int module_frob_arch_sections(Elf32_Ehdr *hdr,
Elf32_Shdr *sechdrs,
char *secstrings,
struct module *me)
{
unsigned int i;
/* Find .plt and .init.plt sections */
for (i = 0; i < hdr->e_shnum; i++) {
if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
me->arch.init_plt_section = i;
else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
me->arch.core_plt_section = i;
}
if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
printk("Module doesn't contain .plt or .init.plt sections.\n");
return -ENOEXEC;
}
/* Override their sizes */
sechdrs[me->arch.core_plt_section].sh_size
= get_plt_size(hdr, sechdrs, secstrings, 0);
sechdrs[me->arch.init_plt_section].sh_size
= get_plt_size(hdr, sechdrs, secstrings, 1);
return 0;
}
addr_t get_plt_by_entry_call( asmelf_t * aelf )
{
/* XXX: only works if the first call of the entrypoint is
* to a plt function
*/
char * start;
addr_t start_addr;
Elf32_Ehdr * ehdr;
if( ! aelf || ! aelf->elf )
error_ret("null arg", -1 );
if( aelf->plt )
return( aelf->plt );
if( ! ( ehdr = get_ehdr( aelf->elf ) ) )
error_ret("can't get ehdr",-1);
start_addr = ehdr->e_entry;
if( ! ( start = data_at_addr( aelf->elf , start_addr ) ) )
error_ret("can't entry point get data", -1 );
/* 1: get our first call */
offset_t offset = 0;
size_t nread;
x86_insn_t insn;
addr_t dst;
addr_t pltaddr;
do
{
nread=x86_disasm( start , 36+offset , start_addr , offset , &insn );
if( nread <= 0 )
error_ret("can't disassemble",-1);
offset += nread;
/* found our first plt call */
if( insn.type == insn_call ){
dst = op_resolve( &insn.operands[op_dest] , &insn );
break;
}
} while( offset < 256 );
if( offset >= 256 )
error_ret("can't find call",-1);
if( crunch_plt_entry( aelf , dst, 0 , &pltaddr , 0 ) < 0 )
error_ret("can't get plt from plt code", -1 );
if( get_plt_size( aelf ) < 0 )
error_ret("can't get size",-1);
return(( aelf->plt = pltaddr ));
}
