qemu/linux-user/cris/signal.c
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   1/*
   2 *  Emulation of Linux signals
   3 *
   4 *  Copyright (c) 2003 Fabrice Bellard
   5 *
   6 *  This program is free software; you can redistribute it and/or modify
   7 *  it under the terms of the GNU General Public License as published by
   8 *  the Free Software Foundation; either version 2 of the License, or
   9 *  (at your option) any later version.
  10 *
  11 *  This program is distributed in the hope that it will be useful,
  12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 *  GNU General Public License for more details.
  15 *
  16 *  You should have received a copy of the GNU General Public License
  17 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19#include "qemu/osdep.h"
  20#include "qemu.h"
  21#include "user-internals.h"
  22#include "signal-common.h"
  23#include "linux-user/trace.h"
  24
  25struct target_sigcontext {
  26    struct target_pt_regs regs;  /* needs to be first */
  27    uint32_t oldmask;
  28    uint32_t usp;    /* usp before stacking this gunk on it */
  29};
  30
  31/* Signal frames. */
  32struct target_signal_frame {
  33    struct target_sigcontext sc;
  34    uint32_t extramask[TARGET_NSIG_WORDS - 1];
  35    uint16_t retcode[4];      /* Trampoline code. */
  36};
  37
  38struct rt_signal_frame {
  39    siginfo_t *pinfo;
  40    void *puc;
  41    siginfo_t info;
  42    ucontext_t uc;
  43    uint16_t retcode[4];      /* Trampoline code. */
  44};
  45
  46static void setup_sigcontext(struct target_sigcontext *sc, CPUCRISState *env)
  47{
  48    __put_user(env->regs[0], &sc->regs.r0);
  49    __put_user(env->regs[1], &sc->regs.r1);
  50    __put_user(env->regs[2], &sc->regs.r2);
  51    __put_user(env->regs[3], &sc->regs.r3);
  52    __put_user(env->regs[4], &sc->regs.r4);
  53    __put_user(env->regs[5], &sc->regs.r5);
  54    __put_user(env->regs[6], &sc->regs.r6);
  55    __put_user(env->regs[7], &sc->regs.r7);
  56    __put_user(env->regs[8], &sc->regs.r8);
  57    __put_user(env->regs[9], &sc->regs.r9);
  58    __put_user(env->regs[10], &sc->regs.r10);
  59    __put_user(env->regs[11], &sc->regs.r11);
  60    __put_user(env->regs[12], &sc->regs.r12);
  61    __put_user(env->regs[13], &sc->regs.r13);
  62    __put_user(env->regs[14], &sc->usp);
  63    __put_user(env->regs[15], &sc->regs.acr);
  64    __put_user(env->pregs[PR_MOF], &sc->regs.mof);
  65    __put_user(env->pregs[PR_SRP], &sc->regs.srp);
  66    __put_user(env->pc, &sc->regs.erp);
  67}
  68
  69static void restore_sigcontext(struct target_sigcontext *sc, CPUCRISState *env)
  70{
  71    __get_user(env->regs[0], &sc->regs.r0);
  72    __get_user(env->regs[1], &sc->regs.r1);
  73    __get_user(env->regs[2], &sc->regs.r2);
  74    __get_user(env->regs[3], &sc->regs.r3);
  75    __get_user(env->regs[4], &sc->regs.r4);
  76    __get_user(env->regs[5], &sc->regs.r5);
  77    __get_user(env->regs[6], &sc->regs.r6);
  78    __get_user(env->regs[7], &sc->regs.r7);
  79    __get_user(env->regs[8], &sc->regs.r8);
  80    __get_user(env->regs[9], &sc->regs.r9);
  81    __get_user(env->regs[10], &sc->regs.r10);
  82    __get_user(env->regs[11], &sc->regs.r11);
  83    __get_user(env->regs[12], &sc->regs.r12);
  84    __get_user(env->regs[13], &sc->regs.r13);
  85    __get_user(env->regs[14], &sc->usp);
  86    __get_user(env->regs[15], &sc->regs.acr);
  87    __get_user(env->pregs[PR_MOF], &sc->regs.mof);
  88    __get_user(env->pregs[PR_SRP], &sc->regs.srp);
  89    __get_user(env->pc, &sc->regs.erp);
  90}
  91
  92static abi_ulong get_sigframe(CPUCRISState *env, int framesize)
  93{
  94    abi_ulong sp;
  95    /* Align the stack downwards to 4.  */
  96    sp = (env->regs[R_SP] & ~3);
  97    return sp - framesize;
  98}
  99
 100static void setup_sigreturn(uint16_t *retcode)
 101{
 102    /* This is movu.w __NR_sigreturn, r9; break 13; */
 103    __put_user(0x9c5f, retcode + 0);
 104    __put_user(TARGET_NR_sigreturn, retcode + 1);
 105    __put_user(0xe93d, retcode + 2);
 106}
 107
 108void setup_frame(int sig, struct target_sigaction *ka,
 109                 target_sigset_t *set, CPUCRISState *env)
 110{
 111    struct target_signal_frame *frame;
 112    abi_ulong frame_addr;
 113    int i;
 114
 115    frame_addr = get_sigframe(env, sizeof *frame);
 116    trace_user_setup_frame(env, frame_addr);
 117    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
 118        goto badframe;
 119
 120    /*
 121     * The CRIS signal return trampoline. A real linux/CRIS kernel doesn't
 122     * use this trampoline anymore but it sets it up for GDB.
 123     */
 124    setup_sigreturn(frame->retcode);
 125
 126    /* Save the mask.  */
 127    __put_user(set->sig[0], &frame->sc.oldmask);
 128
 129    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
 130        __put_user(set->sig[i], &frame->extramask[i - 1]);
 131    }
 132
 133    setup_sigcontext(&frame->sc, env);
 134
 135    /* Move the stack and setup the arguments for the handler.  */
 136    env->regs[R_SP] = frame_addr;
 137    env->regs[10] = sig;
 138    env->pc = (unsigned long) ka->_sa_handler;
 139    /* Link SRP so the guest returns through the trampoline.  */
 140    env->pregs[PR_SRP] = default_sigreturn;
 141
 142    unlock_user_struct(frame, frame_addr, 1);
 143    return;
 144badframe:
 145    force_sigsegv(sig);
 146}
 147
 148void setup_rt_frame(int sig, struct target_sigaction *ka,
 149                    target_siginfo_t *info,
 150                     target_sigset_t *set, CPUCRISState *env)
 151{
 152    qemu_log_mask(LOG_UNIMP, "setup_rt_frame: not implemented\n");
 153}
 154
 155long do_sigreturn(CPUCRISState *env)
 156{
 157    struct target_signal_frame *frame;
 158    abi_ulong frame_addr;
 159    target_sigset_t target_set;
 160    sigset_t set;
 161    int i;
 162
 163    frame_addr = env->regs[R_SP];
 164    trace_user_do_sigreturn(env, frame_addr);
 165    /* Make sure the guest isn't playing games.  */
 166    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1)) {
 167        goto badframe;
 168    }
 169
 170    /* Restore blocked signals */
 171    __get_user(target_set.sig[0], &frame->sc.oldmask);
 172    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
 173        __get_user(target_set.sig[i], &frame->extramask[i - 1]);
 174    }
 175    target_to_host_sigset_internal(&set, &target_set);
 176    set_sigmask(&set);
 177
 178    restore_sigcontext(&frame->sc, env);
 179    unlock_user_struct(frame, frame_addr, 0);
 180    return -QEMU_ESIGRETURN;
 181badframe:
 182    force_sig(TARGET_SIGSEGV);
 183    return -QEMU_ESIGRETURN;
 184}
 185
 186long do_rt_sigreturn(CPUCRISState *env)
 187{
 188    trace_user_do_rt_sigreturn(env, 0);
 189    qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n");
 190    return -TARGET_ENOSYS;
 191}
 192
 193void setup_sigtramp(abi_ulong sigtramp_page)
 194{
 195    uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0);
 196    assert(tramp != NULL);
 197
 198    default_sigreturn = sigtramp_page;
 199    setup_sigreturn(tramp);
 200
 201    unlock_user(tramp, sigtramp_page, 6);
 202}
 203