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Diffstat (limited to 'toolkit/crashreporter/breakpad-client/linux/handler/exception_handler.h')
| -rw-r--r-- | toolkit/crashreporter/breakpad-client/linux/handler/exception_handler.h | 289 |
1 files changed, 289 insertions, 0 deletions
diff --git a/toolkit/crashreporter/breakpad-client/linux/handler/exception_handler.h b/toolkit/crashreporter/breakpad-client/linux/handler/exception_handler.h new file mode 100644 index 0000000000..46ad399419 --- /dev/null +++ b/toolkit/crashreporter/breakpad-client/linux/handler/exception_handler.h @@ -0,0 +1,289 @@ +// Copyright (c) 2010 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. + +#ifndef CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_ +#define CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_ + +#include <signal.h> +#include <stdint.h> +#include <stdio.h> +#include <sys/ucontext.h> + +#include <string> + +#include "linux/crash_generation/crash_generation_client.h" +#include "linux/handler/minidump_descriptor.h" +#include "linux/minidump_writer/minidump_writer.h" +#include "common/scoped_ptr.h" +#include "common/using_std_string.h" +#include "google_breakpad/common/minidump_format.h" + +#ifdef MOZ_PHC +#include "PHC.h" +#else +namespace mozilla { namespace phc { class AddrInfo {}; } } +#endif + +namespace google_breakpad { + +// ExceptionHandler +// +// ExceptionHandler can write a minidump file when an exception occurs, +// or when WriteMinidump() is called explicitly by your program. +// +// To have the exception handler write minidumps when an uncaught exception +// (crash) occurs, you should create an instance early in the execution +// of your program, and keep it around for the entire time you want to +// have crash handling active (typically, until shutdown). +// (NOTE): There should be only be one this kind of exception handler +// object per process. +// +// If you want to write minidumps without installing the exception handler, +// you can create an ExceptionHandler with install_handler set to false, +// then call WriteMinidump. You can also use this technique if you want to +// use different minidump callbacks for different call sites. +// +// In either case, a callback function is called when a minidump is written, +// which receives the full path or file descriptor of the minidump. The +// caller can collect and write additional application state to that minidump, +// and launch an external crash-reporting application. +// +// Caller should try to make the callbacks as crash-friendly as possible, +// it should avoid use heap memory allocation as much as possible. + +class ExceptionHandler { + public: + // A callback function to run before Breakpad performs any substantial + // processing of an exception. A FilterCallback is called before writing + // a minidump. |context| is the parameter supplied by the user as + // callback_context when the handler was created. + // + // If a FilterCallback returns true, Breakpad will continue processing, + // attempting to write a minidump. If a FilterCallback returns false, + // Breakpad will immediately report the exception as unhandled without + // writing a minidump, allowing another handler the opportunity to handle it. + typedef bool (*FilterCallback)(void *context); + + // A callback function to run after the minidump has been written. + // |descriptor| contains the file descriptor or file path containing the + // minidump. |context| is the parameter supplied by the user as + // callback_context when the handler was created. |succeeded| indicates + // whether a minidump file was successfully written. + // + // If an exception occurred and the callback returns true, Breakpad will + // treat the exception as fully-handled, suppressing any other handlers from + // being notified of the exception. If the callback returns false, Breakpad + // will treat the exception as unhandled, and allow another handler to handle + // it. If there are no other handlers, Breakpad will report the exception to + // the system as unhandled, allowing a debugger or native crash dialog the + // opportunity to handle the exception. Most callback implementations + // should normally return the value of |succeeded|, or when they wish to + // not report an exception of handled, false. Callbacks will rarely want to + // return true directly (unless |succeeded| is true). + typedef bool (*MinidumpCallback)(const MinidumpDescriptor& descriptor, + void* context, + const mozilla::phc::AddrInfo* addr_info, + bool succeeded); + + // In certain cases, a user may wish to handle the generation of the minidump + // themselves. In this case, they can install a handler callback which is + // called when a crash has occurred. If this function returns true, no other + // processing of occurs and the process will shortly be crashed. If this + // returns false, the normal processing continues. + typedef bool (*HandlerCallback)(const void* crash_context, + size_t crash_context_size, + void* context); + + // Creates a new ExceptionHandler instance to handle writing minidumps. + // Before writing a minidump, the optional |filter| callback will be called. + // Its return value determines whether or not Breakpad should write a + // minidump. The minidump content will be written to the file path or file + // descriptor from |descriptor|, and the optional |callback| is called after + // writing the dump file, as described above. + // If install_handler is true, then a minidump will be written whenever + // an unhandled exception occurs. If it is false, minidumps will only + // be written when WriteMinidump is called. + // If |server_fd| is valid, the minidump is generated out-of-process. If it + // is -1, in-process generation will always be used. + ExceptionHandler(const MinidumpDescriptor& descriptor, + FilterCallback filter, + MinidumpCallback callback, + void* callback_context, + bool install_handler, + const int server_fd); + ~ExceptionHandler(); + + const MinidumpDescriptor& minidump_descriptor() const { + return minidump_descriptor_; + } + + void set_minidump_descriptor(const MinidumpDescriptor& descriptor) { + minidump_descriptor_ = descriptor; + } + + void set_crash_handler(HandlerCallback callback) { + crash_handler_ = callback; + } + + void set_crash_generation_client(CrashGenerationClient* client) { + crash_generation_client_.reset(client); + } + + // Writes a minidump immediately. This can be used to capture the execution + // state independently of a crash. + // Returns true on success. + // If the ExceptionHandler has been created with a path, a new file is + // generated for each minidump. The file path can be retrieved in the + // MinidumpDescriptor passed to the MinidumpCallback or by accessing the + // MinidumpDescriptor directly from the ExceptionHandler (with + // minidump_descriptor()). + // If the ExceptionHandler has been created with a file descriptor, the file + // descriptor is repositioned to its beginning and the previous generated + // minidump is overwritten. + // Note that this method is not supposed to be called from a compromised + // context as it uses the heap. + bool WriteMinidump(); + + // Convenience form of WriteMinidump which does not require an + // ExceptionHandler instance. + static bool WriteMinidump(const string& dump_path, + MinidumpCallback callback, + void* callback_context); + + // Write a minidump of |child| immediately. This can be used to + // capture the execution state of |child| independently of a crash. + // Pass a meaningful |child_blamed_thread| to make that thread in + // the child process the one from which a crash signature is + // extracted. + // + // WARNING: the return of this function *must* happen before + // the code that will eventually reap |child| executes. + // Otherwise there's a pernicious race condition in which |child| + // exits, is reaped, another process created with its pid, then that + // new process dumped. + static bool WriteMinidumpForChild(pid_t child, + pid_t child_blamed_thread, + const string& dump_path, + MinidumpCallback callback, + void* callback_context); + + // This structure is passed to minidump_writer.h:WriteMinidump via an opaque + // blob. It shouldn't be needed in any user code. + struct CrashContext { + siginfo_t siginfo; + pid_t tid; // the crashing thread. + ucontext_t context; +#if !defined(__ARM_EABI__) && !defined(__mips__) + // #ifdef this out because FP state is not part of user ABI for Linux ARM. + // In case of MIPS Linux FP state is already part of ucontext_t so + // 'float_state' is not required. + fpstate_t float_state; +#endif + }; + + // Returns whether out-of-process dump generation is used or not. + bool IsOutOfProcess() const { + return crash_generation_client_.get() != NULL; + } + + // Add information about a memory mapping. This can be used if + // a custom library loader is used that maps things in a way + // that the linux dumper can't handle by reading the maps file. + void AddMappingInfo(const string& name, + const wasteful_vector<uint8_t>& identifier, + uintptr_t start_address, + size_t mapping_size, + size_t file_offset); + + // Register a block of memory of length bytes starting at address ptr + // to be copied to the minidump when a crash happens. + void RegisterAppMemory(void* ptr, size_t length); + + // Unregister a block of memory that was registered with RegisterAppMemory. + void UnregisterAppMemory(void* ptr); + + // Force signal handling for the specified signal. + bool SimulateSignalDelivery(int sig); + + // Report a crash signal from an SA_SIGINFO signal handler. + bool HandleSignal(int sig, siginfo_t* info, void* uc); + + private: + // Save the old signal handlers and install new ones. + static bool InstallHandlersLocked(); + // Restore the old signal handlers. + static void RestoreHandlersLocked(); + + void PreresolveSymbols(); + bool GenerateDump(CrashContext *context, + const mozilla::phc::AddrInfo* addr_info); + void SendContinueSignalToChild(); + void WaitForContinueSignal(); + + static void SignalHandler(int sig, siginfo_t* info, void* uc); + static int ThreadEntry(void* arg); + bool DoDump(pid_t crashing_process, const void* context, + size_t context_size); + + const FilterCallback filter_; + const MinidumpCallback callback_; + void* const callback_context_; + + scoped_ptr<CrashGenerationClient> crash_generation_client_; + + MinidumpDescriptor minidump_descriptor_; + + // Must be volatile. The compiler is unaware of the code which runs in + // the signal handler which reads this variable. Without volatile the + // compiler is free to optimise away writes to this variable which it + // believes are never read. + volatile HandlerCallback crash_handler_; + + // We need to explicitly enable ptrace of parent processes on some + // kernels, but we need to know the PID of the cloned process before we + // can do this. We create a pipe which we can use to block the + // cloned process after creating it, until we have explicitly enabled + // ptrace. This is used to store the file descriptors for the pipe + int fdes[2] = {-1, -1}; + + // Callers can add extra info about mappings for cases where the + // dumper code cannot extract enough information from /proc/<pid>/maps. + MappingList mapping_list_; + + // Callers can request additional memory regions to be included in + // the dump. + AppMemoryList app_memory_list_; +}; + +typedef bool (*FirstChanceHandler)(int, siginfo_t*, void*); +void SetFirstChanceExceptionHandler(FirstChanceHandler callback); + +} // namespace google_breakpad + +#endif // CLIENT_LINUX_HANDLER_EXCEPTION_HANDLER_H_ |