These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / arch / arm / lib / uaccess_with_memcpy.c

diff --git a/kernel/arch/arm/lib/uaccess_with_memcpy.c b/kernel/arch/arm/lib/uaccess_with_memcpy.c
index 3e58d71..588bbc2 100644 (file)
--- 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