crash_reporter/user_collector.cc - platform/system/core - Git at Google

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "crash-reporter/user_collector.h"

 #include <fcntl.h>  // For creat.
 #include <grp.h>  // For struct group.
 #include <pwd.h>  // For struct passwd.
 #include <sys/types.h>  // For getpwuid_r, getgrnam_r, WEXITSTATUS.
 #include <sys/wait.h>  // For waitpid.
 #include <unistd.h>  // For execv and fork.

 #include <string>
 #include <vector>

 #include "base/eintr_wrapper.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "crash-reporter/system_logging.h"

 // This procfs file is used to cause kernel core file writing to
 // instead pipe the core file into a user space process.  See
 // core(5) man page.
 static const char kCorePatternFile[] = "/proc/sys/kernel/core_pattern";
 static const char kCoreToMinidumpConverterPath[] = "/usr/bin/core2md";
 static const char kLeaveCoreFile[] = "/root/.leave_core";

 const char *UserCollector::kUserId = "Uid:\t";
 const char *UserCollector::kGroupId = "Gid:\t";

 UserCollector::UserCollector()
     : generate_diagnostics_(false),
       core_pattern_file_(kCorePatternFile),
       initialized_(false) {
 }

 void UserCollector::Initialize(
     UserCollector::CountCrashFunction count_crash_function,
     const std::string &our_path,
     UserCollector::IsFeedbackAllowedFunction is_feedback_allowed_function,
     SystemLogging *logger,
     bool generate_diagnostics) {
   CrashCollector::Initialize(count_crash_function,
                              is_feedback_allowed_function,
                              logger);
   our_path_ = our_path;
   initialized_ = true;
   generate_diagnostics_ = generate_diagnostics;
 }

 UserCollector::~UserCollector() {
 }

 std::string UserCollector::GetPattern(bool enabled) const {
   if (enabled) {
     return StringPrintf("|%s --signal=%%s --pid=%%p", our_path_.c_str());
   } else {
     return "core";
   }
 }

 bool UserCollector::SetUpInternal(bool enabled) {
   CHECK(initialized_);
   logger_->LogInfo("%s user crash handling",
                    enabled ? "Enabling" : "Disabling");
   std::string pattern = GetPattern(enabled);
   if (file_util::WriteFile(FilePath(core_pattern_file_),
                            pattern.c_str(),
                            pattern.length()) !=
       static_cast<int>(pattern.length())) {
     logger_->LogError("Unable to write %s", core_pattern_file_.c_str());
     return false;
   }
   return true;
 }

 FilePath UserCollector::GetProcessPath(pid_t pid) {
   return FilePath(StringPrintf("/proc/%d", pid));
 }

 bool UserCollector::GetSymlinkTarget(const FilePath &symlink,
                                      FilePath *target) {
   int max_size = 32;
   scoped_array<char> buffer;
   while (true) {
     buffer.reset(new char[max_size + 1]);
     ssize_t size = readlink(symlink.value().c_str(), buffer.get(), max_size);
     if (size < 0) {
       return false;
     }
     buffer[size] = 0;
     if (size == max_size) {
       // Avoid overflow when doubling.
       if (max_size * 2 > max_size) {
         max_size *= 2;
         continue;
       } else {
         return false;
       }
     }
     break;
   }

   *target = FilePath(buffer.get());
   return true;
 }

 bool UserCollector::GetExecutableBaseNameFromPid(uid_t pid,
                                                  std::string *base_name) {
   FilePath target;
   if (!GetSymlinkTarget(GetProcessPath(pid).Append("exe"), &target))
     return false;
   *base_name = target.BaseName().value();
   return true;
 }

 bool UserCollector::GetIdFromStatus(const char *prefix,
                                     IdKind kind,
                                     const std::string &status_contents,
                                     int *id) {
   // From fs/proc/array.c:task_state(), this file contains:
   // \nUid:\t<uid>\t<euid>\t<suid>\t<fsuid>\n
   std::vector<std::string> status_lines;
   SplitString(status_contents, '\n', &status_lines);
   std::vector<std::string>::iterator line_iterator;
   for (line_iterator = status_lines.begin();
        line_iterator != status_lines.end();
        ++line_iterator) {
     if (line_iterator->find(prefix) == 0)
       break;
   }
   if (line_iterator == status_lines.end()) {
     return false;
   }
   std::string id_substring = line_iterator->substr(strlen(prefix),
                                                    std::string::npos);
   std::vector<std::string> ids;
   SplitString(id_substring, '\t', &ids);
   if (ids.size() != kIdMax || kind < 0 || kind >= kIdMax) {
     return false;
   }
   const char *number = ids[kind].c_str();
   char *end_number = NULL;
   *id = strtol(number, &end_number, 10);
   if (*end_number != '\0')
     return false;
   return true;
 }

 bool UserCollector::CopyOffProcFiles(pid_t pid,
                                      const FilePath &container_dir) {
   if (!file_util::CreateDirectory(container_dir)) {
     logger_->LogInfo("Could not create %s", container_dir.value().c_str());
     return false;
   }
   FilePath process_path = GetProcessPath(pid);
   if (!file_util::PathExists(process_path)) {
     logger_->LogWarning("Path %s does not exist",
                         process_path.value().c_str());
     return false;
   }
   static const char *proc_files[] = {
     "auxv",
     "cmdline",
     "environ",
     "maps",
     "status"
   };
   for (unsigned i = 0; i < arraysize(proc_files); ++i) {
     if (!file_util::CopyFile(process_path.Append(proc_files[i]),
                              container_dir.Append(proc_files[i]))) {
       logger_->LogWarning("Could not copy %s file", proc_files[i]);
       return false;
     }
   }
   return true;
 }

 bool UserCollector::GetCreatedCrashDirectory(pid_t pid,
                                              FilePath *crash_file_path) {
   FilePath process_path = GetProcessPath(pid);
   std::string status;
   if (!file_util::ReadFileToString(process_path.Append("status"),
                                    &status)) {
     logger_->LogError("Could not read status file");
     return false;
   }
   int process_euid;
   if (!GetIdFromStatus(kUserId, kIdEffective, status, &process_euid)) {
     logger_->LogError("Could not find euid in status file");
     return false;
   }
   return GetCreatedCrashDirectoryByEuid(process_euid,
                                         crash_file_path);
 }

 bool UserCollector::CopyStdinToCoreFile(const FilePath &core_path) {
   // Copy off all stdin to a core file.
   FilePath stdin_path("/dev/fd/0");
   if (file_util::CopyFile(stdin_path, core_path)) {
     return true;
   }

   logger_->LogError("Could not write core file");
   // If the file system was full, make sure we remove any remnants.
   file_util::Delete(core_path, false);
   return false;
 }

 int UserCollector::ForkExecAndPipe(std::vector<const char *> &arguments,
                                    const char *output_file) {
   // Copy off a writeable version of arguments.
   scoped_array<char*> argv(new char *[arguments.size() + 1]);
   int total_args_size = 0;
   for (size_t i = 0; i < arguments.size(); ++i) {
     if (arguments[i] == NULL) {
       logger_->LogError("Bad parameter");
       return -1;
     }
     total_args_size += strlen(arguments[i]) + 1;
   }
   scoped_array<char> buffer(new char[total_args_size]);
   char *buffer_pointer = &buffer[0];

   for (size_t i = 0; i < arguments.size(); ++i) {
     argv[i] = buffer_pointer;
     strcpy(buffer_pointer, arguments[i]);
     buffer_pointer += strlen(arguments[i]);
     *buffer_pointer = '\0';
     ++buffer_pointer;
   }
   argv[arguments.size()] = NULL;

   int pid = fork();
   if (pid < 0) {
     logger_->LogError("Fork failed: %d", errno);
     return -1;
   }

   if (pid == 0) {
     int output_handle = creat(output_file, 0700);
     if (output_handle < 0) {
       logger_->LogError("Could not create %s: %d", output_file, errno);
       // Avoid exit() to avoid atexit handlers from parent.
       _exit(127);
     }
     dup2(output_handle, 1);
     dup2(output_handle, 2);
     execv(argv[0], &argv[0]);
     logger_->LogError("Exec failed: %d", errno);
     _exit(127);
   }

   int status = 0;
   if (HANDLE_EINTR(waitpid(pid, &status, 0)) < 0) {
     logger_->LogError("Problem waiting for pid: %d", errno);
     return -1;
   }
   if (!WIFEXITED(status)) {
     logger_->LogError("Process did not exit normally: %x", status);
     return -1;
   }
   return WEXITSTATUS(status);
 }

 bool UserCollector::ConvertCoreToMinidump(const FilePath &core_path,
                                           const FilePath &procfs_directory,
                                           const FilePath &minidump_path,
                                           const FilePath &temp_directory) {
   FilePath output_path = temp_directory.Append("output");
   std::vector<const char *> core2md_arguments;
   core2md_arguments.push_back(kCoreToMinidumpConverterPath);
   core2md_arguments.push_back(core_path.value().c_str());
   core2md_arguments.push_back(procfs_directory.value().c_str());
   core2md_arguments.push_back(minidump_path.value().c_str());

   int errorlevel = ForkExecAndPipe(core2md_arguments,
                                    output_path.value().c_str());

   std::string output;
   file_util::ReadFileToString(output_path, &output);
   if (errorlevel != 0) {
     logger_->LogInfo("Problem during %s [result=%d]: %s",
                      kCoreToMinidumpConverterPath,
                      errorlevel,
                      output.c_str());
     return false;
   }

   if (!file_util::PathExists(minidump_path)) {
     logger_->LogError("Minidump file %s was not created",
                       minidump_path.value().c_str());
     return false;
   }
   return true;
 }

 bool UserCollector::GenerateDiagnostics(pid_t pid,
                                         const std::string &exec_name) {
   FilePath container_dir("/tmp");
   container_dir = container_dir.Append(
       StringPrintf("crash_reporter.%d", pid));

   if (!CopyOffProcFiles(pid, container_dir)) {
     file_util::Delete(container_dir, true);
     return false;
   }

   FilePath crash_path;
   if (!GetCreatedCrashDirectory(pid, &crash_path)) {
     file_util::Delete(container_dir, true);
     return false;
   }
   std::string dump_basename = FormatDumpBasename(exec_name, time(NULL), pid);
   FilePath core_path = crash_path.Append(
       StringPrintf("%s.core", dump_basename.c_str()));

   if (!CopyStdinToCoreFile(core_path)) {
     file_util::Delete(container_dir, true);
     return false;
   }

   FilePath minidump_path = crash_path.Append(
       StringPrintf("%s.dmp", dump_basename.c_str()));

   bool conversion_result = true;
   if (!ConvertCoreToMinidump(core_path,
                              container_dir,  // procfs directory
                              minidump_path,
                              container_dir)) {  // temporary directory
     // Note we leave the container directory for inspection.
     conversion_result = false;
   }

   WriteCrashMetaData(
       crash_path.Append(
           StringPrintf("%s.meta", dump_basename.c_str())),
       exec_name,
       minidump_path.value());

   if (conversion_result) {
     logger_->LogInfo("Stored minidump to %s", minidump_path.value().c_str());
   }

   if (!file_util::PathExists(FilePath(kLeaveCoreFile))) {
     file_util::Delete(core_path, false);
   } else {
     logger_->LogInfo("Leaving core file at %s", core_path.value().c_str());
   }

   return conversion_result;
 }

 bool UserCollector::HandleCrash(int signal, int pid, const char *force_exec) {
   CHECK(initialized_);
   std::string exec;
   if (force_exec) {
     exec.assign(force_exec);
   } else if (!GetExecutableBaseNameFromPid(pid, &exec)) {
     // If for some reason we don't have the base name, avoid completely
     // failing by indicating an unknown name.
     exec = "unknown";
   }
   bool feedback = is_feedback_allowed_function_();
   logger_->LogWarning("Received crash notification for %s[%d] sig %d (%s)",
                       exec.c_str(), pid, signal,
                       feedback ? "handling" : "ignoring");

   if (feedback) {
     count_crash_function_();

     if (generate_diagnostics_) {
       return GenerateDiagnostics(pid, exec);
     }
   }
   return true;
 }
	// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "crash-reporter/user_collector.h"

	#include <fcntl.h> // For creat.
	#include <grp.h> // For struct group.
	#include <pwd.h> // For struct passwd.
	#include <sys/types.h> // For getpwuid_r, getgrnam_r, WEXITSTATUS.
	#include <sys/wait.h> // For waitpid.
	#include <unistd.h> // For execv and fork.

	#include <string>
	#include <vector>

	#include "base/eintr_wrapper.h"
	#include "base/file_util.h"
	#include "base/logging.h"
	#include "base/string_util.h"
	#include "crash-reporter/system_logging.h"

	// This procfs file is used to cause kernel core file writing to
	// instead pipe the core file into a user space process. See
	// core(5) man page.
	static const char kCorePatternFile[] = "/proc/sys/kernel/core_pattern";
	static const char kCoreToMinidumpConverterPath[] = "/usr/bin/core2md";
	static const char kLeaveCoreFile[] = "/root/.leave_core";

	const char *UserCollector::kUserId = "Uid:\t";
	const char *UserCollector::kGroupId = "Gid:\t";

	UserCollector::UserCollector()
	: generate_diagnostics_(false),
	core_pattern_file_(kCorePatternFile),
	initialized_(false) {
	}

	void UserCollector::Initialize(
	UserCollector::CountCrashFunction count_crash_function,
	const std::string &our_path,
	UserCollector::IsFeedbackAllowedFunction is_feedback_allowed_function,
	SystemLogging *logger,
	bool generate_diagnostics) {
	CrashCollector::Initialize(count_crash_function,
	is_feedback_allowed_function,
	logger);
	our_path_ = our_path;
	initialized_ = true;
	generate_diagnostics_ = generate_diagnostics;
	}

	UserCollector::~UserCollector() {
	}

	std::string UserCollector::GetPattern(bool enabled) const {
	if (enabled) {
	return StringPrintf("\|%s --signal=%%s --pid=%%p", our_path_.c_str());
	} else {
	return "core";
	}
	}

	bool UserCollector::SetUpInternal(bool enabled) {
	CHECK(initialized_);
	logger_->LogInfo("%s user crash handling",
	enabled ? "Enabling" : "Disabling");
	std::string pattern = GetPattern(enabled);
	if (file_util::WriteFile(FilePath(core_pattern_file_),
	pattern.c_str(),
	pattern.length()) !=
	static_cast<int>(pattern.length())) {
	logger_->LogError("Unable to write %s", core_pattern_file_.c_str());
	return false;
	}
	return true;
	}

	FilePath UserCollector::GetProcessPath(pid_t pid) {
	return FilePath(StringPrintf("/proc/%d", pid));
	}

	bool UserCollector::GetSymlinkTarget(const FilePath &symlink,
	FilePath *target) {
	int max_size = 32;
	scoped_array<char> buffer;
	while (true) {
	buffer.reset(new char[max_size + 1]);
	ssize_t size = readlink(symlink.value().c_str(), buffer.get(), max_size);
	if (size < 0) {
	return false;
	}
	buffer[size] = 0;
	if (size == max_size) {
	// Avoid overflow when doubling.
	if (max_size * 2 > max_size) {
	max_size *= 2;
	continue;
	} else {
	return false;
	}
	}
	break;
	}

	*target = FilePath(buffer.get());
	return true;
	}

	bool UserCollector::GetExecutableBaseNameFromPid(uid_t pid,
	std::string *base_name) {
	FilePath target;
	if (!GetSymlinkTarget(GetProcessPath(pid).Append("exe"), &target))
	return false;
	*base_name = target.BaseName().value();
	return true;
	}

	bool UserCollector::GetIdFromStatus(const char *prefix,
	IdKind kind,
	const std::string &status_contents,
	int *id) {
	// From fs/proc/array.c:task_state(), this file contains:
	// \nUid:\t<uid>\t<euid>\t<suid>\t<fsuid>\n
	std::vector<std::string> status_lines;
	SplitString(status_contents, '\n', &status_lines);
	std::vector<std::string>::iterator line_iterator;
	for (line_iterator = status_lines.begin();
	line_iterator != status_lines.end();
	++line_iterator) {
	if (line_iterator->find(prefix) == 0)
	break;
	}
	if (line_iterator == status_lines.end()) {
	return false;
	}
	std::string id_substring = line_iterator->substr(strlen(prefix),
	std::string::npos);
	std::vector<std::string> ids;
	SplitString(id_substring, '\t', &ids);
	if (ids.size() != kIdMax \|\| kind < 0 \|\| kind >= kIdMax) {
	return false;
	}
	const char *number = ids[kind].c_str();
	char *end_number = NULL;
	*id = strtol(number, &end_number, 10);
	if (*end_number != '\0')
	return false;
	return true;
	}

	bool UserCollector::CopyOffProcFiles(pid_t pid,
	const FilePath &container_dir) {
	if (!file_util::CreateDirectory(container_dir)) {
	logger_->LogInfo("Could not create %s", container_dir.value().c_str());
	return false;
	}
	FilePath process_path = GetProcessPath(pid);
	if (!file_util::PathExists(process_path)) {
	logger_->LogWarning("Path %s does not exist",
	process_path.value().c_str());
	return false;
	}
	static const char *proc_files[] = {
	"auxv",
	"cmdline",
	"environ",
	"maps",
	"status"
	};
	for (unsigned i = 0; i < arraysize(proc_files); ++i) {
	if (!file_util::CopyFile(process_path.Append(proc_files[i]),
	container_dir.Append(proc_files[i]))) {
	logger_->LogWarning("Could not copy %s file", proc_files[i]);
	return false;
	}
	}
	return true;
	}

	bool UserCollector::GetCreatedCrashDirectory(pid_t pid,
	FilePath *crash_file_path) {
	FilePath process_path = GetProcessPath(pid);
	std::string status;
	if (!file_util::ReadFileToString(process_path.Append("status"),
	&status)) {
	logger_->LogError("Could not read status file");
	return false;
	}
	int process_euid;
	if (!GetIdFromStatus(kUserId, kIdEffective, status, &process_euid)) {
	logger_->LogError("Could not find euid in status file");
	return false;
	}
	return GetCreatedCrashDirectoryByEuid(process_euid,
	crash_file_path);
	}

	bool UserCollector::CopyStdinToCoreFile(const FilePath &core_path) {
	// Copy off all stdin to a core file.
	FilePath stdin_path("/dev/fd/0");
	if (file_util::CopyFile(stdin_path, core_path)) {
	return true;
	}

	logger_->LogError("Could not write core file");
	// If the file system was full, make sure we remove any remnants.
	file_util::Delete(core_path, false);
	return false;
	}

	int UserCollector::ForkExecAndPipe(std::vector<const char *> &arguments,
	const char *output_file) {
	// Copy off a writeable version of arguments.
	scoped_array<char> argv(new char [arguments.size() + 1]);
	int total_args_size = 0;
	for (size_t i = 0; i < arguments.size(); ++i) {
	if (arguments[i] == NULL) {
	logger_->LogError("Bad parameter");
	return -1;
	}
	total_args_size += strlen(arguments[i]) + 1;
	}
	scoped_array<char> buffer(new char[total_args_size]);
	char *buffer_pointer = &buffer[0];

	for (size_t i = 0; i < arguments.size(); ++i) {
	argv[i] = buffer_pointer;
	strcpy(buffer_pointer, arguments[i]);
	buffer_pointer += strlen(arguments[i]);
	*buffer_pointer = '\0';
	++buffer_pointer;
	}
	argv[arguments.size()] = NULL;

	int pid = fork();
	if (pid < 0) {
	logger_->LogError("Fork failed: %d", errno);
	return -1;
	}

	if (pid == 0) {
	int output_handle = creat(output_file, 0700);
	if (output_handle < 0) {
	logger_->LogError("Could not create %s: %d", output_file, errno);
	// Avoid exit() to avoid atexit handlers from parent.
	_exit(127);
	}
	dup2(output_handle, 1);
	dup2(output_handle, 2);
	execv(argv[0], &argv[0]);
	logger_->LogError("Exec failed: %d", errno);
	_exit(127);
	}

	int status = 0;
	if (HANDLE_EINTR(waitpid(pid, &status, 0)) < 0) {
	logger_->LogError("Problem waiting for pid: %d", errno);
	return -1;
	}
	if (!WIFEXITED(status)) {
	logger_->LogError("Process did not exit normally: %x", status);
	return -1;
	}
	return WEXITSTATUS(status);
	}

	bool UserCollector::ConvertCoreToMinidump(const FilePath &core_path,
	const FilePath &procfs_directory,
	const FilePath &minidump_path,
	const FilePath &temp_directory) {
	FilePath output_path = temp_directory.Append("output");
	std::vector<const char *> core2md_arguments;
	core2md_arguments.push_back(kCoreToMinidumpConverterPath);
	core2md_arguments.push_back(core_path.value().c_str());
	core2md_arguments.push_back(procfs_directory.value().c_str());
	core2md_arguments.push_back(minidump_path.value().c_str());

	int errorlevel = ForkExecAndPipe(core2md_arguments,
	output_path.value().c_str());

	std::string output;
	file_util::ReadFileToString(output_path, &output);
	if (errorlevel != 0) {
	logger_->LogInfo("Problem during %s [result=%d]: %s",
	kCoreToMinidumpConverterPath,
	errorlevel,
	output.c_str());
	return false;
	}

	if (!file_util::PathExists(minidump_path)) {
	logger_->LogError("Minidump file %s was not created",
	minidump_path.value().c_str());
	return false;
	}
	return true;
	}

	bool UserCollector::GenerateDiagnostics(pid_t pid,
	const std::string &exec_name) {
	FilePath container_dir("/tmp");
	container_dir = container_dir.Append(
	StringPrintf("crash_reporter.%d", pid));

	if (!CopyOffProcFiles(pid, container_dir)) {
	file_util::Delete(container_dir, true);
	return false;
	}

	FilePath crash_path;
	if (!GetCreatedCrashDirectory(pid, &crash_path)) {
	file_util::Delete(container_dir, true);
	return false;
	}
	std::string dump_basename = FormatDumpBasename(exec_name, time(NULL), pid);
	FilePath core_path = crash_path.Append(
	StringPrintf("%s.core", dump_basename.c_str()));

	if (!CopyStdinToCoreFile(core_path)) {
	file_util::Delete(container_dir, true);
	return false;
	}

	FilePath minidump_path = crash_path.Append(
	StringPrintf("%s.dmp", dump_basename.c_str()));

	bool conversion_result = true;
	if (!ConvertCoreToMinidump(core_path,
	container_dir, // procfs directory
	minidump_path,
	container_dir)) { // temporary directory
	// Note we leave the container directory for inspection.
	conversion_result = false;
	}

	WriteCrashMetaData(
	crash_path.Append(
	StringPrintf("%s.meta", dump_basename.c_str())),
	exec_name,
	minidump_path.value());

	if (conversion_result) {
	logger_->LogInfo("Stored minidump to %s", minidump_path.value().c_str());
	}

	if (!file_util::PathExists(FilePath(kLeaveCoreFile))) {
	file_util::Delete(core_path, false);
	} else {
	logger_->LogInfo("Leaving core file at %s", core_path.value().c_str());
	}

	return conversion_result;
	}

	bool UserCollector::HandleCrash(int signal, int pid, const char *force_exec) {
	CHECK(initialized_);
	std::string exec;
	if (force_exec) {
	exec.assign(force_exec);
	} else if (!GetExecutableBaseNameFromPid(pid, &exec)) {
	// If for some reason we don't have the base name, avoid completely
	// failing by indicating an unknown name.
	exec = "unknown";
	}
	bool feedback = is_feedback_allowed_function_();
	logger_->LogWarning("Received crash notification for %s[%d] sig %d (%s)",
	exec.c_str(), pid, signal,
	feedback ? "handling" : "ignoring");

	if (feedback) {
	count_crash_function_();

	if (generate_diagnostics_) {
	return GenerateDiagnostics(pid, exec);
	}
	}
	return true;
	}