qemu

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/*
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 *  Emulation of Linux signals
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 *
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 *  Copyright (c) 2003 Fabrice Bellard
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; either version 2 of the License, or
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 *  (at your option) any later version.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
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 */
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#include "qemu/osdep.h"
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#include "qemu.h"
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#include "user-internals.h"
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#include "signal-common.h"
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#include "linux-user/trace.h"
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struct target_sigcontext {
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    struct target_pt_regs regs;  /* needs to be first */
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    uint32_t oldmask;
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    uint32_t usp;    /* usp before stacking this gunk on it */
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};
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/* Signal frames. */
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struct target_signal_frame {
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    struct target_sigcontext sc;
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    uint32_t extramask[TARGET_NSIG_WORDS - 1];
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    uint16_t retcode[4];      /* Trampoline code. */
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};
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static void setup_sigcontext(struct target_sigcontext *sc, CPUCRISState *env)
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{
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    __put_user(env->regs[0], &sc->regs.r0);
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    __put_user(env->regs[1], &sc->regs.r1);
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    __put_user(env->regs[2], &sc->regs.r2);
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    __put_user(env->regs[3], &sc->regs.r3);
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    __put_user(env->regs[4], &sc->regs.r4);
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    __put_user(env->regs[5], &sc->regs.r5);
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    __put_user(env->regs[6], &sc->regs.r6);
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    __put_user(env->regs[7], &sc->regs.r7);
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    __put_user(env->regs[8], &sc->regs.r8);
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    __put_user(env->regs[9], &sc->regs.r9);
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    __put_user(env->regs[10], &sc->regs.r10);
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    __put_user(env->regs[11], &sc->regs.r11);
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    __put_user(env->regs[12], &sc->regs.r12);
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    __put_user(env->regs[13], &sc->regs.r13);
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    __put_user(env->regs[14], &sc->usp);
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    __put_user(env->regs[15], &sc->regs.acr);
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    __put_user(env->pregs[PR_MOF], &sc->regs.mof);
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    __put_user(env->pregs[PR_SRP], &sc->regs.srp);
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    __put_user(env->pc, &sc->regs.erp);
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}
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static void restore_sigcontext(struct target_sigcontext *sc, CPUCRISState *env)
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{
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    __get_user(env->regs[0], &sc->regs.r0);
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    __get_user(env->regs[1], &sc->regs.r1);
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    __get_user(env->regs[2], &sc->regs.r2);
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    __get_user(env->regs[3], &sc->regs.r3);
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    __get_user(env->regs[4], &sc->regs.r4);
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    __get_user(env->regs[5], &sc->regs.r5);
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    __get_user(env->regs[6], &sc->regs.r6);
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    __get_user(env->regs[7], &sc->regs.r7);
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    __get_user(env->regs[8], &sc->regs.r8);
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    __get_user(env->regs[9], &sc->regs.r9);
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    __get_user(env->regs[10], &sc->regs.r10);
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    __get_user(env->regs[11], &sc->regs.r11);
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    __get_user(env->regs[12], &sc->regs.r12);
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    __get_user(env->regs[13], &sc->regs.r13);
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    __get_user(env->regs[14], &sc->usp);
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    __get_user(env->regs[15], &sc->regs.acr);
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    __get_user(env->pregs[PR_MOF], &sc->regs.mof);
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    __get_user(env->pregs[PR_SRP], &sc->regs.srp);
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    __get_user(env->pc, &sc->regs.erp);
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}
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static abi_ulong get_sigframe(CPUCRISState *env, int framesize)
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{
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    abi_ulong sp;
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    /* Align the stack downwards to 4.  */
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    sp = (env->regs[R_SP] & ~3);
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    return sp - framesize;
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}
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static void setup_sigreturn(uint16_t *retcode)
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{
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    /* This is movu.w __NR_sigreturn, r9; break 13; */
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    __put_user(0x9c5f, retcode + 0);
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    __put_user(TARGET_NR_sigreturn, retcode + 1);
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    __put_user(0xe93d, retcode + 2);
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}
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void setup_frame(int sig, struct target_sigaction *ka,
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                 target_sigset_t *set, CPUCRISState *env)
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{
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    struct target_signal_frame *frame;
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    abi_ulong frame_addr;
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    int i;
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    frame_addr = get_sigframe(env, sizeof *frame);
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    trace_user_setup_frame(env, frame_addr);
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    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0))
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        goto badframe;
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    /*
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     * The CRIS signal return trampoline. A real linux/CRIS kernel doesn't
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     * use this trampoline anymore but it sets it up for GDB.
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     */
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    setup_sigreturn(frame->retcode);
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    /* Save the mask.  */
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    __put_user(set->sig[0], &frame->sc.oldmask);
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    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
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        __put_user(set->sig[i], &frame->extramask[i - 1]);
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    }
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    setup_sigcontext(&frame->sc, env);
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    /* Move the stack and setup the arguments for the handler.  */
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    env->regs[R_SP] = frame_addr;
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    env->regs[10] = sig;
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    env->pc = (unsigned long) ka->_sa_handler;
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    /* Link SRP so the guest returns through the trampoline.  */
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    env->pregs[PR_SRP] = default_sigreturn;
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    unlock_user_struct(frame, frame_addr, 1);
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    return;
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badframe:
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    force_sigsegv(sig);
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}
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void setup_rt_frame(int sig, struct target_sigaction *ka,
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                    target_siginfo_t *info,
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                     target_sigset_t *set, CPUCRISState *env)
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{
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    qemu_log_mask(LOG_UNIMP, "setup_rt_frame: not implemented\n");
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}
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long do_sigreturn(CPUCRISState *env)
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{
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    struct target_signal_frame *frame;
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    abi_ulong frame_addr;
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    target_sigset_t target_set;
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    sigset_t set;
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    int i;
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    frame_addr = env->regs[R_SP];
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    trace_user_do_sigreturn(env, frame_addr);
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    /* Make sure the guest isn't playing games.  */
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    if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 1)) {
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        goto badframe;
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    }
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    /* Restore blocked signals */
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    __get_user(target_set.sig[0], &frame->sc.oldmask);
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    for(i = 1; i < TARGET_NSIG_WORDS; i++) {
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        __get_user(target_set.sig[i], &frame->extramask[i - 1]);
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    }
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    target_to_host_sigset_internal(&set, &target_set);
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    set_sigmask(&set);
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    restore_sigcontext(&frame->sc, env);
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    unlock_user_struct(frame, frame_addr, 0);
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    return -QEMU_ESIGRETURN;
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badframe:
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    force_sig(TARGET_SIGSEGV);
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    return -QEMU_ESIGRETURN;
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}
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long do_rt_sigreturn(CPUCRISState *env)
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{
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    trace_user_do_rt_sigreturn(env, 0);
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    qemu_log_mask(LOG_UNIMP, "do_rt_sigreturn: not implemented\n");
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    return -TARGET_ENOSYS;
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}
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void setup_sigtramp(abi_ulong sigtramp_page)
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{
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    uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0);
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    assert(tramp != NULL);
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    default_sigreturn = sigtramp_page;
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    setup_sigreturn(tramp);
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    unlock_user(tramp, sigtramp_page, 6);
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}
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