From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 89B26C433FE for ; Mon, 3 Oct 2022 13:23:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=raq2gn0GUQJHpQvjnIBvO7AoYXtLO8YKHSnZPVjheV8=; b=UX4UA9WJP0Qhw9 LzY5eAYx4EgycWTlRo5JN5Ncyx0eA2pvjp5nN625E2+DkUB01T4ShZVE+Ck6smPPGFkkyC88AHlsu lzYGA/SDpxcYc26ZmscXIw0OJwNiOBV6Vuj66ULGTF4YyGCsPiFay1hchP/MowHnGhbAn1cuBZC21 O/C3IZ0rP2SagQ/OVuvYuMrxOgIVQWwGAgZoE5yFelPJdGJNmz2ek4ruEt4v4q/fwqKDIxs+p7OVh mBnu9TtWwGyHe+p3pRUoBlmcUVyHDyqSqDLLEH3xB2XNNqwtmlmmcjbAVU5AJTXhopH4j9tSlgKRs hmd51t5DfAydiahQmMkw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ofLP9-005xR5-FK; Mon, 03 Oct 2022 13:22:43 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ofLP5-005xNK-Uw for linux-arm-kernel@lists.infradead.org; Mon, 03 Oct 2022 13:22:41 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 34C3816F8; Mon, 3 Oct 2022 06:22:42 -0700 (PDT) Received: from e120937-lin (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 80B403F73B; Mon, 3 Oct 2022 06:22:34 -0700 (PDT) Date: Mon, 3 Oct 2022 14:22:32 +0100 From: Cristian Marussi To: Shivnandan Kumar Cc: sudeep.holla@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, quic_rgottimu@quicinc.com, quic_avajid@quicinc.com Subject: Re: Query regarding "firmware: arm_scmi: Free mailbox channels if probe fails" Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221003_062240_065132_0C09D354 X-CRM114-Status: GOOD ( 17.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Sep 30, 2022 at 06:29:02PM +0530, Shivnandan Kumar wrote: > hi Cristian, Hi Shivnandan, > = > Thanks for your support in providing the patch to try. > = > I found one race condition in our downstream mbox controller driver while > accessing con_priv, when I serialized access to this, issue is not seen o= n 3 > days of testing. Good to hear that you find the issue. > = > As you rightly mentioned that your provided patch will impact all the oth= er > users. > = > Also if=A0 we take your provided patch, same race still exists while acce= ssing > con_priv in our downstream mbox controller so this issue will still be > there. > = Yes indeed, even though I think that race in the mailbox core between RX pa= th and chan_free could still be theoretically possible it does not seem to me appropriate to try to fix it now that you cannot reproduce it anymore and no other mailbox user has ever raised this concern (even though, as said, t= he proper solution to that race wont probably be directly in the mailbox-core = as in my experimental two liners..) > So, we are planning to merge the patch( serialized access to con_priv) in > our downstream mbox controller now. > = Ok, just out of curiosity, once done, can you point me at your downstream p= ublic sources so I can see the issue and the fix that you are applying to your tr= ees ? Thanks, Cristian _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel