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>

diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 489d2ba..25f1d10 100644 (file)
--- 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 dbc1416..2406788 100644 (file)
--- 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);