diff --git a/CMakeModules/DuckStationDependencies.cmake b/CMakeModules/DuckStationDependencies.cmake index f2a261989..1f4864076 100644 --- a/CMakeModules/DuckStationDependencies.cmake +++ b/CMakeModules/DuckStationDependencies.cmake @@ -54,10 +54,7 @@ if(LINUX) endif() if(NOT WIN32 AND NOT APPLE) - find_package(Libbacktrace) - if(NOT LIBBACKTRACE_FOUND) - message(WARNING "libbacktrace not found, crashes will not produce backtraces.") - endif() + find_package(Libbacktrace REQUIRED) endif() if(APPLE) diff --git a/src/common/crash_handler.cpp b/src/common/crash_handler.cpp index 076136c39..c3efd94f6 100644 --- a/src/common/crash_handler.cpp +++ b/src/common/crash_handler.cpp @@ -169,7 +169,7 @@ void CrashHandler::WriteDumpForCaller() WriteMinidumpAndCallstack(nullptr); } -#elif defined(ENABLE_LIBBACKTRACE) +#elif !defined(__APPLE__) #include #include @@ -194,15 +194,12 @@ static void AllocateBuffer(BacktraceBuffer* buf); static void FreeBuffer(BacktraceBuffer* buf); static void AppendToBuffer(BacktraceBuffer* buf, const char* format, ...); static int BacktraceFullCallback(void* data, uintptr_t pc, const char* filename, int lineno, const char* function); -static void CallExistingSignalHandler(int signal, siginfo_t* siginfo, void* ctx); -static void CrashSignalHandler(int signal, siginfo_t* siginfo, void* ctx); +static void LogCallstack(int signal, const void* exception_pc); static std::recursive_mutex s_crash_mutex; static bool s_in_signal_handler = false; static backtrace_state* s_backtrace_state = nullptr; -static struct sigaction s_old_sigbus_action; -static struct sigaction s_old_sigsegv_action; } // namespace CrashHandler const char* CrashHandler::GetSignalName(int signal_no) @@ -268,23 +265,25 @@ int CrashHandler::BacktraceFullCallback(void* data, uintptr_t pc, const char* fi return 0; } -void CrashHandler::CallExistingSignalHandler(int signal, siginfo_t* siginfo, void* ctx) +void CrashHandler::LogCallstack(int signal, const void* exception_pc) { - const struct sigaction& sa = (signal == SIGBUS) ? s_old_sigbus_action : s_old_sigsegv_action; - if (sa.sa_flags & SA_SIGINFO) - { - sa.sa_sigaction(signal, siginfo, ctx); - } - else if (sa.sa_handler == SIG_DFL) - { - // Re-raising the signal would just queue it, and since we'd restore the handler back to us, - // we'd end up right back here again. So just abort, because that's probably what it'd do anyway. - abort(); - } - else if (sa.sa_handler != SIG_IGN) - { - sa.sa_handler(signal); - } + BacktraceBuffer buf; + AllocateBuffer(&buf); + if (signal != 0 || exception_pc) + AppendToBuffer(&buf, "*************** Unhandled %s at %p ***************\n", GetSignalName(signal), exception_pc); + else + AppendToBuffer(&buf, "*******************************************************************\n"); + + const int rc = backtrace_full(s_backtrace_state, 0, BacktraceFullCallback, nullptr, &buf); + if (rc != 0) + AppendToBuffer(&buf, " backtrace_full() failed: %d\n"); + + AppendToBuffer(&buf, "*******************************************************************\n"); + + if (buf.used > 0) + write(STDERR_FILENO, buf.buffer, buf.used); + + FreeBuffer(&buf); } void CrashHandler::CrashSignalHandler(int signal, siginfo_t* siginfo, void* ctx) @@ -306,27 +305,17 @@ void CrashHandler::CrashSignalHandler(int signal, siginfo_t* siginfo, void* ctx) void* const exception_pc = nullptr; #endif - BacktraceBuffer buf; - AllocateBuffer(&buf); - AppendToBuffer(&buf, "*************** Unhandled %s at %p ***************\n", GetSignalName(signal), exception_pc); - - const int rc = backtrace_full(s_backtrace_state, 0, BacktraceFullCallback, nullptr, &buf); - if (rc != 0) - AppendToBuffer(&buf, " backtrace_full() failed: %d\n"); - - AppendToBuffer(&buf, "*******************************************************************\n"); - - if (buf.used > 0) - write(STDERR_FILENO, buf.buffer, buf.used); - - FreeBuffer(&buf); + LogCallstack(signal, exception_pc); s_in_signal_handler = false; } - // Chances are we're not going to have anything else to call, but just in case. lock.unlock(); - CallExistingSignalHandler(signal, siginfo, ctx); + + // We can't continue from here. Just bail out and dump core. + std::fputs("Aborting application.\n", stderr); + std::fflush(stderr); + std::abort(); } bool CrashHandler::Install() @@ -341,9 +330,9 @@ bool CrashHandler::Install() sigemptyset(&sa.sa_mask); sa.sa_flags = SA_SIGINFO | SA_NODEFER; sa.sa_sigaction = CrashSignalHandler; - if (sigaction(SIGBUS, &sa, &s_old_sigbus_action) != 0) + if (sigaction(SIGBUS, &sa, nullptr) != 0) return false; - if (sigaction(SIGSEGV, &sa, &s_old_sigsegv_action) != 0) + if (sigaction(SIGSEGV, &sa, nullptr) != 0) return false; return true; @@ -355,6 +344,7 @@ void CrashHandler::SetWriteDirectory(std::string_view dump_directory) void CrashHandler::WriteDumpForCaller() { + LogCallstack(0, nullptr); } #else @@ -372,4 +362,12 @@ void CrashHandler::WriteDumpForCaller() { } +void CrashHandler::CrashSignalHandler(int signal, siginfo_t* siginfo, void* ctx) +{ + // We can't continue from here. Just bail out and dump core. + std::fputs("Aborting application.\n", stderr); + std::fflush(stderr); + std::abort(); +} + #endif diff --git a/src/common/crash_handler.h b/src/common/crash_handler.h index cc1b89dd0..0ca2a3a55 100644 --- a/src/common/crash_handler.h +++ b/src/common/crash_handler.h @@ -1,11 +1,21 @@ -// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin +// SPDX-FileCopyrightText: 2019-2024 Connor McLaughlin // SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0) #include "types.h" #include +#ifndef _WIN32 +#include +#endif + namespace CrashHandler { bool Install(); void SetWriteDirectory(std::string_view dump_directory); void WriteDumpForCaller(); + +#ifndef _WIN32 +// Allow crash handler to be invoked from a signal. +void CrashSignalHandler(int signal, siginfo_t* siginfo, void* ctx); +#endif + } // namespace CrashHandler diff --git a/src/util/page_fault_handler.cpp b/src/util/page_fault_handler.cpp index 0d809d9b1..0cb2d6daa 100644 --- a/src/util/page_fault_handler.cpp +++ b/src/util/page_fault_handler.cpp @@ -4,6 +4,7 @@ #include "page_fault_handler.h" #include "common/assert.h" +#include "common/crash_handler.h" #include "common/error.h" #include "common/log.h" @@ -14,7 +15,7 @@ #if defined(_WIN32) #include "common/windows_headers.h" -#elif defined(__linux__) || defined(__ANDROID__) +#elif defined(__linux__) #include #include #include @@ -139,54 +140,11 @@ bool PageFaultHandler::Install(Error* error) namespace PageFaultHandler { static void SignalHandler(int sig, siginfo_t* info, void* ctx); -static void CallExistingSignalHandler(int signal, siginfo_t* siginfo, void* ctx); - -static struct sigaction s_old_sigsegv_action; -#if defined(__APPLE__) || defined(__aarch64__) -static struct sigaction s_old_sigbus_action; -#endif } // namespace PageFaultHandler -void PageFaultHandler::CallExistingSignalHandler(int signal, siginfo_t* siginfo, void* ctx) -{ -#if defined(__aarch64__) - const struct sigaction& sa = (signal == SIGBUS) ? s_old_sigbus_action : s_old_sigsegv_action; -#elif defined(__APPLE__) - const struct sigaction& sa = s_old_sigbus_action; -#else - const struct sigaction& sa = s_old_sigsegv_action; -#endif - - if (sa.sa_flags & SA_SIGINFO) - { - sa.sa_sigaction(signal, siginfo, ctx); - } - else if (sa.sa_handler == SIG_DFL) - { - // Re-raising the signal would just queue it, and since we'd restore the handler back to us, - // we'd end up right back here again. So just abort, because that's probably what it'd do anyway. - abort(); - } - else if (sa.sa_handler != SIG_IGN) - { - sa.sa_handler(signal); - } -} - void PageFaultHandler::SignalHandler(int sig, siginfo_t* info, void* ctx) { - // Executing the handler concurrently from multiple threads wouldn't go down well. - std::unique_lock lock(s_exception_handler_mutex); - - // Prevent recursive exception filtering. - if (s_in_exception_handler) - { - lock.unlock(); - CallExistingSignalHandler(sig, info, ctx); - return; - } - -#if defined(__linux__) || defined(__ANDROID__) +#if defined(__linux__) void* const exception_address = reinterpret_cast(info->si_addr); #if defined(CPU_ARCH_X64) @@ -241,19 +199,26 @@ void PageFaultHandler::SignalHandler(int sig, siginfo_t* info, void* ctx) #endif - s_in_exception_handler = true; + // Executing the handler concurrently from multiple threads wouldn't go down well. + s_exception_handler_mutex.lock(); - const HandlerResult result = HandlePageFault(exception_pc, exception_address, is_write); - - s_in_exception_handler = false; + // Prevent recursive exception filtering. + HandlerResult result = HandlerResult::ExecuteNextHandler; + if (!s_in_exception_handler) + { + s_in_exception_handler = true; + result = HandlePageFault(exception_pc, exception_address, is_write); + s_in_exception_handler = false; + } + + s_exception_handler_mutex.unlock(); // Resumes execution right where we left off (re-executes instruction that caused the SIGSEGV). if (result == HandlerResult::ContinueExecution) return; - // Call old signal handler, which will likely dump core. - lock.unlock(); - CallExistingSignalHandler(sig, info, ctx); + // We couldn't handle it. Pass it off to the crash dumper. + CrashHandler::CrashSignalHandler(sig, info, ctx); } bool PageFaultHandler::Install(Error* error) @@ -270,14 +235,14 @@ bool PageFaultHandler::Install(Error* error) // Don't block the signal from executing recursively, we want to fire the original handler. sa.sa_flags |= SA_NODEFER; #endif - if (sigaction(SIGSEGV, &sa, &s_old_sigsegv_action) != 0) + if (sigaction(SIGSEGV, &sa, nullptr) != 0) { Error::SetErrno(error, "sigaction() for SIGSEGV failed: ", errno); return false; } #if defined(__APPLE__) || defined(__aarch64__) // MacOS uses SIGBUS for memory permission violations - if (sigaction(SIGBUS, &sa, &s_old_sigbus_action) != 0) + if (sigaction(SIGBUS, &sa, nullptr) != 0) { Error::SetErrno(error, "sigaction() for SIGBUS failed: ", errno); return false;