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.

llvm-svn: 168718
This commit is contained in:
Andrew Kaylor 2012-11-27 19:00:17 +00:00
parent c45c0a304b
commit e6c3b1a551
3 changed files with 205 additions and 63 deletions

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@ -12,10 +12,9 @@
//
//===----------------------------------------------------------------------===//
#include "gtest/gtest.h"
#include "llvm/ExecutionEngine/MCJIT.h"
#include "MCJITTestBase.h"
#include "SectionMemoryManager.h"
#include "gtest/gtest.h"
using namespace llvm;
@ -47,6 +46,7 @@ TEST_F(MCJITTest, global_variable) {
GlobalValue *Global = insertGlobalInt32(M.get(), "test_global", initialValue);
createJIT(M.take());
void *globalPtr = TheJIT->getPointerToGlobal(Global);
MM->applyPermissions();
static_cast<SectionMemoryManager*>(MM)->invalidateInstructionCache();
EXPECT_TRUE(0 != globalPtr)
<< "Unable to get pointer to global value from JIT";
@ -61,6 +61,7 @@ TEST_F(MCJITTest, add_function) {
Function *F = insertAddFunction(M.get());
createJIT(M.take());
void *addPtr = TheJIT->getPointerToFunction(F);
MM->applyPermissions();
static_cast<SectionMemoryManager*>(MM)->invalidateInstructionCache();
EXPECT_TRUE(0 != addPtr)
<< "Unable to get pointer to function from JIT";
@ -78,6 +79,7 @@ TEST_F(MCJITTest, run_main) {
Function *Main = insertMainFunction(M.get(), 6);
createJIT(M.take());
void *vPtr = TheJIT->getPointerToFunction(Main);
MM->applyPermissions();
static_cast<SectionMemoryManager*>(MM)->invalidateInstructionCache();
EXPECT_TRUE(0 != vPtr)
<< "Unable to get pointer to main() from JIT";
@ -100,6 +102,7 @@ TEST_F(MCJITTest, return_global) {
createJIT(M.take());
void *rgvPtr = TheJIT->getPointerToFunction(ReturnGlobal);
MM->applyPermissions();
static_cast<SectionMemoryManager*>(MM)->invalidateInstructionCache();
EXPECT_TRUE(0 != rgvPtr);
@ -169,6 +172,7 @@ TEST_F(MCJITTest, multiple_functions) {
createJIT(M.take());
void *vPtr = TheJIT->getPointerToFunction(Outer);
MM->applyPermissions();
static_cast<SectionMemoryManager*>(MM)->invalidateInstructionCache();
EXPECT_TRUE(0 != vPtr)
<< "Unable to get pointer to outer function from JIT";

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@ -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

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@ -1,4 +1,4 @@
//===-- SectionMemoryManager.h - Memory allocator for MCJIT -----*- C++ -*-===//
//===- SectionMemoryManager.h - Memory manager for MCJIT/RtDyld -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
@ -8,7 +8,7 @@
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of a section-based memory manager used by
// the MCJIT execution engine.
// the MCJIT execution engine and RuntimeDyld.
//
//===----------------------------------------------------------------------===//
@ -22,42 +22,97 @@
namespace llvm {
// Section-based memory manager for MCJIT
/// This is a simple memory manager which implements the methods called by
/// the RuntimeDyld class to allocate memory for section-based loading of
/// objects, usually those generated by the MCJIT execution engine.
///
/// This memory manager allocates all section memory as read-write. The
/// RuntimeDyld will copy JITed section memory into these allocated blocks
/// and perform any necessary linking and relocations.
///
/// Any client using this memory manager MUST ensure that section-specific
/// page permissions have been applied before attempting to execute functions
/// in the JITed object. Permissions can be applied either by calling
/// MCJIT::finalizeObject or by calling SectionMemoryManager::applyPermissions
/// directly. Clients of MCJIT should call MCJIT::finalizeObject.
class SectionMemoryManager : public JITMemoryManager {
SectionMemoryManager(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
void operator=(const SectionMemoryManager&) LLVM_DELETED_FUNCTION;
public:
SectionMemoryManager() { }
~SectionMemoryManager();
virtual ~SectionMemoryManager();
/// \brief Allocates a memory block of (at least) the given size suitable for
/// executable code.
///
/// The value of \p Alignment must be a power of two. If \p Alignment is zero
/// a default alignment of 16 will be used.
virtual uint8_t *allocateCodeSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID);
/// \brief Allocates a memory block of (at least) the given size suitable for
/// executable code.
///
/// The value of \p Alignment must be a power of two. If \p Alignment is zero
/// a default alignment of 16 will be used.
virtual uint8_t *allocateDataSection(uintptr_t Size, unsigned Alignment,
unsigned SectionID, bool IsReadOnly);
unsigned SectionID,
bool isReadOnly);
virtual bool applyPermissions(std::string *ErrMsg) { return false; }
/// \brief Applies section-specific memory permissions.
///
/// This method is called when object loading is complete and section page
/// permissions can be applied. It is up to the memory manager implementation
/// to decide whether or not to act on this method. The memory manager will
/// typically allocate all sections as read-write and then apply specific
/// permissions when this method is called. Code sections cannot be executed
/// until this function has been called.
///
/// \returns true if an error occurred, false otherwise.
virtual bool applyPermissions(std::string *ErrMsg = 0);
/// This method returns the address of the specified function. As such it is
/// only useful for resolving library symbols, not code generated symbols.
///
/// If \p AbortOnFailure is false and no function with the given name is
/// found, this function returns a null pointer. Otherwise, it prints a
/// message to stderr and aborts.
virtual void *getPointerToNamedFunction(const std::string &Name,
bool AbortOnFailure = true);
// Invalidate instruction cache for code sections. Some platforms with
// separate data cache and instruction cache require explicit cache flush,
// otherwise JIT code manipulations (like resolved relocations) will get to
// the data cache but not to the instruction cache.
/// \brief Invalidate instruction cache for code sections.
///
/// Some platforms with separate data cache and instruction cache require
/// explicit cache flush, otherwise JIT code manipulations (like resolved
/// relocations) will get to the data cache but not to the instruction cache.
///
/// This method is not called by RuntimeDyld or MCJIT during the load
/// process. Clients may call this function when needed. See the lli
/// tool for example use.
virtual void invalidateInstructionCache();
private:
struct MemoryGroup {
SmallVector<sys::MemoryBlock, 16> AllocatedMem;
SmallVector<sys::MemoryBlock, 16> FreeMem;
sys::MemoryBlock Near;
};
SmallVector<sys::MemoryBlock, 16> AllocatedDataMem;
SmallVector<sys::MemoryBlock, 16> AllocatedCodeMem;
SmallVector<sys::MemoryBlock, 16> FreeCodeMem;
uint8_t *allocateSection(MemoryGroup &MemGroup, uintptr_t Size,
unsigned Alignment);
error_code applyMemoryGroupPermissions(MemoryGroup &MemGroup,
unsigned Permissions);
MemoryGroup CodeMem;
MemoryGroup RWDataMem;
MemoryGroup RODataMem;
public:
///
/// Functions below are not used by MCJIT, but must be implemented because
/// they are declared as pure virtuals in the base class.
/// Functions below are not used by MCJIT or RuntimeDyld, but must be
/// implemented because they are declared as pure virtuals in the base class.
///
virtual void setMemoryWritable() {
@ -118,3 +173,4 @@ public:
}
#endif // LLVM_EXECUTION_ENGINE_SECTION_MEMORY_MANAGER_H