user-exec.c

   1 /*
   2  *  User emulator execution
   3  *
   4  *  Copyright (c) 2003-2005 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #include "config.h"
  20 #include "cpu.h"
  21 #include "disas.h"
  22 #include "tcg.h"
  23
  24 #undef EAX
  25 #undef ECX
  26 #undef EDX
  27 #undef EBX
  28 #undef ESP
  29 #undef EBP
  30 #undef ESI
  31 #undef EDI
  32 #undef EIP
  33 #include <signal.h>
  34 #ifdef __linux__
  35 #include <sys/ucontext.h>
  36 #endif
  37
  38 //#define DEBUG_SIGNAL
  39
  40 static void exception_action(CPUArchState *env1)
  41 {
  42 #if defined(TARGET_I386)
  43     raise_exception_err(env1, env1->exception_index, env1->error_code);
  44 #else
  45     cpu_loop_exit(env1);
  46 #endif
  47 }
  48
  49 /* exit the current TB from a signal handler. The host registers are
  50    restored in a state compatible with the CPU emulator
  51  */
  52 void cpu_resume_from_signal(CPUArchState *env1, void *puc)
  53 {
  54 #ifdef __linux__
  55     struct ucontext *uc = puc;
  56 #elif defined(__OpenBSD__)
  57     struct sigcontext *uc = puc;
  58 #endif
  59
  60     if (puc) {
  61         /* XXX: use siglongjmp ? */
  62 #ifdef __linux__
  63 #ifdef __ia64
  64         sigprocmask(SIG_SETMASK, (sigset_t *)&uc->uc_sigmask, NULL);
  65 #else
  66         sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
  67 #endif
  68 #elif defined(__OpenBSD__)
  69         sigprocmask(SIG_SETMASK, &uc->sc_mask, NULL);
  70 #endif
  71     }
  72     env1->exception_index = -1;
  73     longjmp(env1->jmp_env, 1);
  74 }
  75
  76 /* 'pc' is the host PC at which the exception was raised. 'address' is
  77    the effective address of the memory exception. 'is_write' is 1 if a
  78    write caused the exception and otherwise 0'. 'old_set' is the
  79    signal set which should be restored */
  80 static inline int handle_cpu_signal(uintptr_t pc, unsigned long address,
  81                                     int is_write, sigset_t *old_set,
  82                                     void *puc)
  83 {
  84     int ret;
  85
  86 #if defined(DEBUG_SIGNAL)
  87     qemu_printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
  88                 pc, address, is_write, *(unsigned long *)old_set);
  89 #endif
  90     /* XXX: locking issue */
  91     if (is_write && h2g_valid(address)
  92         && page_unprotect(h2g(address), pc, puc)) {
  93         return 1;
  94     }
  95
  96     /* see if it is an MMU fault */
  97     ret = cpu_handle_mmu_fault(cpu_single_env, address, is_write,
  98                                MMU_USER_IDX);
  99     if (ret < 0) {
 100         return 0; /* not an MMU fault */
 101     }
 102     if (ret == 0) {
 103         return 1; /* the MMU fault was handled without causing real CPU fault */
 104     }
 105     /* now we have a real cpu fault */
 106     cpu_restore_state(cpu_single_env, pc);
 107
 108     /* we restore the process signal mask as the sigreturn should
 109        do it (XXX: use sigsetjmp) */
 110     sigprocmask(SIG_SETMASK, old_set, NULL);
 111     exception_action(cpu_single_env);
 112
 113     /* never comes here */
 114     return 1;
 115 }
 116
 117 #if defined(__i386__)
 118
 119 #if defined(__APPLE__)
 120 #include <sys/ucontext.h>
 121
 122 #define EIP_sig(context)  (*((unsigned long *)&(context)->uc_mcontext->ss.eip))
 123 #define TRAP_sig(context)    ((context)->uc_mcontext->es.trapno)
 124 #define ERROR_sig(context)   ((context)->uc_mcontext->es.err)
 125 #define MASK_sig(context)    ((context)->uc_sigmask)
 126 #elif defined(__NetBSD__)
 127 #include <ucontext.h>
 128
 129 #define EIP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_EIP])
 130 #define TRAP_sig(context)    ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
 131 #define ERROR_sig(context)   ((context)->uc_mcontext.__gregs[_REG_ERR])
 132 #define MASK_sig(context)    ((context)->uc_sigmask)
 133 #elif defined(__FreeBSD__) || defined(__DragonFly__)
 134 #include <ucontext.h>
 135
 136 #define EIP_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_eip))
 137 #define TRAP_sig(context)    ((context)->uc_mcontext.mc_trapno)
 138 #define ERROR_sig(context)   ((context)->uc_mcontext.mc_err)
 139 #define MASK_sig(context)    ((context)->uc_sigmask)
 140 #elif defined(__OpenBSD__)
 141 #define EIP_sig(context)     ((context)->sc_eip)
 142 #define TRAP_sig(context)    ((context)->sc_trapno)
 143 #define ERROR_sig(context)   ((context)->sc_err)
 144 #define MASK_sig(context)    ((context)->sc_mask)
 145 #else
 146 #define EIP_sig(context)     ((context)->uc_mcontext.gregs[REG_EIP])
 147 #define TRAP_sig(context)    ((context)->uc_mcontext.gregs[REG_TRAPNO])
 148 #define ERROR_sig(context)   ((context)->uc_mcontext.gregs[REG_ERR])
 149 #define MASK_sig(context)    ((context)->uc_sigmask)
 150 #endif
 151
 152 int cpu_signal_handler(int host_signum, void *pinfo,
 153                        void *puc)
 154 {
 155     siginfo_t *info = pinfo;
 156 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
 157     ucontext_t *uc = puc;
 158 #elif defined(__OpenBSD__)
 159     struct sigcontext *uc = puc;
 160 #else
 161     struct ucontext *uc = puc;
 162 #endif
 163     unsigned long pc;
 164     int trapno;
 165
 166 #ifndef REG_EIP
 167 /* for glibc 2.1 */
 168 #define REG_EIP    EIP
 169 #define REG_ERR    ERR
 170 #define REG_TRAPNO TRAPNO
 171 #endif
 172     pc = EIP_sig(uc);
 173     trapno = TRAP_sig(uc);
 174     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 175                              trapno == 0xe ?
 176                              (ERROR_sig(uc) >> 1) & 1 : 0,
 177                              &MASK_sig(uc), puc);
 178 }
 179
 180 #elif defined(__x86_64__)
 181
 182 #ifdef __NetBSD__
 183 #define PC_sig(context)       _UC_MACHINE_PC(context)
 184 #define TRAP_sig(context)     ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
 185 #define ERROR_sig(context)    ((context)->uc_mcontext.__gregs[_REG_ERR])
 186 #define MASK_sig(context)     ((context)->uc_sigmask)
 187 #elif defined(__OpenBSD__)
 188 #define PC_sig(context)       ((context)->sc_rip)
 189 #define TRAP_sig(context)     ((context)->sc_trapno)
 190 #define ERROR_sig(context)    ((context)->sc_err)
 191 #define MASK_sig(context)     ((context)->sc_mask)
 192 #elif defined(__FreeBSD__) || defined(__DragonFly__)
 193 #include <ucontext.h>
 194
 195 #define PC_sig(context)  (*((unsigned long *)&(context)->uc_mcontext.mc_rip))
 196 #define TRAP_sig(context)     ((context)->uc_mcontext.mc_trapno)
 197 #define ERROR_sig(context)    ((context)->uc_mcontext.mc_err)
 198 #define MASK_sig(context)     ((context)->uc_sigmask)
 199 #else
 200 #define PC_sig(context)       ((context)->uc_mcontext.gregs[REG_RIP])
 201 #define TRAP_sig(context)     ((context)->uc_mcontext.gregs[REG_TRAPNO])
 202 #define ERROR_sig(context)    ((context)->uc_mcontext.gregs[REG_ERR])
 203 #define MASK_sig(context)     ((context)->uc_sigmask)
 204 #endif
 205
 206 int cpu_signal_handler(int host_signum, void *pinfo,
 207                        void *puc)
 208 {
 209     siginfo_t *info = pinfo;
 210     unsigned long pc;
 211 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
 212     ucontext_t *uc = puc;
 213 #elif defined(__OpenBSD__)
 214     struct sigcontext *uc = puc;
 215 #else
 216     struct ucontext *uc = puc;
 217 #endif
 218
 219     pc = PC_sig(uc);
 220     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 221                              TRAP_sig(uc) == 0xe ?
 222                              (ERROR_sig(uc) >> 1) & 1 : 0,
 223                              &MASK_sig(uc), puc);
 224 }
 225
 226 #elif defined(_ARCH_PPC)
 227
 228 /***********************************************************************
 229  * signal context platform-specific definitions
 230  * From Wine
 231  */
 232 #ifdef linux
 233 /* All Registers access - only for local access */
 234 #define REG_sig(reg_name, context)              \
 235     ((context)->uc_mcontext.regs->reg_name)
 236 /* Gpr Registers access  */
 237 #define GPR_sig(reg_num, context)              REG_sig(gpr[reg_num], context)
 238 /* Program counter */
 239 #define IAR_sig(context)                       REG_sig(nip, context)
 240 /* Machine State Register (Supervisor) */
 241 #define MSR_sig(context)                       REG_sig(msr, context)
 242 /* Count register */
 243 #define CTR_sig(context)                       REG_sig(ctr, context)
 244 /* User's integer exception register */
 245 #define XER_sig(context)                       REG_sig(xer, context)
 246 /* Link register */
 247 #define LR_sig(context)                        REG_sig(link, context)
 248 /* Condition register */
 249 #define CR_sig(context)                        REG_sig(ccr, context)
 250
 251 /* Float Registers access  */
 252 #define FLOAT_sig(reg_num, context)                                     \
 253     (((double *)((char *)((context)->uc_mcontext.regs + 48 * 4)))[reg_num])
 254 #define FPSCR_sig(context) \
 255     (*(int *)((char *)((context)->uc_mcontext.regs + (48 + 32 * 2) * 4)))
 256 /* Exception Registers access */
 257 #define DAR_sig(context)                       REG_sig(dar, context)
 258 #define DSISR_sig(context)                     REG_sig(dsisr, context)
 259 #define TRAP_sig(context)                      REG_sig(trap, context)
 260 #endif /* linux */
 261
 262 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 263 #include <ucontext.h>
 264 #define IAR_sig(context)               ((context)->uc_mcontext.mc_srr0)
 265 #define MSR_sig(context)               ((context)->uc_mcontext.mc_srr1)
 266 #define CTR_sig(context)               ((context)->uc_mcontext.mc_ctr)
 267 #define XER_sig(context)               ((context)->uc_mcontext.mc_xer)
 268 #define LR_sig(context)                ((context)->uc_mcontext.mc_lr)
 269 #define CR_sig(context)                ((context)->uc_mcontext.mc_cr)
 270 /* Exception Registers access */
 271 #define DAR_sig(context)               ((context)->uc_mcontext.mc_dar)
 272 #define DSISR_sig(context)             ((context)->uc_mcontext.mc_dsisr)
 273 #define TRAP_sig(context)              ((context)->uc_mcontext.mc_exc)
 274 #endif /* __FreeBSD__|| __FreeBSD_kernel__ */
 275
 276 #ifdef __APPLE__
 277 #include <sys/ucontext.h>
 278 typedef struct ucontext SIGCONTEXT;
 279 /* All Registers access - only for local access */
 280 #define REG_sig(reg_name, context)              \
 281     ((context)->uc_mcontext->ss.reg_name)
 282 #define FLOATREG_sig(reg_name, context)         \
 283     ((context)->uc_mcontext->fs.reg_name)
 284 #define EXCEPREG_sig(reg_name, context)         \
 285     ((context)->uc_mcontext->es.reg_name)
 286 #define VECREG_sig(reg_name, context)           \
 287     ((context)->uc_mcontext->vs.reg_name)
 288 /* Gpr Registers access */
 289 #define GPR_sig(reg_num, context)              REG_sig(r##reg_num, context)
 290 /* Program counter */
 291 #define IAR_sig(context)                       REG_sig(srr0, context)
 292 /* Machine State Register (Supervisor) */
 293 #define MSR_sig(context)                       REG_sig(srr1, context)
 294 #define CTR_sig(context)                       REG_sig(ctr, context)
 295 /* Link register */
 296 #define XER_sig(context)                       REG_sig(xer, context)
 297 /* User's integer exception register */
 298 #define LR_sig(context)                        REG_sig(lr, context)
 299 /* Condition register */
 300 #define CR_sig(context)                        REG_sig(cr, context)
 301 /* Float Registers access */
 302 #define FLOAT_sig(reg_num, context)             \
 303     FLOATREG_sig(fpregs[reg_num], context)
 304 #define FPSCR_sig(context)                      \
 305     ((double)FLOATREG_sig(fpscr, context))
 306 /* Exception Registers access */
 307 /* Fault registers for coredump */
 308 #define DAR_sig(context)                       EXCEPREG_sig(dar, context)
 309 #define DSISR_sig(context)                     EXCEPREG_sig(dsisr, context)
 310 /* number of powerpc exception taken */
 311 #define TRAP_sig(context)                      EXCEPREG_sig(exception, context)
 312 #endif /* __APPLE__ */
 313
 314 int cpu_signal_handler(int host_signum, void *pinfo,
 315                        void *puc)
 316 {
 317     siginfo_t *info = pinfo;
 318 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 319     ucontext_t *uc = puc;
 320 #else
 321     struct ucontext *uc = puc;
 322 #endif
 323     unsigned long pc;
 324     int is_write;
 325
 326     pc = IAR_sig(uc);
 327     is_write = 0;
 328 #if 0
 329     /* ppc 4xx case */
 330     if (DSISR_sig(uc) & 0x00800000) {
 331         is_write = 1;
 332     }
 333 #else
 334     if (TRAP_sig(uc) != 0x400 && (DSISR_sig(uc) & 0x02000000)) {
 335         is_write = 1;
 336     }
 337 #endif
 338     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 339                              is_write, &uc->uc_sigmask, puc);
 340 }
 341
 342 #elif defined(__alpha__)
 343
 344 int cpu_signal_handler(int host_signum, void *pinfo,
 345                            void *puc)
 346 {
 347     siginfo_t *info = pinfo;
 348     struct ucontext *uc = puc;
 349     uint32_t *pc = uc->uc_mcontext.sc_pc;
 350     uint32_t insn = *pc;
 351     int is_write = 0;
 352
 353     /* XXX: need kernel patch to get write flag faster */
 354     switch (insn >> 26) {
 355     case 0x0d: /* stw */
 356     case 0x0e: /* stb */
 357     case 0x0f: /* stq_u */
 358     case 0x24: /* stf */
 359     case 0x25: /* stg */
 360     case 0x26: /* sts */
 361     case 0x27: /* stt */
 362     case 0x2c: /* stl */
 363     case 0x2d: /* stq */
 364     case 0x2e: /* stl_c */
 365     case 0x2f: /* stq_c */
 366         is_write = 1;
 367     }
 368
 369     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 370                              is_write, &uc->uc_sigmask, puc);
 371 }
 372 #elif defined(__sparc__)
 373
 374 int cpu_signal_handler(int host_signum, void *pinfo,
 375                        void *puc)
 376 {
 377     siginfo_t *info = pinfo;
 378     int is_write;
 379     uint32_t insn;
 380 #if !defined(__arch64__) || defined(CONFIG_SOLARIS)
 381     uint32_t *regs = (uint32_t *)(info + 1);
 382     void *sigmask = (regs + 20);
 383     /* XXX: is there a standard glibc define ? */
 384     unsigned long pc = regs[1];
 385 #else
 386 #ifdef __linux__
 387     struct sigcontext *sc = puc;
 388     unsigned long pc = sc->sigc_regs.tpc;
 389     void *sigmask = (void *)sc->sigc_mask;
 390 #elif defined(__OpenBSD__)
 391     struct sigcontext *uc = puc;
 392     unsigned long pc = uc->sc_pc;
 393     void *sigmask = (void *)(long)uc->sc_mask;
 394 #endif
 395 #endif
 396
 397     /* XXX: need kernel patch to get write flag faster */
 398     is_write = 0;
 399     insn = *(uint32_t *)pc;
 400     if ((insn >> 30) == 3) {
 401         switch ((insn >> 19) & 0x3f) {
 402         case 0x05: /* stb */
 403         case 0x15: /* stba */
 404         case 0x06: /* sth */
 405         case 0x16: /* stha */
 406         case 0x04: /* st */
 407         case 0x14: /* sta */
 408         case 0x07: /* std */
 409         case 0x17: /* stda */
 410         case 0x0e: /* stx */
 411         case 0x1e: /* stxa */
 412         case 0x24: /* stf */
 413         case 0x34: /* stfa */
 414         case 0x27: /* stdf */
 415         case 0x37: /* stdfa */
 416         case 0x26: /* stqf */
 417         case 0x36: /* stqfa */
 418         case 0x25: /* stfsr */
 419         case 0x3c: /* casa */
 420         case 0x3e: /* casxa */
 421             is_write = 1;
 422             break;
 423         }
 424     }
 425     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 426                              is_write, sigmask, NULL);
 427 }
 428
 429 #elif defined(__arm__)
 430
 431 int cpu_signal_handler(int host_signum, void *pinfo,
 432                        void *puc)
 433 {
 434     siginfo_t *info = pinfo;
 435     struct ucontext *uc = puc;
 436     unsigned long pc;
 437     int is_write;
 438
 439 #if (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
 440     pc = uc->uc_mcontext.gregs[R15];
 441 #else
 442     pc = uc->uc_mcontext.arm_pc;
 443 #endif
 444     /* XXX: compute is_write */
 445     is_write = 0;
 446     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 447                              is_write,
 448                              &uc->uc_sigmask, puc);
 449 }
 450
 451 #elif defined(__mc68000)
 452
 453 int cpu_signal_handler(int host_signum, void *pinfo,
 454                        void *puc)
 455 {
 456     siginfo_t *info = pinfo;
 457     struct ucontext *uc = puc;
 458     unsigned long pc;
 459     int is_write;
 460
 461     pc = uc->uc_mcontext.gregs[16];
 462     /* XXX: compute is_write */
 463     is_write = 0;
 464     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 465                              is_write,
 466                              &uc->uc_sigmask, puc);
 467 }
 468
 469 #elif defined(__ia64)
 470
 471 #ifndef __ISR_VALID
 472   /* This ought to be in <bits/siginfo.h>... */
 473 # define __ISR_VALID    1
 474 #endif
 475
 476 int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
 477 {
 478     siginfo_t *info = pinfo;
 479     struct ucontext *uc = puc;
 480     unsigned long ip;
 481     int is_write = 0;
 482
 483     ip = uc->uc_mcontext.sc_ip;
 484     switch (host_signum) {
 485     case SIGILL:
 486     case SIGFPE:
 487     case SIGSEGV:
 488     case SIGBUS:
 489     case SIGTRAP:
 490         if (info->si_code && (info->si_segvflags & __ISR_VALID)) {
 491             /* ISR.W (write-access) is bit 33:  */
 492             is_write = (info->si_isr >> 33) & 1;
 493         }
 494         break;
 495
 496     default:
 497         break;
 498     }
 499     return handle_cpu_signal(ip, (unsigned long)info->si_addr,
 500                              is_write,
 501                              (sigset_t *)&uc->uc_sigmask, puc);
 502 }
 503
 504 #elif defined(__s390__)
 505
 506 int cpu_signal_handler(int host_signum, void *pinfo,
 507                        void *puc)
 508 {
 509     siginfo_t *info = pinfo;
 510     struct ucontext *uc = puc;
 511     unsigned long pc;
 512     uint16_t *pinsn;
 513     int is_write = 0;
 514
 515     pc = uc->uc_mcontext.psw.addr;
 516
 517     /* ??? On linux, the non-rt signal handler has 4 (!) arguments instead
 518        of the normal 2 arguments.  The 3rd argument contains the "int_code"
 519        from the hardware which does in fact contain the is_write value.
 520        The rt signal handler, as far as I can tell, does not give this value
 521        at all.  Not that we could get to it from here even if it were.  */
 522     /* ??? This is not even close to complete, since it ignores all
 523        of the read-modify-write instructions.  */
 524     pinsn = (uint16_t *)pc;
 525     switch (pinsn[0] >> 8) {
 526     case 0x50: /* ST */
 527     case 0x42: /* STC */
 528     case 0x40: /* STH */
 529         is_write = 1;
 530         break;
 531     case 0xc4: /* RIL format insns */
 532         switch (pinsn[0] & 0xf) {
 533         case 0xf: /* STRL */
 534         case 0xb: /* STGRL */
 535         case 0x7: /* STHRL */
 536             is_write = 1;
 537         }
 538         break;
 539     case 0xe3: /* RXY format insns */
 540         switch (pinsn[2] & 0xff) {
 541         case 0x50: /* STY */
 542         case 0x24: /* STG */
 543         case 0x72: /* STCY */
 544         case 0x70: /* STHY */
 545         case 0x8e: /* STPQ */
 546         case 0x3f: /* STRVH */
 547         case 0x3e: /* STRV */
 548         case 0x2f: /* STRVG */
 549             is_write = 1;
 550         }
 551         break;
 552     }
 553     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 554                              is_write, &uc->uc_sigmask, puc);
 555 }
 556
 557 #elif defined(__mips__)
 558
 559 int cpu_signal_handler(int host_signum, void *pinfo,
 560                        void *puc)
 561 {
 562     siginfo_t *info = pinfo;
 563     struct ucontext *uc = puc;
 564     greg_t pc = uc->uc_mcontext.pc;
 565     int is_write;
 566
 567     /* XXX: compute is_write */
 568     is_write = 0;
 569     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 570                              is_write, &uc->uc_sigmask, puc);
 571 }
 572
 573 #elif defined(__hppa__)
 574
 575 int cpu_signal_handler(int host_signum, void *pinfo,
 576                        void *puc)
 577 {
 578     siginfo_t *info = pinfo;
 579     struct ucontext *uc = puc;
 580     unsigned long pc = uc->uc_mcontext.sc_iaoq[0];
 581     uint32_t insn = *(uint32_t *)pc;
 582     int is_write = 0;
 583
 584     /* XXX: need kernel patch to get write flag faster.  */
 585     switch (insn >> 26) {
 586     case 0x1a: /* STW */
 587     case 0x19: /* STH */
 588     case 0x18: /* STB */
 589     case 0x1b: /* STWM */
 590         is_write = 1;
 591         break;
 592
 593     case 0x09: /* CSTWX, FSTWX, FSTWS */
 594     case 0x0b: /* CSTDX, FSTDX, FSTDS */
 595         /* Distinguish from coprocessor load ... */
 596         is_write = (insn >> 9) & 1;
 597         break;
 598
 599     case 0x03:
 600         switch ((insn >> 6) & 15) {
 601         case 0xa: /* STWS */
 602         case 0x9: /* STHS */
 603         case 0x8: /* STBS */
 604         case 0xe: /* STWAS */
 605         case 0xc: /* STBYS */
 606             is_write = 1;
 607         }
 608         break;
 609     }
 610
 611     return handle_cpu_signal(pc, (unsigned long)info->si_addr,
 612                              is_write, &uc->uc_sigmask, puc);
 613 }
 614
 615 #else
 616
 617 #error host CPU specific signal handler needed
 618
 619 #endif