Function __elfN(enforce_limits)

freebsd/kern/imgact_elf.c:882–957

}

static int
__elfN(enforce_limits)(struct image_params *imgp, const Elf_Ehdr *hdr,
    const Elf_Phdr *phdr, u_long et_dyn_addr)
{
	struct vmspace *vmspace;
	const char *err_str;
	u_long text_size, data_size, total_size, text_addr, data_addr;
	u_long seg_size, seg_addr;
	int i;

	err_str = NULL;
	text_size = data_size = total_size = text_addr = data_addr = 0;

	for (i = 0; i < hdr->e_phnum; i++) {
		if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
			continue;

		seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
		seg_size = round_page(phdr[i].p_memsz +
		    phdr[i].p_vaddr + et_dyn_addr - seg_addr);

		/*
		 * Make the largest executable segment the official
		 * text segment and all others data.
		 *
		 * Note that obreak() assumes that data_addr + data_size == end
		 * of data load area, and the ELF file format expects segments
		 * to be sorted by address.  If multiple data segments exist,
		 * the last one will be used.
		 */

		if ((phdr[i].p_flags & PF_X) != 0 && text_size < seg_size) {
			text_size = seg_size;
			text_addr = seg_addr;
		} else {
			data_size = seg_size;
			data_addr = seg_addr;
		}
		total_size += seg_size;
	}

	if (data_addr == 0 && data_size == 0) {
		data_addr = text_addr;
		data_size = text_size;
	}

	/*
	 * Check limits.  It should be safe to check the
	 * limits after loading the segments since we do
	 * not actually fault in all the segments pages.
	 */
	PROC_LOCK(imgp->proc);
	if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA))
		err_str = "Data segment size exceeds process limit";
	else if (text_size > maxtsiz)
		err_str = "Text segment size exceeds system limit";
	else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM))
		err_str = "Total segment size exceeds process limit";