diff options
Diffstat (limited to 'tccelf.c')
| -rw-r--r-- | tccelf.c | 220 |
1 files changed, 123 insertions, 97 deletions
@@ -84,7 +84,7 @@ static void rebuild_hash(Section *s, unsigned int nb_buckets) } /* return the symbol number */ -ST_FUNC int put_elf_sym(Section *s, uplong value, unsigned long size, +ST_FUNC int put_elf_sym(Section *s, addr_t value, unsigned long size, int info, int other, int shndx, const char *name) { int name_offset, sym_index; @@ -157,7 +157,7 @@ ST_FUNC int find_elf_sym(Section *s, const char *name) } /* return elf symbol value, signal error if 'err' is nonzero */ -static void *get_elf_sym_addr(TCCState *s, const char *name, int err) +ST_FUNC addr_t get_elf_sym_addr(TCCState *s, const char *name, int err) { int sym_index; ElfW(Sym) *sym; @@ -167,26 +167,28 @@ static void *get_elf_sym_addr(TCCState *s, const char *name, int err) if (!sym_index || sym->st_shndx == SHN_UNDEF) { if (err) tcc_error("%s not defined", name); - return NULL; + return 0; } - return (void*)(uplong)sym->st_value; + return sym->st_value; } /* return elf symbol value */ LIBTCCAPI void *tcc_get_symbol(TCCState *s, const char *name) { - return get_elf_sym_addr(s, name, 0); + return (void*)(uintptr_t)get_elf_sym_addr(s, name, 0); } +#ifdef TCC_IS_NATIVE /* return elf symbol value or error */ -ST_FUNC void *tcc_get_symbol_err(TCCState *s, const char *name) +ST_FUNC void* tcc_get_symbol_err(TCCState *s, const char *name) { - return get_elf_sym_addr(s, name, 1); + return (void*)get_elf_sym_addr(s, name, 1); } +#endif /* add an elf symbol : check if it is already defined and patch it. Return symbol index. NOTE that sh_num can be SHN_UNDEF. */ -ST_FUNC int add_elf_sym(Section *s, uplong value, unsigned long size, +ST_FUNC int add_elf_sym(Section *s, addr_t value, unsigned long size, int info, int other, int sh_num, const char *name) { ElfW(Sym) *esym; @@ -238,7 +240,7 @@ ST_FUNC int add_elf_sym(Section *s, uplong value, unsigned long size, } else if (s == tcc_state->dynsymtab_section) { /* we accept that two DLL define the same symbol */ } else { -#if 1 +#if 0 printf("new_bind=%x new_shndx=%x new_vis=%x old_bind=%x old_shndx=%x old_vis=%x\n", sym_bind, sh_num, new_vis, esym_bind, esym->st_shndx, esym_vis); #endif @@ -431,12 +433,12 @@ ST_FUNC void relocate_syms(TCCState *s1, int do_resolve) if (sh_num == SHN_UNDEF) { name = strtab_section->data + sym->st_name; if (do_resolve) { -#if !defined TCC_TARGET_PE || !defined _WIN32 +#if defined TCC_IS_NATIVE && !defined _WIN32 void *addr; name = symtab_section->link->data + sym->st_name; addr = resolve_sym(s1, name); if (addr) { - sym->st_value = (uplong)addr; + sym->st_value = (addr_t)addr; goto found; } #endif @@ -469,10 +471,10 @@ ST_FUNC void relocate_syms(TCCState *s1, int do_resolve) } } -#ifndef TCC_TARGET_PE +#ifdef TCC_HAS_RUNTIME_PLTGOT #ifdef TCC_TARGET_X86_64 #define JMP_TABLE_ENTRY_SIZE 14 -static uplong add_jmp_table(TCCState *s1, uplong val) +static addr_t add_jmp_table(TCCState *s1, addr_t val) { char *p = s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset; s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE; @@ -480,30 +482,30 @@ static uplong add_jmp_table(TCCState *s1, uplong val) p[0] = 0xff; p[1] = 0x25; *(int *)(p + 2) = 0; - *(uplong *)(p + 6) = val; - return (uplong)p; + *(addr_t *)(p + 6) = val; + return (addr_t)p; } -static uplong add_got_table(TCCState *s1, uplong val) +static addr_t add_got_table(TCCState *s1, addr_t val) { - uplong *p = (uplong *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset); - s1->runtime_plt_and_got_offset += sizeof(uplong); + addr_t *p = (addr_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset); + s1->runtime_plt_and_got_offset += sizeof(addr_t); *p = val; - return (uplong)p; + return (addr_t)p; } #elif defined TCC_TARGET_ARM #define JMP_TABLE_ENTRY_SIZE 8 -static uplong add_jmp_table(TCCState *s1, int val) +static addr_t add_jmp_table(TCCState *s1, int val) { uint32_t *p = (uint32_t *)(s1->runtime_plt_and_got + s1->runtime_plt_and_got_offset); s1->runtime_plt_and_got_offset += JMP_TABLE_ENTRY_SIZE; /* ldr pc, [pc, #-4] */ p[0] = 0xE51FF004; p[1] = val; - return (uplong)p; + return (addr_t)p; } #endif -#endif +#endif /* def TCC_HAS_RUNTIME_PLTGOT */ /* relocate a given section (CPU dependent) */ ST_FUNC void relocate_section(TCCState *s1, Section *s) @@ -513,7 +515,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) ElfW(Sym) *sym; int type, sym_index; unsigned char *ptr; - uplong val, addr; + addr_t val, addr; #if defined TCC_TARGET_I386 || defined TCC_TARGET_X86_64 int esym_index; #endif @@ -581,7 +583,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) break; case R_386_GOT32: /* we load the got offset */ - *(int *)ptr += s1->got_offsets[sym_index]; + *(int *)ptr += s1->sym_attrs[sym_index].got_offset; break; case R_386_16: if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) { @@ -612,13 +614,16 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) is_call = (type == R_ARM_CALL); x += val - addr; h = x & 2; -#ifndef TCC_TARGET_PE - if ((x & 3) || x >= 0x4000000 || x < -0x4000000) - if (!(x & 3) || !blx_avail || !is_call) - if (s1->output_type == TCC_OUTPUT_MEMORY) +#ifdef TCC_HAS_RUNTIME_PLTGOT + if (s1->output_type == TCC_OUTPUT_MEMORY) { + if ((x & 3) || x >= 0x2000000 || x < -0x2000000) + if (!(x & 3) || !blx_avail || !is_call) { x += add_jmp_table(s1, val) - val; /* add veneer */ + is_thumb = 0; /* Veneer uses ARM instructions */ + } + } #endif - if ((x & 3) || x >= 0x4000000 || x < -0x4000000) + if ((x & 3) || x >= 0x2000000 || x < -0x2000000) if (!(x & 3) || !blx_avail || !is_call) tcc_error("can't relocate value at %x",addr); x >>= 2; @@ -638,7 +643,8 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) case R_ARM_THM_JUMP24: { int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11; - int to_thumb, is_call, blx_bit = 1 << 12; + int to_thumb, is_call, to_plt, blx_bit = 1 << 12; + Section *plt; /* weak reference */ if (sym->st_shndx == SHN_UNDEF && @@ -662,9 +668,14 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) /* Relocation infos */ to_thumb = val & 1; + plt = s1->plt; + to_plt = (val >= plt->sh_addr) && + (val < plt->sh_addr + plt->data_offset); is_call = (type == R_ARM_THM_CALL); /* Compute final offset */ + if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */ + x -= 4; x += val - addr; if (!to_thumb && is_call) { blx_bit = 0; /* bl -> blx */ @@ -675,9 +686,9 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) * offset must not be out of range * if target is to be entered in arm mode: - bit 1 must not set - - instruction must be a call (bl) */ + - instruction must be a call (bl) or a jump to PLT */ if (!to_thumb || x >= 0x1000000 || x < -0x1000000) - if (to_thumb || (val & 2) || !is_call) + if (to_thumb || (val & 2) || (!is_call && !to_plt)) tcc_error("can't relocate value at %x",addr); /* Compute and store final offset */ @@ -752,7 +763,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) break; case R_ARM_GOT_BREL: /* we load the got offset */ - *(int *)ptr += s1->got_offsets[sym_index]; + *(int *)ptr += s1->sym_attrs[sym_index].got_offset; break; case R_ARM_COPY: break; @@ -762,8 +773,8 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */ break; default: - fprintf(stderr,"FIXME: handle reloc type %x at %x [%.8x] to %x\n", - type, (unsigned)addr, (unsigned)(uplong)ptr, (unsigned)val); + fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n", + type, (unsigned)addr, ptr, (unsigned)val); break; #elif defined(TCC_TARGET_C67) case R_C60_32: @@ -788,8 +799,8 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) case R_C60HI16: break; default: - fprintf(stderr,"FIXME: handle reloc type %x at %x [%.8x] to %x\n", - type, (unsigned)addr, (unsigned)(uplong)ptr, (unsigned)val); + fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n", + type, (unsigned)addr, ptr, (unsigned)val); break; #elif defined(TCC_TARGET_X86_64) case R_X86_64_64: @@ -829,7 +840,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) long long diff; diff = (long long)val - addr; if (diff <= -2147483647 || diff > 2147483647) { -#ifndef TCC_TARGET_PE +#ifdef TCC_HAS_RUNTIME_PLTGOT /* XXX: naive support for over 32bit jump */ if (s1->output_type == TCC_OUTPUT_MEMORY) { val = (add_jmp_table(s1, val - rel->r_addend) + @@ -850,7 +861,7 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) *(int *)ptr = val - rel->r_addend; break; case R_X86_64_GOTPCREL: -#ifndef TCC_TARGET_PE +#ifdef TCC_HAS_RUNTIME_PLTGOT if (s1->output_type == TCC_OUTPUT_MEMORY) { val = add_got_table(s1, val - rel->r_addend) + rel->r_addend; *(int *)ptr += val - addr; @@ -858,14 +869,14 @@ ST_FUNC void relocate_section(TCCState *s1, Section *s) } #endif *(int *)ptr += (s1->got->sh_addr - addr + - s1->got_offsets[sym_index] - 4); + s1->sym_attrs[sym_index].got_offset - 4); break; case R_X86_64_GOTTPOFF: *(int *)ptr += val - s1->got->sh_addr; break; case R_X86_64_GOT32: /* we load the got offset */ - *(int *)ptr += s1->got_offsets[sym_index]; + *(int *)ptr += s1->sym_attrs[sym_index].got_offset; break; #else #error unsupported processor @@ -935,23 +946,23 @@ static int prepare_dynamic_rel(TCCState *s1, Section *sr) return count; } -static void put_got_offset(TCCState *s1, int index, unsigned long val) +static struct sym_attr *alloc_sym_attr(TCCState *s1, int index) { int n; - unsigned long *tab; + struct sym_attr *tab; - if (index >= s1->nb_got_offsets) { + if (index >= s1->nb_sym_attrs) { /* find immediately bigger power of 2 and reallocate array */ n = 1; while (index >= n) n *= 2; - tab = tcc_realloc(s1->got_offsets, n * sizeof(unsigned long)); - s1->got_offsets = tab; - memset(s1->got_offsets + s1->nb_got_offsets, 0, - (n - s1->nb_got_offsets) * sizeof(unsigned long)); - s1->nb_got_offsets = n; + tab = tcc_realloc(s1->sym_attrs, n * sizeof(*s1->sym_attrs)); + s1->sym_attrs = tab; + memset(s1->sym_attrs + s1->nb_sym_attrs, 0, + (n - s1->nb_sym_attrs) * sizeof(*s1->sym_attrs)); + s1->nb_sym_attrs = n; } - s1->got_offsets[index] = val; + return &s1->sym_attrs[index]; } /* XXX: suppress that */ @@ -1015,11 +1026,11 @@ static void put_got_entry(TCCState *s1, build_got(s1); /* if a got entry already exists for that symbol, no need to add one */ - if (sym_index < s1->nb_got_offsets && - s1->got_offsets[sym_index] != 0) + if (sym_index < s1->nb_sym_attrs && + s1->sym_attrs[sym_index].got_offset) return; - - put_got_offset(s1, sym_index, s1->got->data_offset); + + alloc_sym_attr(s1, sym_index)->got_offset = s1->got->data_offset; if (s1->dynsym) { sym = &((ElfW(Sym) *)symtab_section->data)[sym_index]; @@ -1096,10 +1107,16 @@ static void put_got_entry(TCCState *s1, put32(p + 12, 0xe5bef008); } - p = section_ptr_add(plt, 16); - put32(p , 0xe59fc004); - put32(p+4, 0xe08fc00c); - put32(p+8, 0xe59cf000); + if (s1->sym_attrs[sym_index].plt_thumb_stub) { + p = section_ptr_add(plt, 20); + put32(p , 0x4778); // bx pc + put32(p+2, 0x46c0); // nop + p += 4; + } else + p = section_ptr_add(plt, 16); + put32(p , 0xe59fc004); // ldr ip, [pc, #4] // offset in GOT + put32(p+4, 0xe08fc00c); // add ip, pc, ip // absolute address or offset + put32(p+8, 0xe59cf000); // ldr pc, [ip] // load absolute address or load offset put32(p+12, s1->got->data_offset); /* the symbol is modified so that it will be relocated to @@ -1261,7 +1278,7 @@ ST_FUNC Section *new_symtab(TCCState *s1, } /* put dynamic tag */ -static void put_dt(Section *dynamic, int dt, uplong val) +static void put_dt(Section *dynamic, int dt, addr_t val) { ElfW(Dyn) *dyn; dyn = section_ptr_add(dynamic, sizeof(ElfW(Dyn))); @@ -1297,13 +1314,6 @@ static void add_init_array_defines(TCCState *s1, const char *section_name) s->sh_num, sym_end); } -static int tcc_add_support(TCCState *s1, const char *filename) -{ - char buf[1024]; - snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename); - return tcc_add_file(s1, buf); -} - ST_FUNC void tcc_add_bcheck(TCCState *s1) { #ifdef CONFIG_TCC_BCHECK @@ -1321,10 +1331,6 @@ ST_FUNC void tcc_add_bcheck(TCCState *s1) add_elf_sym(symtab_section, 0, 0, ELFW(ST_INFO)(STB_GLOBAL, STT_NOTYPE), 0, bounds_section->sh_num, "__bounds_start"); - /* add bound check code */ -#ifndef TCC_TARGET_PE - tcc_add_support(s1, "bcheck.o"); -#endif #ifdef TCC_TARGET_I386 if (s1->output_type != TCC_OUTPUT_MEMORY) { /* add 'call __bound_init()' in .init section */ @@ -1340,6 +1346,13 @@ ST_FUNC void tcc_add_bcheck(TCCState *s1) #endif } +static inline int tcc_add_support(TCCState *s1, const char *filename) +{ + char buf[1024]; + snprintf(buf, sizeof(buf), "%s/%s", s1->tcc_lib_path, filename); + return tcc_add_file(s1, buf); +} + /* add tcc runtime libraries */ ST_FUNC void tcc_add_runtime(TCCState *s1) { @@ -1483,9 +1496,9 @@ ST_FUNC void fill_got_entry(TCCState *s1, ElfW_Rel *rel) ElfW(Sym) *sym = &((ElfW(Sym) *) symtab_section->data)[sym_index]; unsigned long offset; - if (sym_index >= s1->nb_got_offsets) + if (sym_index >= s1->nb_sym_attrs) return; - offset = s1->got_offsets[sym_index]; + offset = s1->sym_attrs[sym_index].got_offset; section_reserve(s1->got, offset + PTR_SIZE); #ifdef TCC_TARGET_X86_64 /* only works for x86-64 */ @@ -1531,7 +1544,7 @@ static int elf_output_file(TCCState *s1, const char *filename) int *section_order; int shnum, i, phnum, file_offset, offset, size, j, sh_order_index, k; long long tmp; - uplong addr; + addr_t addr; Section *strsec, *s; ElfW(Shdr) shdr, *sh; ElfW(Phdr) *phdr, *ph; @@ -1539,9 +1552,9 @@ static int elf_output_file(TCCState *s1, const char *filename) unsigned long saved_dynamic_data_offset; ElfW(Sym) *sym; int type, file_type; - uplong rel_addr, rel_size; + addr_t rel_addr, rel_size; #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) - uplong bss_addr, bss_size; + addr_t bss_addr, bss_size; #endif file_type = s1->output_type; @@ -1618,8 +1631,16 @@ static int elf_output_file(TCCState *s1, const char *filename) esym = &((ElfW(Sym) *)s1->dynsymtab_section->data)[sym_index]; type = ELFW(ST_TYPE)(esym->st_info); if ((type == STT_FUNC) || (type == STT_GNU_IFUNC)) { + /* Indirect functions shall have STT_FUNC type + * in executable dynsym section. Indeed, a dlsym + * call following a lazy resolution would pick + * the symbol value from the executable dynsym + * entry which would contain the address of the + * function wanted by the caller of dlsym + * instead of the address of the function that + * would return that address */ put_got_entry(s1, R_JMP_SLOT, esym->st_size, - ELFW(ST_INFO)(STB_GLOBAL,type), + ELFW(ST_INFO)(STB_GLOBAL,STT_FUNC), sym - (ElfW(Sym) *)symtab_section->data); } else if (type == STT_OBJECT) { unsigned long offset; @@ -1719,8 +1740,9 @@ static int elf_output_file(TCCState *s1, const char *filename) if ((ELFW(ST_TYPE)(sym->st_info) == STT_FUNC || ELFW(ST_TYPE)(sym->st_info) == STT_GNU_IFUNC) && sym->st_shndx == SHN_UNDEF) { + int visibility = ELFW(ST_BIND)(sym->st_info); put_got_entry(s1, R_JMP_SLOT, sym->st_size, - sym->st_info, + ELFW(ST_INFO)(visibility,STT_FUNC), sym - (ElfW(Sym) *)symtab_section->data); } else if (ELFW(ST_TYPE)(sym->st_info) == STT_OBJECT) { @@ -2057,8 +2079,10 @@ static int elf_output_file(TCCState *s1, const char *filename) #elif defined(TCC_TARGET_ARM) int x; x=s1->got->sh_addr - s1->plt->sh_addr - 12; - p +=16; + p += 16; while (p < p_end) { + if (get32(p) == 0x46c04778) /* PLT Thumb stub present */ + p += 4; put32(p + 12, x + get32(p + 12) + s1->plt->data - p); p += 16; } @@ -2150,7 +2174,7 @@ static int elf_output_file(TCCState *s1, const char *filename) /* XXX: ignore sections with allocated relocations ? */ for(i = 1; i < s1->nb_sections; i++) { s = s1->sections[i]; - if (s->reloc && s != s1->got && (s->sh_flags & SHF_ALLOC)) //gr + if (s->reloc && s != s1->got) relocate_section(s1, s); } @@ -2166,7 +2190,7 @@ static int elf_output_file(TCCState *s1, const char *filename) /* get entry point address */ if (file_type == TCC_OUTPUT_EXE) - ehdr.e_entry = (uplong)tcc_get_symbol_err(s1, "_start"); + ehdr.e_entry = get_elf_sym_addr(s1, "_start", 1); else ehdr.e_entry = text_section->sh_addr; /* XXX: is it correct ? */ } @@ -2292,7 +2316,7 @@ static int elf_output_file(TCCState *s1, const char *filename) tcc_free(s1->symtab_to_dynsym); tcc_free(section_order); tcc_free(phdr); - tcc_free(s1->got_offsets); + tcc_free(s1->sym_attrs); return ret; } @@ -2587,6 +2611,18 @@ ST_FUNC int tcc_load_object_file(TCCState *s1, rel->r_info = ELFW(R_INFO)(sym_index, type); /* offset the relocation offset */ rel->r_offset += offseti; +#ifdef TCC_TARGET_ARM + /* Jumps and branches from a Thumb code to a PLT entry need + special handling since PLT entries are ARM code. + Unconditional bl instructions referencing PLT entries are + handled by converting these instructions into blx + instructions. Other case of instructions referencing a PLT + entry require to add a Thumb stub before the PLT entry to + switch to ARM mode. We set bit 0 of the got offset of a + symbol to indicate such a case. */ + if (type == R_ARM_THM_JUMP24) + alloc_sym_attr(s1, sym_index)->plt_thumb_stub = 1; +#endif } break; default: @@ -2955,20 +2991,6 @@ static int ld_next(TCCState *s1, char *name, int name_size) return c; } -/* - * Extract the file name from the library name - * - * /!\ No test on filename capacity, be careful - */ -static void libname_to_filename(TCCState *s1, const char libname[], char filename[]) -{ - if (!s1->static_link) { - sprintf(filename, "lib%s.so", libname); - } else { - sprintf(filename, "lib%s.a", libname); - } -} - static int ld_add_file(TCCState *s1, const char filename[]) { int ret; @@ -3015,8 +3037,12 @@ static int ld_add_file_list(TCCState *s1, const char *cmd, int as_needed) ret = -1; goto lib_parse_error; } - strcpy(libname, &filename[1]); - libname_to_filename(s1, libname, filename); + pstrcpy(libname, sizeof libname, &filename[1]); + if (s1->static_link) { + snprintf(filename, sizeof filename, "lib%s.a", libname); + } else { + snprintf(filename, sizeof filename, "lib%s.so", libname); + } } else if (t != LD_TOK_NAME) { tcc_error_noabort("filename expected"); ret = -1; |