sparc/uaccess: Enable hardened usercopy

Enables CONFIG_HARDENED_USERCOPY checks on sparc.

Based on code from PaX and grsecurity.

Signed-off-by: Kees Cook <keescook@chromium.org>

1 files changed, 10 insertions, 4 deletions

diff --git a/arch/sparc/include/asm/uaccess_32.h b/arch/sparc/include/asm/uaccess_32.h
index 57aca2792d29..341a5a133f48 100644
--- a/arch/sparc/include/asm/uaccess_32.h
+++ b/arch/sparc/include/asm/uaccess_32.h
@@ -248,22 +248,28 @@ unsigned long __copy_user(void __user *to, const void __user *from, unsigned lon
 
 static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n)
 {
-	if (n && __access_ok((unsigned long) to, n))
+	if (n && __access_ok((unsigned long) to, n)) {
+		if (!__builtin_constant_p(n))
+			check_object_size(from, n, true);
 		return __copy_user(to, (__force void __user *) from, n);
-	else
+	} else
 		return n;
 }
 
 static inline unsigned long __copy_to_user(void __user *to, const void *from, unsigned long n)
 {
+	if (!__builtin_constant_p(n))
+		check_object_size(from, n, true);
 	return __copy_user(to, (__force void __user *) from, n);
 }
 
 static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n)
 {
-	if (n && __access_ok((unsigned long) from, n))
+	if (n && __access_ok((unsigned long) from, n)) {
+		if (!__builtin_constant_p(n))
+			check_object_size(to, n, false);
 		return __copy_user((__force void __user *) to, from, n);
-	else
+	} else
 		return n;
 }