releases/4.9.41/parisc-extend-disabled-preemption-in-copy_user_page.patch

   1 From 56008c04ebc099940021b714da2d7779117cf6a7 Mon Sep 17 00:00:00 2001
   2 From: John David Anglin <dave.anglin@bell.net>
   3 Date: Tue, 25 Jul 2017 17:23:35 -0400
   4 Subject: parisc: Extend disabled preemption in copy_user_page
   5
   6 From: John David Anglin <dave.anglin@bell.net>
   7
   8 commit 56008c04ebc099940021b714da2d7779117cf6a7 upstream.
   9
  10 It's always bothered me that we only disable preemption in
  11 copy_user_page around the call to flush_dcache_page_asm.
  12 This patch extends this to after the copy.
  13
  14 Signed-off-by: John David Anglin <dave.anglin@bell.net>
  15 Signed-off-by: Helge Deller <deller@gmx.de>
  16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  17
  18 ---
  19  arch/parisc/kernel/cache.c |    2 +-
  20  1 file changed, 1 insertion(+), 1 deletion(-)
  21
  22 --- a/arch/parisc/kernel/cache.c
  23 +++ b/arch/parisc/kernel/cache.c
  24 @@ -452,8 +452,8 @@ void copy_user_page(void *vto, void *vfr
  25           before it can be accessed through the kernel mapping. */
  26         preempt_disable();
  27         flush_dcache_page_asm(__pa(vfrom), vaddr);
  28 -       preempt_enable();
  29         copy_page_asm(vto, vfrom);
  30 +       preempt_enable();
  31  }
  32  EXPORT_SYMBOL(copy_user_page);
  33