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 "target_signal.h"
  22 #include "signal-common.h"
  23 #include "linux-user/trace.h"
  24
  25 #define MCONTEXT_VERSION 2
  26
  27 struct target_sigcontext {
  28     int version;
  29     unsigned long gregs[32];
  30 };
  31
  32 struct 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
  40 struct target_rt_sigframe {
  41     struct target_siginfo info;
  42     struct target_ucontext uc;
  43 };
  44
  45 static int 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->regs[R_EA], &gregs[27]);
  77     __put_user(env->regs[R_SP], &gregs[28]);
  78
  79     return 0;
  80 }
  81
  82 static int rt_restore_ucontext(CPUNios2State *env, struct target_ucontext *uc,
  83                                int *pr2)
  84 {
  85     int temp;
  86     abi_ulong off, frame_addr = env->regs[R_SP];
  87     unsigned long *gregs = uc->tuc_mcontext.gregs;
  88     int err;
  89
  90     /* Always make any pending restarted system calls return -EINTR */
  91     /* current->restart_block.fn = do_no_restart_syscall; */
  92
  93     __get_user(temp, &uc->tuc_mcontext.version);
  94     if (temp != MCONTEXT_VERSION) {
  95         return 1;
  96     }
  97
  98     /* restore passed registers */
  99     __get_user(env->regs[1], &gregs[0]);
 100     __get_user(env->regs[2], &gregs[1]);
 101     __get_user(env->regs[3], &gregs[2]);
 102     __get_user(env->regs[4], &gregs[3]);
 103     __get_user(env->regs[5], &gregs[4]);
 104     __get_user(env->regs[6], &gregs[5]);
 105     __get_user(env->regs[7], &gregs[6]);
 106     __get_user(env->regs[8], &gregs[7]);
 107     __get_user(env->regs[9], &gregs[8]);
 108     __get_user(env->regs[10], &gregs[9]);
 109     __get_user(env->regs[11], &gregs[10]);
 110     __get_user(env->regs[12], &gregs[11]);
 111     __get_user(env->regs[13], &gregs[12]);
 112     __get_user(env->regs[14], &gregs[13]);
 113     __get_user(env->regs[15], &gregs[14]);
 114     __get_user(env->regs[16], &gregs[15]);
 115     __get_user(env->regs[17], &gregs[16]);
 116     __get_user(env->regs[18], &gregs[17]);
 117     __get_user(env->regs[19], &gregs[18]);
 118     __get_user(env->regs[20], &gregs[19]);
 119     __get_user(env->regs[21], &gregs[20]);
 120     __get_user(env->regs[22], &gregs[21]);
 121     __get_user(env->regs[23], &gregs[22]);
 122     /* gregs[23] is handled below */
 123     /* Verify, should this be settable */
 124     __get_user(env->regs[R_FP], &gregs[24]);
 125     /* Verify, should this be settable */
 126     __get_user(env->regs[R_GP], &gregs[25]);
 127     /* Not really necessary no user settable bits */
 128     __get_user(temp, &gregs[26]);
 129     __get_user(env->regs[R_EA], &gregs[27]);
 130
 131     __get_user(env->regs[R_RA], &gregs[23]);
 132     __get_user(env->regs[R_SP], &gregs[28]);
 133
 134     off = offsetof(struct target_rt_sigframe, uc.tuc_stack);
 135     err = do_sigaltstack(frame_addr + off, 0, get_sp_from_cpustate(env));
 136     if (err == -EFAULT) {
 137         return 1;
 138     }
 139
 140     *pr2 = env->regs[2];
 141     return 0;
 142 }
 143
 144 static void *get_sigframe(struct target_sigaction *ka, CPUNios2State *env,
 145                           size_t frame_size)
 146 {
 147     unsigned long usp;
 148
 149     /* This is the X/Open sanctioned signal stack switching.  */
 150     usp = target_sigsp(get_sp_from_cpustate(env), ka);
 151
 152     /* Verify, is it 32 or 64 bit aligned */
 153     return (void *)((usp - frame_size) & -8UL);
 154 }
 155
 156 void setup_rt_frame(int sig, struct target_sigaction *ka,
 157                     target_siginfo_t *info,
 158                     target_sigset_t *set,
 159                     CPUNios2State *env)
 160 {
 161     struct target_rt_sigframe *frame;
 162     int i, err = 0;
 163
 164     frame = get_sigframe(ka, env, sizeof(*frame));
 165
 166     if (ka->sa_flags & SA_SIGINFO) {
 167         tswap_siginfo(&frame->info, info);
 168     }
 169
 170     /* Create the ucontext.  */
 171     __put_user(0, &frame->uc.tuc_flags);
 172     __put_user(0, &frame->uc.tuc_link);
 173     target_save_altstack(&frame->uc.tuc_stack, env);
 174     err |= rt_setup_ucontext(&frame->uc, env);
 175     for (i = 0; i < TARGET_NSIG_WORDS; i++) {
 176         __put_user((abi_ulong)set->sig[i],
 177             (abi_ulong *)&frame->uc.tuc_sigmask.sig[i]);
 178     }
 179
 180     if (err) {
 181         goto give_sigsegv;
 182     }
 183
 184     /* Set up to return from userspace; jump to fixed address sigreturn
 185        trampoline on kuser page.  */
 186     env->regs[R_RA] = (unsigned long) (0x1044);
 187
 188     /* Set up registers for signal handler */
 189     env->regs[R_SP] = (unsigned long) frame;
 190     env->regs[4] = (unsigned long) sig;
 191     env->regs[5] = (unsigned long) &frame->info;
 192     env->regs[6] = (unsigned long) &frame->uc;
 193     env->regs[R_EA] = (unsigned long) ka->_sa_handler;
 194     return;
 195
 196 give_sigsegv:
 197     if (sig == TARGET_SIGSEGV) {
 198         ka->_sa_handler = TARGET_SIG_DFL;
 199     }
 200     force_sigsegv(sig);
 201     return;
 202 }
 203
 204 long do_sigreturn(CPUNios2State *env)
 205 {
 206     trace_user_do_sigreturn(env, 0);
 207     fprintf(stderr, "do_sigreturn: not implemented\n");
 208     return -TARGET_ENOSYS;
 209 }
 210
 211 long do_rt_sigreturn(CPUNios2State *env)
 212 {
 213     /* Verify, can we follow the stack back */
 214     abi_ulong frame_addr = env->regs[R_SP];
 215     struct target_rt_sigframe *frame;
 216     sigset_t set;
 217     int rval;
 218
 219     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 220         goto badframe;
 221     }
 222
 223     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 224     do_sigprocmask(SIG_SETMASK, &set, NULL);
 225
 226     if (rt_restore_ucontext(env, &frame->uc, &rval)) {
 227         goto badframe;
 228     }
 229
 230     unlock_user_struct(frame, frame_addr, 0);
 231     return rval;
 232
 233 badframe:
 234     unlock_user_struct(frame, frame_addr, 0);
 235     force_sig(TARGET_SIGSEGV);
 236     return 0;
 237 }