File indexing completed on 2024-05-12 15:56:59

 /*
  * SPDX-FileCopyrightText: 2022 Sharaf Zaman <shzam@sdf.org>
  *
  * SPDX-License-Identifier: LGPL-2.0-or-later
  */
 
 #include "KisAndroidCrashHandler.h"
 
 #include <QDateTime>
 #include <QMap>
 #include <QScopedPointer>
 #include <QStandardPaths>
 #include <QThread>
 #include <android/log.h>
 #include <array>
 #include <fcntl.h>
 #include <signal.h>
 #include <sstream>
 #include <unistd.h>
 #include <unwindstack/Regs.h>
 #include <unwindstack/Unwinder.h>
 
 #define CRASH_LOGGER(...) __android_log_print(ANDROID_LOG_WARN, "KisAndroidCrashHandler", __VA_ARGS__)
 
 namespace KisAndroidCrashHandler {
 
 static const std::array<int, 6> signals = {SIGABRT, SIGBUS, SIGFPE, SIGSEGV, SIGSYS, SIGTERM};
 static QMap<int, struct sigaction> g_old_actions;
 
 // we need to have keep this object alive
 static const std::string path =
     QString(QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + "/kritacrashlog.txt").toStdString();
 static const char *crashlog_path = path.c_str();
 
 static bool g_handling_crash = false;
 
 const char *get_signal_name(const int signo)
 {
     switch (signo) {
     case SIGABRT:
         return "SIGABRT";
     case SIGBUS:
         return "SIGBUS";
     case SIGFPE:
         return "SIGFPE";
     case SIGSEGV:
         return "SIGSEGV";
     case SIGSYS:
         return "SIGSYS";
     case SIGTERM:
         return "SIGTERM";
     default:
         return "?";
     }
 }
 
 void dump_backtrace(siginfo_t *info, void *ucontext)
 {
     QScopedPointer<unwindstack::Regs> regs;
     if (ucontext) {
         regs.reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(), ucontext));
     } else {
         regs.reset(unwindstack::Regs::CreateFromLocal());
     }
 
     unwindstack::UnwinderFromPid unwinder(256, getpid(), unwindstack::Regs::CurrentArch());
     if (!unwinder.Init()) {
         CRASH_LOGGER("Couldn't initialize the unwinder: %s\n", unwinder.LastErrorCodeString());
         return;
     }
 
     unwinder.SetRegs(regs.data());
     unwinder.Unwind();
 
     std::vector<unwindstack::FrameData> frames = unwinder.frames();
     if (frames.size() == 0) {
         CRASH_LOGGER("Couldn't unwind: %s\t code = %d\n", unwinder.LastErrorCodeString(), unwinder.LastErrorCode());
         return;
     }
 
     const int fd = open(crashlog_path, O_CREAT | O_APPEND | O_WRONLY, S_IRUSR | S_IWUSR);
 
     std::stringstream header;
     header << "********************** Dumping backtrace **********************\n"
            << "Signal: " << info->si_signo << " (" << get_signal_name(info->si_signo) << ")"
            << " (Code: " << info->si_code << ")"
            << " Time: " << QDateTime::currentDateTimeUtc().toString().toStdString().c_str()
            << "\n";
     write(fd, header.str().c_str(), header.str().size());
 
     for (size_t i = 0; i < frames.size(); ++i) {
         std::string frame = unwinder.FormatFrame(frames[i]) + "\n";
         write(fd, frame.c_str(), frame.size());
     }
     write(fd, "\n", 1);
     close(fd);
 }
 
 void crash_callback(int sig, siginfo_t *info, void *ucontext)
 {
     // to prevent second invocation of our signal handler
     if (g_handling_crash) {
         // uninstall the handler for the signal
         sigaction(sig, &g_old_actions[sig], nullptr);
         raise(sig);
         return;
     }
 
     g_handling_crash = true;
     dump_backtrace(info, ucontext);
 
     // uninstall the handler for the signal
     sigaction(sig, &g_old_actions[sig], nullptr);
 
     // invoke the previous handler
     // Some other implementations tend to make call to handler functions
     // directly, seemingly to not make another _slow_ syscall.
     raise(sig);
 }
 
 void handler_init()
 {
     // create an alternate stack to make sure we can handle overflows
     stack_t alternate_stack;
     alternate_stack.ss_flags = 0;
     alternate_stack.ss_size = SIGSTKSZ;
     if ((alternate_stack.ss_sp = malloc(SIGSTKSZ)) == nullptr) {
         CRASH_LOGGER("Couldn't allocate memory for alternate stack");
         return;
     }
 
     struct sigaction act = {};
     act.sa_sigaction = crash_callback;
     act.sa_flags = SA_SIGINFO | SA_ONSTACK;
     sigaltstack(&alternate_stack, nullptr);
 
     for (size_t i = 0; i < signals.size(); ++i) {
         sigaction(signals[i], &act, &g_old_actions[signals[i]]);
     }
 }
 
 } // namespace KisAndroidCrashHandler