From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Date: Wed, 7 Jan 2015 14:08:54 +0000 (-0500)
Subject: x86/xen: Free bootmem in free_p2m_page() during early boot
X-Git-Tag: v3.19-rc5~29^2~8
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=701a261ad6c4c1915861673b7e8ab9fee5cef69a;p=platform%2Fkernel%2Flinux-exynos.git

x86/xen: Free bootmem in free_p2m_page() during early boot

With recent changes in p2m we now have legitimate cases when
p2m memory needs to be freed during early boot (i.e. before
slab is initialized).

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index edbc7a6..cab221d 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -167,10 +167,13 @@ static void * __ref alloc_p2m_page(void)
 	return (void *)__get_free_page(GFP_KERNEL | __GFP_REPEAT);
 }
 
-/* Only to be called in case of a race for a page just allocated! */
-static void free_p2m_page(void *p)
+static void __ref free_p2m_page(void *p)
 {
-	BUG_ON(!slab_is_available());
+	if (unlikely(!slab_is_available())) {
+		free_bootmem((unsigned long)p, PAGE_SIZE);
+		return;
+	}
+
 	free_page((unsigned long)p);
 }