tccrun.c

   1 /*
   2  *  TCC - Tiny C Compiler - Support for -run switch
   3  *
   4  *  Copyright (c) 2001-2004 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
  21 #include "tcc.h"
  22
  23 #ifdef _WIN32
  24 #define ucontext_t CONTEXT
  25 #endif
  26
  27 static void set_pages_executable(void *ptr, unsigned long length);
  28 static void set_exception_handler(void);
  29 static int rt_get_caller_pc(uplong *paddr, ucontext_t *uc, int level);
  30 static void rt_error(ucontext_t *uc, const char *fmt, ...);
  31 static int tcc_relocate_ex(TCCState *s1, void *ptr);
  32
  33 /* ------------------------------------------------------------- */
  34 /* Do all relocations (needed before using tcc_get_symbol())
  35    Returns -1 on error. */
  36
  37 int tcc_relocate(TCCState *s1)
  38 {
  39     int ret;
  40 #ifdef HAVE_SELINUX
  41     char tmpfname[] = "/tmp/.tccrunXXXXXX";
  42     int fd = mkstemp (tmpfname);
  43     unlink (tmpfname); ftruncate (fd, 1000);
  44     if ((ret= tcc_relocate_ex(s1,NULL)) < 0)return -1;
  45     s1->mem_size=ret;
  46      /* Use mmap instead of malloc for Selinux */
  47     s1->write_mem = mmap (NULL, ret, PROT_READ|PROT_WRITE,
  48         MAP_SHARED, fd, 0);
  49     if(s1->write_mem == MAP_FAILED){
  50         error("/tmp not writeable");
  51         return -1;
  52     }
  53     s1->runtime_mem = mmap (NULL, ret, PROT_READ|PROT_EXEC,
  54         MAP_SHARED, fd, 0);
  55     if(s1->runtime_mem == MAP_FAILED){
  56         error("/tmp not executable");
  57         return -1;
  58     }
  59     ret = tcc_relocate_ex(s1, s1->write_mem);
  60 #else
  61     ret = tcc_relocate_ex(s1, NULL);
  62     if (-1 != ret) {
  63         s1->runtime_mem = tcc_malloc(ret);
  64         ret = tcc_relocate_ex(s1, s1->runtime_mem);
  65     }
  66 #endif
  67     return ret;
  68 }
  69
  70 /* launch the compiled program with the given arguments */
  71 int tcc_run(TCCState *s1, int argc, char **argv)
  72 {
  73     int (*prog_main)(int, char **);
  74
  75     if (tcc_relocate(s1) < 0)
  76         return -1;
  77
  78     prog_main = tcc_get_symbol_err(s1, "main");
  79
  80 #ifdef CONFIG_TCC_BACKTRACE
  81     if (s1->do_debug)
  82         set_exception_handler();
  83 #endif
  84
  85 #ifdef CONFIG_TCC_BCHECK
  86     if (s1->do_bounds_check) {
  87         void (*bound_init)(void);
  88         void (*bound_exit)(void);
  89         int ret;
  90         /* set error function */
  91         rt_bound_error_msg = tcc_get_symbol_err(s1, "__bound_error_msg");
  92         rt_prog_main = prog_main;
  93         /* XXX: use .init section so that it also work in binary ? */
  94         bound_init = tcc_get_symbol_err(s1, "__bound_init");
  95         bound_exit = tcc_get_symbol_err(s1, "__bound_exit");
  96         bound_init();
  97         ret = (*prog_main)(argc, argv);
  98         bound_exit();
  99         return ret;
 100     }
 101 #endif
 102
 103 #ifdef TCC_TARGET_PE
 104     {
 105       unsigned char *p = tcc_get_symbol(s1, "tinyc_no_getbp");
 106       if (p) *p = 0;
 107     }
 108 #endif
 109     return (*prog_main)(argc, argv);
 110 }
 111
 112
 113 /* relocate code. Return -1 on error, required size if ptr is NULL,
 114    otherwise copy code into buffer passed by the caller */
 115 static int tcc_relocate_ex(TCCState *s1, void *ptr)
 116 {
 117     Section *s;
 118     unsigned long offset, length;
 119     uplong mem;
 120     int i;
 121
 122     if (0 == s1->runtime_added) {
 123         s1->runtime_added = 1;
 124         s1->nb_errors = 0;
 125 #ifdef TCC_TARGET_PE
 126         pe_output_file(s1, NULL);
 127 #else
 128         tcc_add_runtime(s1);
 129         relocate_common_syms();
 130         tcc_add_linker_symbols(s1);
 131         build_got_entries(s1);
 132 #endif
 133         if (s1->nb_errors)
 134             return -1;
 135     }
 136
 137     offset = 0, mem = (uplong)ptr;
 138     for(i = 1; i < s1->nb_sections; i++) {
 139         s = s1->sections[i];
 140         if (0 == (s->sh_flags & SHF_ALLOC))
 141             continue;
 142         length = s->data_offset;
 143         s->sh_addr = mem ? (mem + offset + 15) & ~15 : 0;
 144         offset = (offset + length + 15) & ~15;
 145     }
 146     offset += 16;
 147
 148     /* relocate symbols */
 149     relocate_syms(s1, 1);
 150     if (s1->nb_errors)
 151         return -1;
 152
 153 #if (defined TCC_TARGET_X86_64 || defined TCC_TARGET_ARM) && !defined TCC_TARGET_PE
 154     s1->runtime_plt_and_got_offset = 0;
 155     s1->runtime_plt_and_got = (char *)(mem + offset);
 156     /* double the size of the buffer for got and plt entries
 157        XXX: calculate exact size for them? */
 158     offset *= 2;
 159 #endif
 160
 161     if (0 == mem)
 162         return offset;
 163
 164     /* relocate each section */
 165     for(i = 1; i < s1->nb_sections; i++) {
 166         s = s1->sections[i];
 167         if (s->reloc)
 168             relocate_section(s1, s);
 169     }
 170
 171     for(i = 1; i < s1->nb_sections; i++) {
 172         s = s1->sections[i];
 173         if (0 == (s->sh_flags & SHF_ALLOC))
 174             continue;
 175         length = s->data_offset;
 176         // printf("%-12s %08x %04x\n", s->name, s->sh_addr, length);
 177         ptr = (void*)(uplong)s->sh_addr;
 178         if (NULL == s->data || s->sh_type == SHT_NOBITS)
 179             memset(ptr, 0, length);
 180         else
 181             memcpy(ptr, s->data, length);
 182         /* mark executable sections as executable in memory */
 183         if (s->sh_flags & SHF_EXECINSTR)
 184             set_pages_executable(ptr, length);
 185     }
 186
 187 #if (defined TCC_TARGET_X86_64 || defined TCC_TARGET_ARM) && !defined TCC_TARGET_PE
 188     set_pages_executable(s1->runtime_plt_and_got,
 189                          s1->runtime_plt_and_got_offset);
 190 #endif
 191     return 0;
 192 }
 193
 194 /* ------------------------------------------------------------- */
 195 /* allow to run code in memory */
 196
 197 static void set_pages_executable(void *ptr, unsigned long length)
 198 {
 199 #ifdef _WIN32
 200     unsigned long old_protect;
 201     VirtualProtect(ptr, length, PAGE_EXECUTE_READWRITE, &old_protect);
 202 #else
 203     unsigned long start, end;
 204     start = (uplong)ptr & ~(PAGESIZE - 1);
 205     end = (uplong)ptr + length;
 206     end = (end + PAGESIZE - 1) & ~(PAGESIZE - 1);
 207     mprotect((void *)start, end - start, PROT_READ | PROT_WRITE | PROT_EXEC);
 208 #endif
 209 }
 210
 211 /* ------------------------------------------------------------- */
 212 #ifdef CONFIG_TCC_BACKTRACE
 213
 214 /* print the position in the source file of PC value 'pc' by reading
 215    the stabs debug information */
 216 static uplong rt_printline(uplong wanted_pc)
 217 {
 218     Stab_Sym *sym, *sym_end;
 219     char func_name[128], last_func_name[128];
 220     unsigned long func_addr, last_pc, pc;
 221     const char *incl_files[INCLUDE_STACK_SIZE];
 222     int incl_index, len, last_line_num, i;
 223     const char *str, *p;
 224
 225     fprintf(stderr, "0x%08lx:", (unsigned long)wanted_pc);
 226
 227     func_name[0] = '\0';
 228     func_addr = 0;
 229     incl_index = 0;
 230     last_func_name[0] = '\0';
 231     last_pc = 0xffffffff;
 232     last_line_num = 1;
 233     sym = (Stab_Sym *)stab_section->data + 1;
 234     sym_end = (Stab_Sym *)(stab_section->data + stab_section->data_offset);
 235     while (sym < sym_end) {
 236         switch(sym->n_type) {
 237             /* function start or end */
 238         case N_FUN:
 239             if (sym->n_strx == 0) {
 240                 /* we test if between last line and end of function */
 241                 pc = sym->n_value + func_addr;
 242                 if (wanted_pc >= last_pc && wanted_pc < pc)
 243                     goto found;
 244                 func_name[0] = '\0';
 245                 func_addr = 0;
 246             } else {
 247                 str = stabstr_section->data + sym->n_strx;
 248                 p = strchr(str, ':');
 249                 if (!p) {
 250                     pstrcpy(func_name, sizeof(func_name), str);
 251                 } else {
 252                     len = p - str;
 253                     if (len > sizeof(func_name) - 1)
 254                         len = sizeof(func_name) - 1;
 255                     memcpy(func_name, str, len);
 256                     func_name[len] = '\0';
 257                 }
 258                 func_addr = sym->n_value;
 259             }
 260             break;
 261             /* line number info */
 262         case N_SLINE:
 263             pc = sym->n_value + func_addr;
 264             if (wanted_pc >= last_pc && wanted_pc < pc)
 265                 goto found;
 266             last_pc = pc;
 267             last_line_num = sym->n_desc;
 268             /* XXX: slow! */
 269             strcpy(last_func_name, func_name);
 270             break;
 271             /* include files */
 272         case N_BINCL:
 273             str = stabstr_section->data + sym->n_strx;
 274         add_incl:
 275             if (incl_index < INCLUDE_STACK_SIZE) {
 276                 incl_files[incl_index++] = str;
 277             }
 278             break;
 279         case N_EINCL:
 280             if (incl_index > 1)
 281                 incl_index--;
 282             break;
 283         case N_SO:
 284             if (sym->n_strx == 0) {
 285                 incl_index = 0; /* end of translation unit */
 286             } else {
 287                 str = stabstr_section->data + sym->n_strx;
 288                 /* do not add path */
 289                 len = strlen(str);
 290                 if (len > 0 && str[len - 1] != '/')
 291                     goto add_incl;
 292             }
 293             break;
 294         }
 295         sym++;
 296     }
 297
 298     /* second pass: we try symtab symbols (no line number info) */
 299     incl_index = 0;
 300     {
 301         ElfW(Sym) *sym, *sym_end;
 302         int type;
 303
 304         sym_end = (ElfW(Sym) *)(symtab_section->data + symtab_section->data_offset);
 305         for(sym = (ElfW(Sym) *)symtab_section->data + 1;
 306             sym < sym_end;
 307             sym++) {
 308             type = ELFW(ST_TYPE)(sym->st_info);
 309             if (type == STT_FUNC
 310 #ifdef STT_GNU_IFUNC
 311                 || type == STT_GNU_IFUNC
 312 #endif
 313                 ) {
 314                 if (wanted_pc >= sym->st_value &&
 315                     wanted_pc < sym->st_value + sym->st_size) {
 316                     pstrcpy(last_func_name, sizeof(last_func_name),
 317                             strtab_section->data + sym->st_name);
 318                     func_addr = sym->st_value;
 319                     goto found;
 320                 }
 321             }
 322         }
 323     }
 324     /* did not find any info: */
 325     fprintf(stderr, " ???\n");
 326     return 0;
 327  found:
 328     if (last_func_name[0] != '\0') {
 329         fprintf(stderr, " %s()", last_func_name);
 330     }
 331     if (incl_index > 0) {
 332         fprintf(stderr, " (%s:%d",
 333                 incl_files[incl_index - 1], last_line_num);
 334         for(i = incl_index - 2; i >= 0; i--)
 335             fprintf(stderr, ", included from %s", incl_files[i]);
 336         fprintf(stderr, ")");
 337     }
 338     fprintf(stderr, "\n");
 339     return func_addr;
 340 }
 341
 342 /* emit a run time error at position 'pc' */
 343 static void rt_error(ucontext_t *uc, const char *fmt, ...)
 344 {
 345     va_list ap;
 346     uplong pc;
 347     int i;
 348
 349     va_start(ap, fmt);
 350     fprintf(stderr, "Runtime error: ");
 351     vfprintf(stderr, fmt, ap);
 352     fprintf(stderr, "\n");
 353
 354     for(i=0;i<num_callers;i++) {
 355         if (rt_get_caller_pc(&pc, uc, i) < 0)
 356             break;
 357         if (i == 0)
 358             fprintf(stderr, "at ");
 359         else
 360             fprintf(stderr, "by ");
 361         pc = rt_printline(pc);
 362         if (pc == (uplong)rt_prog_main && pc)
 363             break;
 364     }
 365     exit(255);
 366     va_end(ap);
 367 }
 368
 369 /* ------------------------------------------------------------- */
 370 #ifndef _WIN32
 371
 372 /* signal handler for fatal errors */
 373 static void sig_error(int signum, siginfo_t *siginf, void *puc)
 374 {
 375     ucontext_t *uc = puc;
 376
 377     switch(signum) {
 378     case SIGFPE:
 379         switch(siginf->si_code) {
 380         case FPE_INTDIV:
 381         case FPE_FLTDIV:
 382             rt_error(uc, "division by zero");
 383             break;
 384         default:
 385             rt_error(uc, "floating point exception");
 386             break;
 387         }
 388         break;
 389     case SIGBUS:
 390     case SIGSEGV:
 391         if (rt_bound_error_msg && *rt_bound_error_msg)
 392             rt_error(uc, *rt_bound_error_msg);
 393         else
 394             rt_error(uc, "dereferencing invalid pointer");
 395         break;
 396     case SIGILL:
 397         rt_error(uc, "illegal instruction");
 398         break;
 399     case SIGABRT:
 400         rt_error(uc, "abort() called");
 401         break;
 402     default:
 403         rt_error(uc, "caught signal %d", signum);
 404         break;
 405     }
 406     exit(255);
 407 }
 408
 409 /* Generate a stack backtrace when a CPU exception occurs. */
 410 static void set_exception_handler(void)
 411 {
 412     struct sigaction sigact;
 413     /* install TCC signal handlers to print debug info on fatal
 414        runtime errors */
 415     sigact.sa_flags = SA_SIGINFO | SA_RESETHAND;
 416     sigact.sa_sigaction = sig_error;
 417     sigemptyset(&sigact.sa_mask);
 418     sigaction(SIGFPE, &sigact, NULL);
 419     sigaction(SIGILL, &sigact, NULL);
 420     sigaction(SIGSEGV, &sigact, NULL);
 421     sigaction(SIGBUS, &sigact, NULL);
 422     sigaction(SIGABRT, &sigact, NULL);
 423 }
 424
 425 /* ------------------------------------------------------------- */
 426 #ifdef __i386__
 427
 428 /* fix for glibc 2.1 */
 429 #ifndef REG_EIP
 430 #define REG_EIP EIP
 431 #define REG_EBP EBP
 432 #endif
 433
 434 /* return the PC at frame level 'level'. Return non zero if not found */
 435 static int rt_get_caller_pc(unsigned long *paddr, ucontext_t *uc, int level)
 436 {
 437     unsigned long fp;
 438     int i;
 439
 440     if (level == 0) {
 441 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 442         *paddr = uc->uc_mcontext.mc_eip;
 443 #elif defined(__dietlibc__)
 444         *paddr = uc->uc_mcontext.eip;
 445 #else
 446         *paddr = uc->uc_mcontext.gregs[REG_EIP];
 447 #endif
 448         return 0;
 449     } else {
 450 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 451         fp = uc->uc_mcontext.mc_ebp;
 452 #elif defined(__dietlibc__)
 453         fp = uc->uc_mcontext.ebp;
 454 #else
 455         fp = uc->uc_mcontext.gregs[REG_EBP];
 456 #endif
 457         for(i=1;i<level;i++) {
 458             /* XXX: check address validity with program info */
 459             if (fp <= 0x1000 || fp >= 0xc0000000)
 460                 return -1;
 461             fp = ((unsigned long *)fp)[0];
 462         }
 463         *paddr = ((unsigned long *)fp)[1];
 464         return 0;
 465     }
 466 }
 467
 468 /* ------------------------------------------------------------- */
 469 #elif defined(__x86_64__)
 470
 471 /* return the PC at frame level 'level'. Return non zero if not found */
 472 static int rt_get_caller_pc(unsigned long *paddr,
 473                             ucontext_t *uc, int level)
 474 {
 475     unsigned long fp;
 476     int i;
 477
 478     if (level == 0) {
 479         /* XXX: only support linux */
 480 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 481         *paddr = uc->uc_mcontext.mc_rip;
 482 #else
 483         *paddr = uc->uc_mcontext.gregs[REG_RIP];
 484 #endif
 485         return 0;
 486     } else {
 487 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 488         fp = uc->uc_mcontext.mc_rbp;
 489 #else
 490         fp = uc->uc_mcontext.gregs[REG_RBP];
 491 #endif
 492         for(i=1;i<level;i++) {
 493             /* XXX: check address validity with program info */
 494             if (fp <= 0x1000)
 495                 return -1;
 496             fp = ((unsigned long *)fp)[0];
 497         }
 498         *paddr = ((unsigned long *)fp)[1];
 499         return 0;
 500     }
 501 }
 502
 503 /* ------------------------------------------------------------- */
 504 #elif defined(__arm__)
 505
 506 /* return the PC at frame level 'level'. Return negative if not found */
 507 static int rt_get_caller_pc(unsigned long *paddr,
 508                             ucontext_t *uc, int level)
 509 {
 510     uint32_t fp, sp;
 511     int i;
 512
 513     if (level == 0) {
 514         /* XXX: only supports linux */
 515 #if defined(__linux__)
 516         *paddr = uc->uc_mcontext.arm_pc;
 517 #else
 518         return -1;
 519 #endif
 520         return 0;
 521     } else {
 522 #if defined(__linux__)
 523         fp = uc->uc_mcontext.arm_fp;
 524         sp = uc->uc_mcontext.arm_sp;
 525         if (sp < 0x1000)
 526             sp = 0x1000;
 527 #else
 528         return -1;
 529 #endif
 530         /* XXX: specific to tinycc stack frames */
 531         if (fp < sp + 12 || fp & 3)
 532             return -1;
 533         for(i = 1; i < level; i++) {
 534             sp = ((uint32_t *)fp)[-2];
 535             if (sp < fp || sp - fp > 16 || sp & 3)
 536                 return -1;
 537             fp = ((uint32_t *)fp)[-3];
 538             if (fp <= sp || fp - sp < 12 || fp & 3)
 539                 return -1;
 540         }
 541         /* XXX: check address validity with program info */
 542         *paddr = ((uint32_t *)fp)[-1];
 543         return 0;
 544     }
 545 }
 546
 547 /* ------------------------------------------------------------- */
 548 #else
 549
 550 #warning add arch specific rt_get_caller_pc()
 551 static int rt_get_caller_pc(unsigned long *paddr,
 552                             ucontext_t *uc, int level)
 553 {
 554     return -1;
 555 }
 556
 557 #endif /* !__i386__ */
 558
 559 /* ------------------------------------------------------------- */
 560 #else /* WIN32 */
 561
 562 static long __stdcall cpu_exception_handler(EXCEPTION_POINTERS *ex_info)
 563 {
 564     CONTEXT *uc = ex_info->ContextRecord;
 565 /*
 566     EXCEPTION_RECORD *er = ex_info->ExceptionRecord;
 567     printf("CPU exception: code=%08lx addr=%p\n",
 568         er->ExceptionCode, er->ExceptionAddress);
 569 */
 570     if (rt_bound_error_msg && *rt_bound_error_msg)
 571         rt_error(uc, *rt_bound_error_msg);
 572     else
 573         rt_error(uc, "dereferencing invalid pointer");
 574     exit(255);
 575     //return EXCEPTION_CONTINUE_SEARCH;
 576 }
 577
 578 /* Generate a stack backtrace when a CPU exception occurs. */
 579 static void set_exception_handler(void)
 580 {
 581     SetUnhandledExceptionFilter(cpu_exception_handler);
 582 }
 583
 584 #ifdef _WIN64
 585 #define Eip Rip
 586 #define Ebp Rbp
 587 #endif
 588
 589 /* return the PC at frame level 'level'. Return non zero if not found */
 590 static int rt_get_caller_pc(uplong *paddr, CONTEXT *uc, int level)
 591 {
 592     uplong fp;
 593     int i;
 594
 595     if (level == 0) {
 596         *paddr = uc->Eip;
 597         return 0;
 598     } else {
 599         fp = uc->Ebp;
 600         for(i=1;i<level;i++) {
 601             /* XXX: check address validity with program info */
 602             if (fp <= 0x1000 || fp >= 0xc0000000)
 603                 return -1;
 604             fp = ((uplong*)fp)[0];
 605         }
 606         *paddr = ((uplong*)fp)[1];
 607         return 0;
 608     }
 609 }
 610
 611 #undef Eip
 612 #undef Ebp
 613
 614 #endif /* _WIN32 */
 615 #endif /* CONFIG_TCC_BACKTRACE */
 616 /* ------------------------------------------------------------- */
 617
 618 #ifdef CONFIG_TCC_STATIC
 619
 620 #define RTLD_LAZY       0x001
 621 #define RTLD_NOW        0x002
 622 #define RTLD_GLOBAL     0x100
 623 #define RTLD_DEFAULT    NULL
 624
 625 /* dummy function for profiling */
 626 void *dlopen(const char *filename, int flag)
 627 {
 628     return NULL;
 629 }
 630
 631 void dlclose(void *p)
 632 {
 633 }
 634 /*
 635 const char *dlerror(void)
 636 {
 637     return "error";
 638 }
 639 */
 640 typedef struct TCCSyms {
 641     char *str;
 642     void *ptr;
 643 } TCCSyms;
 644
 645 #define TCCSYM(a) { #a, &a, },
 646
 647 /* add the symbol you want here if no dynamic linking is done */
 648 static TCCSyms tcc_syms[] = {
 649 #if !defined(CONFIG_TCCBOOT)
 650     TCCSYM(printf)
 651     TCCSYM(fprintf)
 652     TCCSYM(fopen)
 653     TCCSYM(fclose)
 654 #endif
 655     { NULL, NULL },
 656 };
 657
 658 void *resolve_sym(TCCState *s1, const char *symbol)
 659 {
 660     TCCSyms *p;
 661     p = tcc_syms;
 662     while (p->str != NULL) {
 663         if (!strcmp(p->str, symbol))
 664             return p->ptr;
 665         p++;
 666     }
 667     return NULL;
 668 }
 669
 670 #elif !defined(_WIN32)
 671
 672 void *resolve_sym(TCCState *s1, const char *sym)
 673 {
 674     return dlsym(RTLD_DEFAULT, sym);
 675 }
 676
 677 #endif /* CONFIG_TCC_STATIC */
 678
 679 /* ------------------------------------------------------------- */