/* exceptions.cc Copyright 1996, 1997, 1998, 1999, 2000 Cygnus Solutions. This file is part of Cygwin. This software is a copyrighted work licensed under the terms of the Cygwin license. Please consult the file "CYGWIN_LICENSE" for details. */ #include #include #define Win32_Winsock #include "winsup.h" #include "exceptions.h" #undef DECLSPEC_IMPORT #define DECLSPEC_IMPORT #include #include "autoload.h" #include "sync.h" char debugger_command[2 * MAX_PATH + 20]; extern "C" { static int handle_exceptions (EXCEPTION_RECORD *, void *, CONTEXT *, void *); extern void sigreturn (); extern void sigdelayed (); extern void siglast (); extern DWORD __sigfirst, __siglast; }; static BOOL WINAPI ctrl_c_handler (DWORD); static void really_exit (int); static char windows_system_directory[1024]; static size_t windows_system_directory_length; /* This is set to indicate that we have already exited. */ static NO_COPY int exit_already = 0; static NO_COPY muto *mask_sync = NULL; HMODULE cygwin_hmodule; HANDLE NO_COPY console_handler_thread_waiter = NULL; static const struct { unsigned int code; const char *name; } status_info[] NO_COPY = { #define X(s) s, #s { X (STATUS_ABANDONED_WAIT_0) }, { X (STATUS_ACCESS_VIOLATION) }, { X (STATUS_ARRAY_BOUNDS_EXCEEDED) }, { X (STATUS_BREAKPOINT) }, { X (STATUS_CONTROL_C_EXIT) }, { X (STATUS_DATATYPE_MISALIGNMENT) }, { X (STATUS_FLOAT_DENORMAL_OPERAND) }, { X (STATUS_FLOAT_DIVIDE_BY_ZERO) }, { X (STATUS_FLOAT_INEXACT_RESULT) }, { X (STATUS_FLOAT_INVALID_OPERATION) }, { X (STATUS_FLOAT_OVERFLOW) }, { X (STATUS_FLOAT_STACK_CHECK) }, { X (STATUS_FLOAT_UNDERFLOW) }, { X (STATUS_GUARD_PAGE_VIOLATION) }, { X (STATUS_ILLEGAL_INSTRUCTION) }, { X (STATUS_INTEGER_DIVIDE_BY_ZERO) }, { X (STATUS_INTEGER_OVERFLOW) }, { X (STATUS_INVALID_DISPOSITION) }, { X (STATUS_IN_PAGE_ERROR) }, { X (STATUS_NONCONTINUABLE_EXCEPTION) }, { X (STATUS_NO_MEMORY) }, { X (STATUS_PENDING) }, { X (STATUS_PRIVILEGED_INSTRUCTION) }, { X (STATUS_SINGLE_STEP) }, { X (STATUS_STACK_OVERFLOW) }, { X (STATUS_TIMEOUT) }, { X (STATUS_USER_APC) }, { X (STATUS_WAIT_0) }, { 0, 0 } #undef X }; /* Initialization code. */ #ifdef __i386__ // Set up the exception handler for the current thread. The PowerPC & Mips // use compiler generated tables to set up the exception handlers for each // region of code, and the kernel walks the call list until it finds a region // of code that handles exceptions. The x86 on the other hand uses segment // register fs, offset 0 to point to the current exception handler. asm (".equ __except_list,0"); extern exception_list *_except_list asm ("%fs:__except_list"); static void init_exception_handler (exception_list *el) { el->handler = handle_exceptions; el->prev = _except_list; _except_list = el; } #define INIT_EXCEPTION_HANDLER(el) init_exception_handler (el) #endif void set_console_handler () { /* Initialize global security attribute stuff */ sec_none.nLength = sec_none_nih.nLength = sec_all.nLength = sec_all_nih.nLength = sizeof (SECURITY_ATTRIBUTES); sec_none.bInheritHandle = sec_all.bInheritHandle = TRUE; sec_none_nih.bInheritHandle = sec_all_nih.bInheritHandle = FALSE; sec_none.lpSecurityDescriptor = sec_none_nih.lpSecurityDescriptor = NULL; sec_all.lpSecurityDescriptor = sec_all_nih.lpSecurityDescriptor = get_null_sd (); /* Allocate the event needed for ctrl_c_handler synchronization with wait_sig. */ if (!console_handler_thread_waiter) CreateEvent (&sec_none_nih, TRUE, TRUE, NULL); (void) SetConsoleCtrlHandler (ctrl_c_handler, FALSE); if (!SetConsoleCtrlHandler (ctrl_c_handler, TRUE)) system_printf ("SetConsoleCtrlHandler failed, %E"); } extern "C" void init_exceptions (exception_list *el) { #ifdef INIT_EXCEPTION_HANDLER INIT_EXCEPTION_HANDLER (el); #endif } extern "C" void error_start_init (const char *buf) { if (!buf || !*buf) { debugger_command[0] = '\0'; return; } char myself_posix_name[MAX_PATH]; /* FIXME: gdb cannot use win32 paths, but what if debugger isn't gdb? */ cygwin_conv_to_posix_path (myself->progname, myself_posix_name); __small_sprintf (debugger_command, "%s %s", buf, myself_posix_name); } /* Utilities for dumping the stack, etc. */ static void exception (EXCEPTION_RECORD *e, CONTEXT *in) { const char *exception_name = 0; if (e) { for (int i = 0; status_info[i].name; i++) { if (status_info[i].code == e->ExceptionCode) { exception_name = status_info[i].name; break; } } } #ifdef __i386__ #define HAVE_STATUS if (exception_name) small_printf ("Exception: %s at eip=%08x\r\n", exception_name, in->Eip); else small_printf ("Exception %d at eip=%08x\r\n", e->ExceptionCode, in->Eip); small_printf ("eax=%08x ebx=%08x ecx=%08x edx=%08x esi=%08x edi=%08x\r\n", in->Eax, in->Ebx, in->Ecx, in->Edx, in->Esi, in->Edi); small_printf ("ebp=%08x esp=%08x program=%s\r\n", in->Ebp, in->Esp, myself->progname); small_printf ("cs=%04x ds=%04x es=%04x fs=%04x gs=%04x ss=%04x\r\n", in->SegCs, in->SegDs, in->SegEs, in->SegFs, in->SegGs, in->SegSs); #endif #ifndef HAVE_STATUS system_printf ("Had an exception"); #endif } extern "C" { static LPVOID __stdcall sfta(HANDLE, DWORD) { return NULL; } static DWORD __stdcall sgmb(HANDLE, DWORD) { return 4; } #ifdef __i386__ /* Print a stack backtrace. */ #define HAVE_STACK_TRACE /* Set from CYGWIN environment variable if want to use old method. */ BOOL NO_COPY oldstack = 0; /* The function used to load the imagehlp DLL. Returns TRUE if the DLL was found. */ static LoadDLLinitfunc (imagehlp) { imagehlp_handle = LoadLibrary ("imagehlp.dll"); return !!imagehlp_handle; } LoadDLLinit (imagehlp) /* Set up storage for imagehlp.dll autoload */ LoadDLLfunc (StackWalk, StackWalk@36, imagehlp) /* A class for manipulating the stack. */ class stack_info { int first_time; /* True if just starting to iterate. */ HANDLE hproc; /* Handle of process to inspect. */ HANDLE hthread; /* Handle of thread to inspect. */ int (stack_info::*get) (HANDLE, HANDLE); /* Gets the next stack frame */ public: STACKFRAME sf; /* For storing the stack information */ int walk (HANDLE, HANDLE); /* Uses the StackWalk function */ int brute_force (HANDLE, HANDLE); /* Uses the "old" method */ void init (CONTEXT *); /* Called the first time that stack info is needed */ /* The constructor remembers hproc and hthread and determines which stack walking method to use */ stack_info (int use_old_stack, HANDLE hp, HANDLE ht): hproc(hp), hthread(ht) { if (!use_old_stack && LoadDLLinitnow (imagehlp)) get = &stack_info::walk; else get = &stack_info::brute_force; } /* Postfix ++ iterates over the stack, returning zero when nothing is left. */ int operator ++(int) { return (this->*get) (hproc, hthread); } }; /* The number of parameters used in STACKFRAME */ #define NPARAMS (sizeof(thestack->sf.Params) / sizeof(thestack->sf.Params[0])) /* This is the main stack frame info for this process. */ static stack_info *thestack = NULL; static signal_dispatch sigsave; /* Initialize everything needed to start iterating. */ void stack_info::init (CONTEXT *cx) { first_time = 1; memset (&sf, 0, sizeof(sf)); sf.AddrPC.Offset = cx->Eip; sf.AddrPC.Mode = AddrModeFlat; sf.AddrStack.Offset = cx->Esp; sf.AddrStack.Mode = AddrModeFlat; sf.AddrFrame.Offset = cx->Ebp; sf.AddrFrame.Mode = AddrModeFlat; } /* Walk the stack by looking at successive stored 'bp' frames. This is not foolproof. */ int stack_info::brute_force (HANDLE, HANDLE) { char **ebp; if (first_time) /* Everything is filled out already */ ebp = (char **) sf.AddrFrame.Offset; else if ((ebp = (char **) *(char **) sf.AddrFrame.Offset) != NULL) { sf.AddrFrame.Offset = (DWORD) ebp; sf.AddrPC.Offset = sf.AddrReturn.Offset; } else return 0; first_time = 0; if (!sf.AddrPC.Offset) return 0; /* stack frames are exhausted */ /* The return address always follows the stack pointer */ sf.AddrReturn.Offset = (DWORD) *++ebp; /* The arguments follow the return address */ for (unsigned i = 0; i < NPARAMS; i++) sf.Params[i] = (DWORD) *++ebp; return 1; } /* Use Win32 StackWalk() API to display the stack. This is theoretically more foolproof than the brute force method above. */ int stack_info::walk (HANDLE hproc, HANDLE hthread) { #ifdef SOMEDAY /* It would be nice to get more information (like DLL symbols and module name) for each stack frame but in order to do that we have to call SymInitialize. It doesn't seem to be possible to do this inside of an excaption handler for some reason. */ static int initialized = 0; if (!initialized && !SymInitialize(hproc, NULL, TRUE)) small_printf("SymInitialize error, %E\n"); initialized = 1; #endif return StackWalk (IMAGE_FILE_MACHINE_I386, hproc, hthread, &sf, NULL, NULL, sfta, sgmb, NULL) && !!sf.AddrFrame.Offset; } /* Dump the stack using either the old method or the new Win32 API method */ void stack (HANDLE hproc, HANDLE hthread, CONTEXT *cx) { int i; /* Set this up if it's the first time. */ if (!thestack) thestack = new stack_info (oldstack, hproc, hthread); thestack->init (cx); /* Initialize from the input CONTEXT */ small_printf ("Stack trace:\r\nFrame Function Args\r\n"); for (i = 0; i < 16 && (*thestack)++ ; i++) { small_printf ("%08x %08x ", thestack->sf.AddrFrame.Offset, thestack->sf.AddrPC.Offset); for (unsigned j = 0; j < NPARAMS; j++) small_printf ("%s%08x", j == 0 ? " (" : ", ", thestack->sf.Params[j]); small_printf (")\r\n"); } small_printf ("End of stack trace%s", i == 16 ? " (more stack frames may be present)" : ""); } /* Temporary (?) function for external callers to get a stack dump */ extern "C" void cygwin_stackdump() { CONTEXT c; c.ContextFlags = CONTEXT_FULL; HANDLE h1 = GetCurrentProcess (); HANDLE h2 = GetCurrentThread (); GetThreadContext (h2, &c); stack(h1, h2, &c); } static int NO_COPY keep_looping = 0; extern "C" int try_to_debug () { debug_printf ("debugger_command %s", debugger_command); if (*debugger_command == '\0') return 0; __small_sprintf (strchr (debugger_command, '\0'), " %u", GetCurrentProcessId ()); BOOL dbg; PROCESS_INFORMATION pi = {NULL, 0, 0, 0}; STARTUPINFO si = {0, NULL, NULL, NULL, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, NULL, NULL}; si.lpReserved = NULL; si.lpDesktop = NULL; si.dwFlags = 0; si.cb = sizeof (si); /* FIXME: need to know handles of all running threads to suspend_all_threads_except (current_thread_id); */ /* if any of these mutexes is owned, we will fail to start any cygwin app until trapped app exits */ ReleaseMutex (pinfo_mutex); ReleaseMutex (title_mutex); dbg = CreateProcess (NULL, debugger_command, NULL, NULL, FALSE, CREATE_NEW_CONSOLE | CREATE_NEW_PROCESS_GROUP, NULL, NULL, &si, &pi); if (!dbg) { system_printf ("Failed to start debugger: %E"); /* FIXME: need to know handles of all running threads to resume_all_threads_except (current_thread_id); */ } else { keep_looping = 1; while (keep_looping) Sleep (10000); } return 0; } void stackdump (HANDLE hproc, HANDLE hthread, EXCEPTION_RECORD *e, CONTEXT *in) { char *p; if (myself->progname[0]) { /* write to progname.stackdump if possible */ if ((p = strrchr (myself->progname, '\\'))) p++; else p = myself->progname; char corefile[strlen(p) + sizeof(".stackdump")]; __small_sprintf (corefile, "%s.stackdump", p); HANDLE h = CreateFile (corefile, GENERIC_WRITE, 0, &sec_none_nih, CREATE_ALWAYS, 0, 0); if (h != INVALID_HANDLE_VALUE) { system_printf ("Dumping stack trace to %s", corefile); SetStdHandle (STD_ERROR_HANDLE, h); } } if (e) exception (e, in); stack (hproc, hthread, in); } /* Main exception handler. */ static int handle_exceptions (EXCEPTION_RECORD *e, void *, CONTEXT *in, void *) { int sig; /* If we've already exited, don't do anything here. Returning 1 tells Windows to keep looking for an exception handler. */ if (exit_already) return 1; /* Coerce win32 value to posix value. */ switch (e->ExceptionCode) { case STATUS_FLOAT_DENORMAL_OPERAND: case STATUS_FLOAT_DIVIDE_BY_ZERO: case STATUS_FLOAT_INEXACT_RESULT: case STATUS_FLOAT_INVALID_OPERATION: case STATUS_FLOAT_OVERFLOW: case STATUS_FLOAT_STACK_CHECK: case STATUS_FLOAT_UNDERFLOW: case STATUS_INTEGER_DIVIDE_BY_ZERO: case STATUS_INTEGER_OVERFLOW: sig = SIGFPE; break; case STATUS_ILLEGAL_INSTRUCTION: case STATUS_PRIVILEGED_INSTRUCTION: case STATUS_NONCONTINUABLE_EXCEPTION: sig = SIGILL; break; case STATUS_TIMEOUT: sig = SIGALRM; break; case STATUS_ACCESS_VIOLATION: case STATUS_DATATYPE_MISALIGNMENT: case STATUS_ARRAY_BOUNDS_EXCEEDED: case STATUS_GUARD_PAGE_VIOLATION: case STATUS_IN_PAGE_ERROR: case STATUS_NO_MEMORY: case STATUS_INVALID_DISPOSITION: case STATUS_STACK_OVERFLOW: sig = SIGSEGV; break; case STATUS_CONTROL_C_EXIT: sig = SIGINT; break; case STATUS_INVALID_HANDLE: /* CloseHandle will throw this exception if it is given an invalid handle. We don't care about the exception; we just want CloseHandle to return an error. This can be revisited if gcc ever supports Windows style structured exception handling. */ return 0; default: /* If we don't recognize the exception, we have to assume that we are doing structured exception handling, and we let something else handle it. */ return 1; } debug_printf ("In cygwin_except_handler exc %p at %p sp %p", e->ExceptionCode, in->Eip, in->Esp); debug_printf ("In cygwin_except_handler sig = %d at %p", sig, in->Eip); if (myself->getsig(sig).sa_mask & SIGTOMASK (sig)) syscall_printf ("signal %d, masked %p", sig, myself->getsig(sig).sa_mask); if (!myself->progname[0] || (void *) myself->getsig(sig).sa_handler == (void *) SIG_DFL || (void *) myself->getsig(sig).sa_handler == (void *) SIG_IGN || (void *) myself->getsig(sig).sa_handler == (void *) SIG_ERR) { static NO_COPY int traced = 0; /* Print the exception to the console */ if (e) { for (int i = 0; status_info[i].name; i++) { if (status_info[i].code == e->ExceptionCode) { system_printf ("Exception: %s", status_info[i].name); break; } } } /* Another exception could happen while tracing or while exiting. Only do this once. */ if (traced++) system_printf ("Error while dumping state (probably corrupted stack)"); else { HANDLE hthread; DuplicateHandle (hMainProc, GetCurrentThread (), hMainProc, &hthread, 0, FALSE, DUPLICATE_SAME_ACCESS); stackdump (hMainProc, hthread, e, in); } try_to_debug (); really_exit (EXIT_SIGNAL | sig); } debug_printf ("In cygwin_except_handler calling %p", myself->getsig(sig).sa_handler); DWORD *bp = (DWORD *)in->Esp; for (DWORD *bpend = bp - 8; bp > bpend; bp--) if (*bp == in->SegCs && bp[-1] == in->Eip) { bp -= 2; break; } in->Ebp = (DWORD) bp; sigsave.cx = in; sig_send (NULL, sig); // Signal myself sigsave.cx = NULL; return 0; } #endif /* __i386__ */ #ifndef HAVE_STACK_TRACE void stack (void) { system_printf ("Stack trace not yet supported on this machine."); } #endif } /* Utilities to call a user supplied exception handler. */ #define SIG_NONMASKABLE (SIGTOMASK (SIGCONT) | SIGTOMASK (SIGKILL) | SIGTOMASK (SIGSTOP)) #ifdef __i386__ #define HAVE_CALL_HANDLER /* Non-raceable sigsuspend * Note: This implementation is based on the Single UNIX Specification * man page. This indicates that sigsuspend always returns -1 and that * attempts to block unblockable signals will be silently ignored. * This is counter to what appears to be documented in some UNIX * man pages, e.g. Linux. */ int __stdcall handle_sigsuspend (sigset_t tempmask) { sigset_t oldmask = myself->getsigmask (); // Remember for restoration set_process_mask (tempmask & ~SIG_NONMASKABLE);// Let signals we're // interested in through. sigproc_printf ("old mask %x, new mask %x", oldmask, tempmask); WaitForSingleObject (signal_arrived, INFINITE); set_sig_errno (EINTR); // Per POSIX /* A signal dispatch function will have been added to our stack and will be hit eventually. Set the old mask to be restored when the signal handler returns. */ sigsave.oldmask = oldmask; // Will be restored by signal handler return -1; } extern DWORD exec_exit; // Possible exit value for exec extern int pending_signals; int interruptible (DWORD pc) { #if 0 DWORD pchigh = pc & 0xf0000000; return ((pc >= (DWORD) &__sigfirst) && (pc <= (DWORD) &__siglast)) || !(pchigh == 0xb0000000 || pchigh == 0x70000000 || pchigh == 0x60000000); #else int res = 1; if ((pc >= (DWORD) &__sigfirst) && (pc <= (DWORD) &__siglast)) res = 0; else { MEMORY_BASIC_INFORMATION m; memset (&m, 0, sizeof m); if (!VirtualQuery ((LPCVOID) pc, &m, sizeof m)) sigproc_printf ("couldn't get memory info, %E"); char *checkdir = (char *) alloca (windows_system_directory_length); # define h ((HMODULE) m.AllocationBase) if (h == cygwin_hmodule) res = 0; else if (!GetModuleFileName (h, checkdir, windows_system_directory_length)) res = 0; else res = !strncasematch (windows_system_directory, checkdir, windows_system_directory_length); } sigproc_printf ("interruptible %d", res); return res; # undef h #endif } static void __stdcall interrupt_setup (int sig, struct sigaction& siga, void *handler, DWORD retaddr) { sigsave.retaddr = retaddr; sigsave.oldmask = myself->getsigmask (); // Remember for restoration /* FIXME: Not multi-thread aware */ set_process_mask (myself->getsigmask () | siga.sa_mask | SIGTOMASK (sig)); sigsave.func = (void (*)(int)) handler; sigsave.sig = sig; sigsave.saved_errno = -1; // Flag: no errno to save } static void interrupt_now (CONTEXT *ctx, int sig, struct sigaction& siga, void *handler) { interrupt_setup (sig, siga, handler, ctx->Eip); ctx->Eip = (DWORD) sigdelayed; SetThreadContext (myself->getthread2signal(), ctx); /* Restart the thread */ } static int interrupt_on_return (CONTEXT *ctx, int sig, struct sigaction& siga, void *handler) { int i; if (sigsave.sig) return 0; /* Already have a signal stacked up */ /* Set this up if it's the first time. */ /* FIXME: Eventually augment to handle more than one thread */ if (!thestack) thestack = new stack_info (oldstack, hMainProc, hMainThread); thestack->init (ctx); /* Initialize from the input CONTEXT */ for (i = 0; i < 32 && (*thestack)++ ; i++) if (interruptible (thestack->sf.AddrReturn.Offset)) { DWORD *addr_retaddr = ((DWORD *)thestack->sf.AddrFrame.Offset) + 1; if (*addr_retaddr == thestack->sf.AddrReturn.Offset) { interrupt_setup (sig, siga, handler, *addr_retaddr); *addr_retaddr = (DWORD) sigdelayed; } break; } return 1; } extern "C" void __stdcall set_sig_errno (int e) { set_errno (e); sigsave.saved_errno = e; debug_printf ("errno %d", e); } static int call_handler (int sig, struct sigaction& siga, void *handler) { CONTEXT *cx, orig; int interrupted = 1; HANDLE hth; int res; if (hExeced != NULL && hExeced != INVALID_HANDLE_VALUE) { SetEvent (signal_arrived); // For an EINTR case sigproc_printf ("armed signal_arrived"); exec_exit = sig; // Maybe we'll exit with this value goto out1; } hth = myself->getthread2signal (); /* Suspend the thread which will receive the signal. But first ensure that this thread doesn't have the sync_proc_subproc and mask_sync mutos, since we need those (hack alert). If the thread-to-be-suspended has either of these mutos, enter a busy loop until it is released. If the thread is already suspended (which should never occur) then just queue the signal. */ for (;;) { sigproc_printf ("suspending mainthread"); res = SuspendThread (hth); /* FIXME: Make multi-thread aware */ for (muto *m = muto_start.next; m != NULL; m = m->next) if (m->unstable () || m->owner () == maintid) goto keep_looping; break; keep_looping: sigproc_printf ("suspended thread owns a muto"); if (res) goto set_pending; ResumeThread (hth); Sleep (0); } sigproc_printf ("SuspendThread returned %d", res); if (sigsave.cx) { cx = sigsave.cx; sigsave.cx = NULL; } else { cx = &orig; /* FIXME - this does not preserve FPU state */ orig.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER; if (!GetThreadContext (hth, cx)) { system_printf ("couldn't get context of main thread, %E"); goto out; } } if (cx == &orig && interruptible (cx->Eip)) interrupt_now (cx, sig, siga, handler); else if (!interrupt_on_return (cx, sig, siga, handler)) { set_pending: pending_signals = 1; /* FIXME: Probably need to be more tricky here */ sig_set_pending (sig); interrupted = 0; } if (interrupted) { (void) SetEvent (signal_arrived); // For an EINTR case sigproc_printf ("armed signal_arrived %p, res %d", signal_arrived, res); /* Clear any waiting threads prior to dispatching to handler function */ proc_subproc(PROC_CLEARWAIT, 1); } out: res = ResumeThread (hth); sigproc_printf ("ResumeThread returned %d", res); out1: sigproc_printf ("returning %d", interrupted); return interrupted; } #endif /* i386 */ #ifndef HAVE_CALL_HANDLER #error "Need to supply machine dependent call_handler" #endif /* Keyboard interrupt handler. */ static BOOL WINAPI ctrl_c_handler (DWORD type) { if (type == CTRL_LOGOFF_EVENT) return TRUE; /* Wait for sigproc_init to tell us that it's safe to send something. This event will always be in a signalled state when wait_sig is ready to process signals. */ (void) WaitForSingleObject (console_handler_thread_waiter, 5000); if ((type == CTRL_CLOSE_EVENT) || (type == CTRL_SHUTDOWN_EVENT)) /* Return FALSE to prevent an "End task" dialog box from appearing for each Cygwin process window that's open when the computer is shut down or console window is closed. */ { sig_send (NULL, SIGHUP); return FALSE; } tty_min *t = cygwin_shared->tty.get_tty(myself->ctty); /* Ignore this if we're not the process group lead since it should be handled *by* the process group leader. */ if (t->getpgid () != myself->pid || (GetTickCount () - t->last_ctrl_c) < MIN_CTRL_C_SLOP) return TRUE; else /* Otherwise we just send a SIGINT to the process group and return TRUE (to indicate that we have handled the signal). At this point, type should be a CTRL_C_EVENT or CTRL_BREAK_EVENT. */ { t->last_ctrl_c = GetTickCount (); kill (-myself->pid, SIGINT); t->last_ctrl_c = GetTickCount (); return TRUE; } } /* Set the signal mask for this process. * Note that some signals are unmaskable, as in UNIX. */ extern "C" void __stdcall set_process_mask (sigset_t newmask) { extern DWORD sigtid; mask_sync->acquire (INFINITE); sigset_t oldmask = myself->getsigmask (); newmask &= ~SIG_NONMASKABLE; sigproc_printf ("old mask = %x, new mask = %x", myself->getsigmask (), newmask); myself->setsigmask (newmask); // Set a new mask mask_sync->release (); if (oldmask != newmask && GetCurrentThreadId () != sigtid) sig_dispatch_pending (); return; } extern "C" { static void sig_handle_tty_stop (int sig) { #if 0 HANDLE waitbuf[2]; /* Be sure that process's main thread isn't an owner of vital mutex to prevent cygwin subsystem lockups */ waitbuf[0] = pinfo_mutex; waitbuf[1] = title_mutex; WaitForMultipleObjects (2, waitbuf, TRUE, INFINITE); ReleaseMutex (pinfo_mutex); ReleaseMutex (title_mutex); #endif myself->stopsig = sig; myself->process_state |= PID_STOPPED; /* See if we have a living parent. If so, send it a special signal. * It will figure out exactly which pid has stopped by scanning * its list of subprocesses. */ if (my_parent_is_alive ()) { pinfo *parent = procinfo(myself->ppid); sig_send (parent, __SIGCHILDSTOPPED); } sigproc_printf ("process %d stopped by signal %d, parent_alive %p", myself->pid, sig, parent_alive); /* There is a small race here with the above two mutexes */ SuspendThread (hMainThread); return; } } int __stdcall sig_handle (int sig) { int rc = 0; sigproc_printf ("signal %d", sig); struct sigaction thissig = myself->getsig(sig); void *handler = (void *) thissig.sa_handler; myself->rusage_self.ru_nsignals++; /* Clear pending SIGCONT on stop signals */ if (sig == SIGSTOP || sig == SIGTSTP || sig == SIGTTIN || sig == SIGTTOU) sig_clear (SIGCONT); if (sig == SIGKILL) goto exit_sig; if (sig == SIGSTOP) goto stop; /* FIXME: Should we still do this if SIGCONT has a handler? */ if (sig == SIGCONT) { myself->stopsig = 0; myself->process_state &= ~PID_STOPPED; /* Clear pending stop signals */ sig_clear (SIGSTOP); sig_clear (SIGTSTP); sig_clear (SIGTTIN); sig_clear (SIGTTOU); /* Windows 95 hangs on resuming non-suspended thread */ SuspendThread (hMainThread); while (ResumeThread (hMainThread) > 1) ; /* process pending signals */ sig_dispatch_pending (); } #if 0 char sigmsg[24]; __small_sprintf (sigmsg, "cygwin: signal %d\n", sig); OutputDebugString (sigmsg); #endif if (handler == (void *) SIG_DFL) { if (sig == SIGCHLD || sig == SIGIO || sig == SIGCONT || sig == SIGWINCH) { sigproc_printf ("default signal %d ignored", sig); goto done; } if (sig == SIGTSTP || sig == SIGTTIN || sig == SIGTTOU) goto stop; goto exit_sig; } if (handler == (void *) SIG_IGN) { sigproc_printf ("signal %d ignored", sig); goto done; } if (handler == (void *) SIG_ERR) goto exit_sig; if ((sig == SIGCHLD) && (thissig.sa_flags & SA_NOCLDSTOP)) goto done; goto dosig; stop: handler = (void *) sig_handle_tty_stop; dosig: /* Dispatch to the appropriate function. */ sigproc_printf ("signal %d, about to call %p", sig, thissig.sa_handler); rc = call_handler (sig, thissig, handler); done: sigproc_printf ("returning %d", rc); return rc; exit_sig: if (sig == SIGQUIT || sig == SIGABRT) { stackdump (NULL, NULL, NULL, NULL); try_to_debug (); } sigproc_printf ("signal %d, about to call do_exit", sig); TerminateThread (hMainThread, 0); /* FIXME: This just works around the problem so that we don't attempt to use a resource lock when exiting. */ user_data->resourcelocks->Delete(); user_data->resourcelocks->Init(); do_exit (EXIT_SIGNAL | (sig << 8)); /* Never returns */ } /* Cover function to `do_exit' to handle exiting even in presence of more exceptions. We use to call exit, but a SIGSEGV shouldn't cause atexit routines to run. */ static void really_exit (int rc) { /* If the exception handler gets a trap, we could recurse awhile. If this is non-zero, skip the cleaning up and exit NOW. */ if (exit_already++) { /* We are going down - reset our process_state without locking. */ myself->record_death (FALSE); ExitProcess (rc); } do_exit (rc); } HANDLE NO_COPY pinfo_mutex = NULL; HANDLE NO_COPY title_mutex = NULL; void events_init (void) { /* pinfo_mutex protects access to process table */ if (!(pinfo_mutex = CreateMutex (&sec_all_nih, FALSE, shared_name ("pinfo_mutex", 0)))) api_fatal ("catastrophic failure - unable to create pinfo_mutex, %E"); ProtectHandle (pinfo_mutex); /* title_mutex protects modification of console title. It's neccessary while finding console window handle */ if (!(title_mutex = CreateMutex (&sec_all_nih, FALSE, shared_name ("title_mutex", 0)))) api_fatal ("can't create title mutex, %E"); ProtectHandle (title_mutex); mask_sync = new_muto (FALSE, NULL); windows_system_directory[0] = '\0'; (void) GetSystemDirectory (windows_system_directory, sizeof (windows_system_directory) - 2); char *end = strchr (windows_system_directory, '\0'); if (end == windows_system_directory) api_fatal ("can't find windows system directory"); if (end[-1] != '\\') { *end++ = '\\'; *end = '\0'; } windows_system_directory_length = end - windows_system_directory; debug_printf ("windows_system_directory '%s', windows_system_directory_length %d", windows_system_directory, windows_system_directory_length); debug_printf ("cygwin_hmodule %p", cygwin_hmodule); } void events_terminate (void) { //CloseHandle (pinfo_mutex); // Use implicit close on exit to avoid race ForceCloseHandle (title_mutex); exit_already = 1; } #define pid_offset (unsigned)(((pinfo *)NULL)->pid) extern "C" { static void __stdcall reset_signal_arrived () __attribute__ ((unused)); static void __stdcall reset_signal_arrived () { (void) ResetEvent (signal_arrived); sigproc_printf ("reset signal_arrived"); } void unused_sig_wrapper() { /* Signal cleanup stuff. Cleans up stack (too bad that we didn't prototype signal handlers as __stdcall), calls _set_process_mask to restore any mask, restores any potentially clobbered registered and returns to orignal caller. */ __asm__ volatile (" .text .globl __raise __raise: pushl %%ebp movl %%esp,%%ebp movl 8(%%ebp),%%eax pushl %%eax movl $_myself,%%eax pushl %6(%%eax) call __kill mov %%ebp,%%esp popl %%ebp ret _sigreturn: addl $4,%%esp call _set_process_mask@4 popl %%eax # saved errno testl %%eax,%%eax # Is it < 0 jl 1f # yup. ignore it movl %1,%%ebx movl %%eax,(%%ebx) 1: popl %%eax popl %%ebx popl %%ecx popl %%edx popl %%edi popl %%esi popf ret _sigdelayed: pushl %2 # original return address pushf pushl %%esi pushl %%edi pushl %%edx pushl %%ecx pushl %%ebx pushl %%eax pushl %7 # saved errno pushl %3 # oldmask pushl %4 # signal argument pushl $_sigreturn call _reset_signal_arrived@0 # pushl _signal_arrived # Everybody waiting for this should # call _ResetEvent@4 # have woken up by now. movl $0,%0 cmpl $0,_pending_signals je 2f ___sigfirst: pushl $0 call _sig_dispatch_pending@4 ___siglast: 2: jmp *%5 " : "=m" (sigsave.sig) : "m" (&_impure_ptr->_errno), "g" (sigsave.retaddr), "g" (sigsave.oldmask), "g" (sigsave.sig), "g" (sigsave.func), "o" (pid_offset), "g" (sigsave.saved_errno) ); } }