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From: Jakub Jelinek <jakub@redhat.com>
To: Ulrich Drepper <drepper@redhat.com>
Cc: Glibc hackers <libc-hacker@sources.redhat.com>
Subject: [PATCH] Fix STB_GNU_UNIQUE handling for > 30 unique symbols
Date: Mon, 27 Jul 2009 14:07:00 -0000	[thread overview]
Message-ID: <20090727140602.GN3101@sunsite.ms.mff.cuni.cz> (raw)

Hi!

There were several issues when the initial 31 entries hashtab filled up.
size * 3 <= tab->n_elements is always false, table can't have more elements
than its size.  I assume from libiberty/hashtab.c this meant to be check for
3/4 full.  Even after fixing that, _dl_higher_prime_number (31) apparently
returns 31, only _dl_higher_prime_number (32) returns 61.  And, size
variable wasn't updated during reallocation, which means during reallocation
the insertion of the new entry was done into a wrong spot.

All this lead to a hang in ld.so, because a search with n_elements 31 size
31 wouldn't ever terminate.

2009-07-27  Jakub Jelinek  <jakub@redhat.com>

	* elf/dl-lookup.c (do_lookup_x): Fix check for table more than
	3/4 full.  Pass size + 1 rather than size to _dl_higher_prime_number.
	Update size when reallocating.

--- libc/elf/dl-lookup.c.jj	2009-07-23 16:44:46.000000000 +0200
+++ libc/elf/dl-lookup.c	2009-07-27 15:58:48.000000000 +0200
@@ -377,10 +377,10 @@ do_lookup_x (const char *undef_name, uin
 			idx -= size;
 		    }
 
-		  if (size * 3 <= tab->n_elements)
+		  if (size * 3 <= tab->n_elements * 4)
 		    {
 		      /* Expand the table.  */
-		      size_t newsize = _dl_higher_prime_number (size);
+		      size_t newsize = _dl_higher_prime_number (size + 1);
 		      struct unique_sym *newentries
 			= calloc (sizeof (struct unique_sym), newsize);
 		      if (newentries == NULL)
@@ -398,6 +398,7 @@ do_lookup_x (const char *undef_name, uin
 
 		      tab->free (entries);
 		      tab->size = newsize;
+		      size = newsize;
 		      entries = tab->entries = newentries;
 		      tab->free = free;
 		    }

	Jakub

                 reply	other threads:[~2009-07-27 14:07 UTC|newest]

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