linux-kernel - [PATCH 3.19.y-ckt 087/170] xtensa: fix preemption in {clear,copy}_user

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Message-Id: <1459558456-24452-88-git-send-email-kamal@canonical.com>
Date:	Fri,  1 Apr 2016 17:52:53 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Max Filippov <jcmvbkbc@...il.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 087/170] xtensa: fix preemption in {clear,copy}_user_highpage

3.19.8-ckt18 -stable review patch.  If anyone has any objections, please let me know.

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

From: Max Filippov <jcmvbkbc@...il.com>

commit a67cc9aa2dfc6e66addf240bbd79e16e01565e81 upstream.

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

Signed-off-by: Max Filippov <jcmvbkbc@...il.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.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