File glibc-2.5-dladdr.diff of Package glibc

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File glibc-2.5-dladdr.diff of Package glibc

elf/dl-addr.c : (_dl_addr)  : Ensure the addres lies in one of the segments loaded for a lib.

Sometimes, an entirely unrelated map (say libB) can be allocated in between the mapped segments of a lib (say libA). So, in these cases the _dl_addr for an address within libB, would return libA as the result. We fix this by ensuring that the  address falls *IN ANY* of the loaded segments.

Index: glibc-2.5/elf/dl-addr.c
===================================================================
--- elf/dl-addr.c	2006-08-27 15:49:04.000000000 -0700
+++ elf/dl-addr.c	2007-02-27 15:34:27.000000000 -0800
@@ -28,6 +28,7 @@
 	  struct link_map **mapp, const ElfW(Sym) **symbolp)
 {
   const ElfW(Addr) addr = DL_LOOKUP_ADDRESS (address);
+  int result = 0;
 
   /* Protect against concurrent loads and unloads.  */
   __rtld_lock_lock_recursive (GL(dl_load_lock));
@@ -39,24 +40,26 @@
       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)
+	     Make sure it lies within one of L's segments.  */
+	  int n = l->l_phnum;
+	  while (--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.  */
+	      if (l->l_phdr[n].p_type != PT_LOAD)
 		continue;
+	      if ((addr >= l->l_addr + 
+			   l->l_phdr[n].p_vaddr) &&
+		  (addr < l->l_addr + 
+			  l->l_phdr[n].p_vaddr + l->l_phdr[n].p_memsz))
+		{
+		  match = l;
+		  goto found_match;
+		}
 	    }
 
-	  match = l;
-	  break;
 	}
 
-  int result = 0;
+found_match:
+
   if (match != NULL)
     {
       /* Now we know what object the address lies in.  */

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File glibc-2.5-dladdr.diff of Package glibc

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