[PATCH] [BZ#15903] INITFIRST flag does not change fini order (ld.so)

[Guillaume Berard <berardgui at gmail dot com>]

Hi,

According to https://sourceware.org/binutils/docs/ld/Options.html
ld.so should call fini for the linked libraries in the reverse order
than the init order.
However, if I build two libraries, lib1 and lib2, lib1 with -z
initfirst and I link an executable with these two libraries, the fini
order in not the reverse order of init (checked with LD_DEBUG).
I changed a bit fl-fini.c in order to take in account the initfirst
flag for sorting the fini order.

Guillaume.

[BZ#15903]
* elf/dl-fini.c
* elf/dl-init.c

diff --git elf/dl-fini.c elf/dl-fini.c
index 6b245f0..56f17c9 100644
--- elf/dl-fini.c
+++ elf/dl-fini.c
@@ -39,6 +39,10 @@ _dl_sort_fini (struct link_map **maps, size_t
nmaps, char *used, Lmid_t ns)
   unsigned int i = ns == LM_ID_BASE;
   uint16_t seen[nmaps];
   memset (seen, 0, nmaps * sizeof (seen[0]));
+
+  /* Maximum index for sorting */
+  size_t nmax = nmaps - 1;
+
   while (1)
     {
       /* Keep track of which object we looked at this round.  */
@@ -50,10 +54,19 @@ _dl_sort_fini (struct link_map **maps, size_t
nmaps, char *used, Lmid_t ns)
       if (thisp != thisp->l_real || thisp->l_idx == -1)
  goto skip;

+      /* If initfirst flag is set, push the library at last. */
+      if (__builtin_expect (thisp == GL(dl_initfirst), 0))
+ {
+  maps[i] = maps[nmax];
+  maps[nmax] = thisp;
+  thisp = maps[i];
+  --nmax;
+ }
+
       /* Find the last object in the list for which the current one is
  a dependency and move the current object behind the object
  with the dependency.  */
-      unsigned int k = nmaps - 1;
+      unsigned int k = nmax;
       while (k > i)
  {
   struct link_map **runp = maps[k]->l_initfini;
diff --git elf/dl-init.c elf/dl-init.c
index a657eb6..6b76a4f 100644
--- elf/dl-init.c
+++ elf/dl-init.c
@@ -97,7 +97,6 @@ _dl_init (struct link_map *main_map, int argc, char
**argv, char **env)
   if (__builtin_expect (GL(dl_initfirst) != NULL, 0))
     {
       call_init (GL(dl_initfirst), argc, argv, env);
-      GL(dl_initfirst) = NULL;
     }

   /* Don't do anything if there is no preinit array.  */