freebsd-dev/contrib/llvm/lib/Support/Unix/Memory.inc
Dimitry Andric f785676f2a Upgrade our copy of llvm/clang to 3.4 release. This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC after:	1 month
2014-02-16 19:44:07 +00:00

361 lines
11 KiB
C++

//===- 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.
//
//===----------------------------------------------------------------------===//
//
// This file defines some functions for various memory management utilities.
//
//===----------------------------------------------------------------------===//
#include "Unix.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/Process.h"
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#ifdef __APPLE__
#include <mach/mach.h>
#endif
#if defined(__mips__)
# if defined(__OpenBSD__)
# include <mips64/sysarch.h>
# else
# include <sys/cachectl.h>
# endif
#endif
#ifdef __APPLE__
extern "C" void sys_icache_invalidate(const void *Addr, size_t len);
#else
extern "C" void __clear_cache(void *, void*);
#endif
namespace {
int getPosixProtectionFlags(unsigned Flags) {
switch (Flags) {
case llvm::sys::Memory::MF_READ:
return PROT_READ;
case llvm::sys::Memory::MF_WRITE:
return PROT_WRITE;
case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_WRITE:
return PROT_READ | PROT_WRITE;
case llvm::sys::Memory::MF_READ|llvm::sys::Memory::MF_EXEC:
return PROT_READ | PROT_EXEC;
case llvm::sys::Memory::MF_READ |
llvm::sys::Memory::MF_WRITE |
llvm::sys::Memory::MF_EXEC:
return PROT_READ | PROT_WRITE | PROT_EXEC;
case llvm::sys::Memory::MF_EXEC:
#if defined(__FreeBSD__)
// 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;
#endif
default:
llvm_unreachable("Illegal memory protection flag specified!");
}
// Provide a default return value as required by some compilers.
return PROT_NONE;
}
} // namespace
namespace llvm {
namespace sys {
MemoryBlock
Memory::allocateMappedMemory(size_t NumBytes,
const MemoryBlock *const NearBlock,
unsigned PFlags,
error_code &EC) {
EC = error_code::success();
if (NumBytes == 0)
return MemoryBlock();
static const size_t PageSize = process::get_self()->page_size();
const size_t NumPages = (NumBytes+PageSize-1)/PageSize;
int fd = -1;
#ifdef NEED_DEV_ZERO_FOR_MMAP
static int zero_fd = open("/dev/zero", O_RDWR);
if (zero_fd == -1) {
EC = error_code(errno, system_category());
return MemoryBlock();
}
fd = zero_fd;
#endif
int MMFlags = MAP_PRIVATE |
#ifdef HAVE_MMAP_ANONYMOUS
MAP_ANONYMOUS
#else
MAP_ANON
#endif
; // Ends statement above
int Protect = getPosixProtectionFlags(PFlags);
// 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;
if (Start && Start % PageSize)
Start += PageSize - Start % PageSize;
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
return allocateMappedMemory(NumBytes, 0, PFlags, EC);
EC = error_code(errno, system_category());
return MemoryBlock();
}
MemoryBlock Result;
Result.Address = Addr;
Result.Size = NumPages*PageSize;
if (PFlags & MF_EXEC)
Memory::InvalidateInstructionCache(Result.Address, Result.Size);
return Result;
}
error_code
Memory::releaseMappedMemory(MemoryBlock &M) {
if (M.Address == 0 || M.Size == 0)
return error_code::success();
if (0 != ::munmap(M.Address, M.Size))
return error_code(errno, system_category());
M.Address = 0;
M.Size = 0;
return error_code::success();
}
error_code
Memory::protectMappedMemory(const MemoryBlock &M, unsigned Flags) {
if (M.Address == 0 || M.Size == 0)
return error_code::success();
if (!Flags)
return error_code(EINVAL, generic_category());
int Protect = getPosixProtectionFlags(Flags);
int Result = ::mprotect(M.Address, M.Size, Protect);
if (Result != 0)
return error_code(errno, system_category());
if (Flags & MF_EXEC)
Memory::InvalidateInstructionCache(M.Address, M.Size);
return error_code::success();
}
/// AllocateRWX - Allocate a slab of memory with read/write/execute
/// permissions. This is typically used for JIT applications where we want
/// to emit code to the memory then jump to it. Getting this type of memory
/// is very OS specific.
///
MemoryBlock
Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
std::string *ErrMsg) {
if (NumBytes == 0) return MemoryBlock();
size_t PageSize = process::get_self()->page_size();
size_t NumPages = (NumBytes+PageSize-1)/PageSize;
int fd = -1;
#ifdef NEED_DEV_ZERO_FOR_MMAP
static int zero_fd = open("/dev/zero", O_RDWR);
if (zero_fd == -1) {
MakeErrMsg(ErrMsg, "Can't open /dev/zero device");
return MemoryBlock();
}
fd = zero_fd;
#endif
int flags = MAP_PRIVATE |
#ifdef HAVE_MMAP_ANONYMOUS
MAP_ANONYMOUS
#else
MAP_ANON
#endif
;
void* start = NearBlock ? (unsigned char*)NearBlock->base() +
NearBlock->size() : 0;
#if defined(__APPLE__) && defined(__arm__)
void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_EXEC,
flags, fd, 0);
#else
void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
flags, fd, 0);
#endif
if (pa == MAP_FAILED) {
if (NearBlock) //Try again without a near hint
return AllocateRWX(NumBytes, 0);
MakeErrMsg(ErrMsg, "Can't allocate RWX Memory");
return MemoryBlock();
}
#if defined(__APPLE__) && defined(__arm__)
kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)pa,
(vm_size_t)(PageSize*NumPages), 0,
VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
if (KERN_SUCCESS != kr) {
MakeErrMsg(ErrMsg, "vm_protect max RX failed");
return MemoryBlock();
}
kr = vm_protect(mach_task_self(), (vm_address_t)pa,
(vm_size_t)(PageSize*NumPages), 0,
VM_PROT_READ | VM_PROT_WRITE);
if (KERN_SUCCESS != kr) {
MakeErrMsg(ErrMsg, "vm_protect RW failed");
return MemoryBlock();
}
#endif
MemoryBlock result;
result.Address = pa;
result.Size = NumPages*PageSize;
return result;
}
bool Memory::ReleaseRWX(MemoryBlock &M, std::string *ErrMsg) {
if (M.Address == 0 || M.Size == 0) return false;
if (0 != ::munmap(M.Address, M.Size))
return MakeErrMsg(ErrMsg, "Can't release RWX Memory");
return false;
}
bool Memory::setWritable (MemoryBlock &M, std::string *ErrMsg) {
#if defined(__APPLE__) && defined(__arm__)
if (M.Address == 0 || M.Size == 0) return false;
Memory::InvalidateInstructionCache(M.Address, M.Size);
kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
(vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_WRITE);
return KERN_SUCCESS == kr;
#else
return true;
#endif
}
bool Memory::setExecutable (MemoryBlock &M, std::string *ErrMsg) {
#if defined(__APPLE__) && defined(__arm__)
if (M.Address == 0 || M.Size == 0) return false;
Memory::InvalidateInstructionCache(M.Address, M.Size);
kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)M.Address,
(vm_size_t)M.Size, 0, VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
return KERN_SUCCESS == kr;
#elif defined(__arm__) || defined(__aarch64__)
Memory::InvalidateInstructionCache(M.Address, M.Size);
return true;
#else
return true;
#endif
}
bool Memory::setRangeWritable(const void *Addr, size_t Size) {
#if defined(__APPLE__) && defined(__arm__)
kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
(vm_size_t)Size, 0,
VM_PROT_READ | VM_PROT_WRITE);
return KERN_SUCCESS == kr;
#else
return true;
#endif
}
bool Memory::setRangeExecutable(const void *Addr, size_t Size) {
#if defined(__APPLE__) && defined(__arm__)
kern_return_t kr = vm_protect(mach_task_self(), (vm_address_t)Addr,
(vm_size_t)Size, 0,
VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_COPY);
return KERN_SUCCESS == kr;
#else
return true;
#endif
}
/// InvalidateInstructionCache - Before the JIT can run a block of code
/// that has been emitted it must invalidate the instruction cache on some
/// platforms.
void Memory::InvalidateInstructionCache(const void *Addr,
size_t Len) {
// icache invalidation for PPC and ARM.
#if defined(__APPLE__)
# if (defined(__POWERPC__) || defined (__ppc__) || \
defined(_POWER) || defined(_ARCH_PPC)) || defined(__arm__)
sys_icache_invalidate(const_cast<void *>(Addr), Len);
# endif
#else
# if (defined(__POWERPC__) || defined (__ppc__) || \
defined(_POWER) || defined(_ARCH_PPC)) && defined(__GNUC__)
const size_t LineSize = 32;
const intptr_t Mask = ~(LineSize - 1);
const intptr_t StartLine = ((intptr_t) Addr) & Mask;
const intptr_t EndLine = ((intptr_t) Addr + Len + LineSize - 1) & Mask;
for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
asm volatile("dcbf 0, %0" : : "r"(Line));
asm volatile("sync");
for (intptr_t Line = StartLine; Line < EndLine; Line += LineSize)
asm volatile("icbi 0, %0" : : "r"(Line));
asm volatile("isync");
# elif (defined(__arm__) || defined(__aarch64__)) && defined(__GNUC__) && !defined(__FreeBSD__)
// FIXME: Can we safely always call this for __GNUC__ everywhere?
const char *Start = static_cast<const char *>(Addr);
const char *End = Start + Len;
__clear_cache(const_cast<char *>(Start), const_cast<char *>(End));
# elif defined(__mips__)
const char *Start = static_cast<const char *>(Addr);
# if defined(ANDROID)
// The declaration of "cacheflush" in Android bionic:
// extern int cacheflush(long start, long end, long flags);
const char *End = Start + Len;
long LStart = reinterpret_cast<long>(const_cast<char *>(Start));
long LEnd = reinterpret_cast<long>(const_cast<char *>(End));
cacheflush(LStart, LEnd, BCACHE);
# else
cacheflush(const_cast<char *>(Start), Len, BCACHE);
# endif
# endif
#endif // end apple
ValgrindDiscardTranslations(Addr, Len);
}
} // namespace sys
} // namespace llvm