[PATCH] Fix LD_DEBUG=statistics

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

LD_DEBUG=statistics someprog leads to segfaults with current glibc.
The problem is that print_statistics doesn't check for NULL _ns_loaded
namespaces and happily dereferences it.

While looking into it, I have noticed the num_relative_relocations
computation doesn't match what do-rel.h is actually doing, particularly
on !ELF_MACHINE_REL_RELATIVE RELA architectures it is processing relative
relocations even if l_addr == 0, but the library is not prelinked.

2004-11-13  Jakub Jelinek  <jakub@redhat.com>

	* elf/rtld.c (print_statistics): Avoid segfaults if not all namespaces
	are used.  Fix computation of num_relative_relocations on RELA
	architectures other than IA-64 and Alpha.

--- libc/elf/rtld.c.jj	2004-11-09 12:26:41.000000000 +0100
+++ libc/elf/rtld.c	2004-11-13 18:56:32.574028935 +0100
@@ -2336,19 +2336,29 @@ print_statistics (hp_timing_t *rtld_tota
   unsigned long int num_relative_relocations = 0;
   for (Lmid_t ns = 0; ns < DL_NNS; ++ns)
     {
+      if (GL(dl_ns)[ns]._ns_loaded == NULL)
+	continue;
+
       struct r_scope_elem *scope = &GL(dl_ns)[ns]._ns_loaded->l_searchlist;
 
       for (unsigned int i = 0; i < scope->r_nlist; i++)
 	{
 	  struct link_map *l = scope->r_list [i];
 
-	  if (!l->l_addr)
-	    continue;
-
-	  if (l->l_info[VERSYMIDX (DT_RELCOUNT)])
+	  if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELCOUNT)])
 	    num_relative_relocations
 	      += l->l_info[VERSYMIDX (DT_RELCOUNT)]->d_un.d_val;
-	  if (l->l_info[VERSYMIDX (DT_RELACOUNT)])
+#ifndef ELF_MACHINE_REL_RELATIVE
+	  /* Relative relocations are processed on these architectures if
+	     library is loaded to different address than p_vaddr or
+	     if not prelinked.  */
+	  if ((l->l_addr != 0 || !map->l_info[VALIDX(DT_GNU_PRELINKED)])
+	      && l->l_info[VERSYMIDX (DT_RELACOUNT)])
+#else
+	  /* On e.g. IA-64 or Alpha, relative relocations are processed
+	     only if library is loaded to different address than p_vaddr.  */
+	  if (l->l_addr != 0 && l->l_info[VERSYMIDX (DT_RELACOUNT)])
+#endif
 	    num_relative_relocations
 	      += l->l_info[VERSYMIDX (DT_RELACOUNT)]->d_un.d_val;
 	}

	Jakub