Avoid an early WARN_ON in Xen (rhbz 1592976)

kernel.spec

@@ -671,6 +671,9 @@ Patch523: 0001-xfs-More-robust-inode-extent-count-validation.patch
 # CVE-2018-13405 rhbz 1599161 1599162
 Patch524: CVE-2018-13405.patch
 
+# rhbz 1592976
+Patch 525: xen-remove-global-bit-from-__default_kernel_pte_mask.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -1920,6 +1923,9 @@ fi
 #
 #
 %changelog
+* Thu Jul 12 2018 Jeremy Cline <jeremy@jcline.org>
+- Avoid an early WARN_ON in Xen (rhbz 1592976)
+
 * Thu Jul 12 2018 Dan Horák <dan@danny.cz>
 - Enable HDA sound drivers on PPC
 

xen-remove-global-bit-from-__default_kernel_pte_mask.patch

@@ -0,0 +1,36 @@
+From e69b5d308da72cbf4e7911c3979f9a46d28532af Mon Sep 17 00:00:00 2001
+From: Juergen Gross <jgross@suse.com>
+Date: Mon, 2 Jul 2018 12:00:18 +0200
+Subject: [PATCH] xen: remove global bit from __default_kernel_pte_mask for pv
+ guests
+
+When removing the global bit from __supported_pte_mask do the same for
+__default_kernel_pte_mask in order to avoid the WARN_ONCE() in
+check_pgprot() when setting a kernel pte before having called
+init_mem_mapping().
+
+Cc: <stable@vger.kernel.org> # 4.17
+Reported-by: Michael Young <m.a.young@durham.ac.uk>
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
+Signed-off-by: Juergen Gross <jgross@suse.com>
+Signed-off-by: Jeremy Cline <jcline@redhat.com>
+---
+ arch/x86/xen/enlighten_pv.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
+index 8d4e2e1ae60b..4816b6f82a9a 100644
+--- a/arch/x86/xen/enlighten_pv.c
++++ b/arch/x86/xen/enlighten_pv.c
+@@ -1229,6 +1229,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
+ 
+ 	/* Prevent unwanted bits from being set in PTEs. */
+ 	__supported_pte_mask &= ~_PAGE_GLOBAL;
++	__default_kernel_pte_mask &= ~_PAGE_GLOBAL;
+ 
+ 	/*
+ 	 * Prevent page tables from being allocated in highmem, even
+-- 
+2.17.1
+