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authorMark Brown <broonie@kernel.org>2016-02-09 21:20:39 +0300
committerMark Brown <broonie@kernel.org>2016-02-09 21:20:39 +0300
commitfcdcc79628a1919bde9acf239e364f65bab6327c (patch)
tree5499be387cf3028c90ac083b1cf866ebed7bf7e0 /arch/arm/lib/uaccess_with_memcpy.c
parent7a8d44bc89e5cddcd5c0704a11a90484d36ba6ba (diff)
parenta0a90718f18264dc904d34a580f332006f5561e9 (diff)
downloadlinux-fcdcc79628a1919bde9acf239e364f65bab6327c.tar.xz
Merge branch 'topic/acpi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-pxa2xx
Diffstat (limited to 'arch/arm/lib/uaccess_with_memcpy.c')
-rw-r--r--arch/arm/lib/uaccess_with_memcpy.c34
1 files changed, 25 insertions, 9 deletions
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c
index d72b90905132..6bd1089b07e0 100644
--- a/arch/arm/lib/uaccess_with_memcpy.c
+++ b/arch/arm/lib/uaccess_with_memcpy.c
@@ -52,14 +52,13 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
*
* Lock the page table for the destination and check
* to see that it's still huge and whether or not we will
- * need to fault on write, or if we have a splitting THP.
+ * need to fault on write.
*/
if (unlikely(pmd_thp_or_huge(*pmd))) {
ptl = &current->mm->page_table_lock;
spin_lock(ptl);
if (unlikely(!pmd_thp_or_huge(*pmd)
- || pmd_hugewillfault(*pmd)
- || pmd_trans_splitting(*pmd))) {
+ || pmd_hugewillfault(*pmd))) {
spin_unlock(ptl);
return 0;
}
@@ -88,6 +87,7 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp)
static unsigned long noinline
__copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
{
+ unsigned long ua_flags;
int atomic;
if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
@@ -118,7 +118,9 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
if (tocopy > n)
tocopy = n;
+ ua_flags = uaccess_save_and_enable();
memcpy((void *)to, from, tocopy);
+ uaccess_restore(ua_flags);
to += tocopy;
from += tocopy;
n -= tocopy;
@@ -145,14 +147,21 @@ arm_copy_to_user(void __user *to, const void *from, unsigned long n)
* With frame pointer disabled, tail call optimization kicks in
* as well making this test almost invisible.
*/
- if (n < 64)
- return __copy_to_user_std(to, from, n);
- return __copy_to_user_memcpy(to, from, n);
+ if (n < 64) {
+ unsigned long ua_flags = uaccess_save_and_enable();
+ n = __copy_to_user_std(to, from, n);
+ uaccess_restore(ua_flags);
+ } else {
+ n = __copy_to_user_memcpy(to, from, n);
+ }
+ return n;
}
static unsigned long noinline
__clear_user_memset(void __user *addr, unsigned long n)
{
+ unsigned long ua_flags;
+
if (unlikely(segment_eq(get_fs(), KERNEL_DS))) {
memset((void *)addr, 0, n);
return 0;
@@ -175,7 +184,9 @@ __clear_user_memset(void __user *addr, unsigned long n)
if (tocopy > n)
tocopy = n;
+ ua_flags = uaccess_save_and_enable();
memset((void *)addr, 0, tocopy);
+ uaccess_restore(ua_flags);
addr += tocopy;
n -= tocopy;
@@ -193,9 +204,14 @@ out:
unsigned long arm_clear_user(void __user *addr, unsigned long n)
{
/* See rational for this in __copy_to_user() above. */
- if (n < 64)
- return __clear_user_std(addr, n);
- return __clear_user_memset(addr, n);
+ if (n < 64) {
+ unsigned long ua_flags = uaccess_save_and_enable();
+ n = __clear_user_std(addr, n);
+ uaccess_restore(ua_flags);
+ } else {
+ n = __clear_user_memset(addr, n);
+ }
+ return n;
}
#if 0