brcm2708-gpu-fw: update to latest version
[lede.git] / target / linux / brcm2708 / patches-4.4 / 0216-copy_from_user-CPU_SW_DOMAIN_PAN-compatibility.patch
1 From a160443a0d967ea6394cd0d1b7a0ab8ef2da3ff1 Mon Sep 17 00:00:00 2001
2 From: Phil Elwell <phil@raspberrypi.org>
3 Date: Tue, 29 Mar 2016 15:32:30 +0100
4 Subject: [PATCH 216/232] copy_from_user: CPU_SW_DOMAIN_PAN compatibility
5
6 The downstream copy_from_user acceleration must also play nice with
7 CONFIG_CPU_SW_DOMAIN_PAN.
8
9 See: https://github.com/raspberrypi/linux/issues/1381
10
11 Signed-off-by: Phil Elwell <phil@raspberrypi.org>
12 ---
13  arch/arm/lib/uaccess_with_memcpy.c | 14 +++++++++++---
14  1 file changed, 11 insertions(+), 3 deletions(-)
15
16 --- a/arch/arm/lib/uaccess_with_memcpy.c
17 +++ b/arch/arm/lib/uaccess_with_memcpy.c
18 @@ -186,6 +186,7 @@ out:
19  unsigned long noinline
20  __copy_from_user_memcpy(void *to, const void __user *from, unsigned long n)
21  {
22 +       unsigned long ua_flags;
23         int atomic;
24  
25         if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
26 @@ -217,7 +218,9 @@ __copy_from_user_memcpy(void *to, const
27                 if (tocopy > n)
28                         tocopy = n;
29  
30 +               ua_flags = uaccess_save_and_enable();
31                 memcpy(to, (const void *)from, tocopy);
32 +               uaccess_restore(ua_flags);
33                 to += tocopy;
34                 from += tocopy;
35                 n -= tocopy;
36 @@ -261,9 +264,14 @@ arm_copy_from_user(void *to, const void
37          * With frame pointer disabled, tail call optimization kicks in
38          * as well making this test almost invisible.
39          */
40 -       if (n < COPY_FROM_USER_THRESHOLD)
41 -               return __copy_from_user_std(to, from, n);
42 -       return __copy_from_user_memcpy(to, from, n);
43 +       if (n < COPY_TO_USER_THRESHOLD) {
44 +               unsigned long ua_flags = uaccess_save_and_enable();
45 +               n = __copy_from_user_std(to, from, n);
46 +               uaccess_restore(ua_flags);
47 +       } else {
48 +               n = __copy_from_user_memcpy(to, from, n);
49 +       }
50 +       return n;
51  }
52         
53  static unsigned long noinline