1 /* readelf.c - display information about ELF files.
2 *
3 * Copyright 2019 The Android Open Source Project
4 *
5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/nm.html
6
7 USE_READELF(NEWTOY(readelf, "<1(dyn-syms)adehlnp:SsWx:", TOYFLAG_USR|TOYFLAG_BIN))
8
9 config READELF
10 bool "readelf"
11 default n
12 help
13 usage: readelf [-adehlnSs] [-p SECTION] [-x SECTION] [file...]
14
15 Displays information about ELF files.
16
17 -a Equivalent to -dhlnSs
18 -d Show dynamic section
19 -e Headers (equivalent to -hlS)
20 -h Show ELF header
21 -l Show program headers
22 -n Show notes
23 -p S Dump strings found in named/numbered section
24 -S Show section headers
25 -s Show symbol tables (.dynsym and .symtab)
26 -x S Hex dump of named/numbered section
27
28 --dyn-syms Show just .dynsym symbol table
29 */
30
31 #define FOR_readelf
32 #include "toys.h"
33
34 GLOBALS(
35 char *x, *p;
36
37 char *elf, *shstrtab, *f;
38 unsigned long long shoff, phoff, size, shstrtabsz;
39 int bits, endian, shnum, shentsize, phentsize;
40 )
41
42 // Section header.
43 struct sh {
44 unsigned type, link, info;
45 unsigned long long flags, addr, offset, size, addralign, entsize;
46 char *name;
47 };
48
49 // Program header.
50 struct ph {
51 unsigned type, flags;
52 unsigned long long offset, vaddr, paddr, filesz, memsz, align;
53 };
54
elf_get(char ** p,int len)55 static long long elf_get(char **p, int len)
56 {
57 long long result = ((TT.endian == 2) ? peek_be : peek_le)(*p, len);
58
59 *p += len;
60 return result;
61 }
62
elf_long(char ** p)63 static unsigned long long elf_long(char **p)
64 {
65 return elf_get(p, 4*(TT.bits+1));
66 }
67
elf_int(char ** p)68 static unsigned elf_int(char **p)
69 {
70 return elf_get(p, 4);
71 }
72
elf_short(char ** p)73 static unsigned short elf_short(char **p)
74 {
75 return elf_get(p, 2);
76 }
77
get_sh(unsigned i,struct sh * s)78 static int get_sh(unsigned i, struct sh *s)
79 {
80 char *shdr = TT.elf+TT.shoff+i*TT.shentsize;
81 unsigned name_offset;
82
83 if (i >= TT.shnum || shdr > TT.elf+TT.size-TT.shentsize) {
84 printf("No shdr %d\n", i);
85 return 0;
86 }
87
88 name_offset = elf_int(&shdr);
89 s->type = elf_int(&shdr);
90 s->flags = elf_long(&shdr);
91 s->addr = elf_long(&shdr);
92 s->offset = elf_long(&shdr);
93 s->size = elf_long(&shdr);
94 s->link = elf_int(&shdr);
95 s->info = elf_int(&shdr);
96 s->addralign = elf_long(&shdr);
97 s->entsize = elf_long(&shdr);
98
99 if (s->type != 8) {
100 if (s->offset>TT.size || s->size>TT.size || s->offset>TT.size-s->size) {
101 printf("Bad offset/size %llu/%llu for sh %d\n", s->offset, s->size, i);
102 return 0;
103 }
104 }
105
106 if (!TT.shstrtab) s->name = "?";
107 else {
108 s->name = TT.shstrtab + name_offset;
109 if (name_offset > TT.shstrtabsz || s->name >= TT.elf+TT.size) {
110 printf("Bad name for sh %d\n", i);
111 return 0;
112 }
113 }
114
115 return 1;
116 }
117
find_section(char * spec,struct sh * s)118 static int find_section(char *spec, struct sh *s)
119 {
120 char *end;
121 int i;
122
123 // Valid section number?
124 errno = 0;
125 i = strtoul(spec, &end, 0);
126 if (!errno && !*end && i < TT.shnum) return get_sh(i, s);
127
128 // Search the section names.
129 for (i=0; i<TT.shnum; i++) {
130 if (get_sh(i, s) && !strcmp(s->name, spec)) return 1;
131 }
132
133 error_msg("%s: no section '%s", TT.f, spec);
134 return 0;
135 }
136
get_ph(int i,struct ph * ph)137 static int get_ph(int i, struct ph *ph)
138 {
139 char *phdr = TT.elf+TT.phoff+i*TT.phentsize;
140
141 if (phdr > TT.elf+TT.size-TT.phentsize) {
142 printf("Bad phdr %d\n", i);
143 return 0;
144 }
145
146 // Elf64_Phdr reordered fields.
147 ph->type = elf_int(&phdr);
148 if (TT.bits) {
149 ph->flags = elf_int(&phdr);
150 ph->offset = elf_long(&phdr);
151 ph->vaddr = elf_long(&phdr);
152 ph->paddr = elf_long(&phdr);
153 ph->filesz = elf_long(&phdr);
154 ph->memsz = elf_long(&phdr);
155 ph->align = elf_long(&phdr);
156 } else {
157 ph->offset = elf_int(&phdr);
158 ph->vaddr = elf_int(&phdr);
159 ph->paddr = elf_int(&phdr);
160 ph->filesz = elf_int(&phdr);
161 ph->memsz = elf_int(&phdr);
162 ph->flags = elf_int(&phdr);
163 ph->align = elf_int(&phdr);
164 }
165
166 if (ph->offset >= TT.size-ph->filesz) {
167 printf("phdr %d has bad offset/size %llu/%llu", i, ph->offset, ph->filesz);
168 return 0;
169 }
170
171 return 1;
172 }
173
174 #define MAP(...) __VA_ARGS__
175 #define DECODER(name, values) \
176 static char *name(int type) { \
177 static char unknown[20]; \
178 struct {int v; char *s;} a[] = values; \
179 int i; \
180 \
181 for (i=0; i<ARRAY_LEN(a); i++) if (type==a[i].v) return a[i].s; \
182 sprintf(unknown, "0x%x", type); \
183 return unknown; \
184 }
185
186 DECODER(dt_type, MAP({{0,"x(NULL)"},{1,"N(NEEDED)"},{2,"b(PLTRELSZ)"},
187 {3,"x(PLTGOT)"},{4,"x(HASH)"},{5,"x(STRTAB)"},{6,"x(SYMTAB)"},{7,"x(RELA)"},
188 {8,"b(RELASZ)"},{9,"b(RELAENT)"},{10,"b(STRSZ)"},{11,"b(SYMENT)"},
189 {12,"x(INIT)"},{13,"x(FINI)"},{14,"S(SONAME)"},{15,"R(RPATH)"},
190 {16,"x(SYMBOLIC)"},{17,"x(REL)"},{18,"b(RELSZ)"},{19,"b(RELENT)"},
191 {20,"P(PLTREL)"},{21,"x(DEBUG)"},{22,"x(TEXTREL)"},{23,"x(JMPREL)"},
192 {24,"d(BIND_NOW)"},{25,"x(INIT_ARRAY)"},{26,"x(FINI_ARRAY)"},
193 {27,"b(INIT_ARRAYSZ)"},{28,"b(FINI_ARRAYSZ)"},{29,"R(RUNPATH)"},
194 {30,"f(FLAGS)"},{32,"x(PREINIT_ARRAY)"},{33,"x(PREINIT_ARRAYSZ)"},
195 {35,"b(RELRSZ)"},{36,"x(RELR)"},{37,"b(RELRENT)"},
196 {0x6000000f,"x(ANDROID_REL)"},{0x60000010,"b(ANDROID_RELSZ)"},
197 {0x60000011,"x(ANDROID_RELA)"},{0x60000012,"b(ANDROID_RELASZ)"},
198 {0x6fffe000,"x(ANDROID_RELR)"},{0x6fffe001,"b(ANDROID_RELRSZ)"},
199 {0x6fffe003,"x(ANDROID_RELRENT)"},{0x6ffffef5,"x(GNU_HASH)"},
200 {0x6ffffef6,"x(TLSDESC_PLT)"},{0x6ffffef7,"x(TLSDESC_GOT)"},
201 {0x6ffffff0,"x(VERSYM)"},{0x6ffffff9,"d(RELACOUNT)"},
202 {0x6ffffffa,"d(RELCOUNT)"},{0x6ffffffb,"F(FLAGS_1)"},
203 {0x6ffffffc," (VERDEF)"},{0x6ffffffd,"d(VERDEFNUM)"},
204 {0x6ffffffe,"x(VERNEED)"},{0x6fffffff,"d(VERNEEDNUM)"}}))
205
206 DECODER(et_type, MAP({{0,"NONE (None)"},{1,"REL (Relocatable file)"},
207 {2,"EXEC (Executable file)"},{3,"DYN (Shared object file)"},
208 {4,"CORE (Core file)"}}))
209
210 DECODER(nt_type_core, MAP({{1,"NT_PRSTATUS"},{2,"NT_FPREGSET"},
211 {3,"NT_PRPSINFO"},{5,"NT_PLATFORM"},{6,"NT_AUXV"},
212 {0x46494c45,"NT_FILE"},{0x53494749,"NT_SIGINFO"}}))
213
214 DECODER(nt_type_linux, MAP({{0x200,"NT_386_TLS"},{0x202, "NT_X86_XSTATE"},
215 {0x400,"NT_ARM_VFP"},{0x401,"NT_ARM_TLS"},{0x405,"NT_ARM_SVE"}}))
216
217 DECODER(os_abi, MAP({{0,"UNIX - System V"}}))
218
219 DECODER(ph_type, MAP({{0,"NULL"},{1,"LOAD"},{2,"DYNAMIC"},{3,"INTERP"},
220 {4,"NOTE"},{5,"SHLIB"},{6,"PHDR"},{7,"TLS"},{0x6474e550,"GNU_EH_FRAME"},
221 {0x6474e551,"GNU_STACK"},{0x6474e552,"GNU_RELRO"},{0x70000001,"EXIDX"}}))
222
223 DECODER(sh_type, MAP({{0,"NULL"},{1,"PROGBITS"},{2,"SYMTAB"},{3,"STRTAB"},
224 {4,"RELA"},{5,"HASH"},{6,"DYNAMIC"},{7,"NOTE"},{8,"NOBITS"},{9,"REL"},
225 {10,"SHLIB"},{11,"DYNSYM"},{14,"INIT_ARRAY"},{15,"FINI_ARRAY"},
226 {16,"PREINIT_ARRAY"},{17,"GROUP"},{18,"SYMTAB_SHNDX"},{19,"RELR"},
227 {0x60000001,"ANDROID_REL"},{0x60000002,"ANDROID_RELA"},
228 {0x6fffff00,"ANDROID_RELR"},{0x6ffffff6,"GNU_HASH"},
229 {0x6ffffffd,"VERDEF"},{0x6ffffffe,"VERNEED"},
230 {0x6fffffff,"VERSYM"},{0x70000001,"ARM_EXIDX"},
231 {0x70000003,"ARM_ATTRIBUTES"}}))
232
233 DECODER(stb_type, MAP({{0,"LOCAL"},{1,"GLOBAL"},{2,"WEAK"}}))
234
235 DECODER(stt_type, MAP({{0,"NOTYPE"},{1,"OBJECT"},{2,"FUNC"},{3,"SECTION"},
236 {4,"FILE"},{5,"COMMON"},{6,"TLS"},{10,"GNU_IFUNC"}}))
237
238 DECODER(stv_type, MAP({{0,"DEFAULT"},{1,"INTERNAL"},{2,"HIDDEN"},
239 {3,"PROTECTED"}}))
240
show_symbols(struct sh * table,struct sh * strtab)241 static void show_symbols(struct sh *table, struct sh *strtab)
242 {
243 char *symtab = TT.elf+table->offset, *ndx;
244 int numsym = table->size/(TT.bits ? 24 : 16), i;
245
246 if (numsym == 0) return;
247
248 xputc('\n');
249 printf("Symbol table '%s' contains %d entries:\n"
250 " Num: %*s Size Type Bind Vis Ndx Name\n",
251 table->name, numsym, 5+8*TT.bits, "Value");
252 for (i=0; i<numsym; i++) {
253 unsigned st_name = elf_int(&symtab), st_value, st_shndx;
254 unsigned char st_info, st_other;
255 unsigned long st_size;
256 char *name;
257
258 // The various fields were moved around for 64-bit.
259 if (TT.bits) {
260 st_info = *symtab++;
261 st_other = *symtab++;
262 st_shndx = elf_short(&symtab);
263 st_value = elf_long(&symtab);
264 st_size = elf_long(&symtab);
265 } else {
266 st_value = elf_int(&symtab);
267 st_size = elf_int(&symtab);
268 st_info = *symtab++;
269 st_other = *symtab++;
270 st_shndx = elf_short(&symtab);
271 }
272
273 name = TT.elf + strtab->offset + st_name;
274 if (name >= TT.elf+TT.size) name = "???";
275
276 if (!st_shndx) ndx = "UND";
277 else if (st_shndx==0xfff1) ndx = "ABS";
278 else sprintf(ndx = toybuf, "%d", st_shndx);
279
280 // TODO: look up and show any symbol versions with @ or @@.
281
282 printf("%6d: %0*x %5lu %-7s %-6s %-9s%3s %s\n", i, 8*(TT.bits+1),
283 st_value, st_size, stt_type(st_info & 0xf), stb_type(st_info >> 4),
284 stv_type(st_other & 3), ndx, name);
285 }
286 }
287
notematch(int namesz,char ** p,char * expected,int len)288 static int notematch(int namesz, char **p, char *expected, int len)
289 {
290 if (namesz != len || memcmp(*p, expected, namesz)) return 0;
291 *p += namesz;
292 return 1;
293 }
294
show_notes(unsigned long offset,unsigned long size)295 static void show_notes(unsigned long offset, unsigned long size)
296 {
297 char *note = TT.elf + offset;
298
299 if (size > TT.size || offset > TT.size-size) {
300 printf("Bad note bounds %lu/%lu\n", offset, size);
301 return;
302 }
303
304 printf(" %-20s %10s\tDescription\n", "Owner", "Data size");
305 while (note < TT.elf+offset+size) {
306 char *p = note, *desc;
307 unsigned namesz=elf_int(&p), descsz=elf_int(&p), type=elf_int(&p), j=0;
308
309 if (namesz > size || descsz > size) {
310 error_msg("%s: bad note @%lu", TT.f, offset);
311 return;
312 }
313 printf(" %-20.*s 0x%08x\t", namesz, p, descsz);
314 if (notematch(namesz, &p, "GNU", 4)) {
315 if (type == 1) {
316 printf("NT_GNU_ABI_TAG\tOS: %s, ABI: %u.%u.%u",
317 !elf_int(&p)?"Linux":"?", elf_int(&p), elf_int(&p), elf_int(&p)), j=1;
318 } else if (type == 3) {
319 printf("NT_GNU_BUILD_ID\t");
320 for (;j<descsz;j++) printf("%02x", *p++);
321 } else if (type == 4) {
322 printf("NT_GNU_GOLD_VERSION\t%.*s", descsz, p), j=1;
323 } else p -= 4;
324 } else if (notematch(namesz, &p, "Android", 8)) {
325 if (type == 1) {
326 printf("NT_VERSION\tAPI level %u", elf_int(&p)), j=1;
327 if (descsz>=132) printf(", NDK %.64s (%.64s)", p, p+64);
328 } else p -= 8;
329 } else if (notematch(namesz, &p, "CORE", 5)) {
330 if (*(desc = nt_type_core(type)) != '0') printf("%s", desc), j=1;
331 } else if (notematch(namesz, &p, "LINUX", 6)) {
332 if (*(desc = nt_type_linux(type)) != '0') printf("%s", desc), j=1;
333 }
334
335 // If we didn't do custom output above, show a hex dump.
336 if (!j) {
337 printf("0x%x\t", type);
338 for (;j<descsz;j++) printf("%c%02x",!j?'\t':' ', *p++/*note[16+j]*/);
339 }
340 xputc('\n');
341 note += 3*4 + ((namesz+3)&~3) + ((descsz+3)&~3);
342 }
343 }
344
scan_elf()345 static void scan_elf()
346 {
347 struct sh dynamic = {}, dynstr = {}, dynsym = {}, shstr = {}, strtab = {},
348 symtab = {}, s;
349 struct ph ph;
350 char *hdr = TT.elf;
351 int type, machine, version, flags, entry, ehsize, phnum, shstrndx, i, j, w;
352
353 if (TT.size < 45 || memcmp(hdr, "\177ELF", 4)) {
354 error_msg("%s: not ELF", TT.f);
355 return;
356 }
357
358 TT.bits = hdr[4] - 1;
359 TT.endian = hdr[5];
360 if (TT.bits<0 || TT.bits>1 || TT.endian<1 || TT.endian>2 || hdr[6]!=1) {
361 error_msg("%s: bad ELF", TT.f);
362 return;
363 }
364
365 hdr += 16; // EI_NIDENT
366 type = elf_short(&hdr);
367 machine = elf_short(&hdr);
368 version = elf_int(&hdr);
369 entry = elf_long(&hdr);
370 TT.phoff = elf_long(&hdr);
371 TT.shoff = elf_long(&hdr);
372 flags = elf_int(&hdr);
373 ehsize = elf_short(&hdr);
374 TT.phentsize = elf_short(&hdr);
375 phnum = elf_short(&hdr);
376 TT.shentsize = elf_short(&hdr);
377 TT.shnum = elf_short(&hdr);
378 shstrndx = elf_short(&hdr);
379
380 if (toys.optc > 1) printf("\nFile: %s\n", TT.f);
381
382 if (FLAG(h)) {
383 printf("ELF Header:\n");
384 printf(" Magic: ");
385 for (i=0; i<16; i++) printf("%02x%c", TT.elf[i], i==15?'\n':' ');
386 printf(" Class: ELF%d\n", TT.bits?64:32);
387 printf(" Data: 2's complement, %s endian\n",
388 (TT.endian==2)?"big":"little");
389 printf(" Version: 1 (current)\n");
390 printf(" OS/ABI: %s\n", os_abi(TT.elf[7]));
391 printf(" ABI Version: %d\n", TT.elf[8]);
392 printf(" Type: %s\n", et_type(type));
393 printf(" Machine: %s\n", elf_arch_name(machine));
394 printf(" Version: 0x%x\n", version);
395 printf(" Entry point address: 0x%x\n", entry);
396 printf(" Start of program headers: %llu (bytes into file)\n",
397 TT.phoff);
398 printf(" Start of section headers: %llu (bytes into file)\n",
399 TT.shoff);
400 printf(" Flags: 0x%x\n", flags);
401 printf(" Size of this header: %d (bytes)\n", ehsize);
402 printf(" Size of program headers: %d (bytes)\n", TT.phentsize);
403 printf(" Number of program headers: %d\n", phnum);
404 printf(" Size of section headers: %d (bytes)\n", TT.shentsize);
405 printf(" Number of section headers: %d\n", TT.shnum);
406 printf(" Section header string table index: %d\n", shstrndx);
407 }
408 if (TT.phoff > TT.size) {
409 error_msg("%s: bad phoff", TT.f);
410 return;
411 }
412 if (TT.shoff > TT.size) {
413 error_msg("%s: bad shoff", TT.f);
414 return;
415 }
416
417 // Set up the section header string table so we can use section header names.
418 // Core files have shstrndx == 0.
419 TT.shstrtab = 0;
420 TT.shstrtabsz = 0;
421 if (shstrndx != 0) {
422 if (!get_sh(shstrndx, &shstr) || shstr.type != 3 /*SHT_STRTAB*/) {
423 error_msg("%s: bad shstrndx", TT.f);
424 return;
425 }
426 TT.shstrtab = TT.elf+shstr.offset;
427 TT.shstrtabsz = shstr.size;
428 }
429
430 w = 8<<TT.bits;
431 if (FLAG(S)) {
432 if (!TT.shnum) printf("\nThere are no sections in this file.\n");
433 else {
434 if (!FLAG(h)) {
435 printf("There are %d section headers, starting at offset %#llx:\n",
436 TT.shnum, TT.shoff);
437 }
438 printf("\n"
439 "Section Headers:\n"
440 " [Nr] %-17s %-15s %-*s %-6s %-6s ES Flg Lk Inf Al\n",
441 "Name", "Type", w, "Address", "Off", "Size");
442 }
443 }
444 // We need to iterate through the section headers even if we're not
445 // dumping them, to find specific sections.
446 for (i=0; i<TT.shnum; i++) {
447 if (!get_sh(i, &s)) continue;
448 if (s.type == 2 /*SHT_SYMTAB*/) symtab = s;
449 else if (s.type == 6 /*SHT_DYNAMIC*/) dynamic = s;
450 else if (s.type == 11 /*SHT_DYNSYM*/) dynsym = s;
451 else if (s.type == 3 /*SHT_STRTAB*/) {
452 if (!strcmp(s.name, ".strtab")) strtab = s;
453 else if (!strcmp(s.name, ".dynstr")) dynstr = s;
454 }
455
456 if (FLAG(S)) {
457 char sh_flags[12] = {}, *p = sh_flags;
458
459 for (j=0; j<12; j++) if (s.flags&(1<<j)) *p++="WAXxMSILOTC"[j];
460 printf(" [%2d] %-17s %-15s %0*llx %06llx %06llx %02llx %3s %2d %2d %2lld\n",
461 i, s.name, sh_type(s.type), w, s.addr, s.offset, s.size,
462 s.entsize, sh_flags, s.link, s.info, s.addralign);
463 }
464 }
465 if (FLAG(S) && TT.shnum) {
466 printf("Key:\n"
467 " (W)rite, (A)lloc, e(X)ecute, (M)erge, (S)trings, (I)nfo\n"
468 " (L)ink order, (O)S, (G)roup, (T)LS, (C)ompressed, x=unknown\n");
469 }
470
471 if (FLAG(l)) {
472 xputc('\n');
473 if (!phnum) printf("There are no program headers in this file.\n");
474 else {
475 if (!FLAG(h)) {
476 printf("Elf file type is %s\n"
477 "Entry point %#x\n"
478 "There are %d program headers, starting at offset %lld\n"
479 "\n",
480 et_type(type), entry, phnum, TT.phoff);
481 }
482 printf("Program Headers:\n"
483 " %-14s %-8s %-*s %-*s %-7s %-7s Flg Align\n", "Type",
484 "Offset", w, "VirtAddr", w, "PhysAddr", "FileSiz", "MemSiz");
485 for (i=0; i<phnum; i++) {
486 if (!get_ph(i, &ph)) continue;
487 printf(" %-14s 0x%06llx 0x%0*llx 0x%0*llx 0x%05llx 0x%05llx %c%c%c %#llx\n",
488 ph_type(ph.type), ph.offset, w, ph.vaddr, w, ph.paddr,
489 ph.filesz, ph.memsz, ph.flags&4?'R':' ', ph.flags&2?'W':' ',
490 ph.flags&1?'E':' ', ph.align);
491 if (ph.type == 3 /*PH_INTERP*/ && ph.filesz<TT.size &&
492 ph.offset<TT.size && ph.filesz - 1 < TT.size - ph.offset) {
493 printf(" [Requesting program interpreter: %*s]\n",
494 (int) ph.filesz-1, TT.elf+ph.offset);
495 }
496 }
497
498 printf("\n"
499 " Section to Segment mapping:\n"
500 " Segment Sections...\n");
501 for (i=0; i<phnum; i++) {
502 if (!get_ph(i, &ph)) continue;
503 printf(" %02d ", i);
504 for (j=0; j<TT.shnum; j++) {
505 if (!get_sh(j, &s)) continue;
506 if (!*s.name) continue;
507 if (s.offset >= ph.offset && s.offset+s.size <= ph.offset+ph.filesz)
508 printf("%s ", s.name);
509 }
510 xputc('\n');
511 }
512 }
513 }
514
515 // binutils ld emits a bunch of extra DT_NULL entries, so binutils readelf
516 // uses two passes here! We just tell the truth, which matches -h.
517 if (FLAG(d)) {
518 char *dyn = TT.elf+dynamic.offset, *end = dyn+dynamic.size;
519
520 xputc('\n');
521 if (!dynamic.size) printf("There is no dynamic section in this file.\n");
522 else if (!dynamic.entsize) printf("Bad dynamic entry size 0!\n");
523 else {
524 printf("Dynamic section at offset 0x%llx contains %lld entries:\n"
525 " %-*s %-20s %s\n",
526 dynamic.offset, dynamic.size/dynamic.entsize,
527 w+2, "Tag", "Type", "Name/Value");
528 while (dyn < end) {
529 unsigned long long tag = elf_long(&dyn), val = elf_long(&dyn);
530 char *type = dt_type(tag);
531
532 printf(" 0x%0*llx %-20s ", w, tag, *type=='0' ? type : type+1);
533 if (*type == 'd') printf("%lld\n", val);
534 else if (*type == 'b') printf("%lld (bytes)\n", val);
535 else if (*type == 's') printf("%s\n", TT.elf+dynstr.offset+val);
536 else if (*type == 'f' || *type == 'F') {
537 struct bitname { int bit; char *s; }
538 df_names[] = {{0, "ORIGIN"},{1,"SYMBOLIC"},{2,"TEXTREL"},
539 {3,"BIND_NOW"},{4,"STATIC_TLS"},{}},
540 df_1_names[]={{0,"NOW"},{1,"GLOBAL"},{2,"GROUP"},{3,"NODELETE"},
541 {5,"INITFIRST"},{27,"PIE"},{}},
542 *names = *type == 'f' ? df_names : df_1_names;
543 int mask;
544
545 if (*type == 'F') printf("Flags: ");
546 for (j=0; names[j].s; j++) {
547 if (val & (mask=(1<<names[j].bit))) {
548 printf("%s%s", names[j].s, (val &= ~mask) ? " " : "");
549 }
550 }
551 if (val) printf("0x%llx", val);
552 xputc('\n');
553 } else if (*type == 'N' || *type == 'R' || *type == 'S') {
554 char *s = TT.elf+dynstr.offset+val;
555
556 if (dynstr.offset>TT.size || val>TT.size || dynstr.offset>TT.size-val)
557 s = "???";
558 printf("%s: [%s]\n", *type=='N' ? "Shared library" :
559 (*type=='R' ? "Library runpath" : "Library soname"), s);
560 } else if (*type == 'P') {
561 type = dt_type(val);
562 j = strlen(type);
563 if (*type != '0') type += 2, j -= 3;
564 printf("%*.*s\n", j, j, type);
565 } else printf("0x%llx\n", val);
566 }
567 }
568 }
569
570 if (FLAG(dyn_syms)) show_symbols(&dynsym, &dynstr);
571 if (FLAG(s)) show_symbols(&symtab, &strtab);
572
573 if (FLAG(n)) {
574 int found = 0;
575
576 for (i=0; i<TT.shnum; i++) {
577 if (!get_sh(i, &s)) continue;
578 if (s.type == 7 /*SHT_NOTE*/) {
579 printf("\nDisplaying notes found in: %s\n", s.name);
580 show_notes(s.offset, s.size);
581 found = 1;
582 }
583 }
584 for (i=0; !found && i<phnum; i++) {
585 if (!get_ph(i, &ph)) continue;
586 if (ph.type == 4 /*PT_NOTE*/) {
587 printf("\n"
588 "Displaying notes found at file offset 0x%llx with length 0x%llx:\n",
589 ph.offset, ph.filesz);
590 show_notes(ph.offset, ph.filesz);
591 }
592 }
593 }
594
595 if (FLAG(x)) {
596 if (find_section(TT.x, &s)) {
597 char *p = TT.elf+s.offset;
598 long offset = 0;
599
600 printf("\nHex dump of section '%s':\n", s.name);
601 while (offset < s.size) {
602 int space = 2*16 + 16/4;
603
604 printf(" 0x%08lx ", offset);
605 for (i=0; i<16 && offset < s.size; offset++) {
606 space -= printf("%02x%s", *p++, ++i%4 ? "" : " ");
607 }
608 printf("%*s", space, "");
609 for (p-=i; i; i--, p++) putchar(*p>=' ' && *p<='~' ? *p : '.');
610 xputc('\n');
611 }
612 printf("\n");
613 }
614 }
615
616 if (FLAG(p)) {
617 if (find_section(TT.p, &s)) {
618 char *begin = TT.elf+s.offset, *end = begin + s.size, *p = begin;
619 int any = 0;
620
621 printf("\nString dump of section '%s':\n", s.name);
622 for (; p < end; p++) {
623 if (isprint(*p)) {
624 printf(" [%6tx] ", p-begin);
625 while (p < end && isprint(*p)) putchar(*p++);
626 xputc('\n');
627 any=1;
628 }
629 }
630 if (!any) printf(" No strings found in this section.\n");
631 printf("\n");
632 }
633 }
634 }
635
readelf_main(void)636 void readelf_main(void)
637 {
638 char **arg;
639 int all = FLAG_d|FLAG_h|FLAG_l|FLAG_n|FLAG_S|FLAG_s|FLAG_dyn_syms;
640
641 if (FLAG(a)) toys.optflags |= all;
642 if (FLAG(e)) toys.optflags |= FLAG_h|FLAG_l|FLAG_S;
643 if (FLAG(s)) toys.optflags |= FLAG_dyn_syms;
644 if (!(toys.optflags & (all|FLAG_p|FLAG_x))) help_exit("needs a flag");
645
646 for (arg = toys.optargs; *arg; arg++) {
647 int fd = open(TT.f = *arg, O_RDONLY);
648 struct stat sb;
649
650 if (fd == -1) perror_msg("%s", TT.f);
651 else {
652 if (fstat(fd, &sb)) perror_msg("%s", TT.f);
653 else if (!sb.st_size) error_msg("%s: empty", TT.f);
654 else if (!S_ISREG(sb.st_mode)) error_msg("%s: not a regular file",TT.f);
655 else {
656 TT.elf = xmmap(NULL, TT.size=sb.st_size, PROT_READ, MAP_SHARED, fd, 0);
657 scan_elf();
658 munmap(TT.elf, TT.size);
659 }
660 close(fd);
661 }
662 }
663 }
664