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.hpp"
  39
  40 #include "vm/jit/builtin.hpp"
  41 #include "vm/signallocal.h"
  42
  43 #include "vm/jit/asmpart.h"
  44 #include "vm/jit/executionstate.h"
  45 #include "vm/jit/stacktrace.hpp"
  46 #include "vm/jit/trap.h"
  47
  48
  49 /* md_signal_handler_sigsegv ***************************************************
  50
  51    Signal handler for hardware exceptions.
  52
  53 *******************************************************************************/
  54
  55 void md_signal_handler_sigsegv(int sig, siginfo_t *siginfo, void *_p)
  56 {
  57         ucontext_t     *_uc;
  58         mcontext_t     *_mc;
  59         u1             *pv;
  60         u1             *sp;
  61         u1             *ra;
  62         u1             *xpc;
  63         u1              opc;
  64         u1              mod;
  65         u1              rm;
  66         s4              d;
  67         s4              disp;
  68         ptrint          val;
  69         s4              type;
  70         void           *p;
  71         java_object_t  *o;
  72
  73         _uc = (ucontext_t *) _p;
  74         _mc = &_uc->uc_mcontext;
  75
  76         pv  = NULL;                 /* is resolved during stackframeinfo creation */
  77         sp  = (u1 *) _mc->gregs[REG_ESP];
  78         xpc = (u1 *) _mc->gregs[REG_EIP];
  79         ra  = xpc;                              /* return address is equal to XPC */
  80
  81         /* get exception-throwing instruction */
  82
  83         opc = M_ALD_MEM_GET_OPC(xpc);
  84         mod = M_ALD_MEM_GET_MOD(xpc);
  85         rm  = M_ALD_MEM_GET_RM(xpc);
  86
  87         /* for values see emit_mov_mem_reg and emit_mem */
  88
  89         if ((opc == 0x8b) && (mod == 0) && (rm == 5)) {
  90                 /* this was a hardware-exception */
  91
  92                 d    = M_ALD_MEM_GET_REG(xpc);
  93                 disp = M_ALD_MEM_GET_DISP(xpc);
  94
  95                 /* we use the exception type as load displacement */
  96
  97                 type = disp;
  98
  99                 /* ATTENTION: The _mc->gregs layout is completely crazy!  The
 100                    registers are reversed starting with number 4 for REG_EDI
 101                    (see /usr/include/sys/ucontext.h).  We have to convert that
 102                    here. */
 103
 104                 val = _mc->gregs[REG_EAX - d];
 105
 106                 if (type == TRAP_COMPILER) {
 107                         /* The PV from the compiler stub is equal to the XPC. */
 108
 109                         pv = xpc;
 110
 111                         /* We use a framesize of zero here because the call pushed
 112                            the return addres onto the stack. */
 113
 114                         ra = md_stacktrace_get_returnaddress(sp, 0);
 115
 116                         /* Skip the RA on the stack. */
 117
 118                         sp = sp + 1 * SIZEOF_VOID_P;
 119
 120                         /* The XPC is the RA minus 2, because the RA points to the
 121                            instruction after the call. */
 122
 123                         xpc = ra - 2;
 124                 }
 125         }
 126         else {
 127                 /* this was a normal NPE */
 128
 129                 type = TRAP_NullPointerException;
 130                 val  = 0;
 131         }
 132
 133         /* Handle the trap. */
 134
 135         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 136
 137         /* Set registers. */
 138
 139         if (type == TRAP_COMPILER) {
 140                 if (p == NULL) {
 141                         o = builtin_retrieve_exception();
 142
 143                         _mc->gregs[REG_ESP] = (uintptr_t) sp;    /* Remove RA from stack. */
 144
 145                         _mc->gregs[REG_EAX] = (uintptr_t) o;
 146                         _mc->gregs[REG_ECX] = (uintptr_t) xpc;           /* REG_ITMP2_XPC */
 147                         _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 148                 }
 149                 else {
 150                         _mc->gregs[REG_EIP] = (uintptr_t) p;
 151                 }
 152         }
 153 #if defined(ENABLE_REPLACEMENT)
 154         else if (type == TRAP_COUNTDOWN) {
 155                 /* context has been written by md_replace_executionstate_write */
 156         }
 157 #endif
 158         else {
 159                 _mc->gregs[REG_EAX] = (uintptr_t) p;
 160                 _mc->gregs[REG_ECX] = (uintptr_t) xpc;               /* REG_ITMP2_XPC */
 161                 _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 162         }
 163 }
 164
 165
 166 /* md_signal_handler_sigfpe ****************************************************
 167
 168    ArithmeticException signal handler for hardware divide by zero
 169    check.
 170
 171 *******************************************************************************/
 172
 173 void md_signal_handler_sigfpe(int sig, siginfo_t *siginfo, void *_p)
 174 {
 175         ucontext_t     *_uc;
 176         mcontext_t     *_mc;
 177         u1             *pv;
 178         u1             *sp;
 179         u1             *ra;
 180         u1             *xpc;
 181         s4              type;
 182         ptrint          val;
 183         void           *p;
 184
 185         _uc = (ucontext_t *) _p;
 186         _mc = &_uc->uc_mcontext;
 187
 188         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 189         sp  = (u1 *) _mc->gregs[REG_ESP];
 190         xpc = (u1 *) _mc->gregs[REG_EIP];
 191         ra  = xpc;                          /* return address is equal to xpc     */
 192
 193         /* This is an ArithmeticException. */
 194
 195         type = TRAP_ArithmeticException;
 196         val  = 0;
 197
 198         /* Handle the trap. */
 199
 200         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 201
 202         /* Set registers. */
 203
 204         _mc->gregs[REG_EAX] = (uintptr_t) p;
 205         _mc->gregs[REG_ECX] = (uintptr_t) xpc;                   /* REG_ITMP2_XPC */
 206         _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 207 }
 208
 209
 210 /* md_signal_handler_sigill ****************************************************
 211
 212    Signal handler for hardware patcher traps (ud2).
 213
 214 *******************************************************************************/
 215
 216 void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
 217 {
 218         ucontext_t        *_uc;
 219         mcontext_t        *_mc;
 220         u1                *pv;
 221         u1                *sp;
 222         u1                *ra;
 223         u1                *xpc;
 224         s4                 type;
 225         ptrint             val;
 226         void              *p;
 227
 228         _uc = (ucontext_t *) _p;
 229         _mc = &_uc->uc_mcontext;
 230
 231         pv  = NULL;                 /* is resolved during stackframeinfo creation */
 232         sp  = (u1 *) _mc->gregs[REG_ESP];
 233         xpc = (u1 *) _mc->gregs[REG_EIP];
 234         ra  = xpc;                            /* return address is equal to xpc   */
 235
 236         type = TRAP_PATCHER;
 237         val  = 0;
 238
 239         /* Handle the trap. */
 240
 241         p = trap_handle(type, val, pv, sp, ra, xpc, _p);
 242
 243         /* Set registers. */
 244
 245         if (p != NULL) {
 246                 _mc->gregs[REG_EAX] = (uintptr_t) p;
 247                 _mc->gregs[REG_ECX] = (uintptr_t) xpc;               /* REG_ITMP2_XPC */
 248                 _mc->gregs[REG_EIP] = (uintptr_t) asm_handle_exception;
 249         }
 250 }
 251
 252
 253 /* md_signal_handler_sigusr1 ***************************************************
 254
 255    Signal handler for suspending threads.
 256
 257 *******************************************************************************/
 258
 259 #if defined(ENABLE_THREADS) && defined(ENABLE_GC_CACAO)
 260 void md_signal_handler_sigusr1(int sig, siginfo_t *siginfo, void *_p)
 261 {
 262         ucontext_t *_uc;
 263         mcontext_t *_mc;
 264         u1         *pc;
 265         u1         *sp;
 266
 267         _uc = (ucontext_t *) _p;
 268         _mc = &_uc->uc_mcontext;
 269
 270         /* get the PC and SP for this thread */
 271         pc = (u1 *) _mc->gregs[REG_EIP];
 272         sp = (u1 *) _mc->gregs[REG_ESP];
 273
 274         /* now suspend the current thread */
 275         threads_suspend_ack(pc, sp);
 276 }
 277 #endif
 278
 279
 280 /* md_signal_handler_sigusr2 ***************************************************
 281
 282    Signal handler for profiling sampling.
 283
 284 *******************************************************************************/
 285
 286 #if defined(ENABLE_THREADS)
 287 void md_signal_handler_sigusr2(int sig, siginfo_t *siginfo, void *_p)
 288 {
 289         threadobject *t;
 290         ucontext_t   *_uc;
 291         mcontext_t   *_mc;
 292         u1           *pc;
 293
 294         t = THREADOBJECT;
 295
 296         _uc = (ucontext_t *) _p;
 297         _mc = &_uc->uc_mcontext;
 298
 299         pc = (u1 *) _mc->gregs[REG_EIP];
 300
 301         t->pc = pc;
 302 }
 303 #endif
 304
 305
 306 /* md_executionstate_read ******************************************************
 307
 308    Read the given context into an executionstate for Replacement.
 309
 310 *******************************************************************************/
 311
 312 void md_executionstate_read(executionstate_t *es, void *context)
 313 {
 314         ucontext_t *_uc;
 315         mcontext_t *_mc;
 316         s4          i;
 317
 318         _uc = (ucontext_t *) context;
 319         _mc = &_uc->uc_mcontext;
 320
 321         /* read special registers */
 322         es->pc = (u1 *) _mc->gregs[REG_EIP];
 323         es->sp = (u1 *) _mc->gregs[REG_ESP];
 324         es->pv = NULL;                   /* pv must be looked up via AVL tree */
 325
 326         /* read integer registers */
 327         for (i = 0; i < INT_REG_CNT; i++)
 328                 es->intregs[i] = _mc->gregs[REG_EAX - i];
 329
 330         /* read float registers */
 331         for (i = 0; i < FLT_REG_CNT; i++)
 332                 es->fltregs[i] = 0xdeadbeefdeadbeefULL;
 333 }
 334
 335
 336 /* md_executionstate_write *****************************************************
 337
 338    Write the given executionstate back to the context for Replacement.
 339
 340 *******************************************************************************/
 341
 342 void md_executionstate_write(executionstate_t *es, void *context)
 343 {
 344         ucontext_t *_uc;
 345         mcontext_t *_mc;
 346         s4          i;
 347
 348         _uc = (ucontext_t *) context;
 349         _mc = &_uc->uc_mcontext;
 350
 351         /* write integer registers */
 352         for (i = 0; i < INT_REG_CNT; i++)
 353                 _mc->gregs[REG_EAX - i] = es->intregs[i];
 354
 355         /* write special registers */
 356         _mc->gregs[REG_EIP] = (ptrint) es->pc;
 357         _mc->gregs[REG_ESP] = (ptrint) es->sp;
 358 }
 359
 360
 361 /*
 362  * These are local overrides for various environment variables in Emacs.
 363  * Please do not remove this and leave it at the end of the file, where
 364  * Emacs will automagically detect them.
 365  * ---------------------------------------------------------------------
 366  * Local variables:
 367  * mode: c
 368  * indent-tabs-mode: t
 369  * c-basic-offset: 4
 370  * tab-width: 4
 371  * End:
 372  */