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// Copyright 2014 The Crashpad Authors. All rights reserved.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.
#include <mach/mach.h>
#include <stdint.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <memory>
#include <string>
#include <vector>
#include "base/macros.h"
#include "build/build_config.h"
#include "util/mach/task_memory.h"
#include "util/misc/initialization_state_dcheck.h"
#include "util/posix/process_info.h"
namespace crashpad {
class MachOImageReader;
//! \brief Accesses information about another process, identified by a Mach
//! task.
class ProcessReader {
//! \brief Contains information about a thread that belongs to a task
//! (process).
struct Thread {
#if defined(ARCH_CPU_X86_FAMILY)
union ThreadContext {
x86_thread_state64_t t64;
x86_thread_state32_t t32;
union FloatContext {
x86_float_state64_t f64;
x86_float_state32_t f32;
union DebugContext {
x86_debug_state64_t d64;
x86_debug_state32_t d32;
~Thread() {}
ThreadContext thread_context;
FloatContext float_context;
DebugContext debug_context;
uint64_t id;
mach_vm_address_t stack_region_address;
mach_vm_size_t stack_region_size;
mach_vm_address_t thread_specific_data_address;
thread_t port;
int suspend_count;
int priority;
//! \brief Contains information about a module loaded into a process.
struct Module {
//! \brief The pathname used to load the module from disk.
std::string name;
//! \brief An image reader for the module.
//! The lifetime of this MachOImageReader is scoped to the lifetime of the
//! ProcessReader that created it.
//! This field may be `nullptr` if a reader could not be created for the
//! module.
const MachOImageReader* reader;
//! \brief The module’s timestamp.
//! This field will be `0` if its value cannot be determined. It can only be
//! determined for images that are loaded by dyld, so it will be `0` for the
//! main executable and for dyld itself.
time_t timestamp;
//! \brief Initializes this object. This method must be called before any
//! other.
//! \param[in] task A send right to the target task’s task port. This object
//! does not take ownership of the send right.
//! \return `true` on success, indicating that this object will respond
//! validly to further method calls. `false` on failure. On failure, no
//! further method calls should be made.
bool Initialize(task_t task);
//! \return `true` if the target task is a 64-bit process.
bool Is64Bit() const { return is_64_bit_; }
//! \return The target task’s process ID.
pid_t ProcessID() const { return process_info_.ProcessID(); }
//! \return The target task’s parent process ID.
pid_t ParentProcessID() const { return process_info_.ParentProcessID(); }
//! \brief Determines the target process’ start time.
//! \param[out] start_time The time that the process started.
void StartTime(timeval* start_time) const;
//! \brief Determines the target process’ execution time.
//! \param[out] user_time The amount of time the process has executed code in
//! user mode.
//! \param[out] system_time The amount of time the process has executed code
//! in system mode.
//! \return `true` on success, `false` on failure, with a warning logged. On
//! failure, \a user_time and \a system_time will be set to represent no
//! time spent executing code in user or system mode.
bool CPUTimes(timeval* user_time, timeval* system_time) const;
//! \return Accesses the memory of the target task.
TaskMemory* Memory() { return task_memory_.get(); }
//! \return The threads that are in the task (process). The first element (at
//! index `0`) corresponds to the main thread.
const std::vector<Thread>& Threads();
//! \return The modules loaded in the process. The first element (at index
//! `0`) corresponds to the main executable, and the final element
//! corresponds to the dynamic loader, dyld.
const std::vector<Module>& Modules();
//! \brief Determines the location of the `dyld_all_image_infos` structure in
//! the process’ address space.
//! This function is an internal implementation detail of Modules(), and
//! should not normally be used directly. It is exposed solely for use by test
//! code.
//! \param[out] all_image_info_size The size of the `dyld_all_image_infos`
//! structure. Optional, may be `nullptr` if not required.
//! \return The address of the `dyld_all_image_infos` structure in the
//! process’ address space, with \a all_image_info_size set appropriately.
//! On failure, returns `0` with a message logged.
mach_vm_address_t DyldAllImageInfo(mach_vm_size_t* all_image_info_size);
//! Performs lazy initialization of the \a threads_ vector on behalf of
//! Threads().
void InitializeThreads();
//! Performs lazy initialization of the \a modules_ vector on behalf of
//! Modules().
void InitializeModules();
//! \brief Calculates the base address and size of the region used as a
//! thread’s stack.
//! The region returned by this method may be formed by merging multiple
//! adjacent regions in a process’ memory map if appropriate. The base address
//! of the returned region may be lower than the \a stack_pointer passed in
//! when the ABI mandates a red zone below the stack pointer.
//! \param[in] stack_pointer The stack pointer, referring to the top (lowest
//! address) of a thread’s stack.
//! \param[out] stack_region_size The size of the memory region used as the
//! thread’s stack.
//! \return The base address (lowest address) of the memory region used as the
//! thread’s stack.
mach_vm_address_t CalculateStackRegion(mach_vm_address_t stack_pointer,
mach_vm_size_t* stack_region_size);
//! \brief Adjusts the region for the red zone, if the ABI requires one.
//! This method performs red zone calculation for CalculateStackRegion(). Its
//! parameters are local variables used within that method, and may be
//! modified as needed.
//! Where a red zone is required, the region of memory captured for a thread’s
//! stack will be extended to include the red zone below the stack pointer,
//! provided that such memory is mapped, readable, and has the correct user
//! tag value. If these conditions cannot be met fully, as much of the red
//! zone will be captured as is possible while meeting these conditions.
//! \param[in,out] start_address The base address of the region to begin
//! capturing stack memory from. On entry, \a start_address is the stack
//! pointer. On return, \a start_address may be decreased to encompass a
//! red zone.
//! \param[in,out] region_base The base address of the region that contains
//! stack memory. This is distinct from \a start_address in that \a
//! region_base will be page-aligned. On entry, \a region_base is the
//! base address of a region that contains \a start_address. On return,
//! if \a start_address is decremented and is outside of the region
//! originally described by \a region_base, \a region_base will also be
//! decremented appropriately.
//! \param[in,out] region_size The size of the region that contains stack
//! memory. This region begins at \a region_base. On return, if \a
//! region_base is decremented, \a region_size will be incremented
//! appropriately.
//! \param[in] user_tag The Mach VM system’s user tag for the region described
//! by the initial values of \a region_base and \a region_size. The red
//! zone will only be allowed to extend out of the region described by
//! these initial values if the user tag is appropriate for stack memory
//! and the expanded region has the same user tag value.
void LocateRedZone(mach_vm_address_t* start_address,
mach_vm_address_t* region_base,
mach_vm_address_t* region_size,
unsigned int user_tag);
ProcessInfo process_info_;
std::vector<Thread> threads_; // owns send rights
std::vector<Module> modules_;
std::vector<std::unique_ptr<MachOImageReader>> module_readers_;
std::unique_ptr<TaskMemory> task_memory_;
task_t task_; // weak
InitializationStateDcheck initialized_;
// This shadows a method of process_info_, but it’s accessed so frequently
// that it’s given a first-class field to save a call and a few bit operations
// on each access.
bool is_64_bit_;
bool initialized_threads_;
bool initialized_modules_;
} // namespace crashpad