| /* |
| * Copyright (C) 2014-2016 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef VMAllocate_h |
| #define VMAllocate_h |
| |
| #include "BAssert.h" |
| #include "Logging.h" |
| #include "Range.h" |
| #include "Sizes.h" |
| #include "Syscall.h" |
| #include <algorithm> |
| #include <sys/mman.h> |
| #include <unistd.h> |
| |
| #if BOS(DARWIN) |
| #include <mach/vm_page_size.h> |
| #include <mach/vm_statistics.h> |
| #endif |
| |
| namespace bmalloc { |
| |
| #if BOS(DARWIN) |
| #define BMALLOC_VM_TAG VM_MAKE_TAG(VM_MEMORY_TCMALLOC) |
| #define BMALLOC_NORESERVE 0 |
| #elif BOS(LINUX) |
| #define BMALLOC_VM_TAG -1 |
| #define BMALLOC_NORESERVE MAP_NORESERVE |
| #else |
| #define BMALLOC_VM_TAG -1 |
| #define BMALLOC_NORESERVE 0 |
| #endif |
| |
| inline size_t vmPageSize() |
| { |
| static size_t cached; |
| if (!cached) |
| cached = sysconf(_SC_PAGESIZE); |
| return cached; |
| } |
| |
| inline size_t vmPageShift() |
| { |
| static size_t cached; |
| if (!cached) |
| cached = log2(vmPageSize()); |
| return cached; |
| } |
| |
| inline size_t vmSize(size_t size) |
| { |
| return roundUpToMultipleOf(vmPageSize(), size); |
| } |
| |
| inline void vmValidate(size_t vmSize) |
| { |
| BUNUSED(vmSize); |
| BASSERT(vmSize); |
| BASSERT(vmSize == roundUpToMultipleOf(vmPageSize(), vmSize)); |
| } |
| |
| inline void vmValidate(void* p, size_t vmSize) |
| { |
| vmValidate(vmSize); |
| |
| BUNUSED(p); |
| BASSERT(p); |
| BASSERT(p == mask(p, ~(vmPageSize() - 1))); |
| } |
| |
| inline size_t vmPageSizePhysical() |
| { |
| #if BPLATFORM(IOS) |
| return vm_kernel_page_size; |
| #else |
| static size_t cached; |
| if (!cached) |
| cached = sysconf(_SC_PAGESIZE); |
| return cached; |
| #endif |
| } |
| |
| inline void vmValidatePhysical(size_t vmSize) |
| { |
| BUNUSED(vmSize); |
| BASSERT(vmSize); |
| BASSERT(vmSize == roundUpToMultipleOf(vmPageSizePhysical(), vmSize)); |
| } |
| |
| inline void vmValidatePhysical(void* p, size_t vmSize) |
| { |
| vmValidatePhysical(vmSize); |
| |
| BUNUSED(p); |
| BASSERT(p); |
| BASSERT(p == mask(p, ~(vmPageSizePhysical() - 1))); |
| } |
| |
| inline void* tryVMAllocate(size_t vmSize) |
| { |
| vmValidate(vmSize); |
| void* result = mmap(0, vmSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | BMALLOC_NORESERVE, BMALLOC_VM_TAG, 0); |
| if (result == MAP_FAILED) |
| return nullptr; |
| return result; |
| } |
| |
| inline void* vmAllocate(size_t vmSize) |
| { |
| void* result = tryVMAllocate(vmSize); |
| RELEASE_BASSERT(result); |
| return result; |
| } |
| |
| inline void vmDeallocate(void* p, size_t vmSize) |
| { |
| vmValidate(p, vmSize); |
| munmap(p, vmSize); |
| } |
| |
| inline void vmRevokePermissions(void* p, size_t vmSize) |
| { |
| vmValidate(p, vmSize); |
| mprotect(p, vmSize, PROT_NONE); |
| } |
| |
| inline void vmZeroAndPurge(void* p, size_t vmSize) |
| { |
| vmValidate(p, vmSize); |
| // MAP_ANON guarantees the memory is zeroed. This will also cause |
| // page faults on accesses to this range following this call. |
| void* result = mmap(p, vmSize, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_FIXED | BMALLOC_NORESERVE, BMALLOC_VM_TAG, 0); |
| RELEASE_BASSERT(result == p); |
| } |
| |
| // Allocates vmSize bytes at a specified power-of-two alignment. |
| // Use this function to create maskable memory regions. |
| |
| inline void* tryVMAllocate(size_t vmAlignment, size_t vmSize) |
| { |
| vmValidate(vmSize); |
| vmValidate(vmAlignment); |
| |
| size_t mappedSize = vmAlignment + vmSize; |
| if (mappedSize < vmAlignment || mappedSize < vmSize) // Check for overflow |
| return nullptr; |
| |
| char* mapped = static_cast<char*>(tryVMAllocate(mappedSize)); |
| if (!mapped) |
| return nullptr; |
| char* mappedEnd = mapped + mappedSize; |
| |
| char* aligned = roundUpToMultipleOf(vmAlignment, mapped); |
| char* alignedEnd = aligned + vmSize; |
| |
| RELEASE_BASSERT(alignedEnd <= mappedEnd); |
| |
| if (size_t leftExtra = aligned - mapped) |
| vmDeallocate(mapped, leftExtra); |
| |
| if (size_t rightExtra = mappedEnd - alignedEnd) |
| vmDeallocate(alignedEnd, rightExtra); |
| |
| return aligned; |
| } |
| |
| inline void* vmAllocate(size_t vmAlignment, size_t vmSize) |
| { |
| void* result = tryVMAllocate(vmAlignment, vmSize); |
| RELEASE_BASSERT(result); |
| return result; |
| } |
| |
| inline void vmDeallocatePhysicalPages(void* p, size_t vmSize) |
| { |
| vmValidatePhysical(p, vmSize); |
| #if BOS(DARWIN) |
| SYSCALL(madvise(p, vmSize, MADV_FREE_REUSABLE)); |
| #else |
| SYSCALL(madvise(p, vmSize, MADV_DONTNEED)); |
| #if BOS(LINUX) |
| SYSCALL(madvise(p, vmSize, MADV_DONTDUMP)); |
| #endif |
| #endif |
| } |
| |
| inline void vmAllocatePhysicalPages(void* p, size_t vmSize) |
| { |
| vmValidatePhysical(p, vmSize); |
| #if BOS(DARWIN) |
| SYSCALL(madvise(p, vmSize, MADV_FREE_REUSE)); |
| #else |
| SYSCALL(madvise(p, vmSize, MADV_NORMAL)); |
| #if BOS(LINUX) |
| SYSCALL(madvise(p, vmSize, MADV_DODUMP)); |
| #endif |
| #endif |
| } |
| |
| // Returns how much memory you would commit/decommit had you called |
| // vmDeallocate/AllocatePhysicalPagesSloppy with p and size. |
| inline size_t physicalPageSizeSloppy(void* p, size_t size) |
| { |
| char* begin = roundUpToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p)); |
| char* end = roundDownToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p) + size); |
| |
| if (begin >= end) |
| return 0; |
| return end - begin; |
| } |
| |
| // Trims requests that are un-page-aligned. |
| inline void vmDeallocatePhysicalPagesSloppy(void* p, size_t size) |
| { |
| char* begin = roundUpToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p)); |
| char* end = roundDownToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p) + size); |
| |
| if (begin >= end) |
| return; |
| |
| vmDeallocatePhysicalPages(begin, end - begin); |
| } |
| |
| // Expands requests that are un-page-aligned. |
| inline void vmAllocatePhysicalPagesSloppy(void* p, size_t size) |
| { |
| char* begin = roundDownToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p)); |
| char* end = roundUpToMultipleOf(vmPageSizePhysical(), static_cast<char*>(p) + size); |
| |
| if (begin >= end) |
| return; |
| |
| vmAllocatePhysicalPages(begin, end - begin); |
| } |
| |
| } // namespace bmalloc |
| |
| #endif // VMAllocate_h |