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