1/* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This software was developed by the Computer Systems Engineering group 6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7 * contributed to Berkeley. 8 * 9 * %sccs.include.redist.c% 10 * 11 * from: $Header: setjmp.s,v 1.2 92/06/25 03:18:43 torek Exp $ 12 */ 13 14#if defined(LIBC_SCCS) && !defined(lint) 15 .asciz "@(#)setjmp.s 8.1 (Berkeley) 06/04/93" 16#endif /* LIBC_SCCS and not lint */ 17 18/* 19 * C library -- setjmp, longjmp 20 * 21 * longjmp(a,v) 22 * will generate a "return(v)" from 23 * the last call to 24 * setjmp(a) 25 * by restoring registers from the stack, 26 * and a struct sigcontext, see <signal.h> 27 */ 28 29#include "SYS.h" 30 31ENTRY(setjmp) 32 /* 33 * We use the caller's `arg dump' area (%sp+0x44; there are 6 ints 34 * reserved there for us) to avoid having to allocate stack space 35 * here. 36 */ 37 mov %o0, %o2 /* build sigcontext in [%o2] */ 38 mov 1, %o0 /* SIG_BLOCK */ 39 mov SYS_sigprocmask, %g1 40 clr %o1 /* sigprocmask(SIG_BLOCK, (sigset_t *)NULL) */ 41 t ST_SYSCALL 42 st %o0, [%o2 + 4] /* sc.sc_mask = current mask; */ 43 mov SYS_sigaltstack, %g1 44 clr %o0 /* sigstack(NULL, &foo) */ 45 add %sp, 0x48, %o1 /* (foo being in arg dump area) */ 46 t ST_SYSCALL 47 ld [%sp + 0x50], %o0 /* foo.ss_flags */ 48 and %o0, 1, %o1 /* onstack = foo.ss_flags & 1; */ 49 st %o0, [%o2 + 0] /* sc.sc_onstack = current onstack; */ 50 st %sp, [%o2 + 8] /* sc.sc_sp = sp (both ours and caller's) */ 51 add %o7, 8, %o0 52 st %o0, [%o2 + 12] /* sc.sc_pc = return_pc */ 53 add %o7, 12, %o0 54 st %o0, [%o2 + 16] /* sc.sc_npc = return_pc + 4 */ 55 st %g0, [%o2 + 20] /* sc.sc_psr = (clean psr) */ 56 st %fp, [%o2 + 24] /* sc.sc_g1 = %fp (misuse, but what the heck) */ 57 /* sc.sc_o0 = random(), set in longjmp */ 58 retl /* return 0 */ 59 clr %o0 60 61/* 62 * All we need to do here is force sigreturn to load a new stack pointer, 63 * new <pc,npc>, and appropriate %o0 return value from the sigcontext built 64 * in setjmp. The %i and %l registers will be reloaded from the place to 65 * which %sp points, due to sigreturn() semantics (sigreturn does not modify 66 * the window pointer in the psr, hence it must force all windows to reload). 67 */ 68ENTRY(longjmp) 69 save %sp, -96, %sp 70 ld [%i0 + 8], %o2 /* make sure sc->sc_sp, sc->sc_fp nonzero */ 71 ld [%i0 + 24], %o3 72 orcc %o2, %o3, %g0 73 bz Lbotch 74 tst %i1 /* if (v == 0) v = 1; */ 75 bz,a 1f 76 mov 1, %i1 771: 78 st %i1, [%i0 + 28] /* sc.sc_o0 = v; */ 79 mov SYS_sigreturn, %g1 80 mov %i0, %o0 81 t ST_SYSCALL /* sigreturn(scp); */ 82 83Lbotch: 84 /* oops, caller botched it */ 85 call _longjmperror 86 nop 87 unimp 0 88