Files
clang-p2996/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp
Adrian Prantl 6eaedbb52f Make CompilerType safe
When a process gets restarted TypeSystem objects associated with it
may get deleted, and any CompilerType objects holding on to a
reference to that type system are a use-after-free in waiting. Because
of the SBAPI, we don't have tight control over where CompilerTypes go
and when they are used. This is particularly a problem in the Swift
plugin, where the scratch TypeSystem can be restarted while the
process is still running. The Swift plugin has a lock to prevent
abuse, but where there's a lock there can be bugs.

This patch changes CompilerType to store a std::weak_ptr<TypeSystem>.
Most of the std::weak_ptr<TypeSystem>* uglyness is hidden by
introducing a wrapper class CompilerType::WrappedTypeSystem that has a
dyn_cast_or_null() method. The only sites that need to know about the
weak pointer implementation detail are the ones that deal with
creating TypeSystems.

rdar://101505232

Differential Revision: https://reviews.llvm.org/D136650
2022-11-16 15:51:26 -08:00

192 lines
6.6 KiB
C++

//===-- InferiorCallPOSIX.cpp ---------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
#include "InferiorCallPOSIX.h"
#include "lldb/Core/Address.h"
#include "lldb/Core/Module.h"
#include "lldb/Core/StreamFile.h"
#include "lldb/Core/ValueObject.h"
#include "lldb/Expression/DiagnosticManager.h"
#include "lldb/Host/Config.h"
#include "lldb/Symbol/SymbolContext.h"
#include "lldb/Symbol/TypeSystem.h"
#include "lldb/Target/ExecutionContext.h"
#include "lldb/Target/Platform.h"
#include "lldb/Target/Process.h"
#include "lldb/Target/Target.h"
#include "lldb/Target/ThreadPlanCallFunction.h"
#if LLDB_ENABLE_POSIX
#include <sys/mman.h>
#else
// define them
#define PROT_NONE 0
#define PROT_READ 1
#define PROT_WRITE 2
#define PROT_EXEC 4
#endif
using namespace lldb;
using namespace lldb_private;
bool lldb_private::InferiorCallMmap(Process *process, addr_t &allocated_addr,
addr_t addr, addr_t length, unsigned prot,
unsigned flags, addr_t fd, addr_t offset) {
Thread *thread =
process->GetThreadList().GetExpressionExecutionThread().get();
if (thread == nullptr)
return false;
ModuleFunctionSearchOptions function_options;
function_options.include_symbols = true;
function_options.include_inlines = false;
SymbolContextList sc_list;
process->GetTarget().GetImages().FindFunctions(
ConstString("mmap"), eFunctionNameTypeFull, function_options, sc_list);
const uint32_t count = sc_list.GetSize();
if (count > 0) {
SymbolContext sc;
if (sc_list.GetContextAtIndex(0, sc)) {
const uint32_t range_scope =
eSymbolContextFunction | eSymbolContextSymbol;
const bool use_inline_block_range = false;
EvaluateExpressionOptions options;
options.SetStopOthers(true);
options.SetUnwindOnError(true);
options.SetIgnoreBreakpoints(true);
options.SetTryAllThreads(true);
options.SetDebug(false);
options.SetTimeout(process->GetUtilityExpressionTimeout());
options.SetTrapExceptions(false);
addr_t prot_arg;
if (prot == eMmapProtNone)
prot_arg = PROT_NONE;
else {
prot_arg = 0;
if (prot & eMmapProtExec)
prot_arg |= PROT_EXEC;
if (prot & eMmapProtRead)
prot_arg |= PROT_READ;
if (prot & eMmapProtWrite)
prot_arg |= PROT_WRITE;
}
AddressRange mmap_range;
if (sc.GetAddressRange(range_scope, 0, use_inline_block_range,
mmap_range)) {
auto type_system_or_err =
process->GetTarget().GetScratchTypeSystemForLanguage(
eLanguageTypeC);
if (!type_system_or_err) {
llvm::consumeError(type_system_or_err.takeError());
return false;
}
auto ts = *type_system_or_err;
if (!ts)
return false;
CompilerType void_ptr_type =
ts->GetBasicTypeFromAST(eBasicTypeVoid).GetPointerType();
const ArchSpec arch = process->GetTarget().GetArchitecture();
MmapArgList args =
process->GetTarget().GetPlatform()->GetMmapArgumentList(
arch, addr, length, prot_arg, flags, fd, offset);
lldb::ThreadPlanSP call_plan_sp(
new ThreadPlanCallFunction(*thread, mmap_range.GetBaseAddress(),
void_ptr_type, args, options));
if (call_plan_sp) {
DiagnosticManager diagnostics;
StackFrame *frame = thread->GetStackFrameAtIndex(0).get();
if (frame) {
ExecutionContext exe_ctx;
frame->CalculateExecutionContext(exe_ctx);
ExpressionResults result = process->RunThreadPlan(
exe_ctx, call_plan_sp, options, diagnostics);
if (result == eExpressionCompleted) {
allocated_addr =
call_plan_sp->GetReturnValueObject()->GetValueAsUnsigned(
LLDB_INVALID_ADDRESS);
if (process->GetAddressByteSize() == 4) {
if (allocated_addr == UINT32_MAX)
return false;
} else if (process->GetAddressByteSize() == 8) {
if (allocated_addr == UINT64_MAX)
return false;
}
return true;
}
}
}
}
}
}
return false;
}
bool lldb_private::InferiorCallMunmap(Process *process, addr_t addr,
addr_t length) {
Thread *thread =
process->GetThreadList().GetExpressionExecutionThread().get();
if (thread == nullptr)
return false;
ModuleFunctionSearchOptions function_options;
function_options.include_symbols = true;
function_options.include_inlines = false;
SymbolContextList sc_list;
process->GetTarget().GetImages().FindFunctions(
ConstString("munmap"), eFunctionNameTypeFull, function_options, sc_list);
const uint32_t count = sc_list.GetSize();
if (count > 0) {
SymbolContext sc;
if (sc_list.GetContextAtIndex(0, sc)) {
const uint32_t range_scope =
eSymbolContextFunction | eSymbolContextSymbol;
const bool use_inline_block_range = false;
EvaluateExpressionOptions options;
options.SetStopOthers(true);
options.SetUnwindOnError(true);
options.SetIgnoreBreakpoints(true);
options.SetTryAllThreads(true);
options.SetDebug(false);
options.SetTimeout(process->GetUtilityExpressionTimeout());
options.SetTrapExceptions(false);
AddressRange munmap_range;
if (sc.GetAddressRange(range_scope, 0, use_inline_block_range,
munmap_range)) {
lldb::addr_t args[] = {addr, length};
lldb::ThreadPlanSP call_plan_sp(
new ThreadPlanCallFunction(*thread, munmap_range.GetBaseAddress(),
CompilerType(), args, options));
if (call_plan_sp) {
DiagnosticManager diagnostics;
StackFrame *frame = thread->GetStackFrameAtIndex(0).get();
if (frame) {
ExecutionContext exe_ctx;
frame->CalculateExecutionContext(exe_ctx);
ExpressionResults result = process->RunThreadPlan(
exe_ctx, call_plan_sp, options, diagnostics);
if (result == eExpressionCompleted) {
return true;
}
}
}
}
}
}
return false;
}