int arch_setup_additional_pages()

in kernel/vdso.c [49:81]

• 24 lines of code
• 4 McCabe index (conditional complexity)

int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
	int ret;
	unsigned long vdso_base;
	struct mm_struct *mm = current->mm;

	if (mmap_write_lock_killable(mm))
		return -EINTR;

	/* Try to get it loaded right near ld.so/glibc. */
	vdso_base = STACK_TOP;

	vdso_base = get_unmapped_area(NULL, vdso_base, PAGE_SIZE, 0, 0);
	if (IS_ERR_VALUE(vdso_base)) {
		ret = vdso_base;
		goto up_fail;
	}

	/* MAYWRITE to allow gdb to COW and set breakpoints. */
	ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
				      VM_READ|VM_EXEC|
				      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
				      &vdso_page);

	if (ret)
		goto up_fail;

	mm->context.vdso = (void *)vdso_base;

up_fail:
	mmap_write_unlock(mm);
	return ret;
}