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

   1 /*      $NetBSD: longjmp.c,v 1.5 2012/03/29 19:27:05 christos 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 and Matt Thomas.
   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
  39 #include <machine/regnum.h>
  40
  41 #define __LIBC12_SOURCE__
  42 #include <setjmp.h>
  43 #include <compat/include/setjmp.h>
  44
  45 void
  46 __longjmp14(jmp_buf env, int val)
  47 {
  48         struct sigcontext *sc = (void *)env;
  49         ucontext_t uc;
  50
  51         /* Ensure non-zero SP and sigcontext magic number is present */
  52         if (sc->sc_regs[_R_SP] == 0 || sc->sc_regs[_R_ZERO] != (mips_reg_t)0xACEDBADEU)
  53                 goto err;
  54
  55         /* Ensure non-zero return value */
  56         if (val == 0)
  57                 val = 1;
  58
  59         /*
  60          * Set _UC_{SET,CLR}STACK according to SS_ONSTACK.
  61          *
  62          * Restore the signal mask with sigprocmask() instead of _UC_SIGMASK,
  63          * since libpthread may want to interpose on signal handling.
  64          */
  65         uc.uc_flags = _UC_CPU | (sc->sc_onstack ? _UC_SETSTACK : _UC_CLRSTACK);
  66
  67         sigprocmask(SIG_SETMASK, &sc->sc_mask, NULL);
  68
  69         /* Clear uc_link */
  70         uc.uc_link = 0;
  71
  72         /* Save return value in context */
  73         uc.uc_mcontext.__gregs[_REG_V0] = val;
  74
  75         /* Copy saved registers */
  76         uc.uc_mcontext.__gregs[_REG_S0] = sc->sc_regs[_R_S0];
  77         uc.uc_mcontext.__gregs[_REG_S1] = sc->sc_regs[_R_S1];
  78         uc.uc_mcontext.__gregs[_REG_S2] = sc->sc_regs[_R_S2];
  79         uc.uc_mcontext.__gregs[_REG_S3] = sc->sc_regs[_R_S3];
  80         uc.uc_mcontext.__gregs[_REG_S4] = sc->sc_regs[_R_S4];
  81         uc.uc_mcontext.__gregs[_REG_S5] = sc->sc_regs[_R_S5];
  82         uc.uc_mcontext.__gregs[_REG_S6] = sc->sc_regs[_R_S6];
  83         uc.uc_mcontext.__gregs[_REG_S7] = sc->sc_regs[_R_S7];
  84         uc.uc_mcontext.__gregs[_REG_S8] = sc->sc_regs[_R_S8];
  85 #if defined(__mips_n32) || defined(__mips_n64)
  86         uc.uc_mcontext.__gregs[_REG_GP] = sc->sc_regs[_R_GP];
  87 #endif
  88         uc.uc_mcontext.__gregs[_REG_SP] = sc->sc_regs[_R_SP];
  89         uc.uc_mcontext.__gregs[_REG_RA] = sc->sc_regs[_R_RA];
  90         uc.uc_mcontext.__gregs[_REG_EPC] = sc->sc_pc;
  91
  92         /* Copy FP state */
  93         if (sc->sc_fpused) {
  94                 /* FP saved regs are $f20 .. $f31 */
  95                 memcpy(&uc.uc_mcontext.__fpregs.__fp_r.__fp_regs[20],
  96                     &sc->sc_fpregs[20], 32 - 20);
  97                 uc.uc_mcontext.__fpregs.__fp_csr =
  98                     sc->sc_fpregs[_R_FSR - _FPBASE];
  99                 /* XXX sc_fp_control */
 100                 uc.uc_flags |= _UC_FPU;
 101         }
 102
 103         setcontext(&uc);
 104  err:
 105         longjmperror();
 106         abort();
 107         /* NOTREACHED */
 108 }