[PATCH] dladdr fix

[Jakub Jelinek]

Hi!

This has been seen in JDK (still does not work, am looking into linuxthreads
right now). Basically, the main object and ld.so have l_map_end set to ~0L,
so if _dl_addr is called with an address from some non-dlopened shared
library (e.g. 
void foo(void)
{
  Dl_info i;
  dladdr(foo, &i);
}
in a dso), then the test chooses the main program as a match (because foo
address is certainly below ~0L and above l_map_start of the main object),
fails in the PHDR check and returns 0.

2000-07-17  Jakub Jelinek  <jakub@redhat.com>

	* elf/dl-addr.c (_dl_addr): Keep searching in the _dl_loaded
	chain if the PHDR check fails.

--- libc/elf/dl-addr.c.jj	Thu Jun  8 04:34:29 2000
+++ libc/elf/dl-addr.c	Mon Jul 17 12:19:16 2000
@@ -36,27 +36,25 @@ _dl_addr (const void *address, Dl_info *
   for (l = _dl_loaded; l; l = l->l_next)
     if (addr >= l->l_map_start && addr < l->l_map_end)
       {
+	/* We know ADDRESS lies within L if in any shared object.
+	   Make sure it isn't past the end of L's segments.  */
+	size_t n = l->l_phnum;
+	if (n > 0)
+	  {
+	    do
+	      --n;
+	    while (l->l_phdr[n].p_type != PT_LOAD);
+	    if (addr >= (l->l_addr +
+			 l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz))
+	      /* Off the end of the highest-addressed shared object.  */
+	      continue;
+	  }
+
 	match = l;
 	break;
       }
 
-  if (__builtin_expect (match != NULL, 1))
-    {
-      /* We know ADDRESS lies within MATCH if in any shared object.
-	 Make sure it isn't past the end of MATCH's segments.  */
-      size_t n = match->l_phnum;
-      if (n > 0)
-	{
-	  do
-	    --n;
-	  while (match->l_phdr[n].p_type != PT_LOAD);
-	  if (addr >= (match->l_addr +
-		       match->l_phdr[n].p_vaddr + match->l_phdr[n].p_memsz))
-	    /* Off the end of the highest-addressed shared object.  */
-	    return 0;
-	}
-    }
-  else
+  if (match == NULL)
     return 0;
 
   /* Now we know what object the address lies in.  */

	Jakub