elf: remove redundant code from _dl_dst_substitute

There are just two users of _dl_dst_substitute: one is expand_dst that
sets is_path argument to 0, another one is expand_dynamic_string_token.
The latter function also has just two users: one is _dl_map_object that
sets is_path argument to 0, another one is fillin_rpath that sets
is_path argument to 1 and name argument contains no ':'.

In any case (is_path && name[i] == ':') is always false and all code
depending on it can be safely removed.

* elf/dl-load.c (_dl_dst_substitute): Remove checks that is_path
is set and name contains ':', and all code depending on these checks.

diff --git a/ChangeLog b/ChangeLog
index 086bb81956294c96d73fecfa3d0418ee42ddc201..297dd703c50aea7832899a5704b6bca59c0ddafa 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2017-12-27  Dmitry V. Levin  <ldv@altlinux.org>
+
+       * elf/dl-load.c (_dl_dst_substitute): Remove checks that is_path
+       is set and name contains ':', and all code depending on these checks.
+
 2017-12-24  Zack Weinberg  <zackw@panix.com>
 
        * libio/libio.h, libio/_G_config.h: New stub headers which issue a

diff --git a/elf/dl-load.c b/elf/dl-load.c
index 2964464158501026c0f332d0b2014395479f011b..a60277d311f5b9959089c1f739910e2aa400585e 100644 (file)
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -291,13 +291,7 @@ _dl_dst_substitute (struct link_map *l, const char *name, char *result,
              /* We cannot use this path element, the value of the
                 replacement is unknown.  */
              wp = last_elem;
-             name += len;
-             while (*name != '\0' && (!is_path || *name != ':'))
-               ++name;
-             /* Also skip following colon if this is the first rpath
-                element, but keep an empty element at the end.  */
-             if (wp == result && is_path && *name == ':' && name[1] != '\0')
-               ++name;
+             break;
            }
          else
            /* No DST we recognize.  */
@@ -306,19 +300,6 @@ _dl_dst_substitute (struct link_map *l, const char *name, char *result,
       else
        {
          *wp++ = *name++;
-         if (is_path && *name == ':')
-           {
-             /* In SUID/SGID programs, after $ORIGIN expansion the
-                normalized path must be rooted in one of the trusted
-                directories.  */
-             if (__glibc_unlikely (check_for_trusted)
-                 && !is_trusted_path_normalize (last_elem, wp - last_elem))
-               wp = last_elem;
-             else
-               last_elem = wp;
-
-             check_for_trusted = false;
-           }
        }
     }
   while (*name != '\0');