1*54389Storek/* 2*54389Storek * Copyright (c) 1992 The Regents of the University of California. 3*54389Storek * All rights reserved. 4*54389Storek * 5*54389Storek * This software was developed by the Computer Systems Engineering group 6*54389Storek * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7*54389Storek * contributed to Berkeley. 8*54389Storek * 9*54389Storek * %sccs.include.redist.c% 10*54389Storek * 11*54389Storek * from: $Header: setjmp.s,v 1.2 92/06/25 03:18:43 torek Exp $ 12*54389Storek */ 13*54389Storek 14*54389Storek#if defined(LIBC_SCCS) && !defined(lint) 15*54389Storek .asciz "@(#)setjmp.s 5.1 (Berkeley) 06/25/92" 16*54389Storek#endif /* LIBC_SCCS and not lint */ 17*54389Storek 18*54389Storek/* 19*54389Storek * C library -- setjmp, longjmp 20*54389Storek * 21*54389Storek * longjmp(a,v) 22*54389Storek * will generate a "return(v)" from 23*54389Storek * the last call to 24*54389Storek * setjmp(a) 25*54389Storek * by restoring registers from the stack, 26*54389Storek * and a struct sigcontext, see <signal.h> 27*54389Storek */ 28*54389Storek 29*54389Storek#include "SYS.h" 30*54389Storek 31*54389StorekENTRY(setjmp) 32*54389Storek /* 33*54389Storek * We use the caller's `arg dump' area (%sp+0x44; there are 6 ints 34*54389Storek * reserved there for us) to avoid having to allocate stack space 35*54389Storek * here. 36*54389Storek */ 37*54389Storek mov %o0, %o2 /* build sigcontext in [%o2] */ 38*54389Storek mov 1, %o0 /* SIG_BLOCK */ 39*54389Storek mov SYS_sigprocmask, %g1 40*54389Storek clr %o1 /* sigprocmask(SIG_BLOCK, (sigset_t *)NULL) */ 41*54389Storek t ST_SYSCALL 42*54389Storek st %o0, [%o2 + 4] /* sc.sc_mask = current mask; */ 43*54389Storek mov SYS_sigaltstack, %g1 44*54389Storek clr %o0 /* sigstack(NULL, &foo) */ 45*54389Storek add %sp, 0x48, %o1 /* (foo being in arg dump area) */ 46*54389Storek t ST_SYSCALL 47*54389Storek ld [%sp + 0x50], %o0 /* foo.ss_flags */ 48*54389Storek and %o0, 1, %o1 /* onstack = foo.ss_flags & 1; */ 49*54389Storek st %o0, [%o2 + 0] /* sc.sc_onstack = current onstack; */ 50*54389Storek st %sp, [%o2 + 8] /* sc.sc_sp = sp (both ours and caller's) */ 51*54389Storek add %o7, 8, %o0 52*54389Storek st %o0, [%o2 + 12] /* sc.sc_pc = return_pc */ 53*54389Storek add %o7, 12, %o0 54*54389Storek st %o0, [%o2 + 16] /* sc.sc_npc = return_pc + 4 */ 55*54389Storek st %g0, [%o2 + 20] /* sc.sc_psr = (clean psr) */ 56*54389Storek st %fp, [%o2 + 24] /* sc.sc_g1 = %fp (misuse, but what the heck) */ 57*54389Storek /* sc.sc_o0 = random(), set in longjmp */ 58*54389Storek retl /* return 0 */ 59*54389Storek clr %o0 60*54389Storek 61*54389Storek/* 62*54389Storek * All we need to do here is force sigreturn to load a new stack pointer, 63*54389Storek * new <pc,npc>, and appropriate %o0 return value from the sigcontext built 64*54389Storek * in setjmp. The %i and %l registers will be reloaded from the place to 65*54389Storek * which %sp points, due to sigreturn() semantics (sigreturn does not modify 66*54389Storek * the window pointer in the psr, hence it must force all windows to reload). 67*54389Storek */ 68*54389StorekENTRY(longjmp) 69*54389Storek save %sp, -96, %sp 70*54389Storek ld [%i0 + 8], %o2 /* make sure sc->sc_sp, sc->sc_fp nonzero */ 71*54389Storek ld [%i0 + 24], %o3 72*54389Storek orcc %o2, %o3, %g0 73*54389Storek bz Lbotch 74*54389Storek tst %i1 /* if (v == 0) v = 1; */ 75*54389Storek bz,a 1f 76*54389Storek mov 1, %i1 77*54389Storek1: 78*54389Storek st %i1, [%i0 + 28] /* sc.sc_o0 = v; */ 79*54389Storek mov SYS_sigreturn, %g1 80*54389Storek mov %i0, %o0 81*54389Storek t ST_SYSCALL /* sigreturn(scp); */ 82*54389Storek 83*54389StorekLbotch: 84*54389Storek /* oops, caller botched it */ 85*54389Storek call _longjmperror 86*54389Storek nop 87*54389Storek unimp 0 88