linux-user/xtensa/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 struct target_sigcontext {
  25     abi_ulong sc_pc;
  26     abi_ulong sc_ps;
  27     abi_ulong sc_lbeg;
  28     abi_ulong sc_lend;
  29     abi_ulong sc_lcount;
  30     abi_ulong sc_sar;
  31     abi_ulong sc_acclo;
  32     abi_ulong sc_acchi;
  33     abi_ulong sc_a[16];
  34     abi_ulong sc_xtregs;
  35 };
  36
  37 struct target_ucontext {
  38     abi_ulong tuc_flags;
  39     abi_ulong tuc_link;
  40     target_stack_t tuc_stack;
  41     struct target_sigcontext tuc_mcontext;
  42     target_sigset_t tuc_sigmask;
  43 };
  44
  45 struct target_rt_sigframe {
  46     target_siginfo_t info;
  47     struct target_ucontext uc;
  48     /* TODO: xtregs */
  49     uint8_t retcode[6];
  50     abi_ulong window[4];
  51 };
  52
  53 static abi_ulong get_sigframe(struct target_sigaction *sa,
  54                               CPUXtensaState *env,
  55                               unsigned long framesize)
  56 {
  57     abi_ulong sp;
  58
  59     sp = target_sigsp(get_sp_from_cpustate(env), sa);
  60
  61     return (sp - framesize) & -16;
  62 }
  63
  64 static int flush_window_regs(CPUXtensaState *env)
  65 {
  66     uint32_t wb = env->sregs[WINDOW_BASE];
  67     uint32_t ws = xtensa_replicate_windowstart(env) >> (wb + 1);
  68     unsigned d = ctz32(ws) + 1;
  69     unsigned i;
  70     int ret = 0;
  71
  72     for (i = d; i < env->config->nareg / 4; i += d) {
  73         uint32_t ssp, osp;
  74         unsigned j;
  75
  76         ws >>= d;
  77         xtensa_rotate_window(env, d);
  78
  79         if (ws & 0x1) {
  80             ssp = env->regs[5];
  81             d = 1;
  82         } else if (ws & 0x2) {
  83             ssp = env->regs[9];
  84             ret |= get_user_ual(osp, env->regs[1] - 12);
  85             osp -= 32;
  86             d = 2;
  87         } else if (ws & 0x4) {
  88             ssp = env->regs[13];
  89             ret |= get_user_ual(osp, env->regs[1] - 12);
  90             osp -= 48;
  91             d = 3;
  92         } else {
  93             g_assert_not_reached();
  94         }
  95
  96         for (j = 0; j < 4; ++j) {
  97             ret |= put_user_ual(env->regs[j], ssp - 16 + j * 4);
  98         }
  99         for (j = 4; j < d * 4; ++j) {
 100             ret |= put_user_ual(env->regs[j], osp - 16 + j * 4);
 101         }
 102     }
 103     xtensa_rotate_window(env, d);
 104     g_assert(env->sregs[WINDOW_BASE] == wb);
 105     return ret == 0;
 106 }
 107
 108 static int setup_sigcontext(struct target_rt_sigframe *frame,
 109                             CPUXtensaState *env)
 110 {
 111     struct target_sigcontext *sc = &frame->uc.tuc_mcontext;
 112     int i;
 113
 114     __put_user(env->pc, &sc->sc_pc);
 115     __put_user(env->sregs[PS], &sc->sc_ps);
 116     __put_user(env->sregs[LBEG], &sc->sc_lbeg);
 117     __put_user(env->sregs[LEND], &sc->sc_lend);
 118     __put_user(env->sregs[LCOUNT], &sc->sc_lcount);
 119     if (!flush_window_regs(env)) {
 120         return 0;
 121     }
 122     for (i = 0; i < 16; ++i) {
 123         __put_user(env->regs[i], sc->sc_a + i);
 124     }
 125     __put_user(0, &sc->sc_xtregs);
 126     /* TODO: xtregs */
 127     return 1;
 128 }
 129
 130 void setup_rt_frame(int sig, struct target_sigaction *ka,
 131                     target_siginfo_t *info,
 132                     target_sigset_t *set, CPUXtensaState *env)
 133 {
 134     abi_ulong frame_addr;
 135     struct target_rt_sigframe *frame;
 136     uint32_t ra;
 137     int i;
 138
 139     frame_addr = get_sigframe(ka, env, sizeof(*frame));
 140     trace_user_setup_rt_frame(env, frame_addr);
 141
 142     if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
 143         goto give_sigsegv;
 144     }
 145
 146     if (ka->sa_flags & SA_SIGINFO) {
 147         tswap_siginfo(&frame->info, info);
 148     }
 149
 150     __put_user(0, &frame->uc.tuc_flags);
 151     __put_user(0, &frame->uc.tuc_link);
 152     target_save_altstack(&frame->uc.tuc_stack, env);
 153     if (!setup_sigcontext(frame, env)) {
 154         unlock_user_struct(frame, frame_addr, 0);
 155         goto give_sigsegv;
 156     }
 157     for (i = 0; i < TARGET_NSIG_WORDS; ++i) {
 158         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
 159     }
 160
 161     if (ka->sa_flags & TARGET_SA_RESTORER) {
 162         ra = ka->sa_restorer;
 163     } else {
 164         ra = frame_addr + offsetof(struct target_rt_sigframe, retcode);
 165 #ifdef TARGET_WORDS_BIGENDIAN
 166         /* Generate instruction:  MOVI a2, __NR_rt_sigreturn */
 167         __put_user(0x22, &frame->retcode[0]);
 168         __put_user(0x0a, &frame->retcode[1]);
 169         __put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
 170         /* Generate instruction:  SYSCALL */
 171         __put_user(0x00, &frame->retcode[3]);
 172         __put_user(0x05, &frame->retcode[4]);
 173         __put_user(0x00, &frame->retcode[5]);
 174 #else
 175         /* Generate instruction:  MOVI a2, __NR_rt_sigreturn */
 176         __put_user(0x22, &frame->retcode[0]);
 177         __put_user(0xa0, &frame->retcode[1]);
 178         __put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
 179         /* Generate instruction:  SYSCALL */
 180         __put_user(0x00, &frame->retcode[3]);
 181         __put_user(0x50, &frame->retcode[4]);
 182         __put_user(0x00, &frame->retcode[5]);
 183 #endif
 184     }
 185     env->sregs[PS] = PS_UM | (3 << PS_RING_SHIFT);
 186     if (xtensa_option_enabled(env->config, XTENSA_OPTION_WINDOWED_REGISTER)) {
 187         env->sregs[PS] |= PS_WOE | (1 << PS_CALLINC_SHIFT);
 188     }
 189     memset(env->regs, 0, sizeof(env->regs));
 190     env->pc = ka->_sa_handler;
 191     env->regs[1] = frame_addr;
 192     env->sregs[WINDOW_BASE] = 0;
 193     env->sregs[WINDOW_START] = 1;
 194
 195     env->regs[4] = (ra & 0x3fffffff) | 0x40000000;
 196     env->regs[6] = sig;
 197     env->regs[7] = frame_addr + offsetof(struct target_rt_sigframe, info);
 198     env->regs[8] = frame_addr + offsetof(struct target_rt_sigframe, uc);
 199     unlock_user_struct(frame, frame_addr, 1);
 200     return;
 201
 202 give_sigsegv:
 203     force_sigsegv(sig);
 204     return;
 205 }
 206
 207 static void restore_sigcontext(CPUXtensaState *env,
 208                                struct target_rt_sigframe *frame)
 209 {
 210     struct target_sigcontext *sc = &frame->uc.tuc_mcontext;
 211     uint32_t ps;
 212     int i;
 213
 214     __get_user(env->pc, &sc->sc_pc);
 215     __get_user(ps, &sc->sc_ps);
 216     __get_user(env->sregs[LBEG], &sc->sc_lbeg);
 217     __get_user(env->sregs[LEND], &sc->sc_lend);
 218     __get_user(env->sregs[LCOUNT], &sc->sc_lcount);
 219
 220     env->sregs[WINDOW_BASE] = 0;
 221     env->sregs[WINDOW_START] = 1;
 222     env->sregs[PS] = deposit32(env->sregs[PS],
 223                                PS_CALLINC_SHIFT,
 224                                PS_CALLINC_LEN,
 225                                extract32(ps, PS_CALLINC_SHIFT,
 226                                          PS_CALLINC_LEN));
 227     for (i = 0; i < 16; ++i) {
 228         __get_user(env->regs[i], sc->sc_a + i);
 229     }
 230     /* TODO: xtregs */
 231 }
 232
 233 long do_rt_sigreturn(CPUXtensaState *env)
 234 {
 235     abi_ulong frame_addr = env->regs[1];
 236     struct target_rt_sigframe *frame;
 237     sigset_t set;
 238
 239     trace_user_do_rt_sigreturn(env, frame_addr);
 240     if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
 241         goto badframe;
 242     }
 243     target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
 244     set_sigmask(&set);
 245
 246     restore_sigcontext(env, frame);
 247
 248     if (do_sigaltstack(frame_addr +
 249                        offsetof(struct target_rt_sigframe, uc.tuc_stack),
 250                        0, get_sp_from_cpustate(env)) == -TARGET_EFAULT) {
 251         goto badframe;
 252     }
 253     unlock_user_struct(frame, frame_addr, 0);
 254     return -TARGET_QEMU_ESIGRETURN;
 255
 256 badframe:
 257     unlock_user_struct(frame, frame_addr, 0);
 258     force_sig(TARGET_SIGSEGV);
 259     return -TARGET_QEMU_ESIGRETURN;
 260 }