SIGFPE -> ArithmeticException ?

Thu Jul 1 05:36:00 GMT 1999

I've found the bug. Here's the routine in libpthread which gets
called when a signal gets sent to a process:
 /* The wrapper around user-provided signal handlers */
 static void pthread_sighandler(int signo)
 {
 pthread_descr self = thread_self();
 char * in_sighandler;
 /* If we're in a sigwait operation, just record the signal received
 and return without calling the user's handler */
 if (THREAD_GETMEM(self, p_sigwaiting)) {
 THREAD_SETMEM(self, p_sigwaiting, 0);
 THREAD_SETMEM(self, p_signal, signo);
 return;
 }
 /* Record that we're in a signal handler and call the user's
 handler function */
 in_sighandler = THREAD_GETMEM(self, p_in_sighandler);
 if (in_sighandler == NULL)
 THREAD_SETMEM(self, p_in_sighandler, CURRENT_STACK_FRAME);
 sighandler[signo](signo);
 if (in_sighandler == NULL)
 THREAD_SETMEM(self, p_in_sighandler, NULL);
 }

[ This is from the glibc sources which I unpacked from the Linux 6.0 CD ]
Note that only one parameter, the signo, is passed on to the user's
handler.
As far as I can see, this bug is still in the current pthreads
sources.
I don't think that there's any reason why the pthread library needs to
be called when a SIGFPE occurs (as far as I know SIGFPE is
synchronous) so try replacing calls to sigaction() in i386-signal.h
with __sigaction(). This isn't an ideal solution, but it should work
until pthreads is fixed.
Here's hoping!
Andrew.