lib/libc/arch/sparc/gen/longjmp.c

   1 /*      $NetBSD: longjmp.c,v 1.3 2011/04/30 23:41:12 martin Exp $       */
   2
   3 /*-
   4  * Copyright (c) 2003 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Christian Limpach.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29  * POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "namespace.h"
  33 #include <sys/types.h>
  34 #include <ucontext.h>
  35 #include <signal.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <stddef.h>
  39
  40 #define __LIBC12_SOURCE__
  41 #include <setjmp.h>
  42 #include <compat/include/setjmp.h>
  43
  44 struct __jmp_buf_regs_t {
  45         __greg_t        g4;
  46         __greg_t        g7;
  47         __greg_t        save_mask;
  48 };
  49
  50 /*
  51  * setjmp.S uses hard coded offsets into the jump_buf,
  52  * make sure any changes cause a compile failure here
  53  */
  54 __CTASSERT(56 == offsetof(struct __jmp_buf_regs_t,save_mask) +
  55         sizeof(struct sigcontext));
  56 __CTASSERT(sizeof(sigjmp_buf) >= sizeof(struct __jmp_buf_regs_t) +
  57         sizeof(struct sigcontext));
  58
  59 /*
  60  * Use setcontext to reload the stack pointer, program counter <pc,npc>, and
  61  * set the return value in %o0.  The %i and %l registers will be reloaded
  62  * from the place to which %sp points.
  63  */
  64 void
  65 __longjmp14(jmp_buf env, int val)
  66 {
  67         struct sigcontext *sc = (void *)env;
  68         struct __jmp_buf_regs_t *r = (void*)&sc[1];
  69         ucontext_t uc;
  70
  71         /* Ensure non-zero SP */
  72         if (sc->sc_sp == 0)
  73                 goto err;
  74
  75         /* Initialise the context */
  76         memset(&uc, 0, sizeof(uc));
  77
  78         /*
  79          * Set _UC_{SET,CLR}STACK according to SS_ONSTACK.
  80          *
  81          * Restore the signal mask with sigprocmask() instead of _UC_SIGMASK,
  82          * since libpthread may want to interpose on signal handling.
  83          */
  84         uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
  85
  86         sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
  87
  88         /* Extract PSR, PC, NPC and SP from jmp_buf */
  89         uc.uc_mcontext.__gregs[_REG_PSR] = sc->sc_psr;
  90         uc.uc_mcontext.__gregs[_REG_PC] = sc->sc_pc;
  91         uc.uc_mcontext.__gregs[_REG_nPC] = sc->sc_pc+4;
  92         uc.uc_mcontext.__gregs[_REG_O6] = sc->sc_sp;
  93         uc.uc_mcontext.__gregs[_REG_G2] = sc->sc_g1;
  94         uc.uc_mcontext.__gregs[_REG_G3] = sc->sc_npc;
  95         uc.uc_mcontext.__gregs[_REG_G4] = r->g4;
  96         uc.uc_mcontext.__gregs[_REG_G7] = r->g7;
  97
  98         /* Set the return value; make sure it's non-zero */
  99         uc.uc_mcontext.__gregs[_REG_O0] = (val != 0 ? val : 1);
 100
 101         setcontext(&uc);
 102
 103 err:
 104         longjmperror();
 105         abort();
 106         /* NOTREACHED */
 107 }