Implementing page permission setting in MCJIT unit test SectionMemoryManager.cpp

This commit is primarily here for the revision history.  I'm about to move the SectionMemoryManager into the RuntimeDyld library, but I wanted to check the changes in here so people could see the differences in the updated implementation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168718 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Kaylor
2012-11-27 19:00:17 +00:00
parent 39834da697
commit cc7773bdcb
3 changed files with 205 additions and 63 deletions

View File

@@ -1,4 +1,4 @@
//===-- SectionMemoryManager.cpp - The memory manager for MCJIT -----------===//
//===- SectionMemoryManager.cpp - Memory manager for MCJIT/RtDyld *- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
@@ -7,25 +7,24 @@
//
//===----------------------------------------------------------------------===//
//
// This file defines the implementation of the section-based memory manager
// used by MCJIT.
// This file implements the section-based memory manager used by the MCJIT
// execution engine and RuntimeDyld
//
//===----------------------------------------------------------------------===//
#include "llvm/Config/config.h"
#include "llvm/Support/DynamicLibrary.h"
#include "llvm/Support/MathExtras.h"
#include "SectionMemoryManager.h"
#ifdef __linux__
// These includes used by SectionMemoryManager::getPointerToNamedFunction()
// for Glibc trickery. Look comments in this function for more information.
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <unistd.h>
// These includes used by SectionMemoryManager::getPointerToNamedFunction()
// for Glibc trickery. See comments in this function for more information.
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#endif
namespace llvm {
@@ -34,65 +33,137 @@ uint8_t *SectionMemoryManager::allocateDataSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID,
bool IsReadOnly) {
if (!Alignment)
Alignment = 16;
// Ensure that enough memory is requested to allow aligning.
size_t NumElementsAligned = 1 + (Size + Alignment - 1)/Alignment;
uint8_t *Addr = (uint8_t*)calloc(NumElementsAligned, Alignment);
// Honour the alignment requirement.
uint8_t *AlignedAddr = (uint8_t*)RoundUpToAlignment((uint64_t)Addr, Alignment);
// Store the original address from calloc so we can free it later.
AllocatedDataMem.push_back(sys::MemoryBlock(Addr, NumElementsAligned*Alignment));
return AlignedAddr;
if (IsReadOnly)
return allocateSection(RODataMem, Size, Alignment);
return allocateSection(RWDataMem, Size, Alignment);
}
uint8_t *SectionMemoryManager::allocateCodeSection(uintptr_t Size,
unsigned Alignment,
unsigned SectionID) {
unsigned Alignment,
unsigned SectionID) {
return allocateSection(CodeMem, Size, Alignment);
}
uint8_t *SectionMemoryManager::allocateSection(MemoryGroup &MemGroup,
uintptr_t Size,
unsigned Alignment) {
if (!Alignment)
Alignment = 16;
unsigned NeedAllocate = Alignment * ((Size + Alignment - 1)/Alignment + 1);
assert(!(Alignment & (Alignment - 1)) && "Alignment must be a power of two.");
uintptr_t RequiredSize = Alignment * ((Size + Alignment - 1)/Alignment + 1);
uintptr_t Addr = 0;
// Look in the list of free code memory regions and use a block there if one
// Look in the list of free memory regions and use a block there if one
// is available.
for (int i = 0, e = FreeCodeMem.size(); i != e; ++i) {
sys::MemoryBlock &MB = FreeCodeMem[i];
if (MB.size() >= NeedAllocate) {
for (int i = 0, e = MemGroup.FreeMem.size(); i != e; ++i) {
sys::MemoryBlock &MB = MemGroup.FreeMem[i];
if (MB.size() >= RequiredSize) {
Addr = (uintptr_t)MB.base();
uintptr_t EndOfBlock = Addr + MB.size();
// Align the address.
Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
// Store cutted free memory block.
FreeCodeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
EndOfBlock - Addr - Size);
MemGroup.FreeMem[i] = sys::MemoryBlock((void*)(Addr + Size),
EndOfBlock - Addr - Size);
return (uint8_t*)Addr;
}
}
// No pre-allocated free block was large enough. Allocate a new memory region.
sys::MemoryBlock MB = sys::Memory::AllocateRWX(NeedAllocate, 0, 0);
// Note that all sections get allocated as read-write. The permissions will
// be updated later based on memory group.
//
// FIXME: It would be useful to define a default allocation size (or add
// it as a constructor parameter) to minimize the number of allocations.
//
// FIXME: Initialize the Near member for each memory group to avoid
// interleaving.
error_code ec;
sys::MemoryBlock MB = sys::Memory::allocateMappedMemory(RequiredSize,
&MemGroup.Near,
sys::Memory::MF_READ |
sys::Memory::MF_WRITE,
ec);
if (ec) {
// FIXME: Add error propogation to the interface.
return NULL;
}
AllocatedCodeMem.push_back(MB);
// Save this address as the basis for our next request
MemGroup.Near = MB;
MemGroup.AllocatedMem.push_back(MB);
Addr = (uintptr_t)MB.base();
uintptr_t EndOfBlock = Addr + MB.size();
// Align the address.
Addr = (Addr + Alignment - 1) & ~(uintptr_t)(Alignment - 1);
// The AllocateRWX may allocate much more memory than we need. In this case,
// we store the unused memory as a free memory block.
// The allocateMappedMemory may allocate much more memory than we need. In
// this case, we store the unused memory as a free memory block.
unsigned FreeSize = EndOfBlock-Addr-Size;
if (FreeSize > 16)
FreeCodeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
MemGroup.FreeMem.push_back(sys::MemoryBlock((void*)(Addr + Size), FreeSize));
// Return aligned address
return (uint8_t*)Addr;
}
bool SectionMemoryManager::applyPermissions(std::string *ErrMsg)
{
// FIXME: Should in-progress permissions be reverted if an error occurs?
error_code ec;
// Make code memory executable.
ec = applyMemoryGroupPermissions(CodeMem,
sys::Memory::MF_READ | sys::Memory::MF_EXEC);
if (ec) {
if (ErrMsg) {
*ErrMsg = ec.message();
}
return true;
}
// Make read-only data memory read-only.
ec = applyMemoryGroupPermissions(RODataMem,
sys::Memory::MF_READ | sys::Memory::MF_EXEC);
if (ec) {
if (ErrMsg) {
*ErrMsg = ec.message();
}
return true;
}
// Read-write data memory already has the correct permissions
return false;
}
error_code SectionMemoryManager::applyMemoryGroupPermissions(MemoryGroup &MemGroup,
unsigned Permissions) {
for (int i = 0, e = MemGroup.AllocatedMem.size(); i != e; ++i) {
error_code ec;
ec = sys::Memory::protectMappedMemory(MemGroup.AllocatedMem[i],
Permissions);
if (ec) {
return ec;
}
}
return error_code::success();
}
void SectionMemoryManager::invalidateInstructionCache() {
for (int i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
sys::Memory::InvalidateInstructionCache(AllocatedCodeMem[i].base(),
AllocatedCodeMem[i].size());
for (int i = 0, e = CodeMem.AllocatedMem.size(); i != e; ++i)
sys::Memory::InvalidateInstructionCache(CodeMem.AllocatedMem[i].base(),
CodeMem.AllocatedMem[i].size());
}
static int jit_noop() {
return 0;
}
void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
@@ -117,6 +188,14 @@ void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
if (Name == "mknod") return (void*)(intptr_t)&mknod;
#endif // __linux__
// We should not invoke parent's ctors/dtors from generated main()!
// On Mingw and Cygwin, the symbol __main is resolved to
// callee's(eg. tools/lli) one, to invoke wrong duplicated ctors
// (and register wrong callee's dtors with atexit(3)).
// We expect ExecutionEngine::runStaticConstructorsDestructors()
// is called before ExecutionEngine::runFunctionAsMain() is called.
if (Name == "__main") return (void*)(intptr_t)&jit_noop;
const char *NameStr = Name.c_str();
void *Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(NameStr);
if (Ptr) return Ptr;
@@ -135,10 +214,13 @@ void *SectionMemoryManager::getPointerToNamedFunction(const std::string &Name,
}
SectionMemoryManager::~SectionMemoryManager() {
for (unsigned i = 0, e = AllocatedCodeMem.size(); i != e; ++i)
sys::Memory::ReleaseRWX(AllocatedCodeMem[i]);
for (unsigned i = 0, e = AllocatedDataMem.size(); i != e; ++i)
free(AllocatedDataMem[i].base());
for (unsigned i = 0, e = CodeMem.AllocatedMem.size(); i != e; ++i)
sys::Memory::releaseMappedMemory(CodeMem.AllocatedMem[i]);
for (unsigned i = 0, e = RWDataMem.AllocatedMem.size(); i != e; ++i)
sys::Memory::releaseMappedMemory(RWDataMem.AllocatedMem[i]);
for (unsigned i = 0, e = RODataMem.AllocatedMem.size(); i != e; ++i)
sys::Memory::releaseMappedMemory(RODataMem.AllocatedMem[i]);
}
} // namespace llvm