Issue 159: reviewer Waylonis

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@150 4c0a9323-5329-0410-9bdc-e9ce6186880e
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ladderbreaker 2007-05-02 21:04:57 +00:00
parent e219ba182e
commit c455a76c03
2 changed files with 540 additions and 0 deletions

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// Copyright (c) 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include <mach-o/nlist.h>
#include <stdlib.h>
#include <stdio.h>
#include <algorithm>
#include "client/mac/handler/dynamic_images.h"
namespace google_breakpad {
//==============================================================================
// Reads an address range from another task. A block of memory is malloced
// and should be freed by the caller.
void* ReadTaskMemory(task_port_t target_task,
const void* address,
size_t length) {
void* result = NULL;
mach_vm_address_t page_address = (uint32_t)address & (-4096);
mach_vm_address_t last_page_address =
((uint32_t)address + length + 4095) & (-4096);
mach_vm_size_t page_size = last_page_address - page_address;
uint8_t* local_start;
uint32_t local_length;
kern_return_t r = vm_read(target_task,
page_address,
page_size,
reinterpret_cast<vm_offset_t*>(&local_start),
&local_length);
if (r == KERN_SUCCESS) {
result = malloc(length);
if (result != NULL) {
memcpy(result, &local_start[(uint32_t)address - page_address], length);
}
vm_deallocate(mach_task_self(), (uintptr_t)local_start, local_length);
}
return result;
}
#pragma mark -
//==============================================================================
// Initializes vmaddr_, vmsize_, and slide_
void DynamicImage::CalculateMemoryInfo() {
mach_header *header = GetMachHeader();
const struct load_command *cmd =
reinterpret_cast<const struct load_command *>(header + 1);
for (unsigned int i = 0; cmd && (i < header->ncmds); ++i) {
if (cmd->cmd == LC_SEGMENT) {
const struct segment_command *seg =
reinterpret_cast<const struct segment_command *>(cmd);
if (!strcmp(seg->segname, "__TEXT")) {
vmaddr_ = seg->vmaddr;
vmsize_ = seg->vmsize;
slide_ = 0;
if (seg->fileoff == 0 && seg->filesize != 0) {
slide_ = (uintptr_t)GetLoadAddress() - (uintptr_t)seg->vmaddr;
}
return;
}
}
cmd = reinterpret_cast<const struct load_command *>
(reinterpret_cast<const char *>(cmd) + cmd->cmdsize);
}
// we failed - a call to IsValid() will return false
vmaddr_ = 0;
vmsize_ = 0;
slide_ = 0;
}
#pragma mark -
//==============================================================================
// Loads information about dynamically loaded code in the given task.
DynamicImages::DynamicImages(mach_port_t task)
: task_(task) {
ReadImageInfoForTask();
}
//==============================================================================
// This code was written using dyld_debug.c (from Darwin) as a guide.
void DynamicImages::ReadImageInfoForTask() {
struct nlist l[8];
memset(l, 0, sizeof(l) );
// First we lookup the address of the "_dyld_all_image_infos" struct
// which lives in "dyld". This structure contains information about all
// of the loaded dynamic images.
struct nlist &list = l[0];
list.n_un.n_name = "_dyld_all_image_infos";
nlist("/usr/lib/dyld", &list);
if (list.n_value) {
// Read the structure inside of dyld that contains information about
// loaded images. We're reading from the desired task's address space.
// Here we make the assumption that dyld loaded at the same address in
// the crashed process vs. this one. This is an assumption made in
// "dyld_debug.c" and is said to be nearly always valid.
dyld_all_image_infos *dyldInfo = reinterpret_cast<dyld_all_image_infos*>
(ReadTaskMemory(task_,
reinterpret_cast<void*>(list.n_value),
sizeof(dyld_all_image_infos)));
if (dyldInfo) {
// number of loaded images
int count = dyldInfo->infoArrayCount;
// Read an array of dyld_image_info structures each containing
// information about a loaded image.
dyld_image_info *infoArray = reinterpret_cast<dyld_image_info*>
(ReadTaskMemory(task_,
dyldInfo->infoArray,
count*sizeof(dyld_image_info)));
image_list_.reserve(count);
for (int i = 0; i < count; ++i) {
dyld_image_info &info = infoArray[i];
// First read just the mach_header from the image in the task.
mach_header *header = reinterpret_cast<mach_header*>
(ReadTaskMemory(task_, info.load_address_, sizeof(mach_header)));
if (!header)
break; // bail on this dynamic image
// Now determine the total amount we really want to read based on the
// size of the load commands. We need the header plus all of the
// load commands.
unsigned int header_size = sizeof(mach_header) + header->sizeofcmds;
free(header);
header = reinterpret_cast<mach_header*>
(ReadTaskMemory(task_, info.load_address_, header_size));
// Read the file name from the task's memory space.
char *file_path = NULL;
if (info.file_path_) {
// Although we're reading 0x2000 bytes, this is copied in the
// the DynamicImage constructor below with the correct string length,
// so it's not really wasting memory.
file_path = reinterpret_cast<char*>
(ReadTaskMemory(task_,
info.file_path_,
0x2000));
}
// Create an object representing this image and add it to our list.
DynamicImage *new_image = new DynamicImage(header,
header_size,
info.load_address_,
file_path,
info.file_mod_date_,
task_);
if (new_image->IsValid()) {
image_list_.push_back(DynamicImageRef(new_image));
} else {
delete new_image;
}
if (file_path) {
free(file_path);
}
}
free(dyldInfo);
free(infoArray);
// sorts based on loading address
sort(image_list_.begin(), image_list_.end() );
}
}
}
//==============================================================================
DynamicImage *DynamicImages::GetExecutableImage() {
int executable_index = GetExecutableImageIndex();
if (executable_index >= 0) {
return GetImage(executable_index);
}
return NULL;
}
//==============================================================================
// returns -1 if failure to find executable
int DynamicImages::GetExecutableImageIndex() {
int image_count = GetImageCount();
for (int i = 0; i < image_count; ++i) {
DynamicImage *image = GetImage(i);
if (image->GetMachHeader()->filetype == MH_EXECUTE) {
return i;
}
}
return -1;
}
} // namespace google_breakpad

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// Copyright (c) 2007, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// dynamic_images.h
//
// Implements most of the function of the dyld API, but allowing an
// arbitrary task to be introspected, unlike the dyld API which
// only allows operation on the current task. The current implementation
// is limited to use by 32-bit tasks.
#ifndef CLIENT_MAC_HANDLER_DYNAMIC_IMAGES_H__
#define CLIENT_MAC_HANDLER_DYNAMIC_IMAGES_H__
#include <mach/mach.h>
#include <mach-o/dyld.h>
#include <mach-o/loader.h>
#include <sys/types.h>
#include <vector>
namespace google_breakpad {
using std::vector;
//==============================================================================
// The memory layout of this struct matches the dyld_image_info struct
// defined in "dyld_gdb.h" in the darwin source.
typedef struct dyld_image_info {
struct mach_header *load_address_;
char *file_path_;
uintptr_t file_mod_date_;
} dyld_image_info;
//==============================================================================
// This is as defined in "dyld_gdb.h" in the darwin source.
// _dyld_all_image_infos (in dyld) is a structure of this type
// which will be used to determine which dynamic code has been loaded.
typedef struct dyld_all_image_infos {
uint32_t version; // == 1 in Mac OS X 10.4
uint32_t infoArrayCount;
const struct dyld_image_info *infoArray;
void* notification;
bool processDetachedFromSharedRegion;
} dyld_all_image_infos;
//==============================================================================
// A simple wrapper for a mach_header
//
// This could be fleshed out with some more interesting methods.
class MachHeader {
public:
explicit MachHeader(const mach_header &header) : header_(header) {}
void Print() {
printf("magic\t\t: %4x\n", header_.magic);
printf("cputype\t\t: %d\n", header_.cputype);
printf("cpusubtype\t: %d\n", header_.cpusubtype);
printf("filetype\t: %d\n", header_.filetype);
printf("ncmds\t\t: %d\n", header_.ncmds);
printf("sizeofcmds\t: %d\n", header_.sizeofcmds);
printf("flags\t\t: %d\n", header_.flags);
}
mach_header header_;
};
//==============================================================================
// Represents a single dynamically loaded mach-o image
class DynamicImage {
public:
DynamicImage(mach_header *header, // we take ownership
int header_size, // includes load commands
mach_header *load_address,
char *inFilePath,
uintptr_t image_mod_date,
mach_port_t task)
: header_(header),
header_size_(header_size),
load_address_(load_address),
file_mod_date_(image_mod_date),
task_(task) {
InitializeFilePath(inFilePath);
CalculateMemoryInfo();
}
~DynamicImage() {
if (file_path_) {
free(file_path_);
}
free(header_);
}
// Returns pointer to a local copy of the mach_header plus load commands
mach_header *GetMachHeader() {return header_;}
// Size of mach_header plus load commands
int GetHeaderSize() const {return header_size_;}
// Full path to mach-o binary
char *GetFilePath() {return file_path_;}
uintptr_t GetModDate() const {return file_mod_date_;}
// Actual address where the image was loaded
mach_header *GetLoadAddress() const {return load_address_;}
// Address where the image should be loaded
uint32_t GetVMAddr() const {return vmaddr_;}
// Difference between GetLoadAddress() and GetVMAddr()
ptrdiff_t GetVMAddrSlide() const {return slide_;}
// Size of the image
uint32_t GetVMSize() const {return vmsize_;}
// Task owning this loaded image
mach_port_t GetTask() {return task_;}
// For sorting
bool operator<(const DynamicImage &inInfo) {
return GetLoadAddress() < inInfo.GetLoadAddress();
}
// Debugging
void Print() {
char *path = GetFilePath();
if (!path) {
path = "(unknown)";
}
printf("%p: %s\n", GetLoadAddress(), path);
MachHeader(*GetMachHeader()).Print();
printf("vmaddr\t\t: %p\n", reinterpret_cast<void*>(GetVMAddr()));
printf("vmsize\t\t: %d\n", GetVMSize());
printf("slide\t\t: %d\n", GetVMAddrSlide());
}
private:
friend class DynamicImages;
// Sanity checking
bool IsValid() {return GetVMAddr() != 0;}
// Makes local copy of file path to mach-o binary
void InitializeFilePath(char *inFilePath) {
if (inFilePath) {
file_path_ = reinterpret_cast<char*>(malloc(strlen(inFilePath)));
strcpy(file_path_, inFilePath);
} else {
file_path_ = NULL;
}
}
// Initializes vmaddr_, vmsize_, and slide_
void CalculateMemoryInfo();
#if 0 // currently not needed
// Copy constructor: we don't want this to be invoked,
// but here's the code in case we need to make it public some day.
DynamicImage(DynamicImage &inInfo)
: load_address_(inInfo.load_address_),
vmaddr_(inInfo.vmaddr_),
vmsize_(inInfo.vmsize_),
slide_(inInfo.slide_),
file_mod_date_(inInfo.file_mod_date_),
task_(inInfo.task_) {
// copy file path string
InitializeFilePath(inInfo.GetFilePath());
// copy mach_header and load commands
header_ = reinterpret_cast<mach_header*>(malloc(inInfo.header_size_));
memcpy(header_, inInfo.header_, inInfo.header_size_);
header_size_ = inInfo.header_size_;
}
#endif
mach_header *header_; // our local copy of the header
int header_size_; // mach_header plus load commands
mach_header *load_address_; // base address image is mapped into
uint32_t vmaddr_;
uint32_t vmsize_;
ptrdiff_t slide_;
char *file_path_; // path dyld used to load the image
uintptr_t file_mod_date_; // time_t of image file
mach_port_t task_;
};
//==============================================================================
// DynamicImageRef is just a simple wrapper for a pointer to
// DynamicImage. The reason we use it instead of a simple typedef is so
// that we can use stl::sort() on a vector of DynamicImageRefs
// and simple class pointers can't implement operator<().
//
class DynamicImageRef {
public:
explicit DynamicImageRef(DynamicImage *inP) : p(inP) {}
DynamicImageRef(const DynamicImageRef &inRef) : p(inRef.p) {} // STL required
bool operator<(const DynamicImageRef &inRef) const {
return (*const_cast<DynamicImageRef*>(this)->p)
< (*const_cast<DynamicImageRef&>(inRef).p);
}
// Be just like DynamicImage*
DynamicImage *operator->() {return p;}
operator DynamicImage*() {return p;}
private:
DynamicImage *p;
};
//==============================================================================
// An object of type DynamicImages may be created to allow introspection of
// an arbitrary task's dynamically loaded mach-o binaries. This makes the
// assumption that the current task has send rights to the target task.
class DynamicImages {
public:
explicit DynamicImages(mach_port_t task);
~DynamicImages() {
for (int i = 0; i < (int)image_list_.size(); ++i) {
delete image_list_[i];
}
}
// Returns the number of dynamically loaded mach-o images.
int GetImageCount() const {return image_list_.size();}
// Returns an individual image.
DynamicImage *GetImage(int i) {
if (i < (int)image_list_.size()) {
return image_list_[i];
}
return NULL;
}
// Returns the image corresponding to the main executable.
DynamicImage *GetExecutableImage();
int GetExecutableImageIndex();
// Returns the task which we're looking at.
mach_port_t GetTask() const {return task_;}
// Debugging
void Print() {
for (int i = 0; i < (int)image_list_.size(); ++i) {
image_list_[i]->Print();
}
}
void TestPrint() {
for (int i = 0; i < (int)image_list_.size(); ++i) {
printf("dyld: %p: name = %s\n", _dyld_get_image_header(i),
_dyld_get_image_name(i) );
MachHeader(*_dyld_get_image_header(i)).Print();
}
}
private:
bool IsOurTask() {return task_ == mach_task_self();}
// Initialization
void ReadImageInfoForTask();
mach_port_t task_;
vector<DynamicImageRef> image_list_;
};
// Returns a malloced block containing the contents of memory at a particular
// location in another task.
void* ReadTaskMemory(task_port_t target_task, const void* address, size_t len);
} // namespace google_breakpad
#endif // CLIENT_MAC_HANDLER_DYNAMIC_IMAGES_H__