alloc_pread
void *alloc_pread(readin_handle_t fd, off_t off, size_t len);
shdr = alloc_pread(VECTX_HANDLE(&ef), ef.ehdr->e_shoff, size);
shstrtab = alloc_pread(VECTX_HANDLE(&ef), shdr[ef.ehdr->e_shstrndx].sh_offset,
shdr = alloc_pread(VECTX_HANDLE(ef), ehdr->e_shoff, chunk);
shstr = alloc_pread(VECTX_HANDLE(ef),
shdr = alloc_pread(VECTX_HANDLE(ef), (off_t)hdr->e_shoff, shdrbytes);