[3.19.y-ckt stable] Patch "xtensa: fix preemption in {clear, copy}_user_highpage" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    xtensa: fix preemption in {clear,copy}_user_highpage

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt18.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 0b4633722e074b256fec0a0d60b318b37a71752f Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc at gmail.com>
Date: Thu, 25 Feb 2016 23:27:51 +0300
Subject: xtensa: fix preemption in {clear,copy}_user_highpage

commit a67cc9aa2dfc6e66addf240bbd79e16e01565e81 upstream.

Disabling pagefault makes little sense there, preemption disabling is
what was meant.

Signed-off-by: Max Filippov <jcmvbkbc at gmail.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/xtensa/mm/cache.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/xtensa/mm/cache.c b/arch/xtensa/mm/cache.c
index d75aa14..1a804a2 100644
--- a/arch/xtensa/mm/cache.c
+++ b/arch/xtensa/mm/cache.c
@@ -97,11 +97,11 @@ void clear_user_highpage(struct page *page, unsigned long vaddr)
 	unsigned long paddr;
 	void *kvaddr = coherent_kvaddr(page, TLBTEMP_BASE_1, vaddr, &paddr);

-	pagefault_disable();
+	preempt_disable();
 	kmap_invalidate_coherent(page, vaddr);
 	set_bit(PG_arch_1, &page->flags);
 	clear_page_alias(kvaddr, paddr);
-	pagefault_enable();
+	preempt_enable();
 }

 void copy_user_highpage(struct page *dst, struct page *src,
@@ -113,11 +113,11 @@ void copy_user_highpage(struct page *dst, struct page *src,
 	void *src_vaddr = coherent_kvaddr(src, TLBTEMP_BASE_2, vaddr,
 					  &src_paddr);

-	pagefault_disable();
+	preempt_disable();
 	kmap_invalidate_coherent(dst, vaddr);
 	set_bit(PG_arch_1, &dst->flags);
 	copy_page_alias(dst_vaddr, src_vaddr, dst_paddr, src_paddr);
-	pagefault_enable();
+	preempt_enable();
 }

 #endif /* DCACHE_WAY_SIZE > PAGE_SIZE */
--
2.7.4