1 files changed, 46 insertions, 0 deletions
diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c
index e215ecc2a6..bba012ed15 100644
--- a/linux-user/uaccess.c
+++ b/linux-user/uaccess.c
@@ -4,6 +4,52 @@
 
 #include "qemu.h"
 
+void *lock_user(int type, abi_ulong guest_addr, long len, int copy)
+{
+    if (!access_ok_untagged(type, guest_addr, len)) {
+        return NULL;
+    }
+#ifdef DEBUG_REMAP
+    {
+        void *addr;
+        addr = g_malloc(len);
+        if (copy) {
+            memcpy(addr, g2h(guest_addr), len);
+        } else {
+            memset(addr, 0, len);
+        }
+        return addr;
+    }
+#else
+    return g2h_untagged(guest_addr);
+#endif
+}
+
+#ifdef DEBUG_REMAP
+void unlock_user(void *host_ptr, abi_ulong guest_addr, long len);
+{
+    if (!host_ptr) {
+        return;
+    }
+    if (host_ptr == g2h_untagged(guest_addr)) {
+        return;
+    }
+    if (len > 0) {
+        memcpy(g2h_untagged(guest_addr), host_ptr, len);
+    }
+    g_free(host_ptr);
+}
+#endif
+
+void *lock_user_string(abi_ulong guest_addr)
+{
+    abi_long len = target_strlen(guest_addr);
+    if (len < 0) {
+        return NULL;
+    }
+    return lock_user(VERIFY_READ, guest_addr, (long)(len + 1), 1);
+}
+
 /* copy_from_user() and copy_to_user() are usually used to copy data
  * buffers between the target and host.  These internally perform
  * locking/unlocking of the memory.