[SCM] Samba Shared Repository - branch master updated

[Andrew Tridgell]

The branch, master has been updated
       via  cf986f2 talloc: ensure the sibling linked list remains valid during a free
      from  1f77710 s3:selftest: run the net rpc registry test under "s3dc" instead "s3dc:local".

http://gitweb.samba.org/?p=samba.git;a=shortlog;h=master


- Log -----------------------------------------------------------------
commit cf986f200804ce873b43c1ecf2d5e1bd08eb8a25
Author: Andrew Tridgell <tridge at samba.org>
Date:   Mon Aug 8 18:24:32 2011 +1000

    talloc: ensure the sibling linked list remains valid during a free
    
    This ensures that the sibling list of a pointer doesn't become invalid
    during a free operation. It is an alternative fix to the fix in
    6f51a1f45bf4de062cce7a562477e8140630a53d, and avoids the problem of
    trying to calculate the parent pointer early
    
    This should fix the subtle spoolss talloc bug that Simo found
    
    Autobuild-User: Andrew Tridgell <tridge at samba.org>
    Autobuild-Date: Tue Aug  9 01:53:17 CEST 2011 on sn-devel-104

-----------------------------------------------------------------------

Summary of changes:
 lib/talloc/talloc.c |   18 +++---------------
 1 files changed, 3 insertions(+), 15 deletions(-)


Changeset truncated at 500 lines:

diff --git a/lib/talloc/talloc.c b/lib/talloc/talloc.c
index a820ebf..19e6a37 100644
--- a/lib/talloc/talloc.c
+++ b/lib/talloc/talloc.c
@@ -838,6 +838,7 @@ static inline int _talloc_free_internal(void *ptr, const char *location)
 	} else {
 		if (tc->prev) tc->prev->next = tc->next;
 		if (tc->next) tc->next->prev = tc->prev;
+		tc->prev = tc->next = NULL;
 	}
 
 	tc->flags |= TALLOC_FLAG_LOOP;
@@ -925,6 +926,7 @@ static void *_talloc_steal_internal(const void *new_ctx, const void *ptr)
 	} else {
 		if (tc->prev) tc->prev->next = tc->next;
 		if (tc->next) tc->next->prev = tc->prev;
+		tc->prev = tc->next = NULL;
 	}
 
 	tc->parent = new_tc;
@@ -1251,23 +1253,9 @@ static inline void _talloc_free_children_internal(struct talloc_chunk *tc,
 			struct talloc_chunk *p = talloc_parent_chunk(tc->child->refs);
 			if (p) new_parent = TC_PTR_FROM_CHUNK(p);
 		}
-		/* finding the parent here is potentially quite
-		   expensive, but the alternative, which is to change
-		   talloc to always have a valid tc->parent pointer,
-		   makes realloc more expensive where there are a
-		   large number of children.
-
-		   The reason we need the parent pointer here is that
-		   if _talloc_free_internal() fails due to references
-		   or a failing destructor we need to re-parent, but
-		   the free call can invalidate the prev pointer.
-		*/
-		if (new_parent == null_context && (tc->child->refs || tc->child->destructor)) {
-			old_parent = talloc_parent_chunk(ptr);
-		}
 		if (unlikely(_talloc_free_internal(child, location) == -1)) {
 			if (new_parent == null_context) {
-				struct talloc_chunk *p = old_parent;
+				struct talloc_chunk *p = talloc_parent_chunk(ptr);
 				if (p) new_parent = TC_PTR_FROM_CHUNK(p);
 			}
 			_talloc_steal_internal(new_parent, child);


-- 
Samba Shared Repository