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
  26 struct target_sigcontext {
  27     int version;
  28     unsigned long gregs[32];
  29 };
  30
  31 struct 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
  39 struct target_rt_sigframe {
  40     struct target_siginfo info;
  41     struct target_ucontext uc;
  42 };
  43
  44 static 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
  81 static 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
 137 static 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
 149 void 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
 189 give_sigsegv:
 190     if (sig == TARGET_SIGSEGV) {
 191         ka->_sa_handler = TARGET_SIG_DFL;
 192     }
 193     force_sigsegv(sig);
 194     return;
 195 }
 196
 197 long 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
 204 long 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
 226 badframe:
 227     unlock_user_struct(frame, frame_addr, 0);
 228     force_sig(TARGET_SIGSEGV);
 229     return 0;
 230 }