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newlib-cygwin/winsup/cygwin/exceptions.cc

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/* 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 <stdio.h>
#include <errno.h>
#define Win32_Winsock
#include "winsup.h"
#include "exceptions.h"
#undef DECLSPEC_IMPORT
#define DECLSPEC_IMPORT
#include <imagehlp.h>
#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
}
#ifdef __i386__
/* Print a stack backtrace. */
#define HAVE_STACK_TRACE
/* 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. */
int walk (); /* Uses the "old" method */
public:
STACKFRAME sf; /* For storing the stack information */
void init (DWORD); /* Called the first time that stack info is needed */
stack_info (): first_time(1) {}
/* Postfix ++ iterates over the stack, returning zero when nothing is left. */
int operator ++(int) { return this->walk (); }
};
/* 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 NO_COPY stack_info thestack;
signal_dispatch NO_COPY sigsave;
/* Initialize everything needed to start iterating. */
void
stack_info::init (DWORD ebp)
{
first_time = 1;
memset (&sf, 0, sizeof(sf));
sf.AddrFrame.Offset = ebp;
sf.AddrPC.Offset = ((DWORD *) ebp)[1];
sf.AddrFrame.Mode = AddrModeFlat;
}
/* Walk the stack by looking at successive stored 'bp' frames.
This is not foolproof. */
int
stack_info::walk ()
{
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;
}
/* Dump the stack using either the old method or the new Win32 API method */
void
stack (HANDLE hproc, HANDLE hthread, CONTEXT *cx)
{
int i;
thestack.init (cx->Ebp); /* 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 *ebp = (DWORD *)in->Esp;
for (DWORD *bpend = ebp - 8; ebp > bpend; ebp--)
if (*ebp == in->SegCs && ebp[-1] == in->Eip)
{
ebp -= 2;
break;
}
sig_send (NULL, sig, (DWORD) ebp); // Signal myself
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
sigsave.ebp = 0;
}
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 (DWORD ebp, int sig, struct sigaction& siga, void *handler)
{
int i;
if (sigsave.sig)
return 0; /* Already have a signal stacked up */
thestack.init (ebp); /* 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, int nonmain)
{
CONTEXT cx;
DWORD ebp;
int interrupted = 1;
HANDLE hth = NULL;
int res;
if (!nonmain)
ebp = sigsave.ebp;
else
{
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);
muto *m;
/* FIXME: Make multi-thread aware */
for (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 (%s)", m->name);
if (res)
goto set_pending;
ResumeThread (hth);
Sleep (0);
}
sigproc_printf ("SuspendThread returned %d", res);
cx.ContextFlags = CONTEXT_CONTROL | CONTEXT_INTEGER;
if (!GetThreadContext (hth, &cx))
{
system_printf ("couldn't get context of main thread, %E");
goto out;
}
ebp = cx.Ebp;
}
if (hExeced != NULL || (nonmain && interruptible (cx.Eip)))
interrupt_now (&cx, sig, siga, handler);
else if (!interrupt_on_return (ebp, sig, siga, handler))
{
set_pending:
pending_signals = 1; /* FIXME: Probably need to be more tricky here */
sig_set_pending (sig);
interrupted = 0;
}
if (interrupted)
{
res = 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:
if (!hth)
sigproc_printf ("modified main-thread stack");
else
{
res = ResumeThread (hth);
sigproc_printf ("ResumeThread returned %d", res);
}
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 nonmain)
{
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, nonmain);
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, "mask_sync");
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)
);
}
}
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