int __init init_vdso_image()

in vdso/vma.c [246:330]

• 64 lines of code
• 17 McCabe index (conditional complexity)

int __init init_vdso_image(const struct vdso_image *image,
			   struct vm_special_mapping *vdso_mapping, bool elf64)
{
	int cnpages = (image->size) / PAGE_SIZE;
	struct page *dp, **dpp = NULL;
	struct page *cp, **cpp = NULL;
	struct vdso_elfinfo ei;
	int i, dnpages = 0;

	if (tlb_type != spitfire) {
		int err = stick_patch(image, &ei, elf64);
		if (err)
			return err;
	}

	/*
	 * First, the vdso text.  This is initialied data, an integral number of
	 * pages long.
	 */
	if (WARN_ON(image->size % PAGE_SIZE != 0))
		goto oom;

	cpp = kcalloc(cnpages, sizeof(struct page *), GFP_KERNEL);
	vdso_mapping->pages = cpp;

	if (!cpp)
		goto oom;

	for (i = 0; i < cnpages; i++) {
		cp = alloc_page(GFP_KERNEL);
		if (!cp)
			goto oom;
		cpp[i] = cp;
		copy_page(page_address(cp), image->data + i * PAGE_SIZE);
	}

	/*
	 * Now the vvar page.  This is uninitialized data.
	 */

	if (vvar_data == NULL) {
		dnpages = (sizeof(struct vvar_data) / PAGE_SIZE) + 1;
		if (WARN_ON(dnpages != 1))
			goto oom;
		dpp = kcalloc(dnpages, sizeof(struct page *), GFP_KERNEL);
		vvar_mapping.pages = dpp;

		if (!dpp)
			goto oom;

		dp = alloc_page(GFP_KERNEL);
		if (!dp)
			goto oom;

		dpp[0] = dp;
		vvar_data = page_address(dp);
		memset(vvar_data, 0, PAGE_SIZE);

		vvar_data->seq = 0;
	}

	return 0;
 oom:
	if (cpp != NULL) {
		for (i = 0; i < cnpages; i++) {
			if (cpp[i] != NULL)
				__free_page(cpp[i]);
		}
		kfree(cpp);
		vdso_mapping->pages = NULL;
	}

	if (dpp != NULL) {
		for (i = 0; i < dnpages; i++) {
			if (dpp[i] != NULL)
				__free_page(dpp[i]);
		}
		kfree(dpp);
		vvar_mapping.pages = NULL;
	}

	pr_warn("Cannot allocate vdso\n");
	vdso_enabled = 0;
	return -ENOMEM;
}