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Diffstat (limited to 'kernel/arch/arm/lib/uaccess_with_memcpy.c')
-rw-r--r--kernel/arch/arm/lib/uaccess_with_memcpy.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/kernel/arch/arm/lib/uaccess_with_memcpy.c b/kernel/arch/arm/lib/uaccess_with_memcpy.c
index 3e58d7100..588bbc288 100644
--- a/kernel/arch/arm/lib/uaccess_with_memcpy.c
+++ b/kernel/arch/arm/lib/uaccess_with_memcpy.c
@@ -88,6 +88,7 @@ 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))) {
@@ -96,7 +97,7 @@ __copy_to_user_memcpy(void __user *to, const void *from, unsigned long n)
}
/* the mmap semaphore is taken only if not in an atomic context */
- atomic = in_atomic();
+ atomic = faulthandler_disabled();
if (!atomic)
down_read(&current->mm->mmap_sem);
@@ -118,7 +119,9 @@ __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;
@@ -136,7 +139,7 @@ out:
}
unsigned long
-__copy_to_user(void __user *to, const void *from, unsigned long n)
+arm_copy_to_user(void __user *to, const void *from, unsigned long n)
{
/*
* This test is stubbed out of the main function above to keep
@@ -145,14 +148,21 @@ __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 +185,9 @@ __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;
@@ -190,12 +202,17 @@ out:
return n;
}
-unsigned long __clear_user(void __user *addr, unsigned long n)
+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