minix/lib/libm2/sigtrp.c

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2005-04-21 16:53:53 +02:00
/*
(c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
See the copyright notice in the ACK home directory, in the file "Copyright".
*/
/*
Module: Mapping of Unix signals to EM traps
(only when not using the MON instruction)
Author: Ceriel J.H. Jacobs
Version: $Header$
*/
#if !defined(__em22) && !defined(__em24) && !defined(__em44)
#define EM_trap(n) TRP(n) /* define to whatever is needed to cause the trap */
#include <signal.h>
#include <errno.h>
int __signo;
static int __traps[] = {
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
};
static void
__ctchsig(signo)
{
signal(signo,__ctchsig);
#ifdef __BSD4_2
sigsetmask(sigblock(0) & ~(1<<(signo - 1)));
#endif
__signo = signo;
EM_trap(__traps[signo]);
}
int
sigtrp(trapno, signo)
{
/* Let Unix signal signo cause EM trap trapno to occur.
If trapno = -2, restore default,
If trapno = -3, ignore.
Return old trapnumber.
Careful, this could be -2 or -3; But return value of -1
indicates failure, with error number in errno.
*/
extern int errno;
void (*ctch)() = __ctchsig;
void (*oldctch)();
int oldtrap;
if (signo <= 0 || signo >= sizeof(__traps)/sizeof(__traps[0])) {
errno = EINVAL;
return -1;
}
if (trapno == -3)
ctch = SIG_IGN;
else if (trapno == -2)
ctch = SIG_DFL;
else if (trapno >= 0 && trapno <= 252)
;
else {
errno = EINVAL;
return -1;
}
oldtrap = __traps[signo];
if ((oldctch = signal(signo, ctch)) == (void (*)())-1) /* errno set by signal */
return -1;
else if (oldctch == SIG_IGN) {
signal(signo, SIG_IGN);
}
else __traps[signo] = trapno;
return oldtrap;
}
#endif