Hi Stefano,

On 16/07/2015 16:23, Stefano Stabellini wrote:

quoted

diff --git a/include/xen/page.h b/include/xen/page.h
index 8ebd37b..b1f7722 100644
--- a/include/xen/page.h
+++ b/include/xen/page.h

@@ -39,4 +39,24 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS];

  extern unsigned long xen_released_pages;

+typedef int (*xen_pfn_fn_t)(struct page *page, unsigned long pfn, void *data);
+/* Break down the page in 4KB granularity and call fn foreach xen pfn */
+static inline int xen_apply_to_page(struct page *page, xen_pfn_fn_t fn,
+				    void *data)
+{
+	unsigned long pfn = xen_page_to_pfn(page);
+	int i;
+	int ret;

please initialize ret to 0

Hmmm... right. I'm not sure why the compiler didn't catch it.

quoted

+	for (i = 0; i < XEN_PFN_PER_PAGE; i++, pfn++) {
+		ret = fn(page, pfn, data);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+
  #endif	/* _XEN_PAGE_H */

Reviewed-by: Stefano Stabellini <redacted>

Thank you,

-- 
Julien Grall