1 files changed, 53 insertions, 0 deletions

diff --git a/arch/s390/lib/uaccess_mvcos.c b/arch/s390/lib/uaccess_mvcos.c
index 78c48f88f5f7..6d8772339d76 100644
--- a/arch/s390/lib/uaccess_mvcos.c
+++ b/arch/s390/lib/uaccess_mvcos.c
@@ -162,6 +162,44 @@ static size_t clear_user_mvcos(size_t size, void __user *to)
         return size;
 }
 
+static size_t strnlen_user_mvcos(size_t count, const char __user *src)
+{
+        char buf[256];
+        int rc;
+        size_t done, len, len_str;
+
+        done = 0;
+        do {
+                len = min(count - done, (size_t) 256);
+                rc = uaccess.copy_from_user(len, src + done, buf);
+                if (unlikely(rc == len))
+                        return 0;
+                len -= rc;
+                len_str = strnlen(buf, len);
+                done += len_str;
+        } while ((len_str == len) && (done < count));
+        return done + 1;
+}
+
+static size_t strncpy_from_user_mvcos(size_t count, const char __user *src,
+                                      char *dst)
+{
+        int rc;
+        size_t done, len, len_str;
+
+        done = 0;
+        do {
+                len = min(count - done, (size_t) 4096);
+                rc = uaccess.copy_from_user(len, src + done, dst);
+                if (unlikely(rc == len))
+                        return -EFAULT;
+                len -= rc;
+                len_str = strnlen(dst, len);
+                done += len_str;
+        } while ((len_str == len) && (done < count));
+        return done;
+}
+
 struct uaccess_ops uaccess_mvcos = {
         .copy_from_user = copy_from_user_mvcos_check,
         .copy_from_user_small = copy_from_user_std,
@@ -174,3 +212,18 @@ struct uaccess_ops uaccess_mvcos = {
         .futex_atomic_op = futex_atomic_op_std,
         .futex_atomic_cmpxchg = futex_atomic_cmpxchg_std,
 };
+
+#ifdef CONFIG_S390_SWITCH_AMODE
+struct uaccess_ops uaccess_mvcos_switch = {
+        .copy_from_user = copy_from_user_mvcos,
+        .copy_from_user_small = copy_from_user_mvcos,
+        .copy_to_user = copy_to_user_mvcos,
+        .copy_to_user_small = copy_to_user_mvcos,
+        .copy_in_user = copy_in_user_mvcos,
+        .clear_user = clear_user_mvcos,
+        .strnlen_user = strnlen_user_mvcos,
+        .strncpy_from_user = strncpy_from_user_mvcos,
+        .futex_atomic_op = futex_atomic_op_pt,
+        .futex_atomic_cmpxchg = futex_atomic_cmpxchg_pt,
+};
+#endif