sparc: copy_from_user() should not return -EFAULT

From: Heiko Carstens <heiko.carstens@de.ibm.com>

Callers of copy_from_user() expect it to return the number of bytes
it could not copy. In no case it is supposed to return -EFAULT.

In case of a detected buffer overflow just return the requested
length. In addition one could think of a memset that would clear
the size of the target object.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 2 insertions, 2 deletions

diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 489d2ba92bcb..25f1d10155e8 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -274,7 +274,7 @@ static inline unsigned long copy_from_user(void *to, const void __user *from, un
 
         if (unlikely(sz != -1 && sz < n)) {
                 copy_from_user_overflow();
-                return -EFAULT;
+                return n;
         }
 
         if (n && __access_ok((unsigned long) from, n))
diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index dbc141660994..2406788bfe5f 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -221,8 +221,8 @@ extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
 static inline unsigned long __must_check
 copy_from_user(void *to, const void __user *from, unsigned long size)
 {
-        unsigned long ret = (unsigned long) -EFAULT;
         int sz = __compiletime_object_size(to);
+        unsigned long ret = size;
 
         if (likely(sz == -1 || sz >= size)) {
                 ret = ___copy_from_user(to, from, size);