diff options
Diffstat (limited to 'toys/other/readelf.c')
| -rw-r--r-- | toys/other/readelf.c | 640 |
1 files changed, 640 insertions, 0 deletions
diff --git a/toys/other/readelf.c b/toys/other/readelf.c new file mode 100644 index 00000000..45afd83a --- /dev/null +++ b/toys/other/readelf.c @@ -0,0 +1,640 @@ +/* readelf.c - display information about ELF files. + * + * Copyright 2019 The Android Open Source Project + * + * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/nm.html + +USE_READELF(NEWTOY(readelf, "<1(dyn-syms)adehlnp:SsWx:", TOYFLAG_USR|TOYFLAG_BIN)) + +config READELF + bool "readelf" + default y + help + usage: readelf [-adehlnSs] [-p SECTION] [-x SECTION] [file...] + + Displays information about ELF files. + + -a Equivalent to -dhlnSs + -d Show dynamic section + -e Headers (equivalent to -hlS) + -h Show ELF header + -l Show program headers + -n Show notes + -p S Dump strings found in named/numbered section + -S Show section headers + -s Show symbol tables (.dynsym and .symtab) + -x S Hex dump of named/numbered section + + --dyn-syms Show just .dynsym symbol table +*/ + +#define FOR_readelf +#include "toys.h" + +GLOBALS( + char *x, *p; + + char *elf, *shstrtab, *f; + unsigned long long shoff, phoff, size, shstrtabsz; + int bits, endian, shnum, shentsize, phentsize; +) + +// Section header. +struct sh { + unsigned type, link, info; + unsigned long long flags, addr, offset, size, addralign, entsize; + char *name; +}; + +// Program header. +struct ph { + unsigned type, flags; + unsigned long long offset, vaddr, paddr, filesz, memsz, align; +}; + +static long long elf_get(char **p, int len) +{ + long long result; + + if (*p+len-TT.elf>TT.size) + perror_exit("Access off end: %ld[%d] of %lld\n", *p-TT.elf, len, TT.size); + + result = ((TT.endian == 2) ? peek_be : peek_le)(*p, len); + *p += len; + return result; +} + +static unsigned long long elf_long(char **p) +{ + return elf_get(p, 4*(TT.bits+1)); +} + +static unsigned elf_int(char **p) +{ + return elf_get(p, 4); +} + +static unsigned short elf_short(char **p) +{ + return elf_get(p, 2); +} + +static int get_sh(unsigned i, struct sh *s) +{ + char *shdr = TT.elf+TT.shoff+i*TT.shentsize; + unsigned name_offset; + + if (i >= TT.shnum || shdr > TT.elf+TT.size-TT.shentsize) { + printf("No shdr %d\n", i); + return 0; + } + + name_offset = elf_int(&shdr); + s->type = elf_int(&shdr); + s->flags = elf_long(&shdr); + s->addr = elf_long(&shdr); + s->offset = elf_long(&shdr); + s->size = elf_long(&shdr); + s->link = elf_int(&shdr); + s->info = elf_int(&shdr); + s->addralign = elf_long(&shdr); + s->entsize = elf_long(&shdr); + + if (s->type != 8) { + if (s->offset>TT.size || s->size>TT.size || s->offset>TT.size-s->size) { + printf("Bad offset/size %llu/%llu for sh %d\n", s->offset, s->size, i); + return 0; + } + } + + if (!TT.shstrtab) s->name = "?"; + else { + s->name = TT.shstrtab + name_offset; + if (name_offset > TT.shstrtabsz || s->name >= TT.elf+TT.size) { + printf("Bad name for sh %d\n", i); + return 0; + } + } + + return 1; +} + +static int find_section(char *spec, struct sh *s) +{ + char *end; + unsigned i; + + // Valid section number? + i = estrtol(spec, &end, 0); + if (!errno && !*end && i<TT.shnum) return get_sh(i, s); + + // Search the section names. + for (i=0; i<TT.shnum; i++) + if (get_sh(i, s) && !strcmp(s->name, spec)) return 1; + + error_msg("%s: no section '%s", TT.f, spec); + return 0; +} + +static int get_ph(int i, struct ph *ph) +{ + char *phdr = TT.elf+TT.phoff+i*TT.phentsize; + + if (phdr > TT.elf+TT.size-TT.phentsize) { + printf("Bad phdr %d\n", i); + return 0; + } + + // Elf64_Phdr reordered fields. + ph->type = elf_int(&phdr); + if (TT.bits) { + ph->flags = elf_int(&phdr); + ph->offset = elf_long(&phdr); + ph->vaddr = elf_long(&phdr); + ph->paddr = elf_long(&phdr); + ph->filesz = elf_long(&phdr); + ph->memsz = elf_long(&phdr); + ph->align = elf_long(&phdr); + } else { + ph->offset = elf_int(&phdr); + ph->vaddr = elf_int(&phdr); + ph->paddr = elf_int(&phdr); + ph->filesz = elf_int(&phdr); + ph->memsz = elf_int(&phdr); + ph->flags = elf_int(&phdr); + ph->align = elf_int(&phdr); + } + + if (ph->offset >= TT.size-ph->filesz) { + printf("phdr %d has bad offset/size %llu/%llu", i, ph->offset, ph->filesz); + return 0; + } + + return 1; +} + +#define MAP(...) __VA_ARGS__ +#define DECODER(name, values) \ + static char *name(int type) { \ + static char unknown[20]; \ + struct {int v; char *s;} a[] = values; \ + int i; \ + \ + for (i=0; i<ARRAY_LEN(a); i++) if (type==a[i].v) return a[i].s; \ + sprintf(unknown, "0x%x", type); \ + return unknown; \ + } + +DECODER(dt_type, MAP({{0,"x(NULL)"},{1,"N(NEEDED)"},{2,"b(PLTRELSZ)"}, + {3,"x(PLTGOT)"},{4,"x(HASH)"},{5,"x(STRTAB)"},{6,"x(SYMTAB)"},{7,"x(RELA)"}, + {8,"b(RELASZ)"},{9,"b(RELAENT)"},{10,"b(STRSZ)"},{11,"b(SYMENT)"}, + {12,"x(INIT)"},{13,"x(FINI)"},{14,"S(SONAME)"},{15,"R(RPATH)"}, + {16,"x(SYMBOLIC)"},{17,"x(REL)"},{18,"b(RELSZ)"},{19,"b(RELENT)"}, + {20,"P(PLTREL)"},{21,"x(DEBUG)"},{22,"x(TEXTREL)"},{23,"x(JMPREL)"}, + {24,"d(BIND_NOW)"},{25,"x(INIT_ARRAY)"},{26,"x(FINI_ARRAY)"}, + {27,"b(INIT_ARRAYSZ)"},{28,"b(FINI_ARRAYSZ)"},{29,"R(RUNPATH)"}, + {30,"f(FLAGS)"},{32,"x(PREINIT_ARRAY)"},{33,"x(PREINIT_ARRAYSZ)"}, + {35,"b(RELRSZ)"},{36,"x(RELR)"},{37,"b(RELRENT)"}, + {0x6000000f,"x(ANDROID_REL)"},{0x60000010,"b(ANDROID_RELSZ)"}, + {0x60000011,"x(ANDROID_RELA)"},{0x60000012,"b(ANDROID_RELASZ)"}, + {0x6fffe000,"x(ANDROID_RELR)"},{0x6fffe001,"b(ANDROID_RELRSZ)"}, + {0x6fffe003,"x(ANDROID_RELRENT)"},{0x6ffffef5,"x(GNU_HASH)"}, + {0x6ffffef6,"x(TLSDESC_PLT)"},{0x6ffffef7,"x(TLSDESC_GOT)"}, + {0x6ffffff0,"x(VERSYM)"},{0x6ffffff9,"d(RELACOUNT)"}, + {0x6ffffffa,"d(RELCOUNT)"},{0x6ffffffb,"F(FLAGS_1)"}, + {0x6ffffffc," (VERDEF)"},{0x6ffffffd,"d(VERDEFNUM)"}, + {0x6ffffffe,"x(VERNEED)"},{0x6fffffff,"d(VERNEEDNUM)"}})) + +DECODER(et_type, MAP({{0,"NONE (None)"},{1,"REL (Relocatable file)"}, + {2,"EXEC (Executable file)"},{3,"DYN (Shared object file)"}, + {4,"CORE (Core file)"}})) + +DECODER(nt_type_core, MAP({{1,"NT_PRSTATUS"},{2,"NT_FPREGSET"}, + {3,"NT_PRPSINFO"},{5,"NT_PLATFORM"},{6,"NT_AUXV"}, + {0x46494c45,"NT_FILE"},{0x53494749,"NT_SIGINFO"}})) + +DECODER(nt_type_linux, MAP({{0x200,"NT_386_TLS"},{0x202, "NT_X86_XSTATE"}, + {0x400,"NT_ARM_VFP"},{0x401,"NT_ARM_TLS"},{0x405,"NT_ARM_SVE"}})) + +DECODER(os_abi, MAP({{0,"UNIX - System V"}})) + +DECODER(ph_type, MAP({{0,"NULL"},{1,"LOAD"},{2,"DYNAMIC"},{3,"INTERP"}, + {4,"NOTE"},{5,"SHLIB"},{6,"PHDR"},{7,"TLS"},{0x6474e550,"GNU_EH_FRAME"}, + {0x6474e551,"GNU_STACK"},{0x6474e552,"GNU_RELRO"},{0x70000001,"EXIDX"}})) + +DECODER(sh_type, MAP({{0,"NULL"},{1,"PROGBITS"},{2,"SYMTAB"},{3,"STRTAB"}, + {4,"RELA"},{5,"HASH"},{6,"DYNAMIC"},{7,"NOTE"},{8,"NOBITS"},{9,"REL"}, + {10,"SHLIB"},{11,"DYNSYM"},{14,"INIT_ARRAY"},{15,"FINI_ARRAY"}, + {16,"PREINIT_ARRAY"},{17,"GROUP"},{18,"SYMTAB_SHNDX"},{19,"RELR"}, + {0x60000001,"ANDROID_REL"},{0x60000002,"ANDROID_RELA"}, + {0x6fffff00,"ANDROID_RELR"},{0x6ffffff6,"GNU_HASH"}, + {0x6ffffffd,"VERDEF"},{0x6ffffffe,"VERNEED"}, + {0x6fffffff,"VERSYM"},{0x70000001,"ARM_EXIDX"}, + {0x70000003,"ARM_ATTRIBUTES"}})) + +DECODER(stb_type, MAP({{0,"LOCAL"},{1,"GLOBAL"},{2,"WEAK"}})) + +DECODER(stt_type, MAP({{0,"NOTYPE"},{1,"OBJECT"},{2,"FUNC"},{3,"SECTION"}, + {4,"FILE"},{5,"COMMON"},{6,"TLS"},{10,"GNU_IFUNC"}})) + +DECODER(stv_type, MAP({{0,"DEFAULT"},{1,"INTERNAL"},{2,"HIDDEN"}, + {3,"PROTECTED"}})) + +static void show_symbols(struct sh *table, struct sh *strtab) +{ + char *symtab = TT.elf+table->offset, *ndx; + int numsym = table->size/(TT.bits ? 24 : 16), i; + + if (!numsym) return; + + xputc('\n'); + printf("Symbol table '%s' contains %d entries:\n" + " Num: %*s Size Type Bind Vis Ndx Name\n", + table->name, numsym, 5+8*TT.bits, "Value"); + for (i=0; i<numsym; i++) { + unsigned st_name = elf_int(&symtab), st_value, st_shndx, st_info, st_other; + unsigned long st_size; + char *name, buf[16]; + + // The various fields were moved around for 64-bit. + if (TT.bits) { + st_info = *symtab++; + st_other = *symtab++; + st_shndx = elf_short(&symtab); + st_value = elf_long(&symtab); + st_size = elf_long(&symtab); + } else { + st_value = elf_int(&symtab); + st_size = elf_int(&symtab); + st_info = *symtab++; + st_other = *symtab++; + st_shndx = elf_short(&symtab); + } + + // TODO: why do we trust name to be null terminated? + name = TT.elf + strtab->offset + st_name; + if (name >= TT.elf+TT.size) name = "???"; + + if (!st_shndx) ndx = "UND"; + else if (st_shndx==0xfff1) ndx = "ABS"; + else sprintf(ndx = buf, "%d", st_shndx); + + // TODO: look up and show any symbol versions with @ or @@. + + printf("%6d: %0*x %5lu %-7s %-6s %-9s%3s %s\n", i, 8*(TT.bits+1), + st_value, st_size, stt_type(st_info & 0xf), stb_type(st_info >> 4), + stv_type(st_other & 3), ndx, name); + } +} + +static int notematch(int namesz, char **p, char *expected) +{ + if (namesz!=strlen(expected)+1 || strcmp(*p, expected)) return 0; + *p += namesz; + + return 1; +} + +static void show_notes(unsigned long offset, unsigned long size) +{ + char *note = TT.elf + offset; + + if (size > TT.size || offset > TT.size-size) { + printf("Bad note bounds %lu/%lu\n", offset, size); + + return; + } + + printf(" %-20s%11s\tDescription\n", "Owner", "Data size"); + while (note < TT.elf+offset+size) { + char *p = note, *desc; + unsigned namesz=elf_int(&p), descsz=elf_int(&p), type=elf_int(&p), j=0; + + if (namesz > size || descsz > size) + return error_msg("%s: bad note @%lu", TT.f, offset); + printf(" %-20.*s 0x%08x\t", namesz, p, descsz); + if (notematch(namesz, &p, "GNU")) { + if (type == 1) { + printf("NT_GNU_ABI_TAG\tOS: %s, ABI: %u.%u.%u", + !elf_int(&p)?"Linux":"?", elf_int(&p), elf_int(&p), elf_int(&p)), j=1; + } else if (type == 3) { +// TODO should this set j=1? + printf("NT_GNU_BUILD_ID\t"); + for (;j<descsz;j++) printf("%02x", *p++); + } else if (type == 4) { + printf("NT_GNU_GOLD_VERSION\t%.*s", descsz, p), j=1; + } else p -= 4; + } else if (notematch(namesz, &p, "Android")) { + if (type == 1) { + printf("NT_VERSION\tAPI level %u", elf_int(&p)), j=1; + if (descsz>=132) printf(", NDK %.64s (%.64s)", p, p+64); + } else p -= 8; + } else if (notematch(namesz, &p, "CORE")) { + if (*(desc = nt_type_core(type)) != '0') printf("%s", desc), j=1; +// TODO else p -= 5? + } else if (notematch(namesz, &p, "LINUX")) { + if (*(desc = nt_type_linux(type)) != '0') printf("%s", desc), j=1; +// TODO else p -= 6? + } + + // If we didn't do custom output above, show a hex dump. + if (!j) { + printf("0x%x\t", type); + for (;j<descsz;j++) printf("%c%02x", j ? ' ' : '\t', *p++/*note[16+j]*/); + } + xputc('\n'); + note += 3*4 + ((namesz+3)&~3) + ((descsz+3)&~3); + } +} + +static void scan_elf() +{ + struct sh dynamic = {}, dynstr = {}, dynsym = {}, shstr = {}, strtab = {}, + symtab = {}, s; + struct ph ph; + char *hdr = TT.elf; + int type, machine, version, flags, entry, ehsize, phnum, shstrndx, i, j, w; + + if (TT.size < 45 || memcmp(hdr, "\177ELF", 4)) + return error_msg("%s: not ELF", TT.f); + + TT.bits = hdr[4] - 1; + TT.endian = hdr[5]; + if (TT.bits<0 || TT.bits>1 || TT.endian<1 || TT.endian>2 || hdr[6]!=1) + return error_msg("%s: bad ELF", TT.f); + + hdr += 16; // EI_NIDENT + type = elf_short(&hdr); + machine = elf_short(&hdr); + version = elf_int(&hdr); + entry = elf_long(&hdr); + TT.phoff = elf_long(&hdr); + TT.shoff = elf_long(&hdr); + flags = elf_int(&hdr); + ehsize = elf_short(&hdr); + TT.phentsize = elf_short(&hdr); + phnum = elf_short(&hdr); + TT.shentsize = elf_short(&hdr); + TT.shnum = elf_short(&hdr); + shstrndx = elf_short(&hdr); + + if (toys.optc > 1) printf("\nFile: %s\n", TT.f); + + if (FLAG(h)) { + printf("ELF Header:\n"); + printf(" Magic: "); + for (i=0; i<16; i++) printf("%02x%c", TT.elf[i], (i==15) ? '\n' : ' '); + printf(" Class: ELF%d\n", TT.bits?64:32); + printf(" Data: 2's complement, %s endian\n", + (TT.endian==2)?"big":"little"); + printf(" Version: 1 (current)\n"); + printf(" OS/ABI: %s\n", os_abi(TT.elf[7])); + printf(" ABI Version: %d\n", TT.elf[8]); + printf(" Type: %s\n", et_type(type)); + printf(" Machine: %s\n", elf_arch_name(machine)); + printf(" Version: 0x%x\n", version); + printf(" Entry point address: 0x%x\n", entry); + printf(" Start of program headers: %llu (bytes into file)\n", + TT.phoff); + printf(" Start of section headers: %llu (bytes into file)\n", + TT.shoff); + printf(" Flags: 0x%x\n", flags); + printf(" Size of this header: %d (bytes)\n", ehsize); + printf(" Size of program headers: %d (bytes)\n", TT.phentsize); + printf(" Number of program headers: %d\n", phnum); + printf(" Size of section headers: %d (bytes)\n", TT.shentsize); + printf(" Number of section headers: %d\n", TT.shnum); + printf(" Section header string table index: %d\n", shstrndx); + } + if (TT.phoff > TT.size) return error_msg("%s: bad phoff", TT.f); + if (TT.shoff > TT.size) return error_msg("%s: bad shoff", TT.f); + + // Set up the section header string table so we can use section header names. + // Core files have shstrndx == 0. + TT.shstrtab = 0; + TT.shstrtabsz = 0; + if (shstrndx) { + if (!get_sh(shstrndx, &shstr) || shstr.type != 3 /*SHT_STRTAB*/) + return error_msg("%s: bad shstrndx", TT.f); + TT.shstrtab = TT.elf+shstr.offset; + TT.shstrtabsz = shstr.size; + } + + w = 8<<TT.bits; + if (FLAG(S)) { + if (!TT.shnum) printf("\nThere are no sections in this file.\n"); + else { + if (!FLAG(h)) + printf("There are %d section headers, starting at offset %#llx:\n", + TT.shnum, TT.shoff); + printf("\nSection Headers:\n" + " [Nr] %-17s %-15s %-*s %-6s %-6s ES Flg Lk Inf Al\n", + "Name", "Type", w, "Address", "Off", "Size"); + } + } + // We need to iterate through the section headers even if we're not + // dumping them, to find specific sections. + for (i=0; i<TT.shnum; i++) { + if (!get_sh(i, &s)) continue; + if (s.type == 2 /*SHT_SYMTAB*/) symtab = s; + else if (s.type == 6 /*SHT_DYNAMIC*/) dynamic = s; + else if (s.type == 11 /*SHT_DYNSYM*/) dynsym = s; + else if (s.type == 3 /*SHT_STRTAB*/) { + if (!strcmp(s.name, ".strtab")) strtab = s; + else if (!strcmp(s.name, ".dynstr")) dynstr = s; + } + + if (FLAG(S)) { + char sh_flags[12] = {}, *p = sh_flags; + + for (j=0; j<12; j++) if (s.flags&(1<<j)) *p++ = "WAXxMSILOTC"[j]; + printf(" [%2d] %-17s %-15s %0*llx %06llx %06llx %02llx %3s %2d %2d %2lld\n", + i, s.name, sh_type(s.type), w, s.addr, s.offset, s.size, + s.entsize, sh_flags, s.link, s.info, s.addralign); + } + } + if (FLAG(S) && TT.shnum) + printf("Key:\n (W)rite, (A)lloc, e(X)ecute, (M)erge, (S)trings, (I)nfo\n" + " (L)ink order, (O)S, (G)roup, (T)LS, (C)ompressed, x=unknown\n"); + + if (FLAG(l)) { + xputc('\n'); + if (!phnum) printf("There are no program headers in this file.\n"); + else { + if (!FLAG(h)) + printf("Elf file type is %s\nEntry point %#x\n" + "There are %d program headers, starting at offset %lld\n\n", + et_type(type), entry, phnum, TT.phoff); + printf("Program Headers:\n" + " %-14s %-8s %-*s %-*s %-7s %-7s Flg Align\n", "Type", + "Offset", w, "VirtAddr", w, "PhysAddr", "FileSiz", "MemSiz"); + for (i = 0; i<phnum; i++) { + if (!get_ph(i, &ph)) continue; + printf(" %-14s 0x%06llx 0x%0*llx 0x%0*llx 0x%05llx 0x%05llx %c%c%c %#llx\n", + ph_type(ph.type), ph.offset, w, ph.vaddr, w, ph.paddr, + ph.filesz, ph.memsz, (ph.flags&4)?'R':' ', (ph.flags&2)?'W':' ', + (ph.flags&1)?'E':' ', ph.align); + if (ph.type == 3 /*PH_INTERP*/ && ph.filesz<TT.size && + ph.offset<TT.size && ph.filesz - 1 < TT.size - ph.offset) { +// TODO: ph.filesz of 0 prints unlimited length string + printf(" [Requesting program interpreter: %*s]\n", + (int) ph.filesz-1, TT.elf+ph.offset); + } + } + + printf("\n Section to Segment mapping:\n Segment Sections...\n"); + for (i=0; i<phnum; i++) { + if (!get_ph(i, &ph)) continue; + printf(" %02d ", i); + for (j=0; j<TT.shnum; j++) { + if (!get_sh(j, &s)) continue; + if (!*s.name) continue; + if (s.offset >= ph.offset && s.offset+s.size <= ph.offset+ph.filesz) + printf("%s ", s.name); + } + xputc('\n'); + } + } + } + + // binutils ld emits a bunch of extra DT_NULL entries, so binutils readelf + // uses two passes here! We just tell the truth, which matches -h. + if (FLAG(d)) { + char *dyn = TT.elf+dynamic.offset, *end = dyn+dynamic.size; + + xputc('\n'); + if (!dynamic.size) printf("There is no dynamic section in this file.\n"); + else if (!dynamic.entsize) printf("Bad dynamic entry size 0!\n"); + else { + printf("Dynamic section at offset 0x%llx contains %lld entries:\n" + " %-*s %-20s %s\n", dynamic.offset, dynamic.size/dynamic.entsize, + w+2, "Tag", "Type", "Name/Value"); + while (dyn < end) { + unsigned long long tag = elf_long(&dyn), val = elf_long(&dyn); + char *type = dt_type(tag); + + printf(" 0x%0*llx %-20s ", w, tag, type+(*type!='0')); + if (*type == 'd') printf("%lld\n", val); + else if (*type == 'b') printf("%lld (bytes)\n", val); +// TODO: trusting this %s to be null terminated + else if (*type == 's') printf("%s\n", TT.elf+dynstr.offset+val); + else if (*type == 'f' || *type == 'F') { + struct bitname { int bit; char *s; } + df_names[] = {{0, "ORIGIN"},{1,"SYMBOLIC"},{2,"TEXTREL"}, + {3,"BIND_NOW"},{4,"STATIC_TLS"},{}}, + df_1_names[]={{0,"NOW"},{1,"GLOBAL"},{2,"GROUP"},{3,"NODELETE"}, + {5,"INITFIRST"},{27,"PIE"},{}}, + *names = *type == 'f' ? df_names : df_1_names; + int mask; + + if (*type == 'F') printf("Flags: "); + for (j=0; names[j].s; j++) + if (val & (mask=(1<<names[j].bit))) + printf("%s%s", names[j].s, (val &= ~mask) ? " " : ""); + if (val) printf("0x%llx", val); + xputc('\n'); + } else if (*type == 'N' || *type == 'R' || *type == 'S') { + char *s = TT.elf+dynstr.offset+val; + + if (dynstr.offset>TT.size || val>TT.size || dynstr.offset>TT.size-val) + s = "???"; + printf("%s: [%s]\n", *type=='N' ? "Shared library" : + (*type=='R' ? "Library runpath" : "Library soname"), s); + } else if (*type == 'P') { + j = strlen(type = dt_type(val)); + if (*type != '0') type += 2, j -= 3; + printf("%*.*s\n", j, j, type); + } else printf("0x%llx\n", val); + } + } + } + + if (FLAG(dyn_syms)) show_symbols(&dynsym, &dynstr); + if (FLAG(s)) show_symbols(&symtab, &strtab); + + if (FLAG(n)) { + int found = 0; + + for (i=0; i<TT.shnum; i++) { + if (!get_sh(i, &s)) continue; + if (s.type == 7 /*SHT_NOTE*/) { + printf("\nDisplaying notes found in: %s\n", s.name); + show_notes(s.offset, s.size); + found = 1; + } + } + for (i=0; !found && i<phnum; i++) { + if (!get_ph(i, &ph)) continue; + if (ph.type == 4 /*PT_NOTE*/) { + printf("\n" + "Displaying notes found at file offset 0x%llx with length 0x%llx:\n", + ph.offset, ph.filesz); + show_notes(ph.offset, ph.filesz); + } + } + } + + if (FLAG(x) && find_section(TT.x, &s)) { + char *p = TT.elf+s.offset; + long offset = 0; + + printf("\nHex dump of section '%s':\n", s.name); + while (offset < s.size) { + int space = 2*16 + 16/4; + + printf(" 0x%08lx ", offset); + for (i=0; i<16 && offset < s.size; offset++) + space -= printf("%02x%s", *p++, " "+!!(++i%4)); + printf("%*s", space, ""); + for (p -= i; i; i--, p++) putchar((*p>=' ' && *p<='~') ? *p : '.'); + xputc('\n'); + } + xputc('\n'); + } + + if (FLAG(p) && find_section(TT.p, &s)) { + char *begin = TT.elf+s.offset, *end = begin + s.size, *p = begin; + int any = 0; + + printf("\nString dump of section '%s':\n", s.name); + for (; p < end; p++) { + if (isprint(*p)) { + printf(" [%6tx] ", p-begin); + while (p < end && isprint(*p)) putchar(*p++); + xputc('\n'); + any=1; + } + } + if (!any) printf(" No strings found in this section.\n"); + xputc('\n'); + } +} + +void readelf_main(void) +{ + char **arg; + int all = FLAG_d|FLAG_h|FLAG_l|FLAG_n|FLAG_S|FLAG_s|FLAG_dyn_syms; + + if (FLAG(a)) toys.optflags |= all; + if (FLAG(e)) toys.optflags |= FLAG_h|FLAG_l|FLAG_S; + if (FLAG(s)) toys.optflags |= FLAG_dyn_syms; + if (!(toys.optflags & (all|FLAG_p|FLAG_x))) help_exit("needs a flag"); + + for (arg = toys.optargs; *arg; arg++) { + int fd = open(TT.f = *arg, O_RDONLY); + struct stat sb; + + if (fd == -1) perror_msg("%s", TT.f); + else { + if (fstat(fd, &sb)) perror_msg("%s", TT.f); + else if (!sb.st_size) error_msg("%s: empty", TT.f); + else if (!S_ISREG(sb.st_mode)) error_msg("%s: not a regular file",TT.f); + else { + TT.elf = xmmap(0, TT.size=sb.st_size, PROT_READ, MAP_SHARED, fd, 0); + scan_elf(); + munmap(TT.elf, TT.size); + } + close(fd); + } + } +} |