crash-reporter/kernel_warning_collector.cc - mirrors/cros/chromiumos/platform2 - Git at Google

 // Copyright (c) 2012 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/kernel_warning_collector.h"

 #include <base/files/file_util.h>
 #include <base/logging.h>
 #include <base/strings/strcat.h>
 #include <base/strings/stringprintf.h>
 #include <re2/re2.h>

 #include "crash-reporter/util.h"

 namespace {
 const char kGenericWarningExecName[] = "kernel-warning";
 const char kWifiWarningExecName[] = "kernel-wifi-warning";
 const char kSMMUFaultExecName[] = "kernel-smmu-fault";
 const char kSuspendWarningExecName[] = "kernel-suspend-warning";
 const char kKernelIwlwifiErrorExecName[] = "kernel-iwlwifi-error";
 const char kKernelWarningSignatureKey[] = "sig";
 const pid_t kKernelPid = 0;
 }  // namespace

 using base::FilePath;
 using base::StringPrintf;

 KernelWarningCollector::KernelWarningCollector()
     : CrashCollector("kernel_warning"), warning_report_path_("/dev/stdin") {}

 KernelWarningCollector::~KernelWarningCollector() {}

 bool KernelWarningCollector::LoadKernelWarning(std::string* content,
                                                std::string* signature,
                                                std::string* func_name,
                                                WarningType type) {
   FilePath kernel_warning_path(warning_report_path_.c_str());
   if (!base::ReadFileToString(kernel_warning_path, content)) {
     PLOG(ERROR) << "Could not open " << kernel_warning_path.value();
     return false;
   }

   if (type == kIwlwifi) {
     if (!ExtractIwlwifiSignature(*content, signature, func_name)) {
       return false;
     } else if (signature->length() > 0) {
       return true;
     }
   } else if (type == kSMMUFault) {
     if (!ExtractSMMUFaultSignature(*content, signature, func_name)) {
       return false;
     } else if (signature->length() > 0) {
       return true;
     }
   } else {
     if (!ExtractSignature(*content, signature, func_name)) {
       return false;
     } else if (signature->length() > 0) {
       return true;
     }
   }

   LOG(WARNING) << "Couldn't find match for signature line. "
                << "Falling back to first line of warning.";
   *signature = content->substr(0, content->find('\n'));
   return true;
 }

 // Extract the crashing function name from the signature.
 // Signature example: 6a839c19-lkdtm_do_action+0x225/0x5bc
 // Signature example2: 6a839c19-unknown-function+0x161/0x344 [iwlmvm]
 constexpr LazyRE2 sig_re = {R"(^[0-9a-fA-F]+-([0-9a-zA-Z_-]+)\+.*$)"};

 bool KernelWarningCollector::ExtractSignature(const std::string& content,
                                               std::string* signature,
                                               std::string* func_name) {
   // The signature is in the first or second line.
   // First, try the first, and if it's not there, try the second.
   std::string::size_type end_position = content.find('\n');
   if (end_position == std::string::npos) {
     LOG(ERROR) << "unexpected kernel warning format";
     return false;
   }
   size_t start = 0;
   for (int i = 0; i < 2; i++) {
     *signature = content.substr(start, end_position - start);

     if (RE2::FullMatch(*signature, *sig_re, func_name)) {
       return true;
     } else {
       LOG(INFO) << *signature << " does not match regex";
       signature->clear();
       func_name->clear();
     }

     // Else, try the next line.
     start = end_position + 1;
     end_position = content.find('\n', start);
   }

   return true;
 }

 // Extract the crashing function name from the signature.
 // The crashing function for the lmac appears after the line:
 // Loaded firmware version: 46.b20aefee.0
 // Signature example: 0x00000084 | NMI_INTERRUPT_UNKNOWN
 // The crashing function for the umac appears after the line:
 // iwlwifi 0000:00:0c.0: Status: 0x00000100, count: 7
 // Signature example: 0x20000066 | NMI_INTERRUPT_HOST
 constexpr LazyRE2 before_iwlwifi_assert_lmac = {
     R"(iwlwifi (?:.+): Loaded firmware version:)"};
 constexpr LazyRE2 before_iwlwifi_assert_umac = {R"(iwlwifi (?:.+): Status:)"};
 constexpr LazyRE2 iwlwifi_sig_re = {
     R"(iwlwifi (?:.+): \b(\w+)\b \| \b(\w+)\b)"};

 enum class LineType {
   Umac,
   Lmac,
   None,
   CheckUmac,
 };

 bool KernelWarningCollector::ExtractIwlwifiSignature(const std::string& content,
                                                      std::string* signature,
                                                      std::string* func_name) {
   LineType last_line = LineType::None;
   // Extracting the function name depends on where the assert occurs in
   // lmac/umac:
   // 1- Assert in lmac:
   //       The umac have the default assert value in its signature
   //       (0x20000070).
   // 2- Assert in umac:
   //       The lmac have the default assert value in its signature
   //       (0x00000071).
   // Based on that, the function name in lmac/umac should be ignored if the
   // assert number in the signature is equal to 0x00000071 in lmac or 0x20000070
   // in umac.
   const std::string default_lmac_assert = "0x00000071";
   const std::string default_umac_assert = "0x20000070";
   std::string assert_number;
   std::string::size_type end_position = content.find('\n');
   if (end_position == std::string::npos) {
     LOG(ERROR) << "unexpected kernel iwlwifi error format";
     return false;
   }

   // Look for the signature in the lmac and check the assert number. if the lmac
   // assert number not equal (0x00000071), then return that as the signature.
   // Otherwise, check the signature of the umac. if the umac assert number not
   // equal (0x20000070), then return that as the signature. Otherwise, break.
   size_t start = 0;
   size_t end = content.size();
   while (start < end && end_position != std::string::npos) {
     *signature = content.substr(start, end_position - start);

     if (last_line == LineType::None) {
       if (RE2::PartialMatch(*signature, *before_iwlwifi_assert_lmac)) {
         last_line = LineType::Lmac;
       }
     } else if (last_line == LineType::Lmac) {
       // Check the signature of the lmac.
       if (RE2::PartialMatch(*signature, *iwlwifi_sig_re, &assert_number,
                             func_name)) {
         if (default_lmac_assert != assert_number) {
           return true;
         } else {
           // Check umac if the lmac assertion number == default_lmac_assert.
           last_line = LineType::CheckUmac;
           signature->clear();
           func_name->clear();
         }
       } else {
         // Break if the signature of the lmac didn't match.
         LOG(INFO) << *signature << " does not match regex";
         signature->clear();
         func_name->clear();
         break;
       }
     } else if (last_line == LineType::CheckUmac) {
       // Check the line before the umac signature.
       if (RE2::PartialMatch(*signature, *before_iwlwifi_assert_umac)) {
         last_line = LineType::Umac;
       }
     } else if (last_line == LineType::Umac) {
       // Check the signature of the umac.
       if (RE2::PartialMatch(*signature, *iwlwifi_sig_re, &assert_number,
                             func_name)) {
         if (default_umac_assert != assert_number) {
           return true;
         } else {
           // Break if the umac assertion number == default_umac_assert.
           LOG(ERROR) << "unexpected kernel iwlwifi error format. "
                         "Both umac/lmac dumps have the default assert numbers.";
           signature->clear();
           func_name->clear();
           break;
         }
       } else {
         // Break if the signature of the umac didn't match.
         LOG(INFO) << *signature << " does not match regex";
         signature->clear();
         func_name->clear();
         break;
       }
     }

     // Else, try the next line.
     start = end_position + 1;
     end_position = content.find('\n', start);
   }

   return true;
 }

 constexpr LazyRE2 smmu_sig_re = {R"((\S+): Unhandled context fault: (.*))"};

 bool KernelWarningCollector::ExtractSMMUFaultSignature(
     const std::string& content,
     std::string* signature,
     std::string* func_name) {
   // The signature is the part of the line after "Unhandled context fault:"
   std::string line;
   std::string::size_type end_position = content.find('\n');
   if (end_position == std::string::npos) {
     LOG(ERROR) << "unexpected smmu fault warning format";
     return false;
   }

   line = content.substr(0, end_position);
   if (RE2::PartialMatch(line, *smmu_sig_re, func_name, signature)) {
     return true;
   }
   LOG(INFO) << line << " does not match regex";
   signature->clear();
   func_name->clear();
   return false;
 }

 bool KernelWarningCollector::Collect(WarningType type) {
   LOG(INFO) << "Processing kernel warning";

   std::string kernel_warning;
   std::string warning_signature;
   std::string func_name;
   if (!LoadKernelWarning(&kernel_warning, &warning_signature, &func_name,
                          type)) {
     return false;
   }

   FilePath root_crash_directory;
   if (!GetCreatedCrashDirectoryByEuid(kRootUid, &root_crash_directory,
                                       nullptr)) {
     return false;
   }

   const char* exec_name;
   if (type == kWifi)
     exec_name = kWifiWarningExecName;
   else if (type == kSMMUFault)
     exec_name = kSMMUFaultExecName;
   else if (type == kSuspend)
     exec_name = kSuspendWarningExecName;
   else if (type == kGeneric)
     exec_name = kGenericWarningExecName;
   else
     exec_name = kKernelIwlwifiErrorExecName;

   // Attempt to make the exec_name more unique to avoid collisions.
   if (!func_name.empty()) {
     func_name.insert(func_name.begin(), '_');
   } else {
     LOG(WARNING) << "Couldn't extract function name from signature. "
                     "Going on without it.";
   }

   std::string dump_basename = FormatDumpBasename(
       base::StrCat({exec_name, func_name}), time(nullptr), kKernelPid);
   FilePath log_path =
       GetCrashPath(root_crash_directory, dump_basename, "log.gz");
   FilePath meta_path =
       GetCrashPath(root_crash_directory, dump_basename, "meta");
   FilePath kernel_crash_path = root_crash_directory.Append(
       StringPrintf("%s.kcrash", dump_basename.c_str()));

   // We must use WriteNewFile instead of base::WriteFile as we
   // do not want to write with root access to a symlink that an attacker
   // might have created.
   if (WriteNewFile(kernel_crash_path, kernel_warning.data(),
                    kernel_warning.length()) !=
       static_cast<int>(kernel_warning.length())) {
     LOG(INFO) << "Failed to write kernel warning to "
               << kernel_crash_path.value().c_str();
     return true;
   }

   AddCrashMetaData(kKernelWarningSignatureKey, warning_signature);

   // Get the log contents, compress, and attach to crash report.
   bool result = GetLogContents(log_config_path_, exec_name, log_path);
   if (result) {
     AddCrashMetaUploadFile("log", log_path.BaseName().value());
   }

   FinishCrash(meta_path, exec_name, kernel_crash_path.BaseName().value());

   return true;
 }
	// Copyright (c) 2012 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/kernel_warning_collector.h"

	#include <base/files/file_util.h>
	#include <base/logging.h>
	#include <base/strings/strcat.h>
	#include <base/strings/stringprintf.h>
	#include <re2/re2.h>

	#include "crash-reporter/util.h"

	namespace {
	const char kGenericWarningExecName[] = "kernel-warning";
	const char kWifiWarningExecName[] = "kernel-wifi-warning";
	const char kSMMUFaultExecName[] = "kernel-smmu-fault";
	const char kSuspendWarningExecName[] = "kernel-suspend-warning";
	const char kKernelIwlwifiErrorExecName[] = "kernel-iwlwifi-error";
	const char kKernelWarningSignatureKey[] = "sig";
	const pid_t kKernelPid = 0;
	} // namespace

	using base::FilePath;
	using base::StringPrintf;

	KernelWarningCollector::KernelWarningCollector()
	: CrashCollector("kernel_warning"), warning_report_path_("/dev/stdin") {}

	KernelWarningCollector::~KernelWarningCollector() {}

	bool KernelWarningCollector::LoadKernelWarning(std::string* content,
	std::string* signature,
	std::string* func_name,
	WarningType type) {
	FilePath kernel_warning_path(warning_report_path_.c_str());
	if (!base::ReadFileToString(kernel_warning_path, content)) {
	PLOG(ERROR) << "Could not open " << kernel_warning_path.value();
	return false;
	}

	if (type == kIwlwifi) {
	if (!ExtractIwlwifiSignature(*content, signature, func_name)) {
	return false;
	} else if (signature->length() > 0) {
	return true;
	}
	} else if (type == kSMMUFault) {
	if (!ExtractSMMUFaultSignature(*content, signature, func_name)) {
	return false;
	} else if (signature->length() > 0) {
	return true;
	}
	} else {
	if (!ExtractSignature(*content, signature, func_name)) {
	return false;
	} else if (signature->length() > 0) {
	return true;
	}
	}

	LOG(WARNING) << "Couldn't find match for signature line. "
	<< "Falling back to first line of warning.";
	*signature = content->substr(0, content->find('\n'));
	return true;
	}

	// Extract the crashing function name from the signature.
	// Signature example: 6a839c19-lkdtm_do_action+0x225/0x5bc
	// Signature example2: 6a839c19-unknown-function+0x161/0x344 [iwlmvm]
	constexpr LazyRE2 sig_re = {R"(^[0-9a-fA-F]+-([0-9a-zA-Z_-]+)\+.*$)"};

	bool KernelWarningCollector::ExtractSignature(const std::string& content,
	std::string* signature,
	std::string* func_name) {
	// The signature is in the first or second line.
	// First, try the first, and if it's not there, try the second.
	std::string::size_type end_position = content.find('\n');
	if (end_position == std::string::npos) {
	LOG(ERROR) << "unexpected kernel warning format";
	return false;
	}
	size_t start = 0;
	for (int i = 0; i < 2; i++) {
	*signature = content.substr(start, end_position - start);

	if (RE2::FullMatch(signature, sig_re, func_name)) {
	return true;
	} else {
	LOG(INFO) << *signature << " does not match regex";
	signature->clear();
	func_name->clear();
	}

	// Else, try the next line.
	start = end_position + 1;
	end_position = content.find('\n', start);
	}

	return true;
	}

	// Extract the crashing function name from the signature.
	// The crashing function for the lmac appears after the line:
	// Loaded firmware version: 46.b20aefee.0
	// Signature example: 0x00000084 \| NMI_INTERRUPT_UNKNOWN
	// The crashing function for the umac appears after the line:
	// iwlwifi 0000:00:0c.0: Status: 0x00000100, count: 7
	// Signature example: 0x20000066 \| NMI_INTERRUPT_HOST
	constexpr LazyRE2 before_iwlwifi_assert_lmac = {
	R"(iwlwifi (?:.+): Loaded firmware version:)"};
	constexpr LazyRE2 before_iwlwifi_assert_umac = {R"(iwlwifi (?:.+): Status:)"};
	constexpr LazyRE2 iwlwifi_sig_re = {
	R"(iwlwifi (?:.+): \b(\w+)\b \\| \b(\w+)\b)"};

	enum class LineType {
	Umac,
	Lmac,
	None,
	CheckUmac,
	};

	bool KernelWarningCollector::ExtractIwlwifiSignature(const std::string& content,
	std::string* signature,
	std::string* func_name) {
	LineType last_line = LineType::None;
	// Extracting the function name depends on where the assert occurs in
	// lmac/umac:
	// 1- Assert in lmac:
	// The umac have the default assert value in its signature
	// (0x20000070).
	// 2- Assert in umac:
	// The lmac have the default assert value in its signature
	// (0x00000071).
	// Based on that, the function name in lmac/umac should be ignored if the
	// assert number in the signature is equal to 0x00000071 in lmac or 0x20000070
	// in umac.
	const std::string default_lmac_assert = "0x00000071";
	const std::string default_umac_assert = "0x20000070";
	std::string assert_number;
	std::string::size_type end_position = content.find('\n');
	if (end_position == std::string::npos) {
	LOG(ERROR) << "unexpected kernel iwlwifi error format";
	return false;
	}

	// Look for the signature in the lmac and check the assert number. if the lmac
	// assert number not equal (0x00000071), then return that as the signature.
	// Otherwise, check the signature of the umac. if the umac assert number not
	// equal (0x20000070), then return that as the signature. Otherwise, break.
	size_t start = 0;
	size_t end = content.size();
	while (start < end && end_position != std::string::npos) {
	*signature = content.substr(start, end_position - start);

	if (last_line == LineType::None) {
	if (RE2::PartialMatch(signature, before_iwlwifi_assert_lmac)) {
	last_line = LineType::Lmac;
	}
	} else if (last_line == LineType::Lmac) {
	// Check the signature of the lmac.
	if (RE2::PartialMatch(signature, iwlwifi_sig_re, &assert_number,
	func_name)) {
	if (default_lmac_assert != assert_number) {
	return true;
	} else {
	// Check umac if the lmac assertion number == default_lmac_assert.
	last_line = LineType::CheckUmac;
	signature->clear();
	func_name->clear();
	}
	} else {
	// Break if the signature of the lmac didn't match.
	LOG(INFO) << *signature << " does not match regex";
	signature->clear();
	func_name->clear();
	break;
	}
	} else if (last_line == LineType::CheckUmac) {
	// Check the line before the umac signature.
	if (RE2::PartialMatch(signature, before_iwlwifi_assert_umac)) {
	last_line = LineType::Umac;
	}
	} else if (last_line == LineType::Umac) {
	// Check the signature of the umac.
	if (RE2::PartialMatch(signature, iwlwifi_sig_re, &assert_number,
	func_name)) {
	if (default_umac_assert != assert_number) {
	return true;
	} else {
	// Break if the umac assertion number == default_umac_assert.
	LOG(ERROR) << "unexpected kernel iwlwifi error format. "
	"Both umac/lmac dumps have the default assert numbers.";
	signature->clear();
	func_name->clear();
	break;
	}
	} else {
	// Break if the signature of the umac didn't match.
	LOG(INFO) << *signature << " does not match regex";
	signature->clear();
	func_name->clear();
	break;
	}
	}

	// Else, try the next line.
	start = end_position + 1;
	end_position = content.find('\n', start);
	}

	return true;
	}

	constexpr LazyRE2 smmu_sig_re = {R"((\S+): Unhandled context fault: (.*))"};

	bool KernelWarningCollector::ExtractSMMUFaultSignature(
	const std::string& content,
	std::string* signature,
	std::string* func_name) {
	// The signature is the part of the line after "Unhandled context fault:"
	std::string line;
	std::string::size_type end_position = content.find('\n');
	if (end_position == std::string::npos) {
	LOG(ERROR) << "unexpected smmu fault warning format";
	return false;
	}

	line = content.substr(0, end_position);
	if (RE2::PartialMatch(line, *smmu_sig_re, func_name, signature)) {
	return true;
	}
	LOG(INFO) << line << " does not match regex";
	signature->clear();
	func_name->clear();
	return false;
	}

	bool KernelWarningCollector::Collect(WarningType type) {
	LOG(INFO) << "Processing kernel warning";

	std::string kernel_warning;
	std::string warning_signature;
	std::string func_name;
	if (!LoadKernelWarning(&kernel_warning, &warning_signature, &func_name,
	type)) {
	return false;
	}

	FilePath root_crash_directory;
	if (!GetCreatedCrashDirectoryByEuid(kRootUid, &root_crash_directory,
	nullptr)) {
	return false;
	}

	const char* exec_name;
	if (type == kWifi)
	exec_name = kWifiWarningExecName;
	else if (type == kSMMUFault)
	exec_name = kSMMUFaultExecName;
	else if (type == kSuspend)
	exec_name = kSuspendWarningExecName;
	else if (type == kGeneric)
	exec_name = kGenericWarningExecName;
	else
	exec_name = kKernelIwlwifiErrorExecName;

	// Attempt to make the exec_name more unique to avoid collisions.
	if (!func_name.empty()) {
	func_name.insert(func_name.begin(), '_');
	} else {
	LOG(WARNING) << "Couldn't extract function name from signature. "
	"Going on without it.";
	}

	std::string dump_basename = FormatDumpBasename(
	base::StrCat({exec_name, func_name}), time(nullptr), kKernelPid);
	FilePath log_path =
	GetCrashPath(root_crash_directory, dump_basename, "log.gz");
	FilePath meta_path =
	GetCrashPath(root_crash_directory, dump_basename, "meta");
	FilePath kernel_crash_path = root_crash_directory.Append(
	StringPrintf("%s.kcrash", dump_basename.c_str()));

	// We must use WriteNewFile instead of base::WriteFile as we
	// do not want to write with root access to a symlink that an attacker
	// might have created.
	if (WriteNewFile(kernel_crash_path, kernel_warning.data(),
	kernel_warning.length()) !=
	static_cast<int>(kernel_warning.length())) {
	LOG(INFO) << "Failed to write kernel warning to "
	<< kernel_crash_path.value().c_str();
	return true;
	}

	AddCrashMetaData(kKernelWarningSignatureKey, warning_signature);

	// Get the log contents, compress, and attach to crash report.
	bool result = GetLogContents(log_config_path_, exec_name, log_path);
	if (result) {
	AddCrashMetaUploadFile("log", log_path.BaseName().value());
	}

	FinishCrash(meta_path, exec_name, kernel_crash_path.BaseName().value());

	return true;
	}