usr/src/lib/libc/tahoe/sys/sigprocmask.s

/*
 * Copyright (c) 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the University of California, Berkeley.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(SYSLIBC_SCCS) && !defined(lint)
        .asciz "@(#)sigprocmask.s       5.1 (Berkeley) %G%"
#endif /* SYSLIBC_SCCS and not lint */

#include "SYS.h"

err:
        jmp     cerror

ENTRY(sigprocmask)
        tstl    8(fp)                   # check new sigset pointer
        bneq    1f                      # if not null, indirect
        movl    $0,8(fp)                # null mask pointer: block empty set
        movl    $1,4(fp)                # SIG_BLOCK
        jbr     2f
1:      movl    *8(fp),8(fp)            # indirect to new mask arg
2:      kcall   $SYS_sigprocmask
        jcs     err
        tstl    12(fp)                  # test if old mask requested
        beql    out
        movl    r0,*12(fp)              # store old mask
out:
        clrl    r0
        ret