From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:60117) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R9jni-0007EZ-4d for qemu-devel@nongnu.org; Fri, 30 Sep 2011 16:35:20 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1R9jnf-0008AT-Uq for qemu-devel@nongnu.org; Fri, 30 Sep 2011 16:35:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:10386) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1R9jnf-0008AC-Hg for qemu-devel@nongnu.org; Fri, 30 Sep 2011 16:35:15 -0400 From: Luiz Capitulino Date: Fri, 30 Sep 2011 17:34:31 -0300 Message-Id: <1317414891-4042-7-git-send-email-lcapitulino@redhat.com> In-Reply-To: <1317414891-4042-1-git-send-email-lcapitulino@redhat.com> References: <1317414891-4042-1-git-send-email-lcapitulino@redhat.com> Subject: [Qemu-devel] [PATCH 06/26] qapi: dealloc visitor, fix premature free and iteration logic List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, aliguori@us.ibm.com, mdroth@linux.vnet.ibm.com, armbru@redhat.com From: Michael Roth Currently we do 3 things wrong: 1) The list iterator, in practice, is used in a manner where the pointer we pass in is the same as the pointer we assign the output to from visit_next_list(). This causes an infinite loop where we keep freeing the same structures. 2) We attempt to free list->value rather than list. visit_type_ handles this. We should only be concerned with the containing list. 3) We free prematurely: iterator function will continue accessing values we've already freed. This patch should fix all of these issues. QmpOutputVisitor also suffers from 1). Reviewed-by: Anthony Liguori Signed-off-by: Michael Roth Signed-off-by: Luiz Capitulino --- qapi/qapi-dealloc-visitor.c | 20 +++++++++++++++----- 1 files changed, 15 insertions(+), 5 deletions(-) diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c index f629061..6b586ad 100644 --- a/qapi/qapi-dealloc-visitor.c +++ b/qapi/qapi-dealloc-visitor.c @@ -26,6 +26,7 @@ struct QapiDeallocVisitor { Visitor visitor; QTAILQ_HEAD(, StackEntry) stack; + bool is_list_head; }; static QapiDeallocVisitor *to_qov(Visitor *v) @@ -70,15 +71,24 @@ static void qapi_dealloc_end_struct(Visitor *v, Error **errp) static void qapi_dealloc_start_list(Visitor *v, const char *name, Error **errp) { + QapiDeallocVisitor *qov = to_qov(v); + qov->is_list_head = true; } -static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList **list, +static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList **listp, Error **errp) { - GenericList *retval = *list; - g_free(retval->value); - *list = retval->next; - return retval; + GenericList *list = *listp; + QapiDeallocVisitor *qov = to_qov(v); + + if (!qov->is_list_head) { + *listp = list->next; + g_free(list); + return *listp; + } + + qov->is_list_head = false; + return list; } static void qapi_dealloc_end_list(Visitor *v, Error **errp) -- 1.7.7.rc0.72.g4b5ea