ldt.c: manually set modify_ldt's error code

* ldt.c (modify_ldt): Move parsing under entering(tcp). Check whether
return code is erroneous and set tcp->u_error appropriately along with
RVAL_PRINT_ERR_VAL flag.

diff --git a/ldt.c b/ldt.c
index 735cb137d0ea2ffc72dd2388a52804d99b5593ef..4ede5ba08f1ffc07f17726dc3879da9cc0c8fd2c 100644 (file)
--- a/ldt.c
+++ b/ldt.c
@@ -70,14 +70,28 @@ print_user_desc(struct tcb *const tcp, const kernel_ulong_t addr)
 
 SYS_FUNC(modify_ldt)
 {
-       tprintf("%d, ", (int) tcp->u_arg[0]);
-       if (tcp->u_arg[2] != sizeof(struct user_desc))
-               printaddr(tcp->u_arg[1]);
-       else
-               print_user_desc(tcp, tcp->u_arg[1]);
-       tprintf(", %" PRI_klu, tcp->u_arg[2]);
+       if (entering(tcp)) {
+               tprintf("%d, ", (int) tcp->u_arg[0]);
+               if (tcp->u_arg[2] != sizeof(struct user_desc))
+                       printaddr(tcp->u_arg[1]);
+               else
+                       print_user_desc(tcp, tcp->u_arg[1]);
+               tprintf(", %" PRI_klu, tcp->u_arg[2]);
+
+               return 0;
+       }
 
-       return RVAL_DECODED;
+       /*
+        * For some reason ("tht ABI for sys_modify_ldt() expects
+        * 'int'"), modify_ldt clips higher bits on x86_64.
+        */
+
+       if (syserror(tcp) || (kernel_ulong_t) tcp->u_rval < 0xfffff000)
+               return 0;
+
+       tcp->u_error = -(unsigned int) tcp->u_rval;
+
+       return RVAL_PRINT_ERR_VAL;
 }
 
 SYS_FUNC(set_thread_area)