LXR qemu/linux-user/nios2/signal.c

   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 "signal-common.h"
  22#include "linux-user/trace.h"
  23
  24#define MCONTEXT_VERSION 2
  25
  26struct target_sigcontext {
  27    int version;
  28    unsigned long gregs[32];
  29};
  30
  31struct target_ucontext {
  32    abi_ulong tuc_flags;
  33    abi_ulong tuc_link;
  34    target_stack_t tuc_stack;
  35    struct target_sigcontext tuc_mcontext;
  36    target_sigset_t tuc_sigmask;   /* mask last for extensibility */
  37};
  38
  39struct target_rt_sigframe {
  40    struct target_siginfo info;
  41    struct target_ucontext uc;
  42};
  43
  44static int rt_setup_ucontext(struct target_ucontext *uc, CPUNios2State *env)
  45{
  46    unsigned long *gregs = uc->tuc_mcontext.gregs;
  47
  48    __put_user(MCONTEXT_VERSION, &uc->tuc_mcontext.version);
  49    __put_user(env->regs[1], &gregs[0]);
  50    __put_user(env->regs[2], &gregs[1]);
  51    __put_user(env->regs[3], &gregs[2]);
  52    __put_user(env->regs[4], &gregs[3]);
  53    __put_user(env->regs[5], &gregs[4]);
  54    __put_user(env->regs[6], &gregs[5]);
  55    __put_user(env->regs[7], &gregs[6]);
  56    __put_user(env->regs[8], &gregs[7]);
  57    __put_user(env->regs[9], &gregs[8]);
  58    __put_user(env->regs[10], &gregs[9]);
  59    __put_user(env->regs[11], &gregs[10]);
  60    __put_user(env->regs[12], &gregs[11]);
  61    __put_user(env->regs[13], &gregs[12]);
  62    __put_user(env->regs[14], &gregs[13]);
  63    __put_user(env->regs[15], &gregs[14]);
  64    __put_user(env->regs[16], &gregs[15]);
  65    __put_user(env->regs[17], &gregs[16]);
  66    __put_user(env->regs[18], &gregs[17]);
  67    __put_user(env->regs[19], &gregs[18]);
  68    __put_user(env->regs[20], &gregs[19]);
  69    __put_user(env->regs[21], &gregs[20]);
  70    __put_user(env->regs[22], &gregs[21]);
  71    __put_user(env->regs[23], &gregs[22]);
  72    __put_user(env->regs[R_RA], &gregs[23]);
  73    __put_user(env->regs[R_FP], &gregs[24]);
  74    __put_user(env->regs[R_GP], &gregs[25]);
  75    __put_user(env->regs[R_EA], &gregs[27]);
  76    __put_user(env->regs[R_SP], &gregs[28]);
  77
  78    return 0;
  79}
  80
  81static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc,
  82                               int *pr2)
  83{
  84    int temp;
  85    unsigned long *gregs = uc->tuc_mcontext.gregs;
  86
  87    /* Always make any pending restarted system calls return -EINTR */
  88    /* current->restart_block.fn = do_no_restart_syscall; */
  89
  90    __get_user(temp, &uc->tuc_mcontext.version);
  91    if (temp != MCONTEXT_VERSION) {
  92        return 1;
  93    }
  94
  95    /* restore passed registers */
  96    __get_user(env->regs[1], &gregs[0]);
  97    __get_user(env->regs[2], &gregs[1]);
  98    __get_user(env->regs[3], &gregs[2]);
  99    __get_user(env->regs[4], &gregs[3]);
 100    __get_user(env->regs[5], &gregs[4]);
 101    __get_user(env->regs[6], &gregs[5]);
 102    __get_user(env->regs[7], &gregs[6]);
 103    __get_user(env->regs[8], &gregs[7]);
 104    __get_user(env->regs[9], &gregs[8]);
 105    __get_user(env->regs[10], &gregs[9]);
 106    __get_user(env->regs[11], &gregs[10]);
 107    __get_user(env->regs[12], &gregs[11]);
 108    __get_user(env->regs[13], &gregs[12]);
 109    __get_user(env->regs[14], &gregs[13]);
 110    __get_user(env->regs[15], &gregs[14]);
 111    __get_user(env->regs[16], &gregs[15]);
 112    __get_user(env->regs[17], &gregs[16]);
 113    __get_user(env->regs[18], &gregs[17]);
 114    __get_user(env->regs[19], &gregs[18]);
 115    __get_user(env->regs[20], &gregs[19]);
 116    __get_user(env->regs[21], &gregs[20]);
 117    __get_user(env->regs[22], &gregs[21]);
 118    __get_user(env->regs[23], &gregs[22]);
 119    /* gregs[23] is handled below */
 120    /* Verify, should this be settable */
 121    __get_user(env->regs[R_FP], &gregs[24]);
 122    /* Verify, should this be settable */
 123    __get_user(env->regs[R_GP], &gregs[25]);
 124    /* Not really necessary no user settable bits */
 125    __get_user(temp, &gregs[26]);
 126    __get_user(env->regs[R_EA], &gregs[27]);
 127
 128    __get_user(env->regs[R_RA], &gregs[23]);
 129    __get_user(env->regs[R_SP], &gregs[28]);
 130
 131    target_restore_altstack(&uc->tuc_stack, env);
 132
 133    *pr2 = env->regs[2];
 134    return 0;
 135}
 136
 137static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
 138                          size_t frame_size)
 139{
 140    unsigned long usp;
 141
 142    /* This is the X/Open sanctioned signal stack switching.  */
 143    usp = target_sigsp(get_sp_from_cpustate(env), ka);
 144
 145    /* Verify, is it 32 or 64 bit aligned */
 146    return (void *)((usp - frame_size) & -8UL);
 147}
 148
 149void setup_rt_frame(int sig, struct target_sigaction *ka,
 150                    target_siginfo_t *info,
 151                    target_sigset_t *set,
 152                    CPUNios2State *env)
 153{
 154    struct target_rt_sigframe *frame;
 155    int i, err = 0;
 156
 157    frame = get_sigframe(ka, env, sizeof(*frame));
 158
 159    if (ka->sa_flags & SA_SIGINFO) {
 160        tswap_siginfo(&frame->info, info);
 161    }
 162
 163    /* Create the ucontext.  */
 164    __put_user(0, &frame->uc.tuc_flags);
 165    __put_user(0, &frame->uc.tuc_link);
 166    target_save_altstack(&frame->uc.tuc_stack, env);
 167    err |= rt_setup_ucontext(&frame->uc, env);
 168    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 169        __put_user((abi_ulong)set->sig[i],
 170            (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
 171    }
 172
 173    if (err) {
 174        goto give_sigsegv;
 175    }
 176
 177    /* Set up to return from userspace; jump to fixed address sigreturn
 178       trampoline on kuser page.  */
 179    env->regs[R_RA] = (unsigned long) (0x1044);
 180
 181    /* Set up registers for signal handler */
 182    env->regs[R_SP] = (unsigned long) frame;
 183    env->regs[4] = (unsigned long) sig;
 184    env->regs[5] = (unsigned long) &frame->info;
 185    env->regs[6] = (unsigned long) &frame->uc;
 186    env->regs[R_EA] = (unsigned long) ka->_sa_handler;
 187    return;
 188
 189give_sigsegv:
 190    if (sig == TARGET_SIGSEGV) {
 191        ka->_sa_handler = TARGET_SIG_DFL;
 192    }
 193    force_sigsegv(sig);
 194    return;
 195}
 196
 197long do_sigreturn(CPUNios2State *env)
 198{
 199    trace_user_do_sigreturn(env, 0);
 200    qemu_log_mask(LOG_UNIMP, "do_sigreturn: not implemented\n");
 201    return -TARGET_ENOSYS;
 202}
 203
 204long do_rt_sigreturn(CPUNios2State *env)
 205{
 206    /* Verify, can we follow the stack back */
 207    abi_ulong frame_addr = env->regs[R_SP];
 208    struct target_rt_sigframe *frame;
 209    sigset_t set;
 210    int rval;
 211
 212    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 213        goto badframe;
 214    }
 215
 216    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 217    do_sigprocmask(SIG_SETMASK, &set, NULL);
 218
 219    if (rt_restore_ucontext(env, &frame->uc, &rval)) {
 220        goto badframe;
 221    }
 222
 223    unlock_user_struct(frame, frame_addr, 0);
 224    return rval;
 225
 226badframe:
 227    unlock_user_struct(frame, frame_addr, 0);
 228    force_sig(TARGET_SIGSEGV);
 229    return 0;
 230}
 231