/* * TCC - Tiny C Compiler - Support for -run switch * * Copyright (c) 2001-2004 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "tcc.h" /* only native compiler supports -run */#ifdef TCC_IS_NATIVE #ifdef CONFIG_TCC_BACKTRACE/* runtime debug info block */typedef struct rt_context{ /* tccelf.c:tcc_add_btstub() wants these in that order: */ union { struct { Stab_Sym *stab_sym; Stab_Sym *stab_sym_end; char *stab_str; }; struct { unsigned char *dwarf_line; unsigned char *dwarf_line_end; unsigned char *dwarf_line_str; }; }; ElfW(Sym) *esym_start; ElfW(Sym) *esym_end; char *elf_str; // 6 * PTR_SIZE addr_t prog_base; void *bounds_start; void *top_func; struct rt_context *next; // 10 * PTR_SIZE int num_callers; int dwarf;} rt_context; /* linked list of rt_contexts */static rt_context *g_rc;static int signal_set;static void set_exception_handler(void);#endif /* def CONFIG_TCC_BACKTRACE */ typedef struct rt_frame { addr_t ip, fp, sp;} rt_frame; static TCCState *g_s1;/* semaphore to protect it */TCC_SEM(static rt_sem);static void rt_wait_sem(void) { WAIT_SEM(&rt_sem); }static void rt_post_sem(void) { POST_SEM(&rt_sem); }static int rt_get_caller_pc(addr_t *paddr, rt_frame *f, int level);static void rt_exit(rt_frame *f, int code); /* ------------------------------------------------------------- *//* defined when included from lib/bt-exe.c */#ifndef CONFIG_TCC_BACKTRACE_ONLY #ifndef _WIN32# include <sys/mman.h>#endif static int protect_pages(void *ptr, unsigned long length, int mode);static int tcc_relocate_ex(TCCState *s1, void *ptr, unsigned ptr_diff);static void st_link(TCCState *s1);static void st_unlink(TCCState *s1);#ifdef CONFIG_TCC_BACKTRACEstatic int _tcc_backtrace(rt_frame *f, const char *fmt, va_list ap);#endif#ifdef _WIN64static void *win64_add_function_table(TCCState *s1);static void win64_del_function_table(void *);#endif #if !defined PAGESIZE# if defined _SC_PAGESIZE# define PAGESIZE sysconf(_SC_PAGESIZE)# elif defined __APPLE__# include <libkern/OSCacheControl.h># define PAGESIZE getpagesize()# else# define PAGESIZE 4096# endif#endif #define PAGEALIGN(n) ((addr_t)n + (-(addr_t)n & (PAGESIZE-1))) #if !_WIN32 && !__APPLE__//#define CONFIG_SELINUX 1#endif /* use VirtualAlloc() instead of tcc_malloc() */#if defined _WIN32 && !defined CONFIG_RUNMEM_VIRTUALALLOC# define CONFIG_RUNMEM_VIRTUALALLOC 1#endif static int rt_mem(TCCState *s1, int size){ void *ptr; int ptr_diff = 0;#ifdef CONFIG_SELINUX /* Using mmap instead of malloc */ void *prw; char tmpfname[] = "/tmp/.tccrunXXXXXX"; int fd = mkstemp(tmpfname); unlink(tmpfname); ftruncate(fd, size); ptr = mmap(NULL, size * 2, PROT_READ|PROT_EXEC, MAP_SHARED, fd, 0); /* mmap RW memory at fixed distance */ prw = mmap((char*)ptr + size, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0); close(fd); if (ptr == MAP_FAILED || prw == MAP_FAILED) return tcc_error_noabort("tccrun: could not map memory"); ptr_diff = (char*)prw - (char*)ptr; /* = size; */ //printf("map %p %p %p\n", ptr, prw, (void*)ptr_diff); size *= 2;#elif CONFIG_RUNMEM_VIRTUALALLOC /* always page-aligned */ ptr = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); if (!ptr) return tcc_error_noabort("tccrun: could not allocate memory");#else ptr = tcc_malloc(size += PAGESIZE); /* one extra page to align malloc memory */#endif s1->run_ptr = ptr; s1->run_size = size; return ptr_diff;} /* ------------------------------------------------------------- *//* Do all relocations (needed before using tcc_get_symbol()) Returns -1 on error. */ LIBTCCAPI int tcc_relocate(TCCState *s1){ int size, ret, ptr_diff; if (s1->run_ptr) exit(tcc_error_noabort("'tcc_relocate()' twice is no longer supported"));#ifdef CONFIG_TCC_BACKTRACE if (s1->do_backtrace) tcc_add_symbol(s1, "_tcc_backtrace", _tcc_backtrace); /* for bt-log.c */#endif size = tcc_relocate_ex(s1, NULL, 0); if (size < 0) return -1; ptr_diff = rt_mem(s1, size); if (ptr_diff < 0) return -1; ret = tcc_relocate_ex(s1, s1->run_ptr, ptr_diff); if (ret == 0) st_link(s1); return ret;} ST_FUNC void tcc_run_free(TCCState *s1){ unsigned size; void *ptr; int i; /* free any loaded DLLs */ for ( i = 0; i < s1->nb_loaded_dlls; i++) { DLLReference *ref = s1->loaded_dlls[i]; if ( ref->handle )#ifdef _WIN32 FreeLibrary((HMODULE)ref->handle);#else dlclose(ref->handle);#endif } /* unmap or unprotect and free memory */ ptr = s1->run_ptr; if (NULL == ptr) return; st_unlink(s1);#ifdef _WIN64 win64_del_function_table(s1->run_function_table);#endif size = s1->run_size;#ifdef CONFIG_SELINUX munmap(ptr, size);#elif CONFIG_RUNMEM_VIRTUALALLOC VirtualFree(ptr, size, MEM_RELEASE);#else /* unprotect memory to make it usable for malloc again */ protect_pages((void*)PAGEALIGN(ptr), size - PAGESIZE, 2 /*rw*/); tcc_free(ptr);#endif} #define RT_EXIT_ZERO 0xE0E00E0E /* passed from longjmp instead of '0' */ /* launch the compiled program with the given arguments */LIBTCCAPI int tcc_run(TCCState *s1, int argc, char **argv){ int (*prog_main)(int, char **, char **), ret; const char *top_sym; jmp_buf main_jb; #if defined(__APPLE__) extern char ***_NSGetEnviron(void); char **envp = *_NSGetEnviron();#elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) extern char **environ; char **envp = environ;#else char **envp = environ;#endif /* tcc -dt -run ... nothing to do if no main() */ if ((s1->dflag & 16) && (addr_t)-1 == get_sym_addr(s1, "main", 0, 1)) return 0; tcc_add_symbol(s1, "__rt_exit", rt_exit); s1->run_main = "_runmain", top_sym = "main"; if (s1->elf_entryname) s1->run_main = top_sym = s1->elf_entryname; tcc_add_support(s1, "runmain.o"); if (tcc_relocate(s1) < 0) return -1; prog_main = (void*)get_sym_addr(s1, s1->run_main, 1, 1); if ((addr_t)-1 == (addr_t)prog_main) return -1; /* custom stdin for run_main, mainly if stdin is/was an input file. * fileno(stdin) should remain 0, as posix mandates to use the smallest * free fd, which is 0 after the initial fclose in freopen. windows too. * to set stdin to the tty, use /dev/tty (posix) or con (windows). */ if (s1->run_stdin && !freopen(s1->run_stdin, "r", stdin)) { tcc_error_noabort("failed to reopen stdin from '%s'", s1->run_stdin); return -1; } errno = 0; /* clean errno value */ fflush(stdout); fflush(stderr); ret = tcc_setjmp(s1, main_jb, tcc_get_symbol(s1, top_sym)); if (0 == ret) { ret = prog_main(argc, argv, envp); } else if (RT_EXIT_ZERO == ret) { ret = 0; } if (s1->dflag & 16 && ret) /* tcc -dt -run ... */ fprintf(s1->ppfp, "[returns %d]\n", ret), fflush(s1->ppfp); return ret;} /* ------------------------------------------------------------- *//* remove all STB_LOCAL symbols */static void cleanup_symbols(TCCState *s1){ Section *s = s1->symtab; int sym_index, end_sym = s->data_offset / sizeof (ElfSym); /* reset symtab */ s->data_offset = s->link->data_offset = s->hash->data_offset = 0; init_symtab(s); /* add global symbols again */ for (sym_index = 1; sym_index < end_sym; ++sym_index) { ElfW(Sym) *sym = &((ElfW(Sym) *)s->data)[sym_index]; const char *name = (char *)s->link->data + sym->st_name; if (ELFW(ST_BIND)(sym->st_info) == STB_LOCAL) continue; //printf("sym %s\n", name); put_elf_sym(s, sym->st_value, sym->st_size, sym->st_info, sym->st_other, sym->st_shndx, name); }} /* free all sections except symbols */static void cleanup_sections(TCCState *s1){ struct { Section **secs; int nb_secs; } *p = (void*)&s1->sections; int i, f = 2; do { for (i = --f; i < p->nb_secs; i++) { Section *s = p->secs[i]; if (s == s1->symtab || s == s1->symtab->link || s == s1->symtab->hash) { s->data = tcc_realloc(s->data, s->data_allocated = s->data_offset); } else { free_section(s), tcc_free(s), p->secs[i] = NULL; } } } while (++p, f);} /* ------------------------------------------------------------- *//* 0 = .text rwx other rwx (memory >= 2 pages a 4096 bytes) *//* 1 = .text rx other rw (memory >= 3 pages) *//* 2 = .text rx .rdata ro .data/.bss rw (memory >= 4 pages) */ /* Some targets implement secutiry options that do not allow write in executable code. These targets need CONFIG_RUNMEM_RO=1. The disadvantage of this is that it requires a little bit more memory. */ #ifndef CONFIG_RUNMEM_RO# ifdef __APPLE__# define CONFIG_RUNMEM_RO 1# else# define CONFIG_RUNMEM_RO 0# endif#endif /* relocate code. Return -1 on error, required size if ptr is NULL, otherwise copy code into buffer passed by the caller */static int tcc_relocate_ex(TCCState *s1, void *ptr, unsigned ptr_diff){ Section *s; unsigned offset, length, align, i, k, f; unsigned n, copy; addr_t mem, addr; if (NULL == ptr) { s1->nb_errors = 0;#ifdef TCC_TARGET_PE pe_output_file(s1, NULL);#else tcc_add_runtime(s1); resolve_common_syms(s1); build_got_entries(s1, 0);#endif } offset = copy = 0; mem = (addr_t)ptr;redo: if (s1->verbose == 2 && copy) printf(&"-----------------------------------------------------\n"[PTR_SIZE*2 - 8]); if (s1->nb_errors) return -1; if (copy == 3) return 0; for (k = 0; k < 3; ++k) { /* 0:rx, 1:ro, 2:rw sections */ n = 0; addr = 0; for(i = 1; i < s1->nb_sections; i++) { static const char shf[] = { SHF_ALLOC|SHF_EXECINSTR, SHF_ALLOC, SHF_ALLOC|SHF_WRITE }; s = s1->sections[i]; if (shf[k] != (s->sh_flags & (SHF_ALLOC|SHF_WRITE|SHF_EXECINSTR))) continue; length = s->data_offset; if (copy == 2) { if (addr == 0) addr = s->sh_addr; n = (s->sh_addr - addr) + length; continue; } if (copy) { /* final step: copy section data to memory */ if (s1->verbose == 2) printf("%d: %-16s %p len %05x align %04x\n", k, s->name, (void*)s->sh_addr, length, s->sh_addralign); ptr = (void*)s->sh_addr; if (k == 0) ptr = (void*)(s->sh_addr + ptr_diff); if (NULL == s->data || s->sh_type == SHT_NOBITS) memset(ptr, 0, length); else memcpy(ptr, s->data, length); continue; } if ((s->sh_flags & SHF_TLS) && length) return tcc_error_noabort("thread-local storage not supported with -run"); align = s->sh_addralign; if (++n == 1) {#if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64 /* To avoid that x86 processors would reload cached instructions each time when data is written in the near, we need to make sure that code and data do not share the same 64 byte unit */ if (align < 64) align = 64;#endif /* start new page for different permissions */ if (k <= CONFIG_RUNMEM_RO) align = PAGESIZE; } s->sh_addralign = align; addr = k ? mem + ptr_diff : mem; offset += -(addr + offset) & (align - 1); s->sh_addr = mem ? addr + offset : 0; offset += length; } if (copy == 2) { /* set permissions */ if (n == 0) /* no data */ continue;#ifdef CONFIG_SELINUX if (k == 0) /* SHF_EXECINSTR has its own mapping */ continue;#endif f = k; if (f >= CONFIG_RUNMEM_RO) { if (f != 0) continue; f = 3; /* change only SHF_EXECINSTR to rwx */ } n = PAGEALIGN(n); if (s1->verbose == 2) { printf("protect %3s %p len %05x\n", &"rx\0ro\0rw\0rwx"[f*3], (void*)addr, (unsigned)n); } if (protect_pages((void*)addr, n, f) < 0) return tcc_error_noabort(#ifdef _WIN32 "VirtualProtect failed");#else "mprotect failed (did you mean to configure --with-selinux?)");#endif } } if (0 == mem) return PAGEALIGN(offset); if (++copy == 2) { goto redo; } if (copy == 3) {#ifdef _WIN64 s1->run_function_table = win64_add_function_table(s1);#endif /* remove local symbols and free sections except symtab */ cleanup_symbols(s1); cleanup_sections(s1); goto redo; } /* relocate symbols */ relocate_syms(s1, s1->symtab, 1); if (s1->nb_errors) goto redo; /* relocate sections */#ifdef TCC_TARGET_PE s1->pe_imagebase = mem;#else relocate_plt(s1);#endif relocate_sections(s1); goto redo;} /* ------------------------------------------------------------- *//* allow to run code in memory */ static int protect_pages(void *ptr, unsigned long length, int mode){#ifdef _WIN32 static const unsigned char protect[] = { PAGE_EXECUTE_READ, PAGE_READONLY, PAGE_READWRITE, PAGE_EXECUTE_READWRITE }; DWORD old; if (!VirtualProtect(ptr, length, protect[mode], &old)) return -1;#else static const unsigned char protect[] = { PROT_READ | PROT_EXEC, PROT_READ, PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE | PROT_EXEC }; if (mprotect(ptr, length, protect[mode])) return -1;#endif/* XXX: BSD sometimes dump core with bad system call */#if (defined TCC_TARGET_ARM && !TARGETOS_BSD) \ || defined TCC_TARGET_ARM64 || defined TCC_TARGET_RISCV64 if (mode == 0 || mode == 3) {#ifdef _WIN32 FlushInstructionCache(GetCurrentProcess(), ptr, length);#else void __clear_cache(void *beginning, void *end);Lines 1–500 of 1588. 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/* * TCC - Tiny C Compiler - Support for -run switch * * Copyright (c) 2001-2004 Fabrice Bellard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include "tcc.h" /* only native compiler supports -run */ #ifdef TCC_IS_NATIVE #ifdef CONFIG_TCC_BACKTRACE /* runtime debug info block */ typedef struct rt_context { /* tccelf.c:tcc_add_btstub() wants these in that order: */ union { struct { Stab_Sym *stab_sym; Stab_Sym *stab_sym_end; char *stab_str; }; struct { unsigned char *dwarf_line; unsigned char *dwarf_line_end; unsigned char *dwarf_line_str; }; }; ElfW(Sym) *esym_start; ElfW(Sym) *esym_end; char *elf_str; // 6 * PTR_SIZE addr_t prog_base; void *bounds_start; void *top_func; struct rt_context *next; // 10 * PTR_SIZE int num_callers; int dwarf; } rt_context; /* linked list of rt_contexts */ static rt_context *g_rc; static int signal_set; static void set_exception_handler(void); #endif /* def CONFIG_TCC_BACKTRACE */ typedef struct rt_frame { addr_t ip, fp, sp; } rt_frame; static TCCState *g_s1; /* semaphore to protect it */ TCC_SEM(static rt_sem); static void rt_wait_sem(void) { WAIT_SEM(&rt_sem); } static void rt_post_sem(void) { POST_SEM(&rt_sem); } static int rt_get_caller_pc(addr_t *paddr, rt_frame *f, int level); static void rt_exit(rt_frame *f, int code); /* ------------------------------------------------------------- */ /* defined when included from lib/bt-exe.c */ #ifndef CONFIG_TCC_BACKTRACE_ONLY #ifndef _WIN32 # include <sys/mman.h> #endif static int protect_pages(void *ptr, unsigned long length, int mode); static int tcc_relocate_ex(TCCState *s1, void *ptr, unsigned ptr_diff); static void st_link(TCCState *s1); static void st_unlink(TCCState *s1); #ifdef CONFIG_TCC_BACKTRACE static int _tcc_backtrace(rt_frame *f, const char *fmt, va_list ap); #endif #ifdef _WIN64 static void *win64_add_function_table(TCCState *s1); static void win64_del_function_table(void *); #endif #if !defined PAGESIZE # if defined _SC_PAGESIZE # define PAGESIZE sysconf(_SC_PAGESIZE) # elif defined __APPLE__ # include <libkern/OSCacheControl.h> # define PAGESIZE getpagesize() # else # define PAGESIZE 4096 # endif #endif #define PAGEALIGN(n) ((addr_t)n + (-(addr_t)n & (PAGESIZE-1))) #if !_WIN32 && !__APPLE__ //#define CONFIG_SELINUX 1 #endif /* use VirtualAlloc() instead of tcc_malloc() */ #if defined _WIN32 && !defined CONFIG_RUNMEM_VIRTUALALLOC # define CONFIG_RUNMEM_VIRTUALALLOC 1 #endif static int rt_mem(TCCState *s1, int size) { void *ptr; int ptr_diff = 0; #ifdef CONFIG_SELINUX /* Using mmap instead of malloc */ void *prw; char tmpfname[] = "/tmp/.tccrunXXXXXX"; int fd = mkstemp(tmpfname); unlink(tmpfname); ftruncate(fd, size); ptr = mmap(NULL, size * 2, PROT_READ|PROT_EXEC, MAP_SHARED, fd, 0); /* mmap RW memory at fixed distance */ prw = mmap((char*)ptr + size, size, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_FIXED, fd, 0); close(fd); if (ptr == MAP_FAILED || prw == MAP_FAILED) return tcc_error_noabort("tccrun: could not map memory"); ptr_diff = (char*)prw - (char*)ptr; /* = size; */ //printf("map %p %p %p\n", ptr, prw, (void*)ptr_diff); size *= 2; #elif CONFIG_RUNMEM_VIRTUALALLOC /* always page-aligned */ ptr = VirtualAlloc(NULL, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE); if (!ptr) return tcc_error_noabort("tccrun: could not allocate memory"); #else ptr = tcc_malloc(size += PAGESIZE); /* one extra page to align malloc memory */ #endif s1->run_ptr = ptr; s1->run_size = size; return ptr_diff; } /* ------------------------------------------------------------- */ /* Do all relocations (needed before using tcc_get_symbol()) Returns -1 on error. */ LIBTCCAPI int tcc_relocate(TCCState *s1) { int size, ret, ptr_diff; if (s1->run_ptr) exit(tcc_error_noabort("'tcc_relocate()' twice is no longer supported")); #ifdef CONFIG_TCC_BACKTRACE if (s1->do_backtrace) tcc_add_symbol(s1, "_tcc_backtrace", _tcc_backtrace); /* for bt-log.c */ #endif size = tcc_relocate_ex(s1, NULL, 0); if (size < 0) return -1; ptr_diff = rt_mem(s1, size); if (ptr_diff < 0) return -1; ret = tcc_relocate_ex(s1, s1->run_ptr, ptr_diff); if (ret == 0) st_link(s1); return ret; } ST_FUNC void tcc_run_free(TCCState *s1) { unsigned size; void *ptr; int i; /* free any loaded DLLs */ for ( i = 0; i < s1->nb_loaded_dlls; i++) { DLLReference *ref = s1->loaded_dlls[i]; if ( ref->handle ) #ifdef _WIN32 FreeLibrary((HMODULE)ref->handle); #else dlclose(ref->handle); #endif } /* unmap or unprotect and free memory */ ptr = s1->run_ptr; if (NULL == ptr) return; st_unlink(s1); #ifdef _WIN64 win64_del_function_table(s1->run_function_table); #endif size = s1->run_size; #ifdef CONFIG_SELINUX munmap(ptr, size); #elif CONFIG_RUNMEM_VIRTUALALLOC VirtualFree(ptr, size, MEM_RELEASE); #else /* unprotect memory to make it usable for malloc again */ protect_pages((void*)PAGEALIGN(ptr), size - PAGESIZE, 2 /*rw*/); tcc_free(ptr); #endif } #define RT_EXIT_ZERO 0xE0E00E0E /* passed from longjmp instead of '0' */ /* launch the compiled program with the given arguments */ LIBTCCAPI int tcc_run(TCCState *s1, int argc, char **argv) { int (*prog_main)(int, char **, char **), ret; const char *top_sym; jmp_buf main_jb; #if defined(__APPLE__) extern char ***_NSGetEnviron(void); char **envp = *_NSGetEnviron(); #elif defined(__OpenBSD__) || defined(__NetBSD__) || defined(__FreeBSD__) extern char **environ; char **envp = environ; #else char **envp = environ; #endif /* tcc -dt -run ... nothing to do if no main() */ if ((s1->dflag & 16) && (addr_t)-1 == get_sym_addr(s1, "main", 0, 1)) return 0; tcc_add_symbol(s1, "__rt_exit", rt_exit); s1->run_main = "_runmain", top_sym = "main"; if (s1->elf_entryname) s1->run_main = top_sym = s1->elf_entryname; tcc_add_support(s1, "runmain.o"); if (tcc_relocate(s1) < 0) return -1; prog_main = (void*)get_sym_addr(s1, s1->run_main, 1, 1); if ((addr_t)-1 == (addr_t)prog_main) return -1; /* custom stdin for run_main, mainly if stdin is/was an input file. * fileno(stdin) should remain 0, as posix mandates to use the smallest * free fd, which is 0 after the initial fclose in freopen. windows too. * to set stdin to the tty, use /dev/tty (posix) or con (windows). */ if (s1->run_stdin && !freopen(s1->run_stdin, "r", stdin)) { tcc_error_noabort("failed to reopen stdin from '%s'", s1->run_stdin); return -1; } errno = 0; /* clean errno value */ fflush(stdout); fflush(stderr); ret = tcc_setjmp(s1, main_jb, tcc_get_symbol(s1, top_sym)); if (0 == ret) { ret = prog_main(argc, argv, envp); } else if (RT_EXIT_ZERO == ret) { ret = 0; } if (s1->dflag & 16 && ret) /* tcc -dt -run ... */ fprintf(s1->ppfp, "[returns %d]\n", ret), fflush(s1->ppfp); return ret; } /* ------------------------------------------------------------- */ /* remove all STB_LOCAL symbols */ static void cleanup_symbols(TCCState *s1) { Section *s = s1->symtab; int sym_index, end_sym = s->data_offset / sizeof (ElfSym); /* reset symtab */ s->data_offset = s->link->data_offset = s->hash->data_offset = 0; init_symtab(s); /* add global symbols again */ for (sym_index = 1; sym_index < end_sym; ++sym_index) { ElfW(Sym) *sym = &((ElfW(Sym) *)s->data)[sym_index]; const char *name = (char *)s->link->data + sym->st_name; if (ELFW(ST_BIND)(sym->st_info) == STB_LOCAL) continue; //printf("sym %s\n", name); put_elf_sym(s, sym->st_value, sym->st_size, sym->st_info, sym->st_other, sym->st_shndx, name); } } /* free all sections except symbols */ static void cleanup_sections(TCCState *s1) { struct { Section **secs; int nb_secs; } *p = (void*)&s1->sections; int i, f = 2; do { for (i = --f; i < p->nb_secs; i++) { Section *s = p->secs[i]; if (s == s1->symtab || s == s1->symtab->link || s == s1->symtab->hash) { s->data = tcc_realloc(s->data, s->data_allocated = s->data_offset); } else { free_section(s), tcc_free(s), p->secs[i] = NULL; } } } while (++p, f); } /* ------------------------------------------------------------- */ /* 0 = .text rwx other rwx (memory >= 2 pages a 4096 bytes) */ /* 1 = .text rx other rw (memory >= 3 pages) */ /* 2 = .text rx .rdata ro .data/.bss rw (memory >= 4 pages) */ /* Some targets implement secutiry options that do not allow write in executable code. These targets need CONFIG_RUNMEM_RO=1. The disadvantage of this is that it requires a little bit more memory. */ #ifndef CONFIG_RUNMEM_RO # ifdef __APPLE__ # define CONFIG_RUNMEM_RO 1 # else # define CONFIG_RUNMEM_RO 0 # endif #endif /* relocate code. Return -1 on error, required size if ptr is NULL, otherwise copy code into buffer passed by the caller */ static int tcc_relocate_ex(TCCState *s1, void *ptr, unsigned ptr_diff) { Section *s; unsigned offset, length, align, i, k, f; unsigned n, copy; addr_t mem, addr; if (NULL == ptr) { s1->nb_errors = 0; #ifdef TCC_TARGET_PE pe_output_file(s1, NULL); #else tcc_add_runtime(s1); resolve_common_syms(s1); build_got_entries(s1, 0); #endif } offset = copy = 0; mem = (addr_t)ptr; redo: if (s1->verbose == 2 && copy) printf(&"-----------------------------------------------------\n"[PTR_SIZE*2 - 8]); if (s1->nb_errors) return -1; if (copy == 3) return 0; for (k = 0; k < 3; ++k) { /* 0:rx, 1:ro, 2:rw sections */ n = 0; addr = 0; for(i = 1; i < s1->nb_sections; i++) { static const char shf[] = { SHF_ALLOC|SHF_EXECINSTR, SHF_ALLOC, SHF_ALLOC|SHF_WRITE }; s = s1->sections[i]; if (shf[k] != (s->sh_flags & (SHF_ALLOC|SHF_WRITE|SHF_EXECINSTR))) continue; length = s->data_offset; if (copy == 2) { if (addr == 0) addr = s->sh_addr; n = (s->sh_addr - addr) + length; continue; } if (copy) { /* final step: copy section data to memory */ if (s1->verbose == 2) printf("%d: %-16s %p len %05x align %04x\n", k, s->name, (void*)s->sh_addr, length, s->sh_addralign); ptr = (void*)s->sh_addr; if (k == 0) ptr = (void*)(s->sh_addr + ptr_diff); if (NULL == s->data || s->sh_type == SHT_NOBITS) memset(ptr, 0, length); else memcpy(ptr, s->data, length); continue; } if ((s->sh_flags & SHF_TLS) && length) return tcc_error_noabort("thread-local storage not supported with -run"); align = s->sh_addralign; if (++n == 1) { #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64 /* To avoid that x86 processors would reload cached instructions each time when data is written in the near, we need to make sure that code and data do not share the same 64 byte unit */ if (align < 64) align = 64; #endif /* start new page for different permissions */ if (k <= CONFIG_RUNMEM_RO) align = PAGESIZE; } s->sh_addralign = align; addr = k ? mem + ptr_diff : mem; offset += -(addr + offset) & (align - 1); s->sh_addr = mem ? addr + offset : 0; offset += length; } if (copy == 2) { /* set permissions */ if (n == 0) /* no data */ continue; #ifdef CONFIG_SELINUX if (k == 0) /* SHF_EXECINSTR has its own mapping */ continue; #endif f = k; if (f >= CONFIG_RUNMEM_RO) { if (f != 0) continue; f = 3; /* change only SHF_EXECINSTR to rwx */ } n = PAGEALIGN(n); if (s1->verbose == 2) { printf("protect %3s %p len %05x\n", &"rx\0ro\0rw\0rwx"[f*3], (void*)addr, (unsigned)n); } if (protect_pages((void*)addr, n, f) < 0) return tcc_error_noabort( #ifdef _WIN32 "VirtualProtect failed"); #else "mprotect failed (did you mean to configure --with-selinux?)"); #endif } } if (0 == mem) return PAGEALIGN(offset); if (++copy == 2) { goto redo; } if (copy == 3) { #ifdef _WIN64 s1->run_function_table = win64_add_function_table(s1); #endif /* remove local symbols and free sections except symtab */ cleanup_symbols(s1); cleanup_sections(s1); goto redo; } /* relocate symbols */ relocate_syms(s1, s1->symtab, 1); if (s1->nb_errors) goto redo; /* relocate sections */ #ifdef TCC_TARGET_PE s1->pe_imagebase = mem; #else relocate_plt(s1); #endif relocate_sections(s1); goto redo; } /* ------------------------------------------------------------- */ /* allow to run code in memory */ static int protect_pages(void *ptr, unsigned long length, int mode) { #ifdef _WIN32 static const unsigned char protect[] = { PAGE_EXECUTE_READ, PAGE_READONLY, PAGE_READWRITE, PAGE_EXECUTE_READWRITE }; DWORD old; if (!VirtualProtect(ptr, length, protect[mode], &old)) return -1; #else static const unsigned char protect[] = { PROT_READ | PROT_EXEC, PROT_READ, PROT_READ | PROT_WRITE, PROT_READ | PROT_WRITE | PROT_EXEC }; if (mprotect(ptr, length, protect[mode])) return -1; #endif /* XXX: BSD sometimes dump core with bad system call */ #if (defined TCC_TARGET_ARM && !TARGETOS_BSD) \ || defined TCC_TARGET_ARM64 || defined TCC_TARGET_RISCV64 if (mode == 0 || mode == 3) { #ifdef _WIN32 FlushInstructionCache(GetCurrentProcess(), ptr, length); #else void __clear_cache(void *beginning, void *end);