exec.c

   1 /*
   2  *  virtual page mapping and translated block handling
   3  *
   4  *  Copyright (c) 2003 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, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <stdarg.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27 #include <sys/mman.h>
  28
  29 #include "config.h"
  30 #ifdef TARGET_I386
  31 #include "cpu-i386.h"
  32 #endif
  33 #ifdef TARGET_ARM
  34 #include "cpu-arm.h"
  35 #endif
  36 #include "exec.h"
  37
  38 //#define DEBUG_TB_INVALIDATE
  39 //#define DEBUG_FLUSH
  40
  41 /* make various TB consistency checks */
  42 //#define DEBUG_TB_CHECK
  43
  44 /* threshold to flush the translated code buffer */
  45 #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
  46
  47 #define CODE_GEN_MAX_BLOCKS    (CODE_GEN_BUFFER_SIZE / 64)
  48
  49 TranslationBlock tbs[CODE_GEN_MAX_BLOCKS];
  50 TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE];
  51 int nb_tbs;
  52 /* any access to the tbs or the page table must use this lock */
  53 spinlock_t tb_lock = SPIN_LOCK_UNLOCKED;
  54
  55 uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE];
  56 uint8_t *code_gen_ptr;
  57
  58 /* XXX: pack the flags in the low bits of the pointer ? */
  59 typedef struct PageDesc {
  60     unsigned long flags;
  61     TranslationBlock *first_tb;
  62 } PageDesc;
  63
  64 #define L2_BITS 10
  65 #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
  66
  67 #define L1_SIZE (1 << L1_BITS)
  68 #define L2_SIZE (1 << L2_BITS)
  69
  70 static void tb_invalidate_page(unsigned long address);
  71
  72 unsigned long real_host_page_size;
  73 unsigned long host_page_bits;
  74 unsigned long host_page_size;
  75 unsigned long host_page_mask;
  76
  77 static PageDesc *l1_map[L1_SIZE];
  78
  79 static void page_init(void)
  80 {
  81     /* NOTE: we can always suppose that host_page_size >=
  82        TARGET_PAGE_SIZE */
  83     real_host_page_size = getpagesize();
  84     if (host_page_size == 0)
  85         host_page_size = real_host_page_size;
  86     if (host_page_size < TARGET_PAGE_SIZE)
  87         host_page_size = TARGET_PAGE_SIZE;
  88     host_page_bits = 0;
  89     while ((1 << host_page_bits) < host_page_size)
  90         host_page_bits++;
  91     host_page_mask = ~(host_page_size - 1);
  92 }
  93
  94 /* dump memory mappings */
  95 void page_dump(FILE *f)
  96 {
  97     unsigned long start, end;
  98     int i, j, prot, prot1;
  99     PageDesc *p;
 100
 101     fprintf(f, "%-8s %-8s %-8s %s\n",
 102             "start", "end", "size", "prot");
 103     start = -1;
 104     end = -1;
 105     prot = 0;
 106     for(i = 0; i <= L1_SIZE; i++) {
 107         if (i < L1_SIZE)
 108             p = l1_map[i];
 109         else
 110             p = NULL;
 111         for(j = 0;j < L2_SIZE; j++) {
 112             if (!p)
 113                 prot1 = 0;
 114             else
 115                 prot1 = p[j].flags;
 116             if (prot1 != prot) {
 117                 end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
 118                 if (start != -1) {
 119                     fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
 120                             start, end, end - start,
 121                             prot & PAGE_READ ? 'r' : '-',
 122                             prot & PAGE_WRITE ? 'w' : '-',
 123                             prot & PAGE_EXEC ? 'x' : '-');
 124                 }
 125                 if (prot1 != 0)
 126                     start = end;
 127                 else
 128                     start = -1;
 129                 prot = prot1;
 130             }
 131             if (!p)
 132                 break;
 133         }
 134     }
 135 }
 136
 137 static inline PageDesc *page_find_alloc(unsigned int index)
 138 {
 139     PageDesc **lp, *p;
 140
 141     lp = &l1_map[index >> L2_BITS];
 142     p = *lp;
 143     if (!p) {
 144         /* allocate if not found */
 145         p = malloc(sizeof(PageDesc) * L2_SIZE);
 146         memset(p, 0, sizeof(PageDesc) * L2_SIZE);
 147         *lp = p;
 148     }
 149     return p + (index & (L2_SIZE - 1));
 150 }
 151
 152 static inline PageDesc *page_find(unsigned int index)
 153 {
 154     PageDesc *p;
 155
 156     p = l1_map[index >> L2_BITS];
 157     if (!p)
 158         return 0;
 159     return p + (index & (L2_SIZE - 1));
 160 }
 161
 162 int page_get_flags(unsigned long address)
 163 {
 164     PageDesc *p;
 165
 166     p = page_find(address >> TARGET_PAGE_BITS);
 167     if (!p)
 168         return 0;
 169     return p->flags;
 170 }
 171
 172 /* modify the flags of a page and invalidate the code if
 173    necessary. The flag PAGE_WRITE_ORG is positionned automatically
 174    depending on PAGE_WRITE */
 175 void page_set_flags(unsigned long start, unsigned long end, int flags)
 176 {
 177     PageDesc *p;
 178     unsigned long addr;
 179
 180     start = start & TARGET_PAGE_MASK;
 181     end = TARGET_PAGE_ALIGN(end);
 182     if (flags & PAGE_WRITE)
 183         flags |= PAGE_WRITE_ORG;
 184     spin_lock(&tb_lock);
 185     for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
 186         p = page_find_alloc(addr >> TARGET_PAGE_BITS);
 187         /* if the write protection is set, then we invalidate the code
 188            inside */
 189         if (!(p->flags & PAGE_WRITE) &&
 190             (flags & PAGE_WRITE) &&
 191             p->first_tb) {
 192             tb_invalidate_page(addr);
 193         }
 194         p->flags = flags;
 195     }
 196     spin_unlock(&tb_lock);
 197 }
 198
 199 void cpu_exec_init(void)
 200 {
 201     if (!code_gen_ptr) {
 202         code_gen_ptr = code_gen_buffer;
 203         page_init();
 204     }
 205 }
 206
 207 /* set to NULL all the 'first_tb' fields in all PageDescs */
 208 static void page_flush_tb(void)
 209 {
 210     int i, j;
 211     PageDesc *p;
 212
 213     for(i = 0; i < L1_SIZE; i++) {
 214         p = l1_map[i];
 215         if (p) {
 216             for(j = 0; j < L2_SIZE; j++)
 217                 p[j].first_tb = NULL;
 218         }
 219     }
 220 }
 221
 222 /* flush all the translation blocks */
 223 /* XXX: tb_flush is currently not thread safe */
 224 void tb_flush(void)
 225 {
 226     int i;
 227 #ifdef DEBUG_FLUSH
 228     printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
 229            code_gen_ptr - code_gen_buffer,
 230            nb_tbs,
 231            (code_gen_ptr - code_gen_buffer) / nb_tbs);
 232 #endif
 233     nb_tbs = 0;
 234     for(i = 0;i < CODE_GEN_HASH_SIZE; i++)
 235         tb_hash[i] = NULL;
 236     page_flush_tb();
 237     code_gen_ptr = code_gen_buffer;
 238     /* XXX: flush processor icache at this point if cache flush is
 239        expensive */
 240 }
 241
 242 #ifdef DEBUG_TB_CHECK
 243
 244 static void tb_invalidate_check(unsigned long address)
 245 {
 246     TranslationBlock *tb;
 247     int i;
 248     address &= TARGET_PAGE_MASK;
 249     for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
 250         for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
 251             if (!(address + TARGET_PAGE_SIZE <= tb->pc ||
 252                   address >= tb->pc + tb->size)) {
 253                 printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
 254                        address, tb->pc, tb->size);
 255             }
 256         }
 257     }
 258 }
 259
 260 /* verify that all the pages have correct rights for code */
 261 static void tb_page_check(void)
 262 {
 263     TranslationBlock *tb;
 264     int i, flags1, flags2;
 265
 266     for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
 267         for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
 268             flags1 = page_get_flags(tb->pc);
 269             flags2 = page_get_flags(tb->pc + tb->size - 1);
 270             if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
 271                 printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
 272                        tb->pc, tb->size, flags1, flags2);
 273             }
 274         }
 275     }
 276 }
 277
 278 void tb_jmp_check(TranslationBlock *tb)
 279 {
 280     TranslationBlock *tb1;
 281     unsigned int n1;
 282
 283     /* suppress any remaining jumps to this TB */
 284     tb1 = tb->jmp_first;
 285     for(;;) {
 286         n1 = (long)tb1 & 3;
 287         tb1 = (TranslationBlock *)((long)tb1 & ~3);
 288         if (n1 == 2)
 289             break;
 290         tb1 = tb1->jmp_next[n1];
 291     }
 292     /* check end of list */
 293     if (tb1 != tb) {
 294         printf("ERROR: jmp_list from 0x%08lx\n", (long)tb);
 295     }
 296 }
 297
 298 #endif
 299
 300 /* invalidate one TB */
 301 static inline void tb_remove(TranslationBlock **ptb, TranslationBlock *tb,
 302                              int next_offset)
 303 {
 304     TranslationBlock *tb1;
 305     for(;;) {
 306         tb1 = *ptb;
 307         if (tb1 == tb) {
 308             *ptb = *(TranslationBlock **)((char *)tb1 + next_offset);
 309             break;
 310         }
 311         ptb = (TranslationBlock **)((char *)tb1 + next_offset);
 312     }
 313 }
 314
 315 static inline void tb_jmp_remove(TranslationBlock *tb, int n)
 316 {
 317     TranslationBlock *tb1, **ptb;
 318     unsigned int n1;
 319
 320     ptb = &tb->jmp_next[n];
 321     tb1 = *ptb;
 322     if (tb1) {
 323         /* find tb(n) in circular list */
 324         for(;;) {
 325             tb1 = *ptb;
 326             n1 = (long)tb1 & 3;
 327             tb1 = (TranslationBlock *)((long)tb1 & ~3);
 328             if (n1 == n && tb1 == tb)
 329                 break;
 330             if (n1 == 2) {
 331                 ptb = &tb1->jmp_first;
 332             } else {
 333                 ptb = &tb1->jmp_next[n1];
 334             }
 335         }
 336         /* now we can suppress tb(n) from the list */
 337         *ptb = tb->jmp_next[n];
 338
 339         tb->jmp_next[n] = NULL;
 340     }
 341 }
 342
 343 /* reset the jump entry 'n' of a TB so that it is not chained to
 344    another TB */
 345 static inline void tb_reset_jump(TranslationBlock *tb, int n)
 346 {
 347     tb_set_jmp_target(tb, n, (unsigned long)(tb->tc_ptr + tb->tb_next_offset[n]));
 348 }
 349
 350 static inline void tb_invalidate(TranslationBlock *tb, int parity)
 351 {
 352     PageDesc *p;
 353     unsigned int page_index1, page_index2;
 354     unsigned int h, n1;
 355     TranslationBlock *tb1, *tb2;
 356
 357     /* remove the TB from the hash list */
 358     h = tb_hash_func(tb->pc);
 359     tb_remove(&tb_hash[h], tb,
 360               offsetof(TranslationBlock, hash_next));
 361     /* remove the TB from the page list */
 362     page_index1 = tb->pc >> TARGET_PAGE_BITS;
 363     if ((page_index1 & 1) == parity) {
 364         p = page_find(page_index1);
 365         tb_remove(&p->first_tb, tb,
 366                   offsetof(TranslationBlock, page_next[page_index1 & 1]));
 367     }
 368     page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
 369     if ((page_index2 & 1) == parity) {
 370         p = page_find(page_index2);
 371         tb_remove(&p->first_tb, tb,
 372                   offsetof(TranslationBlock, page_next[page_index2 & 1]));
 373     }
 374
 375     /* suppress this TB from the two jump lists */
 376     tb_jmp_remove(tb, 0);
 377     tb_jmp_remove(tb, 1);
 378
 379     /* suppress any remaining jumps to this TB */
 380     tb1 = tb->jmp_first;
 381     for(;;) {
 382         n1 = (long)tb1 & 3;
 383         if (n1 == 2)
 384             break;
 385         tb1 = (TranslationBlock *)((long)tb1 & ~3);
 386         tb2 = tb1->jmp_next[n1];
 387         tb_reset_jump(tb1, n1);
 388         tb1->jmp_next[n1] = NULL;
 389         tb1 = tb2;
 390     }
 391     tb->jmp_first = (TranslationBlock *)((long)tb | 2); /* fail safe */
 392 }
 393
 394 /* invalidate all TBs which intersect with the target page starting at addr */
 395 static void tb_invalidate_page(unsigned long address)
 396 {
 397     TranslationBlock *tb_next, *tb;
 398     unsigned int page_index;
 399     int parity1, parity2;
 400     PageDesc *p;
 401 #ifdef DEBUG_TB_INVALIDATE
 402     printf("tb_invalidate_page: %lx\n", address);
 403 #endif
 404
 405     page_index = address >> TARGET_PAGE_BITS;
 406     p = page_find(page_index);
 407     if (!p)
 408         return;
 409     tb = p->first_tb;
 410     parity1 = page_index & 1;
 411     parity2 = parity1 ^ 1;
 412     while (tb != NULL) {
 413         tb_next = tb->page_next[parity1];
 414         tb_invalidate(tb, parity2);
 415         tb = tb_next;
 416     }
 417     p->first_tb = NULL;
 418 }
 419
 420 /* add the tb in the target page and protect it if necessary */
 421 static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index)
 422 {
 423     PageDesc *p;
 424     unsigned long host_start, host_end, addr, page_addr;
 425     int prot;
 426
 427     p = page_find_alloc(page_index);
 428     tb->page_next[page_index & 1] = p->first_tb;
 429     p->first_tb = tb;
 430     if (p->flags & PAGE_WRITE) {
 431         /* force the host page as non writable (writes will have a
 432            page fault + mprotect overhead) */
 433         page_addr = (page_index << TARGET_PAGE_BITS);
 434         host_start = page_addr & host_page_mask;
 435         host_end = host_start + host_page_size;
 436         prot = 0;
 437         for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
 438             prot |= page_get_flags(addr);
 439         mprotect((void *)host_start, host_page_size,
 440                  (prot & PAGE_BITS) & ~PAGE_WRITE);
 441 #ifdef DEBUG_TB_INVALIDATE
 442         printf("protecting code page: 0x%08lx\n",
 443                host_start);
 444 #endif
 445         p->flags &= ~PAGE_WRITE;
 446 #ifdef DEBUG_TB_CHECK
 447         tb_page_check();
 448 #endif
 449     }
 450 }
 451
 452 /* Allocate a new translation block. Flush the translation buffer if
 453    too many translation blocks or too much generated code. */
 454 TranslationBlock *tb_alloc(unsigned long pc)
 455 {
 456     TranslationBlock *tb;
 457
 458     if (nb_tbs >= CODE_GEN_MAX_BLOCKS ||
 459         (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
 460         return NULL;
 461     tb = &tbs[nb_tbs++];
 462     tb->pc = pc;
 463     return tb;
 464 }
 465
 466 /* link the tb with the other TBs */
 467 void tb_link(TranslationBlock *tb)
 468 {
 469     unsigned int page_index1, page_index2;
 470
 471     /* add in the page list */
 472     page_index1 = tb->pc >> TARGET_PAGE_BITS;
 473     tb_alloc_page(tb, page_index1);
 474     page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
 475     if (page_index2 != page_index1) {
 476         tb_alloc_page(tb, page_index2);
 477     }
 478     tb->jmp_first = (TranslationBlock *)((long)tb | 2);
 479     tb->jmp_next[0] = NULL;
 480     tb->jmp_next[1] = NULL;
 481
 482     /* init original jump addresses */
 483     if (tb->tb_next_offset[0] != 0xffff)
 484         tb_reset_jump(tb, 0);
 485     if (tb->tb_next_offset[1] != 0xffff)
 486         tb_reset_jump(tb, 1);
 487 }
 488
 489 /* called from signal handler: invalidate the code and unprotect the
 490    page. Return TRUE if the fault was succesfully handled. */
 491 int page_unprotect(unsigned long address)
 492 {
 493     unsigned int page_index, prot, pindex;
 494     PageDesc *p, *p1;
 495     unsigned long host_start, host_end, addr;
 496
 497     host_start = address & host_page_mask;
 498     page_index = host_start >> TARGET_PAGE_BITS;
 499     p1 = page_find(page_index);
 500     if (!p1)
 501         return 0;
 502     host_end = host_start + host_page_size;
 503     p = p1;
 504     prot = 0;
 505     for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) {
 506         prot |= p->flags;
 507         p++;
 508     }
 509     /* if the page was really writable, then we change its
 510        protection back to writable */
 511     if (prot & PAGE_WRITE_ORG) {
 512         mprotect((void *)host_start, host_page_size,
 513                  (prot & PAGE_BITS) | PAGE_WRITE);
 514         pindex = (address - host_start) >> TARGET_PAGE_BITS;
 515         p1[pindex].flags |= PAGE_WRITE;
 516         /* and since the content will be modified, we must invalidate
 517            the corresponding translated code. */
 518         tb_invalidate_page(address);
 519 #ifdef DEBUG_TB_CHECK
 520         tb_invalidate_check(address);
 521 #endif
 522         return 1;
 523     } else {
 524         return 0;
 525     }
 526 }
 527
 528 /* call this function when system calls directly modify a memory area */
 529 void page_unprotect_range(uint8_t *data, unsigned long data_size)
 530 {
 531     unsigned long start, end, addr;
 532
 533     start = (unsigned long)data;
 534     end = start + data_size;
 535     start &= TARGET_PAGE_MASK;
 536     end = TARGET_PAGE_ALIGN(end);
 537     for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
 538         page_unprotect(addr);
 539     }
 540 }
 541
 542 /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
 543    tb[1].tc_ptr. Return NULL if not found */
 544 TranslationBlock *tb_find_pc(unsigned long tc_ptr)
 545 {
 546     int m_min, m_max, m;
 547     unsigned long v;
 548     TranslationBlock *tb;
 549
 550     if (nb_tbs <= 0)
 551         return NULL;
 552     if (tc_ptr < (unsigned long)code_gen_buffer ||
 553         tc_ptr >= (unsigned long)code_gen_ptr)
 554         return NULL;
 555     /* binary search (cf Knuth) */
 556     m_min = 0;
 557     m_max = nb_tbs - 1;
 558     while (m_min <= m_max) {
 559         m = (m_min + m_max) >> 1;
 560         tb = &tbs[m];
 561         v = (unsigned long)tb->tc_ptr;
 562         if (v == tc_ptr)
 563             return tb;
 564         else if (tc_ptr < v) {
 565             m_max = m - 1;
 566         } else {
 567             m_min = m + 1;
 568         }
 569     }
 570     return &tbs[m_max];
 571 }
 572
 573 static void tb_reset_jump_recursive(TranslationBlock *tb);
 574
 575 static inline void tb_reset_jump_recursive2(TranslationBlock *tb, int n)
 576 {
 577     TranslationBlock *tb1, *tb_next, **ptb;
 578     unsigned int n1;
 579
 580     tb1 = tb->jmp_next[n];
 581     if (tb1 != NULL) {
 582         /* find head of list */
 583         for(;;) {
 584             n1 = (long)tb1 & 3;
 585             tb1 = (TranslationBlock *)((long)tb1 & ~3);
 586             if (n1 == 2)
 587                 break;
 588             tb1 = tb1->jmp_next[n1];
 589         }
 590         /* we are now sure now that tb jumps to tb1 */
 591         tb_next = tb1;
 592
 593         /* remove tb from the jmp_first list */
 594         ptb = &tb_next->jmp_first;
 595         for(;;) {
 596             tb1 = *ptb;
 597             n1 = (long)tb1 & 3;
 598             tb1 = (TranslationBlock *)((long)tb1 & ~3);
 599             if (n1 == n && tb1 == tb)
 600                 break;
 601             ptb = &tb1->jmp_next[n1];
 602         }
 603         *ptb = tb->jmp_next[n];
 604         tb->jmp_next[n] = NULL;
 605
 606         /* suppress the jump to next tb in generated code */
 607         tb_reset_jump(tb, n);
 608
 609         /* suppress jumps in the tb on which we could have jump */
 610         tb_reset_jump_recursive(tb_next);
 611     }
 612 }
 613
 614 static void tb_reset_jump_recursive(TranslationBlock *tb)
 615 {
 616     tb_reset_jump_recursive2(tb, 0);
 617     tb_reset_jump_recursive2(tb, 1);
 618 }
 619
 620 void cpu_interrupt(CPUState *env)
 621 {
 622     TranslationBlock *tb;
 623
 624     env->interrupt_request = 1;
 625     /* if the cpu is currently executing code, we must unlink it and
 626        all the potentially executing TB */
 627     tb = env->current_tb;
 628     if (tb) {
 629         tb_reset_jump_recursive(tb);
 630     }
 631 }
 632
 633
 634 void cpu_abort(CPUState *env, const char *fmt, ...)
 635 {
 636     va_list ap;
 637
 638     va_start(ap, fmt);
 639     fprintf(stderr, "qemu: fatal: ");
 640     vfprintf(stderr, fmt, ap);
 641     fprintf(stderr, "\n");
 642 #ifdef TARGET_I386
 643     cpu_x86_dump_state(env, stderr, X86_DUMP_FPU | X86_DUMP_CCOP);
 644 #endif
 645     va_end(ap);
 646     abort();
 647 }
 648
 649 #ifdef TARGET_I386
 650 /* unmap all maped pages and flush all associated code */
 651 void page_unmap(void)
 652 {
 653     PageDesc *p, *pmap;
 654     unsigned long addr;
 655     int i, j, ret, j1;
 656
 657     for(i = 0; i < L1_SIZE; i++) {
 658         pmap = l1_map[i];
 659         if (pmap) {
 660             p = pmap;
 661             for(j = 0;j < L2_SIZE;) {
 662                 if (p->flags & PAGE_VALID) {
 663                     addr = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
 664                     /* we try to find a range to make less syscalls */
 665                     j1 = j;
 666                     p++;
 667                     j++;
 668                     while (j < L2_SIZE && (p->flags & PAGE_VALID)) {
 669                         p++;
 670                         j++;
 671                     }
 672                     ret = munmap((void *)addr, (j - j1) << TARGET_PAGE_BITS);
 673                     if (ret != 0) {
 674                         fprintf(stderr, "Could not unmap page 0x%08lx\n", addr);
 675                         exit(1);
 676                     }
 677                 } else {
 678                     p++;
 679                     j++;
 680                 }
 681             }
 682             free(pmap);
 683             l1_map[i] = NULL;
 684         }
 685     }
 686     tb_flush();
 687 }
 688 #endif