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From: David Miller <davem@davemloft.net>
To: kuba@kernel.org
Cc: eric.dumazet@gmail.com, michael.chan@broadcom.com,
	netdev@vger.kernel.org, kernel-team@fb.com
Subject: Re: [PATCH net 0/2] net: fix netpoll crash with bnxt
Date: Wed, 26 Aug 2020 16:17:30 -0700 (PDT)	[thread overview]
Message-ID: <20200826.161730.2188402243333115569.davem@davemloft.net> (raw)
In-Reply-To: <20200826194007.1962762-1-kuba@kernel.org>

From: Jakub Kicinski <kuba@kernel.org>
Date: Wed, 26 Aug 2020 12:40:05 -0700

> Rob run into crashes when using XDP on bnxt. Upon investigation
> it turns out that during driver reconfig irq core produces
> a warning message when IRQs are requested. This triggers netpoll,
> which in turn accesses uninitialized driver state. Same crash can
> also be triggered on this platform by changing the number of rings.
> 
> Looks like we have two missing pieces here, netif_napi_add() has
> to make sure we start out with netpoll blocked. The driver also
> has to be more careful about when napi gets enabled.
> 
> Tested XDP and channel count changes, the warning message no longer
> causes a crash. Not sure if the memory barriers added in patch 1
> are necessary, but it seems we should have them.

Series applied and queued up for -stable, thanks Jakub.

      parent reply	other threads:[~2020-08-26 23:17 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-26 19:40 [PATCH net 0/2] net: fix netpoll crash with bnxt Jakub Kicinski
2020-08-26 19:40 ` [PATCH net 1/2] net: disable netpoll on fresh napis Jakub Kicinski
2020-08-27  7:25   ` Eric Dumazet
2020-08-27 15:10     ` Jakub Kicinski
2020-08-27 15:43       ` Eric Dumazet
2020-08-27 17:47         ` Jakub Kicinski
2020-08-27 22:32           ` [RFC -next 0/3] " Jakub Kicinski
2020-08-27 22:32             ` [RFC -next 1/3] net: remove napi_hash_del() from driver-facing API Jakub Kicinski
2020-08-27 22:32             ` [RFC -next 2/3] net: manage napi add/del idempotence explicitly Jakub Kicinski
2020-08-27 22:32             ` [RFC -next 3/3] net: make sure napi_list is safe for RCU traversal Jakub Kicinski
2020-08-26 19:40 ` [PATCH net 2/2] bnxt: don't enable NAPI until rings are ready Jakub Kicinski
2020-08-26 20:23   ` Michael Chan
2020-08-26 23:17 ` David Miller [this message]

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