src/vm/jit/i386/linux/md-os.c

   1 /* src/vm/jit/i386/linux/md-os.c - machine dependent i386 Linux functions
   2
   3    Copyright (C) 1996-2005, 2006, 2007, 2008
   4    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
   5
   6    This file is part of CACAO.
   7
   8    This program is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU General Public License as
  10    published by the Free Software Foundation; either version 2, or (at
  11    your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful, but
  14    WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21    02110-1301, USA.
  22
  23 */
  24
  25
  26 #define _GNU_SOURCE                   /* include REG_ defines from ucontext.h */
  27
  28 #include "config.h"
  29
  30 #include <stdint.h>
  31 #include <ucontext.h>
  32
  33 #include "vm/types.h"
  34
  35 #include "vm/jit/i386/codegen.h"
  36 #include "vm/jit/i386/md.h"
  37
  38 #include "threads/thread.h"
  39
  40 #include "vm/builtin.h"
  41 #include "vm/exceptions.h"
  42 #include "vm/signallocal.h"
  43 #include "vm/stringlocal.h"
  44
  45 #include "vm/jit/asmpart.h"
  46 #include "vm/jit/executionstate.h"
  47 #include "vm/jit/stacktrace.h"
  48
  49
  50 /* md_signal_handler_sigsegv ***************************************************
  51
  52    Signal handler for hardware exceptions.
  53
  54 *******************************************************************************/
  55
  56 void md_signal_handler_sigsegv(int sig, siginfo_t *siginfo, void *_p)
  57 {
  58         ucontext_t     *_uc;
  59         mcontext_t     *_mc;
  60         u1             *pv;
  61         u1             *sp;
  62         u1             *ra;
  63         u1             *xpc;
  64         u1              opc;
  65         u1              mod;
  66         u1              rm;
  67         s4              d;
  68         s4              disp;
  69         ptrint          val;
  70         s4              type;
  71         void           *p;
  72         java_object_t  *o;
  73
  74         _uc = (ucontext_t *) _p;
  75         _mc = &_uc->uc_mcontext;
  76
  77         pv  = NULL;                 /* is resolved during stackframeinfo creation */
  78         sp  = (u1 *) _mc->gregs[REG_ESP];
  79         xpc = (u1 *) _mc->gregs[REG_EIP];
  80         ra  = xpc;                              /* return address is equal to XPC */
  81
  82         /* get exception-throwing instruction */
  83
  84         opc = M_ALD_MEM_GET_OPC(xpc);
  85         mod = M_ALD_MEM_GET_MOD(xpc);
  86         rm  = M_ALD_MEM_GET_RM(xpc);
  87
  88         /* for values see emit_mov_mem_reg and emit_mem */
  89
  90         if ((opc == 0x8b) && (mod == 0) && (rm == 5)) {
  91                 /* this was a hardware-exception */
  92
  93                 d    = M_ALD_MEM_GET_REG(xpc);
  94                 disp = M_ALD_MEM_GET_DISP(xpc);
  95
  96                 /* we use the exception type as load displacement */
  97
  98                 type = disp;
  99
 100                 /* ATTENTION: The _mc->gregs layout is completely crazy!  The
 101                    registers are reversed starting with number 4 for REG_EDI
 102                    (see /usr/include/sys/ucontext.h).  We have to convert that
 103                    here. */
 104
 105                 val = _mc->gregs[REG_EAX - d];
 106
 107                 if (type == EXCEPTION_HARDWARE_COMPILER) {
 108                         /* The PV from the compiler stub is equal to the XPC. */
 109
 110                         pv = xpc;
 111
 112                         /* We use a framesize of zero here because the call pushed
 113                            the return addres onto the stack. */
 114
 115                         ra = md_stacktrace_get_returnaddress(sp, 0);
 116
 117                         /* Skip the RA on the stack. */
 118
 119                         sp = sp + 1 * SIZEOF_VOID_P;
 120
 121                         /* The XPC is the RA minus 2, because the RA points to the
 122                            instruction after the call. */
 123
 124                         xpc = ra - 2;
 125                 }
 126         }
 127         else {
 128                 /* this was a normal NPE */
 129
 130                 type = EXCEPTION_HARDWARE_NULLPOINTER;
 131                 val  = 0;
 132         }
 133
 134         /* Handle the type. */
 135
 136         p = signal_handle(type, val, pv, sp, ra, xpc, _p);
 137
 138         /* Set registers. */
 139
 140         if (type == EXCEPTION_HARDWARE_COMPILER) {
 141                 if (p == NULL) {
 142                         o = builtin_retrieve_exception();
 143
 144                         _mc->gregs[REG_ESP] = (uintptr_t) sp;    /* Remove RA from stack. */
 145
 146                         _mc->gregs[REG_EAX] = (uintptr_t) o;
 147                         _mc->gregs[REG_ECX] = (uintptr_t) xpc;           /* REG_ITMP2_XPC */
 148                         _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 149                 }
 150                 else {
 151                         _mc->gregs[REG_EIP] = (uintptr_t) p;
 152                 }
 153         }
 154         else {
 155                 _mc->gregs[REG_EAX] = (intptr_t) p;
 156                 _mc->gregs[REG_ECX] = (intptr_t) xpc;                /* REG_ITMP2_XPC */
 157                 _mc->gregs[REG_EIP] = (intptr_t) asm_handle_exception;
 158         }
 159 }
 160
 161
 162 /* md_signal_handler_sigfpe ****************************************************
 163
 164    ArithmeticException signal handler for hardware divide by zero
 165    check.
 166
 167 *******************************************************************************/
 168
 169 void md_signal_handler_sigfpe(int sig, siginfo_t *siginfo, void *_p)
 170 {
 171         ucontext_t     *_uc;
 172         mcontext_t     *_mc;
 173         u1             *pv;
 174         u1             *sp;
 175         u1             *ra;
 176         u1             *xpc;
 177         s4              type;
 178         ptrint          val;
 179         void           *p;
 180
 181         _uc = (ucontext_t *) _p;
 182         _mc = &_uc->uc_mcontext;
 183
 184         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 185         sp  = (u1 *) _mc->gregs[REG_ESP];
 186         xpc = (u1 *) _mc->gregs[REG_EIP];
 187         ra  = xpc;                          /* return address is equal to xpc     */
 188
 189         /* this is an ArithmeticException */
 190
 191         type = EXCEPTION_HARDWARE_ARITHMETIC;
 192         val  = 0;
 193
 194         /* Handle the type. */
 195
 196         p = signal_handle(type, val, pv, sp, ra, xpc, _p);
 197
 198         /* set registers */
 199
 200         _mc->gregs[REG_EAX] = (intptr_t) p;
 201         _mc->gregs[REG_ECX] = (intptr_t) xpc;                    /* REG_ITMP2_XPC */
 202         _mc->gregs[REG_EIP] = (intptr_t) asm_handle_exception;
 203 }
 204
 205
 206 /* md_signal_handler_sigill ****************************************************
 207
 208    Signal handler for hardware patcher traps (ud2).
 209
 210 *******************************************************************************/
 211
 212 void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
 213 {
 214         ucontext_t        *_uc;
 215         mcontext_t        *_mc;
 216         u1                *pv;
 217         u1                *sp;
 218         u1                *ra;
 219         u1                *xpc;
 220         s4                 type;
 221         ptrint             val;
 222         void              *p;
 223
 224         _uc = (ucontext_t *) _p;
 225         _mc = &_uc->uc_mcontext;
 226
 227         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 228         sp  = (u1 *) _mc->gregs[REG_ESP];
 229         xpc = (u1 *) _mc->gregs[REG_EIP];
 230         ra  = xpc;                            /* return address is equal to xpc   */
 231
 232         /* this is an ArithmeticException */
 233
 234         type = EXCEPTION_HARDWARE_PATCHER;
 235         val  = 0;
 236
 237         /* generate appropriate exception */
 238
 239         p = signal_handle(type, val, pv, sp, ra, xpc, _p);
 240
 241         /* set registers (only if exception object ready) */
 242
 243         if (p != NULL) {
 244                 _mc->gregs[REG_EAX] = (ptrint) p;
 245                 _mc->gregs[REG_ECX] = (ptrint) xpc;                      /* REG_ITMP2_XPC */
 246                 _mc->gregs[REG_EIP] = (ptrint) asm_handle_exception;
 247         }
 248 }
 249
 250
 251 /* md_signal_handler_sigusr1 ***************************************************
 252
 253    Signal handler for suspending threads.
 254
 255 *******************************************************************************/
 256
 257 #if defined(ENABLE_THREADS) && defined(ENABLE_GC_CACAO)
 258 void md_signal_handler_sigusr1(int sig, siginfo_t *siginfo, void *_p)
 259 {
 260         ucontext_t *_uc;
 261         mcontext_t *_mc;
 262         u1         *pc;
 263         u1         *sp;
 264
 265         _uc = (ucontext_t *) _p;
 266         _mc = &_uc->uc_mcontext;
 267
 268         /* get the PC and SP for this thread */
 269         pc = (u1 *) _mc->gregs[REG_EIP];
 270         sp = (u1 *) _mc->gregs[REG_ESP];
 271
 272         /* now suspend the current thread */
 273         threads_suspend_ack(pc, sp);
 274 }
 275 #endif
 276
 277
 278 /* md_signal_handler_sigusr2 ***************************************************
 279
 280    Signal handler for profiling sampling.
 281
 282 *******************************************************************************/
 283
 284 #if defined(ENABLE_THREADS)
 285 void md_signal_handler_sigusr2(int sig, siginfo_t *siginfo, void *_p)
 286 {
 287         threadobject *t;
 288         ucontext_t   *_uc;
 289         mcontext_t   *_mc;
 290         u1           *pc;
 291
 292         t = THREADOBJECT;
 293
 294         _uc = (ucontext_t *) _p;
 295         _mc = &_uc->uc_mcontext;
 296
 297         pc = (u1 *) _mc->gregs[REG_EIP];
 298
 299         t->pc = pc;
 300 }
 301 #endif
 302
 303
 304 /* md_executionstate_read ******************************************************
 305
 306    Read the given context into an executionstate for Replacement.
 307
 308 *******************************************************************************/
 309
 310 void md_executionstate_read(executionstate_t *es, void *context)
 311 {
 312         ucontext_t *_uc;
 313         mcontext_t *_mc;
 314         s4          i;
 315
 316         _uc = (ucontext_t *) context;
 317         _mc = &_uc->uc_mcontext;
 318
 319         /* read special registers */
 320         es->pc = (u1 *) _mc->gregs[REG_EIP];
 321         es->sp = (u1 *) _mc->gregs[REG_ESP];
 322         es->pv = NULL;                   /* pv must be looked up via AVL tree */
 323
 324         /* read integer registers */
 325         for (i = 0; i < INT_REG_CNT; i++)
 326                 es->intregs[i] = _mc->gregs[REG_EAX - i];
 327
 328         /* read float registers */
 329         for (i = 0; i < FLT_REG_CNT; i++)
 330                 es->fltregs[i] = 0xdeadbeefdeadbeefULL;
 331 }
 332
 333
 334 /* md_executionstate_write *****************************************************
 335
 336    Write the given executionstate back to the context for Replacement.
 337
 338 *******************************************************************************/
 339
 340 void md_executionstate_write(executionstate_t *es, void *context)
 341 {
 342         ucontext_t *_uc;
 343         mcontext_t *_mc;
 344         s4          i;
 345
 346         _uc = (ucontext_t *) context;
 347         _mc = &_uc->uc_mcontext;
 348
 349         /* write integer registers */
 350         for (i = 0; i < INT_REG_CNT; i++)
 351                 _mc->gregs[REG_EAX - i] = es->intregs[i];
 352
 353         /* write special registers */
 354         _mc->gregs[REG_EIP] = (ptrint) es->pc;
 355         _mc->gregs[REG_ESP] = (ptrint) es->sp;
 356 }
 357
 358
 359 /* md_critical_section_restart *************************************************
 360
 361    Search the critical sections tree for a matching section and set
 362    the PC to the restart point, if necessary.
 363
 364 *******************************************************************************/
 365
 366 #if defined(ENABLE_THREADS)
 367 void md_critical_section_restart(ucontext_t *_uc)
 368 {
 369         mcontext_t *_mc;
 370         u1         *pc;
 371         u1         *npc;
 372
 373         _mc = &_uc->uc_mcontext;
 374
 375         pc = (u1 *) _mc->gregs[REG_EIP];
 376
 377         npc = critical_find_restart_point(pc);
 378
 379         if (npc != NULL)
 380                 _mc->gregs[REG_EIP] = (ptrint) npc;
 381 }
 382 #endif
 383
 384
 385 /*
 386  * These are local overrides for various environment variables in Emacs.
 387  * Please do not remove this and leave it at the end of the file, where
 388  * Emacs will automagically detect them.
 389  * ---------------------------------------------------------------------
 390  * Local variables:
 391  * mode: c
 392  * indent-tabs-mode: t
 393  * c-basic-offset: 4
 394  * tab-width: 4
 395  * End:
 396  */