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     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
 143 static 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
 155 void 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
 195 give_sigsegv:
 196     if (sig == TARGET_SIGSEGV) {
 197         ka->_sa_handler = TARGET_SIG_DFL;
 198     }
 199     force_sigsegv(sig);
 200     return;
 201 }
 202
 203 long 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
 210 long 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
 232 badframe:
 233     unlock_user_struct(frame, frame_addr, 0);
 234     force_sig(TARGET_SIGSEGV);
 235     return 0;
 236 }