1/* 2 * Copyright (c) 1983 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 */ 6 7#ifndef lint 8 .asciz "@(#)setjmp.s 5.3 (Berkeley) 08/16/85" 9#endif not lint 10 11/* 12 * C library -- setjmp, longjmp 13 * 14 * longjmp(a,v) 15 * will generate a "return(v)" from 16 * the last call to 17 * setjmp(a) 18 * by restoring registers from the stack, 19 * and a struct sigcontext, see <signal.h> 20 */ 21 22#include "DEFS.h" 23 24ENTRY(setjmp, R6) 25 movl 4(ap),r6 # construct sigcontext 26 subl2 $8,sp # space for current struct sigstack 27 pushl sp # get current values 28 pushl $0 # no new values 29 calls $3,_sigstack # pop args plus signal stack value 30 movl (sp)+,(r6)+ # save onsigstack status of caller 31 pushl $0 32 calls $1,_sigblock # get signal mask 33 movl r0,(r6)+ # save signal mask of caller 34 movl (ap),r0 35 moval 4(ap)[r0],(r6)+ # save sp of caller 36 movl 12(fp),(r6)+ # save frame pointer of caller 37 movl 8(fp),(r6)+ # save argument pointer of caller 38 movl 16(fp),(r6)+ # save pc of caller 39 movpsl (r6) # save psl of caller 40 movw 4(fp),(r6) 41 clrl r0 42 ret 43 44ENTRY(longjmp, 0) 45 movl 8(ap),r0 # return(v) 46 movl 4(ap),r1 # fetch buffer 47 tstl 12(r1) 48 beql botch 49loop: 50 cmpl 12(r1),fp # are we there yet? 51 beql done 52 blssu botch 53 moval 20(fp),r2 54 blbc 6(fp),1f # was r0 saved? 55 movl r0,(r2)+ 561: 57 bbc $1,6(fp),2f # was r1 saved? 58 movl r1,(r2) 592: 60 movl $loop,16(fp) 61 ret # pop another frame 62 63done: 64 65#ifndef NOCOMPAT 66/* 67 * This code checks to see if it can use the new sigreturn. 68 * If it finds that sigtramp is using the new system call, 69 * it will also use it. Otherwise it uses the old system call 70 * to preserve compatibility. 71 */ 72#include <vax/machparam.h> 73#define U (0x80000000-UPAGES*NBPG) 74#define PCB_SIGC 0x6c 75#define CHMKINS 7 76 cmpl 3f,U+PCB_SIGC+CHMKINS # check to see how sigtramp returns 77 beql 4f # sigtramp uses the new system call 78 pushl r1 # must use the old signal return 79 chmk $139 # restore previous context 80 jmp *20(r1) # done, return 813: 82 chmk $103 # the new system call for sigreturn 834: 84#endif NOCOMPAT 85 86 pushl r1 # pointer to sigcontext 87 calls $1,_sigreturn # restore previous context 88 # we should never return 89botch: 90 pushl $msgend-msg 91 pushl $msg 92 pushl $2 93 calls $3,_write 94 halt 95 96 .data 97msg: .ascii "longjmp botch\n" 98msgend: 99