/
elf.c
957 lines (868 loc) · 26.8 KB
/
elf.c
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#include <sys/types.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/procfs.h>
#include "queue.h"
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <assert.h>
#include <elf.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <link.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <unistd.h>
#include "myelf.h"
/*
* Culled from System V Application Binary Interface
*/
static unsigned long
elfhash(const char *name)
{
unsigned long h = 0, g;
while (*name != '\0') {
h = (h << 4) + *name++;
if ((g = h & 0xf0000000) != 0)
h ^= g >> 24;
h &= ~g;
}
return (h);
}
static int
sortFuncTab(const void *a, const void *b)
{
const struct FunctionInfo *l, *r;
l = *(const struct FunctionInfo **)a;
r = *(const struct FunctionInfo **)b;
if (l->elfSym->st_value < r->elfSym->st_value)
return -1;
if (l->elfSym->st_value == r->elfSym->st_value)
return 0;
return 1;
}
static int
findFunction(const void *a, const void *b)
{
const struct FunctionInfo *fi = *(struct FunctionInfo **)b;
Elf32_Addr addr = (Elf32_Addr)a;
if (fi->elfSym->st_value > addr)
return -1;
if (fi->elfSym->st_value + fi->elfSym->st_size <= addr)
return 1;
return 0;
}
/*
* Parse out an ELF file into an ElfObject structure.
* XXX: We probably don't use all the information we parse, and can probably
* pear this down a bit.
*/
int
elf32LoadObjectFile(const char *fileName, struct ElfObject *obj)
{
FILE *file;
if ((file = fopen(fileName, "r")) == 0) {
fprintf(stderr, "unable to open executable '%s': %s\n", fileName, strerror(errno));
return (-1);
}
int rc = elf32LoadObject(file, obj);
if (rc == 0) {
obj->fileName = strdup(fileName);
obj->baseName = strrchr(obj->fileName, '/');
obj->baseName = obj->baseName ? obj->baseName + 1 : obj->fileName;
} else {
fclose(file);
}
return rc;
}
int
elf32UnloadObjectFile(struct ElfObject *obj)
{
int rc = elf32UnloadObject(obj);
fclose(obj->file);
free(obj->fileName);
return rc;
}
int
elf32LoadObject(FILE *file, struct ElfObject *obj)
{
int i;
Elf32_Ehdr *eHdr;
struct Section *sHdrs;
struct Segment *pHdrs;
struct Section *section;
memset(obj, 0, sizeof *obj);
obj->file = file;
eHdr = &obj->elfHeader;
int rc = fread(eHdr, sizeof *eHdr, 1, file);
/* Validate the ELF header */
if (rc != 1
|| !IS_ELF(obj->elfHeader)
|| eHdr->e_ident[EI_CLASS] != ELFCLASS32
|| eHdr->e_ident[EI_VERSION] > EV_CURRENT) {
fprintf(stderr, "not an ELF image");
free(obj);
return (-1);
}
obj->programHeaders = pHdrs = malloc(sizeof(struct Segment) * eHdr->e_phnum);
obj->mappedData = 0;
off_t off;
for (off = eHdr->e_phoff, i = 0; i < eHdr->e_phnum; i++) {
struct Segment *seg = &pHdrs[i];
seg->data = 0;
Elf32_Phdr *phdr = &seg->phdr;
fseeko(obj->file, off, SEEK_SET);
ssize_t rc = fread(phdr, sizeof *phdr, 1, file);
if (rc != 1)
abort();
switch (pHdrs[i].phdr.p_type) {
case PT_INTERP:
obj->interpreterName = elf32MapSegment(obj, seg);
break;
case PT_DYNAMIC:
obj->dynamic = &pHdrs[i];
break;
}
off += eHdr->e_phentsize;
}
obj->sectionHeaders = sHdrs = malloc(sizeof(struct Section) * eHdr->e_shnum);
for (off = eHdr->e_shoff, i = 0; i < eHdr->e_shnum; i++) {
fseeko(file, off, SEEK_SET);
sHdrs[i].data = 0;
ssize_t rc = fread(&sHdrs[i].shdr, sizeof (Elf32_Shdr), 1, file);
if (rc != 1)
abort();
off += eHdr->e_shentsize;
}
int ssi = eHdr->e_shstrndx;
obj->sectionStrings = ssi != SHN_UNDEF ? elf32MapSection(obj, &sHdrs[ssi]) : 0;
if (elf32FindSectionByName(obj, ".stab", §ion) != -1) {
obj->stabs = elf32MapSection(obj, section);
obj->stabCount = section->shdr.sh_size / sizeof (struct stab);
if (section->shdr.sh_link)
obj->stabStrings = elf32MapSection(obj, &sHdrs[section->shdr.sh_link]);
else if (elf32FindSectionByName(obj, ".stabstr", §ion) != -1)
obj->stabStrings = elf32MapSection(obj, section);
else
obj->stabStrings = 0;
} else {
obj->stabs = 0;
obj->stabCount = 0;
}
elf32ProcessFunctions(obj);
return (0);
}
/*
* Locate a symbol in an ELF image.
*/
int
elf32FindSymbolByName(struct ElfObject *o, const char *name,
const Elf32_Sym **symp, const char **namep)
{
struct Section *shdrs, *hash, *syms;
const char *symStrings;
const Elf32_Sym *sym;
Elf32_Word nbucket;
Elf32_Word nchain;
Elf32_Word i;
const Elf32_Word *buckets;
const Elf32_Word *chains;
const Elf32_Word *hashData;
unsigned long hashv;
shdrs = o->sectionHeaders;
/* First, search the hashed symbols in .dynsym. */
if (elf32FindSectionByName(o, ".hash", &hash) != -1) {
syms = &shdrs[hash->shdr.sh_link];
hashData = elf32MapSection(o, hash);
sym = elf32MapSection(o, syms);
symStrings = elf32MapSection(o, &shdrs[syms->shdr.sh_link]);
nbucket = hashData[0];
nchain = hashData[1];
buckets = hashData + 2;
chains = buckets + nbucket;
hashv = elfhash(name) % nbucket;
for (i = buckets[hashv]; i != STN_UNDEF; i = chains[i])
if (strcmp(symStrings + sym[i].st_name, name) == 0) {
*symp = sym + i;
if (namep)
*namep = symStrings + sym[i].st_name;
return (0);
}
} else if (elf32FindSectionByName(o, ".dynsym", &syms) != -1) {
/* No ".hash", but have ".dynsym": do linear search */
if (elf32LinearSymSearch(o, syms, name, symp, namep) != -1) {
return (0);
}
}
/* Do a linear search of ".symtab" if present */
if (elf32FindSectionByName(o, ".symtab", &syms) != -1 &&
elf32LinearSymSearch(o, syms, name, symp, namep) != -1) {
return (0);
}
return -1;
}
void
elf32SymbolIterate(struct ElfObject *o, symiterfunc_t cb, void *state)
{
struct Section *hdr;
if (elf32FindSectionByName(o, ".dynsym", &hdr) != -1)
elf32SymbolIterateSection(o, hdr, cb, state);
if (elf32FindSectionByName(o, ".symtab", &hdr) != -1)
elf32SymbolIterateSection(o, hdr, cb, state);
}
void
elf32SymbolIterateSection(struct ElfObject *o, struct Section *section, symiterfunc_t cb, void *state)
{
struct Section *shdrs;
const char *symStrings;
const Elf32_Sym *sym;
int symCount, i;
shdrs = o->sectionHeaders;
sym = elf32MapSection(o, section);
symStrings = elf32MapSection(o, &shdrs[section->shdr.sh_link]);
symCount = section->shdr.sh_size / sizeof (Elf32_Sym);
for (i = 0; i < symCount; i++)
cb(state, o, section, sym + i, symStrings + sym[i].st_name);
}
/*
* Given an Elf32 object, find a particular section.
*/
int
elf32FindSectionByName(struct ElfObject *obj, const char *name, struct Section **shdrp)
{
int i;
for (i = 0; i < obj->elfHeader.e_shnum; i++)
if (strcmp(obj->sectionHeaders[i].shdr.sh_name + obj->sectionStrings, name) == 0) {
*shdrp = &obj->sectionHeaders[i];
return (i);
}
return (-1);
}
int
elf32LinearSymSearch(struct ElfObject *o, struct Section *section,
const char *name, const Elf32_Sym **symp,
const char **namep)
{
struct Section *shdrs;
const char *symStrings;
const Elf32_Sym *sym;
int symCount, i;
shdrs = o->sectionHeaders;
sym = elf32MapSection(o, section);
symStrings = elf32MapSection(o, &shdrs[section->shdr.sh_link]);
symCount = section->shdr.sh_size / sizeof (Elf32_Sym);
for (i = 0; i < symCount; i++) {
if (!strcmp(symStrings + sym[i].st_name, name)) {
if (namep)
*namep = symStrings + sym->st_name;
*symp = sym + i;
return (i);
}
}
return (-1);
}
void
elf32ProcessFunctions(struct ElfObject *obj)
{
struct FunctionInfo *si;
int section;
const struct stab *lineNumbers = 0, *function = 0, *args = 0;
const Elf32_Sym *sym;
struct Section *symtab, *shdrs;
static char *symsections[] = {
".dynsym",
".symtab",
0
};
int stringOffset = 0, nextStringOffset = 0, i, j, fileSp = 0;
int symCount, funcCount = 0, funcTabSize = 0;
const char *symStrings;
struct FunctionInfo **funcTab = 0, *funcInfo;
const char *fileStack[128];
fileStack[0] = 0;
obj->functionTable = 0;
obj->functionTableLength = 0;
/* Run through the ELF symbol tables, locating all the functions */
shdrs = obj->sectionHeaders;
for (i = 0; symsections[i]; i++) {
if (elf32FindSectionByName(obj, symsections[i], &symtab) == -1)
continue;
symStrings = elf32MapSection(obj, &shdrs[symtab->shdr.sh_link]);
sym = elf32MapSection(obj, symtab);
symCount = symtab->shdr.sh_size / sizeof(Elf32_Sym);
for (j = 0; j < symCount; j++) {
if (ELF32_ST_TYPE(sym[j].st_info) != STT_FUNC)
continue;
section = sym[j].st_shndx;
if (section >= obj->elfHeader.e_shnum || (shdrs[section].shdr.sh_flags & SHF_ALLOC) == 0)
continue;
if (funcCount == funcTabSize) {
funcTabSize += 1024;
funcTabSize = funcTabSize + funcTabSize / 2;
funcTab = realloc(funcTab, sizeof (*funcTab) *
funcTabSize);
}
funcTab[funcCount++] = funcInfo = malloc(sizeof *funcInfo);
funcInfo->elfSym = sym + j;
funcInfo->elfName = symStrings + sym[j].st_name;
funcInfo->stabStringOffset = 0;
funcInfo->fileName = 0;
funcInfo->function = 0;
funcInfo->args = 0;
funcInfo->lineNumbers = 0;
}
}
if (!funcCount)
return;
/* Sort the functions by address */
qsort(funcTab, funcCount, sizeof *funcTab, sortFuncTab);
/* Remove duplicates */
for (i = 1, j = 0; i < funcCount; i++) {
if (funcTab[i]->elfSym->st_value !=
funcTab[j]->elfSym->st_value)
funcTab[++j] = funcTab[i];
else
free(funcTab[i]);
}
obj->functionTableLength = j + 1;
obj->functionTable = funcTab;
for (i = 0; i < obj->stabCount; i++) {
const struct stab *stab = obj->stabs + i;
switch (stab->n_type) {
case N_UNDF:
stringOffset += nextStringOffset;
nextStringOffset = stab->n_value;
break;
case N_SO:
fileSp = 0;
fileStack[0] = stab->n_strx + obj->stabStrings + stringOffset;
break;
case N_SOL:
fileStack[fileSp] = stab->n_strx + obj->stabStrings + stringOffset;
break;
case N_BINCL:
assert(fileSp < 128);
fileStack[++fileSp] = stab->n_strx + obj->stabStrings + stringOffset;
break;
case N_EINCL:
--fileSp;
assert(fileSp >= 0);
break;
case N_PSYM:
if (!args)
args = stab;
break;
case N_SLINE:
if (!lineNumbers)
lineNumbers = stab;
break;
case N_FUN:
if (stab->n_strx == 0 ||
*(obj->stabStrings + stringOffset +
stab->n_strx) == 0) {
/* End of a function: fill in funcinfo */
if (elf32FindFunction(obj, function->n_value,
&si) != -1) {
si->stabStringOffset = stringOffset;
si->fileName = fileStack[fileSp];
si->function = function;
si->args = args;
si->lineNumbers = lineNumbers;
}
} else if (!function || function->n_value !=
stab->n_value) {
args = lineNumbers = 0;
function = stab;
}
break;
}
}
}
int
elf32FindFunction(struct ElfObject *obj, Elf32_Addr loc,
struct FunctionInfo **f)
{
void *p;
if (obj->functionTable == 0)
return -1;
p = bsearch((const void *)loc, obj->functionTable,
obj->functionTableLength, sizeof *obj->functionTable, findFunction);
if (!p)
return -1;
*f = *(struct FunctionInfo **)p;
return 0;
}
/*
* Free any resources assoiated with an ElfObject
*/
int
elf32UnloadObject(struct ElfObject *obj)
{
int i;
for (i = 0; i < obj->functionTableLength; i++)
free(obj->functionTable[i]);
for (i = 0; i < obj->elfHeader.e_phnum; i++)
free(obj->programHeaders[i].data);
for (i = 0; i < obj->elfHeader.e_shnum; i++)
if (obj->sectionHeaders[i].owns)
free(obj->sectionHeaders[i].data);
free(obj->programHeaders);
free(obj->sectionHeaders);
free(obj->functionTable);
fprintf(stderr, "mapped data: %lu\n", obj->mappedData);
return (0);
}
/*
* Debug output of the contents of an ELF32 section
*/
void
elf32DumpSection(FILE *f, struct ElfObject *obj, struct Section *hdr,
int indent)
{
const Elf32_Sym * sym, *esym;
int i;
const char *symStrings, *padding = pad(indent);
static const char *sectionTypeNames[] = {
"SHT_NULL",
"SHT_PROGBITS",
"SHT_SYMTAB",
"SHT_STRTAB",
"SHT_RELA",
"SHT_HASH",
"SHT_DYNAMIC",
"SHT_NOTE",
"SHT_NOBITS",
"SHT_REL",
"SHT_SHLIB",
"SHT_DYNSYM",
};
fprintf(f, "%sname= %s\n"
"%stype= %d (%s)\n"
"%sflags= %xH (%s%s%s)\n"
"%saddress= %xH\n"
"%soffset= %d (%xH)\n"
"%ssize= %d (%xH)\n"
"%slink= %d (%xH)\n"
"%sinfo= %d (%xH)\n" ,
padding, obj->sectionStrings + hdr->shdr.sh_name,
padding, hdr->shdr.sh_type, hdr->shdr.sh_type <= SHT_DYNSYM ?
sectionTypeNames[hdr->shdr.sh_type] : "unknown",
padding,
hdr->shdr.sh_flags,
hdr->shdr.sh_flags & SHF_WRITE ? "write " : "",
hdr->shdr.sh_flags & SHF_ALLOC ? "alloc " : "",
hdr->shdr.sh_flags & SHF_EXECINSTR ? "instructions " : "",
padding, hdr->shdr.sh_addr,
padding, hdr->shdr.sh_offset, hdr->shdr.sh_offset,
padding, hdr->shdr.sh_size, hdr->shdr.sh_size,
padding, hdr->shdr.sh_link, hdr->shdr.sh_link,
padding, hdr->shdr.sh_info, hdr->shdr.sh_info);
switch (hdr->shdr.sh_type) {
case SHT_SYMTAB:
case SHT_DYNSYM:
symStrings = elf32MapSection(obj, &obj->sectionHeaders[hdr->shdr.sh_link]);
sym = elf32MapSection(obj, hdr);
esym = (const Elf32_Sym *) ((char *)sym + hdr->shdr.sh_size);
for (i = 0; sym < esym; i++) {
printf("%ssymbol %d:\n", padding, i);
elf32DumpSymbol(f, sym, symStrings, indent + 4);
sym++;
}
break;
}
}
/*
* Debug output of an ELF32 program segment
*/
void
elf32DumpProgramSegment(FILE *f, struct ElfObject *obj, const Elf32_Phdr *hdr,
int indent)
{
const char *padding = pad(indent);
static const char *segmentTypeNames[] = {
"PT_NULL",
"PT_LOAD",
"PT_DYNAMIC",
"PT_INTERP",
"PT_NOTE",
"PT_SHLIB",
"PT_PHDR"
};
fprintf(f, "%stype = %xH (%s)\n"
"%soffset = %xH (%d)\n"
"%svirtual address = %xH (%d)\n"
"%sphysical address = %xH (%d)\n"
"%sfile size = %xH (%d)\n"
"%smemory size = %xH (%d)\n"
"%sflags = %xH (%s %s %s)\n"
"%salignment = %xH (%d)\n",
padding, hdr->p_type,
hdr->p_type <= PT_PHDR ? segmentTypeNames[hdr->p_type] : "unknown",
padding, hdr->p_offset, hdr->p_offset,
padding, hdr->p_vaddr, hdr->p_vaddr,
padding, hdr->p_paddr, hdr->p_paddr,
padding, hdr->p_filesz, hdr->p_filesz,
padding, hdr->p_memsz, hdr->p_memsz,
padding, hdr->p_flags,
hdr->p_flags & PF_R ? "PF_R" : "",
hdr->p_flags & PF_W ? "PF_W" : "",
hdr->p_flags & PF_X ? "PF_X" : "",
padding, hdr->p_align, hdr->p_align);
}
/*
* Debug output of an Elf32 symbol.
*/
void
elf32DumpSymbol(FILE *f, const Elf32_Sym * sym, const char *strings, int indent)
{
static const char *bindingNames[] = {
"STB_LOCAL",
"STB_GLOBAL",
"STB_WEAK",
"unknown3",
"unknown4",
"unknown5",
"unknown6",
"unknown7",
"unknown8",
"unknown9",
"unknowna",
"unknownb",
"unknownc",
"STB_LOPROC",
"STB_LOPROC + 1",
"STB_HIPROC + 1",
};
static const char *typeNames[] = {
"STT_NOTYPE",
"STT_OBJECT",
"STT_FUNC",
"STT_SECTION",
"STT_FILE",
"STT_5",
"STT_6",
"STT_7",
"STT_8",
"STT_9",
"STT_A",
"STT_B",
"STT_C",
"STT_LOPROC",
"STT_LOPROC + 1",
"STT_HIPROC"
};
const char *padding = pad(indent);
fprintf(f,
"%sname = %s\n"
"%svalue = %d (%xH)\n"
"%ssize = %d (%xH)\n"
"%sinfo = %d (%xH)\n"
"%sbinding = %s\n"
"%stype = %s\n"
"%sother = %d (%xH)\n"
"%sshndx = %d (%xH)\n",
padding, sym->st_name ? strings + sym->st_name : "(unnamed)",
padding, sym->st_value, sym->st_value,
padding, sym->st_size, sym->st_size,
padding, sym->st_info, sym->st_info,
pad(indent + 4), bindingNames[sym->st_info >> 4],
pad(indent + 4), typeNames[sym->st_info & 0xf],
padding, sym->st_other, sym->st_other,
padding, sym->st_shndx, sym->st_shndx);
}
/*
* Debug output of an ELF32 dynamic item
*/
void
elf32DumpDynamic(FILE *f, const Elf32_Dyn *dyn, int indent)
{
const char *padding = pad(indent);
static const char *tagNames[] = {
"DT_NULL",
"DT_NEEDED",
"DT_PLTRELSZ",
"DT_PLTGOT",
"DT_HASH",
"DT_STRTAB",
"DT_SYMTAB",
"DT_RELA",
"DT_RELASZ",
"DT_RELAENT",
"DT_STRSZ",
"DT_SYMENT",
"DT_INIT",
"DT_FINI",
"DT_SONAME",
"DT_RPATH",
"DT_SYMBOLIC",
"DT_REL",
"DT_RELSZ",
"DT_RELENT",
"DT_PLTREL",
"DT_DEBUG",
"DT_TEXTREL",
"DT_JMPREL",
"DT_BIND_NOW"
};
#ifndef DT_COUNT
#define DT_COUNT (sizeof tagNames / sizeof tagNames[0])
#endif
fprintf(f, "%stag: %d (%s)\n", padding, dyn->d_tag,
dyn->d_tag >= 0 && dyn->d_tag <= DT_COUNT ?
tagNames[dyn->d_tag] : "(unknown)");
fprintf(f, "%sword/addr: %d (%x)\n",
padding, dyn->d_un.d_val, dyn->d_un.d_val);
}
/*
* Debug output of an ELF32 object.
*/
static const char *
stabType(enum StabType t)
{
switch (t) {
case N_UNDF: return "N_UNDF";
case N_ABS: return "N_ABS";
case N_ABS_EXT: return "N_ABS_EXT";
case N_TEXT: return "N_TEXT";
case N_TEXT_EXT: return "N_TEXT_EXT";
case N_DATA: return "N_DATA";
case N_DATA_EXT: return "N_DATA_EXT";
case N_BSS: return "N_BSS";
case N_BSS_EXT: return "N_BSS_EXT";
case N_FN_SEQ: return "N_FN_SEQ";
case N_INDR: return "N_INDR";
case N_COMM: return "N_COMM";
case N_SETA: return "N_SETA";
case N_SETA_EXT: return "N_SETA_EXT";
case N_SETT: return "N_SETT";
case N_SETT_EXT: return "N_SETT_EXT";
case N_SETD: return "N_SETD";
case N_SETD_EXT: return "N_SETD_EXT";
case N_SETB: return "N_SETB";
case N_SETB_EXT: return "N_SETB_EXT";
case N_SETV: return "N_SETV";
case N_SETV_EXT: return "N_SETV_EXT";
case N_WARNING: return "N_WARNING";
case N_FN: return "N_FN";
case N_GSYM: return "N_GSYM";
case N_FNAME: return "N_FNAME";
case N_FUN: return "N_FUN";
case N_STSYM: return "N_STSYM";
case N_LCSYM: return "N_LCSYM";
case N_MAIN: return "N_MAIN";
case N_PC: return "N_PC";
case N_NSYMS: return "N_NSYMS";
case N_NOMAP: return "N_NOMAP";
case N_OBJ: return "N_OBJ";
case N_OPT: return "N_OPT";
case N_RSYM: return "N_RSYM";
case N_M2C: return "N_M2C";
case N_SLINE: return "N_SLINE";
case N_DSLINE: return "N_DSLINE";
case N_BSLINE: return "N_BSLINE";
case N_DEFD: return "N_DEFD";
case N_FLINE: return "N_FLINE";
case N_EHDECL: return "N_EHDECL";
case N_CATCH: return "N_CATCH";
case N_SSYM: return "N_SSYM";
case N_ENDM: return "N_ENDM";
case N_SO: return "N_SO";
case N_LSYM: return "N_LSYM";
case N_BINCL: return "N_BINCL";
case N_SOL: return "N_SOL";
case N_PSYM: return "N_PSYM";
case N_EINCL: return "N_EINCL";
case N_ENTRY: return "N_ENTRY";
case N_LBRAC: return "N_LBRAC";
case N_EXCL: return "N_EXCL";
case N_SCOPE: return "N_SCOPE";
case N_RBRAC: return "N_RBRAC";
case N_BCOMM: return "N_BCOMM";
case N_ECOMM: return "N_ECOMM";
case N_ECOML: return "N_ECOML";
case N_WITH: return "N_WITH";
case N_NBTEXT: return "N_NBTEXT";
case N_NBDATA: return "N_NBDATA";
case N_NBBSS: return "N_NBBSS";
case N_NBSTS: return "N_NBSTS";
case N_NBLCS: return "N_NBLCS";
default: return "unknown";
}
}
void
elf32DumpObject(FILE *f, struct ElfObject *obj, int indent)
{
int brand;
int i;
static const char *typeNames[] = {
"ET_NONE",
"ET_REL",
"ET_EXEC",
"ET_DYN",
"ET_CORE"
};
static const char *abiNames[] = {
"SYSV/NONE",
"HP-UX",
"NetBSD",
"Linux",
"Hurd",
"86Open",
"Solaris",
"Monterey",
"Irix",
"FreeBSD",
"Tru64",
"Modesto",
"OpenBSD"
};
const Elf32_Ehdr *ehdr = &obj->elfHeader;
const Elf32_Dyn *dyn, *edyn;
const char *padding = pad(indent);
brand = ehdr->e_ident[EI_OSABI];
fprintf(f, "%sType= %s\n", padding, typeNames[ehdr->e_type]);
fprintf(f, "%sEntrypoint= %x\n", padding, ehdr->e_entry);
fprintf(f, "%sExetype= %d (%s)\n", padding, brand,
brand >= 0 && brand <= sizeof abiNames / sizeof abiNames[0] ?
abiNames[brand] : "unknown");
for (i = 1; i < obj->elfHeader.e_shnum; i++) {
fprintf(f, "%ssection %d:\n", padding, i);
elf32DumpSection(f, obj, &obj->sectionHeaders[i], indent + 4);
}
for (i = 0; i < obj->elfHeader.e_phnum; i++) {
fprintf(f, "%ssegment %d:\n", padding, i);
elf32DumpProgramSegment(f, obj, &obj->programHeaders[i].phdr, indent + 4);
}
if (obj->dynamic) {
dyn = elf32MapSegment(obj, obj->dynamic);
edyn = (const Elf32_Dyn *) ((char *)dyn + obj->dynamic->phdr.p_filesz);
while (dyn < edyn) {
printf("%sdynamic entry\n", padding - 4);
elf32DumpDynamic(f, dyn, indent + 8);
dyn++;
}
}
if (obj->interpreterName)
fprintf(f, "%sinterpreter %s\n", padding, obj->interpreterName);
if (obj->stabs) {
const struct stab *stab;
int i;
int stringOffset = 0;
int nextStringOffset = 0;
printf("%sstabs:\n", padding);
for (i = 0; i < obj->stabCount; i++) {
stab = obj->stabs + i;
printf("%sstab %d\n", pad(indent + 4), i);
printf("%stype %s(%d)\n", pad(indent + 8), stabType(stab->n_type), stab->n_type);
printf("%svalue %ld %lxh\n", pad(indent + 8), (long)stab->n_value, (long)stab->n_value);
printf("%sstring \"%s\" %s\n", pad(indent + 8), obj->stabStrings + stringOffset + stab->n_strx, stab->n_strx ? "" : "(not-present)");
printf("%sdesc %d\n", pad(indent + 8), stab->n_desc);
printf("%sother %d\n", pad(indent + 8), stab->n_other);
if (stab->n_type == N_UNDF) {
stringOffset += nextStringOffset;
nextStringOffset = stab->n_value;
}
}
}
}
/*
* Helps for pretty-printing
*/
const char *
pad(int size)
{
static const char paddingChars[] = " ";
if (size > sizeof paddingChars - 1)
size = sizeof paddingChars - 1;
return (paddingChars + sizeof paddingChars - 1 - size);
}
void
hexdump(FILE *f, int indent, const char *p, int len)
{
const unsigned char *cp = (const unsigned char *)p;
char hex[16 * 3 + 1], *hp, ascii[16 + 1], *ap;
int i, c;
while (len) {
hp = hex;
ap = ascii;
for (i = 0; len && i < 16; i++) {
c = *cp++;
len--;
hp += sprintf(hp, "%02x ", c);
*ap++ = c < 127 && c >= 32 ? c : '.';
}
*ap = 0;
fprintf(f, "%s%-48s |%-16s|\n", pad(indent), hex, ascii);
}
}
/*
* Find the mapped object within which "addr" lies
*/
int
elf32FindObject(struct ElfObject *objlist, Elf32_Addr addr, struct ElfObject **objp)
{
const Elf32_Phdr *phdr;
Elf32_Addr segAddr;
int i;
for (; objlist; objlist = objlist->next) {
for (i = 0; i < objlist->elfHeader.e_phnum; i++) {
phdr = &objlist->programHeaders[i].phdr;
segAddr = phdr->p_vaddr + objlist->baseAddr;
if (addr >= segAddr && addr < segAddr + phdr->p_memsz) {
*objp = objlist;
return (0);
}
}
}
return (-1);
}
void *
loadData(struct ElfObject *obj, off_t offset, size_t count)
{
void *p;
p = malloc(count);
obj->mappedData += count;
fseeko(obj->file, offset, SEEK_SET);
int countIn = fread(p, 1, count, obj->file);
if (countIn != count) {
free(p);
return 0;
} else {
return p;
}
}
void *
elf32MapSegment(struct ElfObject *obj, struct Segment *segment)
{
if (segment->data)
return segment->data;
segment->data = loadData(obj, segment->phdr.p_offset, segment->phdr.p_filesz);
return segment->data;
}
void *
elf32MapSection(struct ElfObject *obj, struct Section *section)
{
if (section->data)
return section->data;
// Find what segment this section is in.
Elf32_Addr secStart = section->shdr.sh_offset;
Elf32_Addr secEnd = secStart + section->shdr.sh_size;
size_t i;
for (i = 0; i < obj->elfHeader.e_phnum; i++) {
struct Segment *seg = &obj->programHeaders[i];
Elf32_Phdr *phdr = &seg->phdr;
if (phdr->p_offset <= secStart && secEnd <= phdr->p_offset + phdr->p_filesz) {
section->owns = 0;
return section->data = elf32MapSegment(obj, seg) + secStart - phdr->p_offset;
}
}
section->data = loadData(obj, section->shdr.sh_offset, section->shdr.sh_size);
section->owns = 1;
return section->data;
}