// equivalent of PAGE_MASK. -static uintptr_t -GetPageMask() -{ - static uintptr_t mask = 0; - - if (mask == 0) { - uintptr_t pageSize = sysconf(_SC_PAGESIZE); - mask = ~(pageSize - 1); - MOZ_ASSERT((pageSize & (pageSize - 1)) == 0, - "Page size must be a power of 2!"); - } - return mask; -} - -} // namespace mozilla - -int -MozTaggedMemoryIsSupported(void) -{ - static int supported = -1; - - if (supported == -1) { - // Tagging an empty range always "succeeds" if the feature is supported, - // regardless of the start pointer. - supported = mozilla::TagAnonymousMemoryAligned(nullptr, 0, nullptr) == 0; - } - return supported; -} - -void -MozTagAnonymousMemory(const void* aPtr, size_t aLength, const char* aTag) -{ - if (MozTaggedMemoryIsSupported()) { - // The kernel will round up the end of the range to the next page - // boundary if it's not aligned (comments indicate this behavior - // is based on that of madvise), but it will reject the request if - // the start is not aligned. We therefore round down the start - // address and adjust the length accordingly. - uintptr_t addr = reinterpret_cast<uintptr_t>(aPtr); - uintptr_t end = addr + aLength; - uintptr_t addrRounded = addr & mozilla::GetPageMask(); - const void* ptrRounded = reinterpret_cast<const void*>(addrRounded); - - mozilla::TagAnonymousMemoryAligned(ptrRounded, end - addrRounded, aTag); - } -} - -void* -MozTaggedAnonymousMmap(void* aAddr, size_t aLength, int aProt, int aFlags, - int aFd, off_t aOffset, const char* aTag) -{ - void* mapped = mmap(aAddr, aLength, aProt, aFlags, aFd, aOffset); - if (MozTaggedMemoryIsSupported() && - (aFlags & MAP_ANONYMOUS) == MAP_ANONYMOUS && - mapped != MAP_FAILED) { - mozilla::TagAnonymousMemoryAligned(mapped, aLength, aTag); - } - return mapped; -} - -#endif // ANDROID |