80484dd: 83 c4 08 addl x8,%esp
80484e0: c9 leave
80484e1: c3 ret
ld.so-1.9.9/d-link/i386/resolve.S
#define ALIGN 4
#define RUN linux_run
#define RESOLVE _dl_linux_resolve
#define RESOLVER _dl_linux_resolver
#define EXIT _interpreter_exit
#define INIT __loader_bootstrap
.text
.align ALIGN
.align 16
.globl RESOLVE
.type RESOLVE,@function
RESOLVE:
pusha
lea 0x20(%esp),陎 /* eax = tpnt and reloc_entry params */
pushl 4(陎) /* push copy of reloc_entry param */
pushl (陎) /* push copy of tpnt param */
pushl 陎 /* _dl_linux_resolver expects a dummy
* param - this could be removed */
#ifdef __PIC__
call .L24
.L24:
popl 離
addl $_GLOBAL_OFFSET_TABLE_ [.-.L24],離
movl RESOLVER@GOT(離),離 /* eax = resolved func */
call *離
#else
call RESOLVER
#endif
movl 陎,0x2C(%esp) /* store func addr over original
* tpnt param */
addl xC,%esp /* remove copy parameters */
popa /* restore regs */
ret /* jump to func removing original
* reloc_entry param from stack */
.LFE2:
.size RESOLVE,.LFE2-RESOLVE
d-link/i386/elfinterp.c:
unsigned int _dl_linux_resolver(int dummy, int i)
{
unsigned int * sp;
int reloc_entry;
int reloc_type;
struct elf32_rel * this_reloc;
char * strtab;
struct elf32_sym * symtab;
struct elf32_rel * rel_addr;
struct elf_resolve * tpnt;
int symtab_index;
char * new_addr;
char ** got_addr;
unsigned int instr_addr;
sp = &i;
reloc_entry = sp[1];
tpnt = (struct elf_resolve *) sp[0];
rel_addr = (struct elf32_rel *) (tpnt->dynamic_info[DT_JMPREL]
tpnt->loadaddr); 取可执行程式的GOT重定位表
this_reloc = rel_addr (reloc_entry >> 3);
reloc_type = ELF32_R_TYPE(this_reloc->r_info);
symtab_index = ELF32_R_SYM(this_reloc->r_info);
symtab = (struct elf32_sym *) (tpnt->dynamic_info[DT_SYMTAB] tpnt->loadaddr);
strtab = (char *) (tpnt->dynamic_info[DT_STRTAB] tpnt->loadaddr);
if (reloc_type != R_386_JMP_SLOT) {
_dl_fdprintf(2, "%s: Incorrect relocation type in jump relocations\n",
_dl_progname);
_dl_exit(1);
};
/* Address of jump instruction to fix up */
instr_addr = ((int)this_reloc->r_offset (int)tpnt->loadaddr);
got_addr = (char **) instr_addr;
#ifdef DEBUG
_dl_fdprintf(2, "Resolving symbol %s\n",
strtab symtab[symtab_index].st_name);
#endif
/* Get the address of the GOT entry */
new_addr = _dl_find_hash(strtab symtab[symtab_index].st_name,
tpnt->symbol_scope, (int) got_addr, tpnt, 0);
if(!new_addr) {
_dl_fdprintf(2, "%s: can't resolve symbol '%s'\n",
_dl_progname, strtab symtab[symtab_index].st_name);
_dl_exit(1);
};
/* #define DEBUG_LIBRARY */
#ifdef DEBUG_LIBRARY
if((unsigned int) got_addr < 0x40000000) {
_dl_fdprintf(2, "Calling library function: %s\n",
strtab symtab[symtab_index].st_name);
} else {
*got_addr = new_addr;
}
#else
*got_addr = new_addr; 更新GOT函数指针
#endif
return (unsigned int) new_addr;
}
