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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3095C433FE for ; Wed, 19 Oct 2022 23:30:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 4B2504B8F2; Wed, 19 Oct 2022 19:30:05 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@google.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OYULPnPPc3A5; Wed, 19 Oct 2022 19:30:04 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 02CBE4B912; Wed, 19 Oct 2022 19:30:04 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id E5F284B908 for ; Wed, 19 Oct 2022 19:30:02 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6JJ5FXlTvi-L for ; Wed, 19 Oct 2022 19:30:01 -0400 (EDT) Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id DDC1E4B8F2 for ; Wed, 19 Oct 2022 19:30:01 -0400 (EDT) Received: by mail-pj1-f53.google.com with SMTP id pq16so18244778pjb.2 for ; Wed, 19 Oct 2022 16:30:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=pNS4i1/uTE4ZjPfTxUlttdhibsboeayO977TaMrS1sYkQiDeEdxdrNp8fYJxt/nlLl rY+UubEWMRQGyUBH2CE+gvS0hQUwfZ/g/f+7WQ6ctLMQLVeSVueJHSewAFzsjHLFpDjv 0q8T/L/ZOjlxQwcPOUqlV8+Qcu76Jd9tybLqBjXd5Kc+YuYYIEkeQn3/nUUnm7j1b7QX kY3YVqJu2O4STBO5JPK3vMHrMDesVjvETNBxFs/zxcBLH4y84LB7dem38QmEhj3zJ1Wj /vVR/HnRTX4H68Fhk5dHUkhFlI0AlPNABY+kfiysYV98/fuDZZoF7SKrdyuyByK+7H2G ++8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=VhHuBk/OT7mwjKnDxdygAqeCcl01tGi4z3xwyLiPe1aNAlRV8jveFvNs7IqaybMBdM ig/iKe2ysLjUwvB+etmWhiH5vEUNxHL1hP5/2Uc5BUu5I8zXirb0Wiz3fV+WhnVazRdQ tUnpPxeLnG/KbKzTQhC6W/tSdMwrjM8Vhq/nrzD9hrV5ZAqADVCdE7ikVCiu/5G6rJo8 5PfN2qym/FnppS2aEv8MB7PYmUNPVX0c3p2cpJkckIVXKx80JBwPrYPe2G/o7gGrq6mH Cleb1vxgZRYOysRCek8+jn8TEV4wG4Mmjq2IzVNTSsujbcs0G0yYYNUFceO33MH4/9pp rNZA== X-Gm-Message-State: ACrzQf0x7DJAAmtnnH0LFX81V0JZqhoo8SaY2++L9Bzu5DR/XqOGQxTq vdmrhfJqmM2nX43WHyhDCQ+soQ== X-Google-Smtp-Source: AMsMyM51FW42zS56Z56v3OpmK3a6FlWgAAbvrNLxA+8YZJ8dKFrQg5/eqpzDYRzimT6KdDBkOpGsRQ== X-Received: by 2002:a17:902:e890:b0:185:4ac7:9757 with SMTP id w16-20020a170902e89000b001854ac79757mr10900658plg.150.1666222200834; Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id d25-20020aa797b9000000b00561f8fdba8esm12367909pfq.12.2022.10.19.16.30.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Date: Wed, 19 Oct 2022 23:29:56 +0000 From: Sean Christopherson To: Oliver Upton Subject: Re: [PATCH v2 08/15] KVM: arm64: Protect stage-2 traversal with RCU Message-ID: References: <20221007232818.459650-1-oliver.upton@linux.dev> <20221007232818.459650-9-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221007232818.459650-9-oliver.upton@linux.dev> Cc: kvm@vger.kernel.org, Marc Zyngier , Will Deacon , kvmarm@lists.linux.dev, Ben Gardon , David Matlack , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu On Fri, Oct 07, 2022, Oliver Upton wrote: > The use of RCU is necessary to safely change the stage-2 page tables in > parallel. Acquire and release the RCU read lock when traversing the page > tables. > > Use the _raw() flavor of rcu_dereference when changes to the page tables > are otherwise protected from parallel software walkers (e.g. holding the > write lock). > > Signed-off-by: Oliver Upton > --- ... > @@ -32,6 +39,33 @@ static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared > return pteref; > } > > +static inline void kvm_pgtable_walk_begin(void) {} > +static inline void kvm_pgtable_walk_end(void) {} > + > +#else > + > +typedef kvm_pte_t __rcu *kvm_pteref_t; > + > +static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared) > +{ > + if (shared) > + return rcu_dereference(pteref); > + > + return rcu_dereference_raw(pteref); Rather than use raw, use rcu_dereference_check(). If you can plumb down @kvm or @mmu_lock, the ideal check would be (apparently there's no lockdep_is_held_write() wrapper?) return READ_ONCE(*rcu_dereference_check(ptep, lockdep_is_held_type(mmu_lock, 0))); If getting at mmu_lock is too difficult, this can still be return READ_ONCE(*rcu_dereference_check(ptep, !shared); Doubt it matters for code generation, but IMO it's cleaner overall. _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f174.google.com (mail-pl1-f174.google.com [209.85.214.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 818B653BD for ; Wed, 19 Oct 2022 23:30:01 +0000 (UTC) Received: by mail-pl1-f174.google.com with SMTP id d24so18696867pls.4 for ; Wed, 19 Oct 2022 16:30:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=pNS4i1/uTE4ZjPfTxUlttdhibsboeayO977TaMrS1sYkQiDeEdxdrNp8fYJxt/nlLl rY+UubEWMRQGyUBH2CE+gvS0hQUwfZ/g/f+7WQ6ctLMQLVeSVueJHSewAFzsjHLFpDjv 0q8T/L/ZOjlxQwcPOUqlV8+Qcu76Jd9tybLqBjXd5Kc+YuYYIEkeQn3/nUUnm7j1b7QX kY3YVqJu2O4STBO5JPK3vMHrMDesVjvETNBxFs/zxcBLH4y84LB7dem38QmEhj3zJ1Wj /vVR/HnRTX4H68Fhk5dHUkhFlI0AlPNABY+kfiysYV98/fuDZZoF7SKrdyuyByK+7H2G ++8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=PabUAwMoCbhP7iB4LDMmplZ+hW56EH3d7PE3+lDCPiYVaVKhGlU7gEGe5qAkNw8A7C ITKIbb8jlQpOk+UVWju4WAmihhyTQp6MOoyfCnAUfbAkuRI6UONV9yFzZzTcgqlQ0G3c Nf0RbHwYjRcKjXk+34/gpcsmKfTa6SP7y996d/fK6yHmtMo0X1kSB75xCkvve0GtvpQX UbCOu69b2Xbg4eyGMRFYm8aPTeCxAC9jIcg44v3g5I1kRxVUhncSqnMx/2EP7qFYeVuV 7tVbWW1D1QtkY9CheHtIwDlWbKolvsNnhjJ4a5S4RgN0hslErLQYtCYH7LJnWBrbcCHA unjw== X-Gm-Message-State: ACrzQf2i6sYkbR8w4t7prvbsdeiY3BtnUJAWP0m4TXf3KuNecRx2QJEN hJbDpOaeNO4K+7yOAfJK8OszcQ== X-Google-Smtp-Source: AMsMyM51FW42zS56Z56v3OpmK3a6FlWgAAbvrNLxA+8YZJ8dKFrQg5/eqpzDYRzimT6KdDBkOpGsRQ== X-Received: by 2002:a17:902:e890:b0:185:4ac7:9757 with SMTP id w16-20020a170902e89000b001854ac79757mr10900658plg.150.1666222200834; Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id d25-20020aa797b9000000b00561f8fdba8esm12367909pfq.12.2022.10.19.16.30.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Date: Wed, 19 Oct 2022 23:29:56 +0000 From: Sean Christopherson To: Oliver Upton Cc: Marc Zyngier , James Morse , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Reiji Watanabe , Ricardo Koller , David Matlack , Quentin Perret , Ben Gardon , Gavin Shan , Peter Xu , Will Deacon , kvmarm@lists.linux.dev Subject: Re: [PATCH v2 08/15] KVM: arm64: Protect stage-2 traversal with RCU Message-ID: References: <20221007232818.459650-1-oliver.upton@linux.dev> <20221007232818.459650-9-oliver.upton@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221007232818.459650-9-oliver.upton@linux.dev> Message-ID: <20221019232956.SQPEJjLbR8vvqyQvSffCittyO3CcaFTDdNWE_KtCotY@z> On Fri, Oct 07, 2022, Oliver Upton wrote: > The use of RCU is necessary to safely change the stage-2 page tables in > parallel. Acquire and release the RCU read lock when traversing the page > tables. > > Use the _raw() flavor of rcu_dereference when changes to the page tables > are otherwise protected from parallel software walkers (e.g. holding the > write lock). > > Signed-off-by: Oliver Upton > --- ... > @@ -32,6 +39,33 @@ static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared > return pteref; > } > > +static inline void kvm_pgtable_walk_begin(void) {} > +static inline void kvm_pgtable_walk_end(void) {} > + > +#else > + > +typedef kvm_pte_t __rcu *kvm_pteref_t; > + > +static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared) > +{ > + if (shared) > + return rcu_dereference(pteref); > + > + return rcu_dereference_raw(pteref); Rather than use raw, use rcu_dereference_check(). If you can plumb down @kvm or @mmu_lock, the ideal check would be (apparently there's no lockdep_is_held_write() wrapper?) return READ_ONCE(*rcu_dereference_check(ptep, lockdep_is_held_type(mmu_lock, 0))); If getting at mmu_lock is too difficult, this can still be return READ_ONCE(*rcu_dereference_check(ptep, !shared); Doubt it matters for code generation, but IMO it's cleaner overall. 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 442D6C433FE for ; Wed, 19 Oct 2022 23:31:18 +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=3VpenOjEZhz9qe/MuQd/3EJYFuQqggQsKX4s4dtvD9Y=; b=jH0kw3FTcVMOSn y4nq9006howSK55F7CNEy+04XjNP6H99wtlYAd0r5SMJSzUqIGFUipPiHwSL0YwxgYPeL8mumC1bL syWtIqvodqW3nPbR0f+mGB7cXxleO/ou6ZDCKmCYXZkU0U62JMDUNuVJ/2Mf+yIWlHwGB1tvBDoMY mPzQ+KBp2W7FXLno09dIh344/gh7UkeU+EASY1D/cBNOSUw67kzfXKQcfUlwUQesNXgOBXL7QZy+c mMO79CU3ZBDBD2itOCQAv3924AObGvR353v4rpcUeHG9Ipg0RIpMZ1rCvaTfwThPqco7ztuZ9I2xN o+5woXD7RqCvKx+IoALw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olIVi-005pW0-Tn; Wed, 19 Oct 2022 23:30:07 +0000 Received: from mail-pl1-x633.google.com ([2607:f8b0:4864:20::633]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1olIVg-005pUU-0Y for linux-arm-kernel@lists.infradead.org; Wed, 19 Oct 2022 23:30:05 +0000 Received: by mail-pl1-x633.google.com with SMTP id j12so25809plj.5 for ; Wed, 19 Oct 2022 16:30:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=pNS4i1/uTE4ZjPfTxUlttdhibsboeayO977TaMrS1sYkQiDeEdxdrNp8fYJxt/nlLl rY+UubEWMRQGyUBH2CE+gvS0hQUwfZ/g/f+7WQ6ctLMQLVeSVueJHSewAFzsjHLFpDjv 0q8T/L/ZOjlxQwcPOUqlV8+Qcu76Jd9tybLqBjXd5Kc+YuYYIEkeQn3/nUUnm7j1b7QX kY3YVqJu2O4STBO5JPK3vMHrMDesVjvETNBxFs/zxcBLH4y84LB7dem38QmEhj3zJ1Wj /vVR/HnRTX4H68Fhk5dHUkhFlI0AlPNABY+kfiysYV98/fuDZZoF7SKrdyuyByK+7H2G ++8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=qruOvYNq6YtcLgC8q9oi5W0wV4Pui1eBKPtr9rOj7ao=; b=d5sdOrH/fUy3ZjAszHQE1bKsYMknlIaM95jYVEMpxasboUXDEb0bpXD2UWZnUN2Z1g +lhI5kUCRHFpISuBSoD9Y97XsXZrasAFf133Bq1ISFXxXXlflpLYYlsPalJhnifj8gsv JvDV8l+Mh88VGAsT7Rkc5oDUaLOZOxq+2HZU5Z5ZiiA1+nMeZn7G6wavvDmZkOyZ/CR8 m7+eCFUF7849Eovuv6bGQtSVsV7FbzBsNR/seOOHM/qlOaAaDkdEnfDaoooOnDLui/fo LWy8MrXTo/0/AII468NDd+9wL1TFQ4tBPpqbxMpSXW5uHt74KLUIV3AkXFcCDOG3GiXz 8t8w== X-Gm-Message-State: ACrzQf0uVZLEGxUOyLkz/iQ0mf2ueFmYCEXmLUB4e7IbOwwTllWXs1KT F+y2se2IFKFwg8gSVItRJVQ78g== X-Google-Smtp-Source: AMsMyM51FW42zS56Z56v3OpmK3a6FlWgAAbvrNLxA+8YZJ8dKFrQg5/eqpzDYRzimT6KdDBkOpGsRQ== X-Received: by 2002:a17:902:e890:b0:185:4ac7:9757 with SMTP id w16-20020a170902e89000b001854ac79757mr10900658plg.150.1666222200834; Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id d25-20020aa797b9000000b00561f8fdba8esm12367909pfq.12.2022.10.19.16.30.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 16:30:00 -0700 (PDT) Date: Wed, 19 Oct 2022 23:29:56 +0000 From: Sean Christopherson To: Oliver Upton Cc: Marc Zyngier , James Morse , Alexandru Elisei , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, Reiji Watanabe , Ricardo Koller , David Matlack , Quentin Perret , Ben Gardon , Gavin Shan , Peter Xu , Will Deacon , kvmarm@lists.linux.dev Subject: Re: [PATCH v2 08/15] KVM: arm64: Protect stage-2 traversal with RCU Message-ID: References: <20221007232818.459650-1-oliver.upton@linux.dev> <20221007232818.459650-9-oliver.upton@linux.dev> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221007232818.459650-9-oliver.upton@linux.dev> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221019_163004_099861_782F5BC7 X-CRM114-Status: GOOD ( 14.68 ) 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="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Oct 07, 2022, Oliver Upton wrote: > The use of RCU is necessary to safely change the stage-2 page tables in > parallel. Acquire and release the RCU read lock when traversing the page > tables. > > Use the _raw() flavor of rcu_dereference when changes to the page tables > are otherwise protected from parallel software walkers (e.g. holding the > write lock). > > Signed-off-by: Oliver Upton > --- ... > @@ -32,6 +39,33 @@ static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared > return pteref; > } > > +static inline void kvm_pgtable_walk_begin(void) {} > +static inline void kvm_pgtable_walk_end(void) {} > + > +#else > + > +typedef kvm_pte_t __rcu *kvm_pteref_t; > + > +static inline kvm_pte_t *kvm_dereference_pteref(kvm_pteref_t pteref, bool shared) > +{ > + if (shared) > + return rcu_dereference(pteref); > + > + return rcu_dereference_raw(pteref); Rather than use raw, use rcu_dereference_check(). If you can plumb down @kvm or @mmu_lock, the ideal check would be (apparently there's no lockdep_is_held_write() wrapper?) return READ_ONCE(*rcu_dereference_check(ptep, lockdep_is_held_type(mmu_lock, 0))); If getting at mmu_lock is too difficult, this can still be return READ_ONCE(*rcu_dereference_check(ptep, !shared); Doubt it matters for code generation, but IMO it's cleaner overall. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel