From: Olivier Houchard <ohouchard@haproxy.com>
Date: Fri, 8 Nov 2019 14:41:55 +0000 (+0100)
Subject: BUG/MEDIUM: tasks: Make tasklet_remove_from_tasklet_list() no matter the tasklet.
X-Git-Tag: v2.1-dev5~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7031e3daced2169a2ebc5041611a2f05310f130f;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: tasks: Make tasklet_remove_from_tasklet_list() no matter the tasklet.

In tasklet_remove_from_tasket_list(), we can be called for a tasklet that is
either in the private task list, or in the shared tasklet list. Take that into
account and always use MT_LIST_DEL() to remove it, otherwise if we're in the
shared list and another thread attempts to add a tasklet in it, bad things
will happen.

__tasklet_remove_from_tasklet_list() is left unchanged, it's only supposed
to be used by process_runnable_task() to remove task/tasklets from the private
tast list.

This should not be backported.
This should fix github issue #357.
---

diff --git a/include/proto/task.h b/include/proto/task.h
index 5f2b144a7a..b29d84a914 100644
--- a/include/proto/task.h
+++ b/include/proto/task.h
@@ -270,8 +270,8 @@ static inline void __tasklet_remove_from_tasklet_list(struct tasklet *t)
 
 static inline void tasklet_remove_from_tasklet_list(struct tasklet *t)
 {
-	if (likely(!LIST_ISEMPTY(&t->list)))
-		__tasklet_remove_from_tasklet_list(t);
+	if (MT_LIST_DEL((struct mt_list *)&t->list))
+		_HA_ATOMIC_SUB(&tasks_run_queue, 1);
 }
 
 /*