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/signallocal.h"
  42 #include "vm/stringlocal.h"
  43
  44 #include "vm/jit/asmpart.h"
  45 #include "vm/jit/executionstate.h"
  46 #include "vm/jit/stacktrace.h"
  47 #include "vm/jit/trap.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 == TRAP_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 = TRAP_NullPointerException;
 131                 val  = 0;
 132         }
 133
 134         /* Handle the trap. */
 135
 136         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 137
 138         /* Set registers. */
 139
 140         if (type == TRAP_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 #if defined(ENABLE_REPLACEMENT)
 155         else if (type == TRAP_COUNTDOWN) {
 156                 /* context has been written by md_replace_executionstate_write */
 157         }
 158 #endif
 159         else {
 160                 _mc->gregs[REG_EAX] = (uintptr_t) p;
 161                 _mc->gregs[REG_ECX] = (uintptr_t) xpc;               /* REG_ITMP2_XPC */
 162                 _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 163         }
 164 }
 165
 166
 167 /* md_signal_handler_sigfpe ****************************************************
 168
 169    ArithmeticException signal handler for hardware divide by zero
 170    check.
 171
 172 *******************************************************************************/
 173
 174 void md_signal_handler_sigfpe(int sig, siginfo_t *siginfo, void *_p)
 175 {
 176         ucontext_t     *_uc;
 177         mcontext_t     *_mc;
 178         u1             *pv;
 179         u1             *sp;
 180         u1             *ra;
 181         u1             *xpc;
 182         s4              type;
 183         ptrint          val;
 184         void           *p;
 185
 186         _uc = (ucontext_t *) _p;
 187         _mc = &_uc->uc_mcontext;
 188
 189         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 190         sp  = (u1 *) _mc->gregs[REG_ESP];
 191         xpc = (u1 *) _mc->gregs[REG_EIP];
 192         ra  = xpc;                          /* return address is equal to xpc     */
 193
 194         /* This is an ArithmeticException. */
 195
 196         type = TRAP_ArithmeticException;
 197         val  = 0;
 198
 199         /* Handle the trap. */
 200
 201         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 202
 203         /* Set registers. */
 204
 205         _mc->gregs[REG_EAX] = (uintptr_t) p;
 206         _mc->gregs[REG_ECX] = (uintptr_t) xpc;                   /* REG_ITMP2_XPC */
 207         _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 208 }
 209
 210
 211 /* md_signal_handler_sigill ****************************************************
 212
 213    Signal handler for hardware patcher traps (ud2).
 214
 215 *******************************************************************************/
 216
 217 void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
 218 {
 219         ucontext_t        *_uc;
 220         mcontext_t        *_mc;
 221         u1                *pv;
 222         u1                *sp;
 223         u1                *ra;
 224         u1                *xpc;
 225         s4                 type;
 226         ptrint             val;
 227         void              *p;
 228
 229         _uc = (ucontext_t *) _p;
 230         _mc = &_uc->uc_mcontext;
 231
 232         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 233         sp  = (u1 *) _mc->gregs[REG_ESP];
 234         xpc = (u1 *) _mc->gregs[REG_EIP];
 235         ra  = xpc;                            /* return address is equal to xpc   */
 236
 237         type = TRAP_PATCHER;
 238         val  = 0;
 239
 240         /* Handle the trap. */
 241
 242         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 243
 244         /* Set registers. */
 245
 246         if (p != NULL) {
 247                 _mc->gregs[REG_EAX] = (uintptr_t) p;
 248                 _mc->gregs[REG_ECX] = (uintptr_t) xpc;               /* REG_ITMP2_XPC */
 249                 _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 250         }
 251 }
 252
 253
 254 /* md_signal_handler_sigusr1 ***************************************************
 255
 256    Signal handler for suspending threads.
 257
 258 *******************************************************************************/
 259
 260 #if defined(ENABLE_THREADS) && defined(ENABLE_GC_CACAO)
 261 void md_signal_handler_sigusr1(int sig, siginfo_t *siginfo, void *_p)
 262 {
 263         ucontext_t *_uc;
 264         mcontext_t *_mc;
 265         u1         *pc;
 266         u1         *sp;
 267
 268         _uc = (ucontext_t *) _p;
 269         _mc = &_uc->uc_mcontext;
 270
 271         /* get the PC and SP for this thread */
 272         pc = (u1 *) _mc->gregs[REG_EIP];
 273         sp = (u1 *) _mc->gregs[REG_ESP];
 274
 275         /* now suspend the current thread */
 276         threads_suspend_ack(pc, sp);
 277 }
 278 #endif
 279
 280
 281 /* md_signal_handler_sigusr2 ***************************************************
 282
 283    Signal handler for profiling sampling.
 284
 285 *******************************************************************************/
 286
 287 #if defined(ENABLE_THREADS)
 288 void md_signal_handler_sigusr2(int sig, siginfo_t *siginfo, void *_p)
 289 {
 290         threadobject *t;
 291         ucontext_t   *_uc;
 292         mcontext_t   *_mc;
 293         u1           *pc;
 294
 295         t = THREADOBJECT;
 296
 297         _uc = (ucontext_t *) _p;
 298         _mc = &_uc->uc_mcontext;
 299
 300         pc = (u1 *) _mc->gregs[REG_EIP];
 301
 302         t->pc = pc;
 303 }
 304 #endif
 305
 306
 307 /* md_executionstate_read ******************************************************
 308
 309    Read the given context into an executionstate for Replacement.
 310
 311 *******************************************************************************/
 312
 313 void md_executionstate_read(executionstate_t *es, void *context)
 314 {
 315         ucontext_t *_uc;
 316         mcontext_t *_mc;
 317         s4          i;
 318
 319         _uc = (ucontext_t *) context;
 320         _mc = &_uc->uc_mcontext;
 321
 322         /* read special registers */
 323         es->pc = (u1 *) _mc->gregs[REG_EIP];
 324         es->sp = (u1 *) _mc->gregs[REG_ESP];
 325         es->pv = NULL;                   /* pv must be looked up via AVL tree */
 326
 327         /* read integer registers */
 328         for (i = 0; i < INT_REG_CNT; i++)
 329                 es->intregs[i] = _mc->gregs[REG_EAX - i];
 330
 331         /* read float registers */
 332         for (i = 0; i < FLT_REG_CNT; i++)
 333                 es->fltregs[i] = 0xdeadbeefdeadbeefULL;
 334 }
 335
 336
 337 /* md_executionstate_write *****************************************************
 338
 339    Write the given executionstate back to the context for Replacement.
 340
 341 *******************************************************************************/
 342
 343 void md_executionstate_write(executionstate_t *es, void *context)
 344 {
 345         ucontext_t *_uc;
 346         mcontext_t *_mc;
 347         s4          i;
 348
 349         _uc = (ucontext_t *) context;
 350         _mc = &_uc->uc_mcontext;
 351
 352         /* write integer registers */
 353         for (i = 0; i < INT_REG_CNT; i++)
 354                 _mc->gregs[REG_EAX - i] = es->intregs[i];
 355
 356         /* write special registers */
 357         _mc->gregs[REG_EIP] = (ptrint) es->pc;
 358         _mc->gregs[REG_ESP] = (ptrint) es->sp;
 359 }
 360
 361
 362 /*
 363  * These are local overrides for various environment variables in Emacs.
 364  * Please do not remove this and leave it at the end of the file, where
 365  * Emacs will automagically detect them.
 366  * ---------------------------------------------------------------------
 367  * Local variables:
 368  * mode: c
 369  * indent-tabs-mode: t
 370  * c-basic-offset: 4
 371  * tab-width: 4
 372  * End:
 373  */