diff options
Diffstat (limited to 'lib/Support/Unix/Memory.inc')
| -rw-r--r-- | lib/Support/Unix/Memory.inc | 81 |
1 files changed, 50 insertions, 31 deletions
diff --git a/lib/Support/Unix/Memory.inc b/lib/Support/Unix/Memory.inc index adbfff2f59a5..a0927da50e48 100644 --- a/lib/Support/Unix/Memory.inc +++ b/lib/Support/Unix/Memory.inc @@ -1,9 +1,8 @@ //===- Unix/Memory.cpp - Generic UNIX System Configuration ------*- C++ -*-===// // -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// // @@ -46,7 +45,7 @@ extern "C" void __clear_cache(void *, void*); namespace { int getPosixProtectionFlags(unsigned Flags) { - switch (Flags) { + switch (Flags & llvm::sys::Memory::MF_RWE_MASK) { case llvm::sys::Memory::MF_READ: return PROT_READ; case llvm::sys::Memory::MF_WRITE: @@ -59,14 +58,13 @@ int getPosixProtectionFlags(unsigned Flags) { llvm::sys::Memory::MF_EXEC: return PROT_READ | PROT_WRITE | PROT_EXEC; case llvm::sys::Memory::MF_EXEC: -#if defined(__FreeBSD__) +#if (defined(__FreeBSD__) || defined(__POWERPC__) || defined (__ppc__) || \ + defined(_POWER) || defined(_ARCH_PPC)) // On PowerPC, having an executable page that has no read permission // can have unintended consequences. The function InvalidateInstruction- // Cache uses instructions dcbf and icbi, both of which are treated by // the processor as loads. If the page has no read permissions, // executing these instructions will result in a segmentation fault. - // Somehow, this problem is not present on Linux, but it does happen - // on FreeBSD. return PROT_READ | PROT_EXEC; #else return PROT_EXEC; @@ -92,19 +90,24 @@ Memory::allocateMappedMemory(size_t NumBytes, if (NumBytes == 0) return MemoryBlock(); - static const size_t PageSize = Process::getPageSize(); - const size_t NumPages = (NumBytes+PageSize-1)/PageSize; - - int fd = -1; - - int MMFlags = MAP_PRIVATE | -#ifdef MAP_ANONYMOUS - MAP_ANONYMOUS + // On platforms that have it, we can use MAP_ANON to get a memory-mapped + // page without file backing, but we need a fallback of opening /dev/zero + // for strictly POSIX platforms instead. + int fd; +#if defined(MAP_ANON) + fd = -1; #else - MAP_ANON + fd = open("/dev/zero", O_RDWR); + if (fd == -1) { + EC = std::error_code(errno, std::generic_category()); + return MemoryBlock(); + } #endif - ; // Ends statement above + int MMFlags = MAP_PRIVATE; +#if defined(MAP_ANON) + MMFlags |= MAP_ANON; +#endif int Protect = getPosixProtectionFlags(PFlags); #if defined(__NetBSD__) && defined(PROT_MPROTECT) @@ -113,23 +116,39 @@ Memory::allocateMappedMemory(size_t NumBytes, // Use any near hint and the page size to set a page-aligned starting address uintptr_t Start = NearBlock ? reinterpret_cast<uintptr_t>(NearBlock->base()) + - NearBlock->size() : 0; + NearBlock->allocatedSize() : 0; + static const size_t PageSize = Process::getPageSizeEstimate(); + const size_t NumPages = (NumBytes+PageSize-1)/PageSize; + if (Start && Start % PageSize) Start += PageSize - Start % PageSize; - void *Addr = ::mmap(reinterpret_cast<void*>(Start), PageSize*NumPages, - Protect, MMFlags, fd, 0); + // FIXME: Handle huge page requests (MF_HUGE_HINT). + void *Addr = ::mmap(reinterpret_cast<void *>(Start), PageSize*NumPages, Protect, + MMFlags, fd, 0); if (Addr == MAP_FAILED) { - if (NearBlock) //Try again without a near hint + if (NearBlock) { //Try again without a near hint +#if !defined(MAP_ANON) + close(fd); +#endif return allocateMappedMemory(NumBytes, nullptr, PFlags, EC); + } EC = std::error_code(errno, std::generic_category()); +#if !defined(MAP_ANON) + close(fd); +#endif return MemoryBlock(); } +#if !defined(MAP_ANON) + close(fd); +#endif + MemoryBlock Result; Result.Address = Addr; - Result.Size = NumPages*PageSize; + Result.AllocatedSize = PageSize*NumPages; + Result.Flags = PFlags; // Rely on protectMappedMemory to invalidate instruction cache. if (PFlags & MF_EXEC) { @@ -143,22 +162,22 @@ Memory::allocateMappedMemory(size_t NumBytes, std::error_code Memory::releaseMappedMemory(MemoryBlock &M) { - if (M.Address == nullptr || M.Size == 0) + if (M.Address == nullptr || M.AllocatedSize == 0) return std::error_code(); - if (0 != ::munmap(M.Address, M.Size)) + if (0 != ::munmap(M.Address, M.AllocatedSize)) return std::error_code(errno, std::generic_category()); M.Address = nullptr; - M.Size = 0; + M.AllocatedSize = 0; return std::error_code(); } std::error_code Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) { - static const size_t PageSize = Process::getPageSize(); - if (M.Address == nullptr || M.Size == 0) + static const size_t PageSize = Process::getPageSizeEstimate(); + if (M.Address == nullptr || M.AllocatedSize == 0) return std::error_code(); if (!Flags) @@ -166,7 +185,7 @@ Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) { int Protect = getPosixProtectionFlags(Flags); uintptr_t Start = alignAddr((uint8_t *)M.Address - PageSize + 1, PageSize); - uintptr_t End = alignAddr((uint8_t *)M.Address + M.Size, PageSize); + uintptr_t End = alignAddr((uint8_t *)M.Address + M.AllocatedSize, PageSize); bool InvalidateCache = (Flags & MF_EXEC); @@ -179,7 +198,7 @@ Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) { if (Result != 0) return std::error_code(errno, std::generic_category()); - Memory::InvalidateInstructionCache(M.Address, M.Size); + Memory::InvalidateInstructionCache(M.Address, M.AllocatedSize); InvalidateCache = false; } #endif @@ -190,7 +209,7 @@ Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) { return std::error_code(errno, std::generic_category()); if (InvalidateCache) - Memory::InvalidateInstructionCache(M.Address, M.Size); + Memory::InvalidateInstructionCache(M.Address, M.AllocatedSize); return std::error_code(); } |