Files
clang-p2996/lldb/tools/debugserver/source/MacOSX/MachTask.h
Jason Molenda 83a131b276 Fix an over-suspend bug with LaunchInNewTerminalWithAppleScript sessions
When launching an inferior in a new terminal window via AppleScript
and the darwin-debug helper program, we could often end up with the
inferior process having a too-high suspend count, and it would never
resume execution.

lldb tries to wait until darwin-debug has finished its work and has
launched the inferior (WaitForProcessToSIGSTOP) but this wasn't
working correctly - and cannot be made to work.

This patch removes WaitForProcessToSIGSTOP, adds a special tiny
segment to the darwin-debug executable so it can be identified as
that binary (ExecExtraSuspend), and adds code to debugserver to
detect this segment.  When debugserver sees this segment, it notes
that the next exec will be done with a launch-suspended flag.  When
the next exec happens, debugserver forces an extra task_resume when
we resume the inferior.

An alternative approach would be if lldb could detect when the
inferior has been launched by darwin-debug unambiguously; monitoring
when the unix socket between darwin-debug and lldb was closed would
have been a reasonable way to do this too.

<rdar://problem/29760580>

Differential Revision: https://reviews.llvm.org/D72963
2020-01-21 14:55:46 -08:00

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4.0 KiB
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//===-- MachTask.h ----------------------------------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// MachTask.h
// debugserver
//
// Created by Greg Clayton on 12/5/08.
//
//===----------------------------------------------------------------------===//
#ifndef __MachTask_h__
#define __MachTask_h__
#include <mach/mach.h>
#include <sys/socket.h>
#include <map>
#include <string>
#include "DNBDefs.h"
#include "MachException.h"
#include "MachVMMemory.h"
#include "PThreadMutex.h"
class MachProcess;
typedef uint64_t MachMallocEventId;
enum MachMallocEventType {
eMachMallocEventTypeAlloc = 2,
eMachMallocEventTypeDealloc = 4,
eMachMallocEventTypeOther = 1
};
struct MachMallocEvent {
mach_vm_address_t m_base_address;
uint64_t m_size;
MachMallocEventType m_event_type;
MachMallocEventId m_event_id;
};
class MachTask {
public:
// Constructors and Destructors
MachTask(MachProcess *process);
virtual ~MachTask();
void Clear();
kern_return_t Suspend();
kern_return_t Resume();
nub_size_t ReadMemory(nub_addr_t addr, nub_size_t size, void *buf);
nub_size_t WriteMemory(nub_addr_t addr, nub_size_t size, const void *buf);
int GetMemoryRegionInfo(nub_addr_t addr, DNBRegionInfo *region_info);
std::string GetProfileData(DNBProfileDataScanType scanType);
nub_addr_t AllocateMemory(nub_size_t size, uint32_t permissions);
nub_bool_t DeallocateMemory(nub_addr_t addr);
mach_port_t ExceptionPort() const;
bool ExceptionPortIsValid() const;
kern_return_t SaveExceptionPortInfo();
kern_return_t RestoreExceptionPortInfo();
kern_return_t ShutDownExcecptionThread();
bool StartExceptionThread(DNBError &err);
nub_addr_t GetDYLDAllImageInfosAddress(DNBError &err);
kern_return_t BasicInfo(struct task_basic_info *info);
static kern_return_t BasicInfo(task_t task, struct task_basic_info *info);
bool IsValid() const;
static bool IsValid(task_t task);
static void *ExceptionThread(void *arg);
void TaskPortChanged(task_t task);
task_t TaskPort() const { return m_task; }
task_t TaskPortForProcessID(DNBError &err, bool force = false);
static task_t TaskPortForProcessID(pid_t pid, DNBError &err,
uint32_t num_retries = 10,
uint32_t usec_interval = 10000);
MachProcess *Process() { return m_process; }
const MachProcess *Process() const { return m_process; }
nub_size_t PageSize();
void TaskWillExecProcessesSuspended() { m_exec_will_be_suspended = true; }
protected:
MachProcess *m_process; // The mach process that owns this MachTask
task_t m_task;
MachVMMemory m_vm_memory; // Special mach memory reading class that will take
// care of watching for page and region boundaries
MachException::PortInfo
m_exc_port_info; // Saved settings for all exception ports
pthread_t m_exception_thread; // Thread ID for the exception thread in case we
// need it
mach_port_t m_exception_port; // Exception port on which we will receive child
// exceptions
bool m_exec_will_be_suspended; // If this task exec's another process, that
// process will be launched suspended and we will
// need to execute one extra Resume to get it
// to progress from dyld_start.
bool m_do_double_resume; // next time we task_resume(), do it twice to
// fix a too-high suspend count.
typedef std::map<mach_vm_address_t, size_t> allocation_collection;
allocation_collection m_allocations;
private:
MachTask(const MachTask &) = delete;
MachTask &operator=(const MachTask &rhs) = delete;
};
#endif // __MachTask_h__