ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]

Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection).  This makes
the hand-over from the minimal malloc to the full malloc more
explicit.

Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/inline-hashtab.h b/include/inline-hashtab.h
index 3c09978199..856719cf9d 100644
--- a/include/inline-hashtab.h
+++ b/include/inline-hashtab.h
@@ -51,7 +51,7 @@ htab_create (void)
     return NULL;
   ht->size = 3;
   ht->entries = malloc (sizeof (void *) * ht->size);
-  ht->free = free;
+  ht->free = __rtld_free;
   if (! ht->entries)
     {
       free (ht);
@@ -167,7 +167,7 @@ htab_expand (struct hashtab *htab, int (*hash_fn) (void *))
 
   /* Use the free() corresponding to the malloc() above to free this
      up.  */
-  htab->free = free;
+  htab->free = __rtld_free;
 
   return 1;
 }