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    abi_ulong off, frame_addr = env->regs[R_SP];
  86    unsigned long *gregs = uc->tuc_mcontext.gregs;
  87    int err;
  88
  89    /* Always make any pending restarted system calls return -EINTR */
  90    /* current->restart_block.fn = do_no_restart_syscall; */
  91
  92    __get_user(temp, &uc->tuc_mcontext.version);
  93    if (temp != MCONTEXT_VERSION) {
  94        return 1;
  95    }
  96
  97    /* restore passed registers */
  98    __get_user(env->regs[1], &gregs[0]);
  99    __get_user(env->regs[2], &gregs[1]);
 100    __get_user(env->regs[3], &gregs[2]);
 101    __get_user(env->regs[4], &gregs[3]);
 102    __get_user(env->regs[5], &gregs[4]);
 103    __get_user(env->regs[6], &gregs[5]);
 104    __get_user(env->regs[7], &gregs[6]);
 105    __get_user(env->regs[8], &gregs[7]);
 106    __get_user(env->regs[9], &gregs[8]);
 107    __get_user(env->regs[10], &gregs[9]);
 108    __get_user(env->regs[11], &gregs[10]);
 109    __get_user(env->regs[12], &gregs[11]);
 110    __get_user(env->regs[13], &gregs[12]);
 111    __get_user(env->regs[14], &gregs[13]);
 112    __get_user(env->regs[15], &gregs[14]);
 113    __get_user(env->regs[16], &gregs[15]);
 114    __get_user(env->regs[17], &gregs[16]);
 115    __get_user(env->regs[18], &gregs[17]);
 116    __get_user(env->regs[19], &gregs[18]);
 117    __get_user(env->regs[20], &gregs[19]);
 118    __get_user(env->regs[21], &gregs[20]);
 119    __get_user(env->regs[22], &gregs[21]);
 120    __get_user(env->regs[23], &gregs[22]);
 121    /* gregs[23] is handled below */
 122    /* Verify, should this be settable */
 123    __get_user(env->regs[R_FP], &gregs[24]);
 124    /* Verify, should this be settable */
 125    __get_user(env->regs[R_GP], &gregs[25]);
 126    /* Not really necessary no user settable bits */
 127    __get_user(temp, &gregs[26]);
 128    __get_user(env->regs[R_EA], &gregs[27]);
 129
 130    __get_user(env->regs[R_RA], &gregs[23]);
 131    __get_user(env->regs[R_SP], &gregs[28]);
 132
 133    off = offsetof(struct target_rt_sigframe, uc.tuc_stack);
 134    err = do_sigaltstack(frame_addr + off, 0, get_sp_from_cpustate(env));
 135    if (err == -EFAULT) {
 136        return 1;
 137    }
 138
 139    *pr2 = env->regs[2];
 140    return 0;
 141}
 142
 143static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
 144                          size_t frame_size)
 145{
 146    unsigned long usp;
 147
 148    /* This is the X/Open sanctioned signal stack switching.  */
 149    usp = target_sigsp(get_sp_from_cpustate(env), ka);
 150
 151    /* Verify, is it 32 or 64 bit aligned */
 152    return (void *)((usp - frame_size) & -8UL);
 153}
 154
 155void setup_rt_frame(int sig, struct target_sigaction *ka,
 156                    target_siginfo_t *info,
 157                    target_sigset_t *set,
 158                    CPUNios2State *env)
 159{
 160    struct target_rt_sigframe *frame;
 161    int i, err = 0;
 162
 163    frame = get_sigframe(ka, env, sizeof(*frame));
 164
 165    if (ka->sa_flags & SA_SIGINFO) {
 166        tswap_siginfo(&frame->info, info);
 167    }
 168
 169    /* Create the ucontext.  */
 170    __put_user(0, &frame->uc.tuc_flags);
 171    __put_user(0, &frame->uc.tuc_link);
 172    target_save_altstack(&frame->uc.tuc_stack, env);
 173    err |= rt_setup_ucontext(&frame->uc, env);
 174    for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 175        __put_user((abi_ulong)set->sig[i],
 176            (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
 177    }
 178
 179    if (err) {
 180        goto give_sigsegv;
 181    }
 182
 183    /* Set up to return from userspace; jump to fixed address sigreturn
 184       trampoline on kuser page.  */
 185    env->regs[R_RA] = (unsigned long) (0x1044);
 186
 187    /* Set up registers for signal handler */
 188    env->regs[R_SP] = (unsigned long) frame;
 189    env->regs[4] = (unsigned long) sig;
 190    env->regs[5] = (unsigned long) &frame->info;
 191    env->regs[6] = (unsigned long) &frame->uc;
 192    env->regs[R_EA] = (unsigned long) ka->_sa_handler;
 193    return;
 194
 195give_sigsegv:
 196    if (sig == TARGET_SIGSEGV) {
 197        ka->_sa_handler = TARGET_SIG_DFL;
 198    }
 199    force_sigsegv(sig);
 200    return;
 201}
 202
 203long do_sigreturn(CPUNios2State *env)
 204{
 205    trace_user_do_sigreturn(env, 0);
 206    qemu_log_mask(LOG_UNIMP, "do_sigreturn: not implemented\n");
 207    return -TARGET_ENOSYS;
 208}
 209
 210long do_rt_sigreturn(CPUNios2State *env)
 211{
 212    /* Verify, can we follow the stack back */
 213    abi_ulong frame_addr = env->regs[R_SP];
 214    struct target_rt_sigframe *frame;
 215    sigset_t set;
 216    int rval;
 217
 218    if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 219        goto badframe;
 220    }
 221
 222    target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 223    do_sigprocmask(SIG_SETMASK, &set, NULL);
 224
 225    if (rt_restore_ucontext(env, &frame->uc, &rval)) {
 226        goto badframe;
 227    }
 228
 229    unlock_user_struct(frame, frame_addr, 0);
 230    return rval;
 231
 232badframe:
 233    unlock_user_struct(frame, frame_addr, 0);
 234    force_sig(TARGET_SIGSEGV);
 235    return 0;
 236}
 237