blob: e6e1623fc8dcdb3283b8312773ba5688a46c89e9 [file] [log] [blame]
/* 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 n
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 = ((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;
int i;
// Valid section number?
errno = 0;
i = strtoul(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 == 0) 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;
unsigned char st_info, st_other;
unsigned long st_size;
char *name;
// 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);
}
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 = toybuf, "%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, int len)
{
if (namesz != len || memcmp(*p, expected, namesz)) 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 %10s\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) {
error_msg("%s: bad note @%lu", TT.f, offset);
return;
}
printf(" %-20.*s 0x%08x\t", namesz, p, descsz);
if (notematch(namesz, &p, "GNU", 4)) {
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) {
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", 8)) {
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", 5)) {
if (*(desc = nt_type_core(type)) != '0') printf("%s", desc), j=1;
} else if (notematch(namesz, &p, "LINUX", 6)) {
if (*(desc = nt_type_linux(type)) != '0') printf("%s", desc), j=1;
}
// 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)) {
error_msg("%s: not ELF", TT.f);
return;
}
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) {
error_msg("%s: bad ELF", TT.f);
return;
}
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) {
error_msg("%s: bad phoff", TT.f);
return;
}
if (TT.shoff > TT.size) {
error_msg("%s: bad shoff", TT.f);
return;
}
// 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 != 0) {
if (!get_sh(shstrndx, &shstr) || shstr.type != 3 /*SHT_STRTAB*/) {
error_msg("%s: bad shstrndx", TT.f);
return;
}
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("\n"
"Section 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\n"
"Entry 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) {
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=='0' ? type : type+1);
if (*type == 'd') printf("%lld\n", val);
else if (*type == 'b') printf("%lld (bytes)\n", val);
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') {
type = dt_type(val);
j = strlen(type);
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)) {
if (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');
}
printf("\n");
}
}
if (FLAG(p)) {
if (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");
printf("\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(NULL, TT.size=sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
scan_elf();
munmap(TT.elf, TT.size);
}
close(fd);
}
}
}