From 5666dd19dd95d966be00d0c3e7efdfaecc096ff3 Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Thu, 15 Sep 2011 14:39:52 -0500 Subject: qapi: dealloc visitor, fix premature free and iteration logic 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 file changed, 15 insertions(+), 5 deletions(-) (limited to 'qapi') diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c index f6290611fe..6b586ade13 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) -- cgit v1.2.3