Re: [PATCH v2] cgroup: net_cls: fix false-positive "suspicious RCU usage"
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2015-07-22 11:56:50
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On 07/22/2015 11:23 AM, Konstantin Khlebnikov wrote:
In dev_queue_xmit() net_cls protected with rcu-bh.
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quoted hunk ↗ jump to hunk
Signed-off-by: Konstantin Khlebnikov <redacted> --- net/core/netclassid_cgroup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c index 1f2a126f4ffa..6441f47b1a8f 100644 --- a/net/core/netclassid_cgroup.c +++ b/net/core/netclassid_cgroup.c@@ -23,7 +23,8 @@ static inline struct cgroup_cls_state *css_cls_state(struct cgroup_subsys_state struct cgroup_cls_state *task_cls_state(struct task_struct *p) { - return css_cls_state(task_css(p, net_cls_cgrp_id)); + return css_cls_state(task_css_check(p, net_cls_cgrp_id, + rcu_read_lock_bh_held()));
Did you also check that after your patch this doesn't trigger on ingress either? There, this code path could be invoked under rcu_read_lock(). So, perhaps you need to check for both.
} EXPORT_SYMBOL_GPL(task_cls_state);