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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2885BC43613 for ; Mon, 24 Jun 2019 16:45:07 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E681320665 for ; Mon, 24 Jun 2019 16:45:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YzsS1C/X" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E681320665 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ei+CERRFnrEMlCm3cOe+8Kng8V6z14WZ9vTrh/pnvDU=; b=YzsS1C/XU7f+pnkczz3H5kfDe 94WLvC6p92hPRCWxOwEIyfkJG4vjhHrG64iXZxis16RJzgLtFfDTf8BBMWUdks+qpuJyC+VYvfoOC MhgLxUbqy0jEoRcQmc/xf0JfinBk4wH4UD+sJkN4/dNzX8qpoe92c4bPlZsZrwQxz2U1vmzHbbU3a Jt3AjJdznMYeUx8ROStjrN2yBf8CGkm8EpIr4iv1zQRFSyqlDhjdcvTTENwcp5vXrdbujWcBgDj9L 3QkLF+jbOI8cpdaiucSCzigGuTl412ju8vCuTKg6BT7c0gXs+hkOkj7zJHCwuW/x7TLtJeC6nlwmd s3ng67QQA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hfS5S-0003GL-VO; Mon, 24 Jun 2019 16:44:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hfS5Q-0003G2-Gl for linux-arm-kernel@lists.infradead.org; Mon, 24 Jun 2019 16:44:57 +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 C503D360; Mon, 24 Jun 2019 09:44:55 -0700 (PDT) Received: from [10.37.12.219] (unknown [10.37.12.219]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4D68A3F71E; Mon, 24 Jun 2019 09:44:54 -0700 (PDT) Subject: Re: [RFC PATCH v2 7/8] arm64/sve: Don't disable SVE on syscalls return To: Dave Martin References: <20190613161656.20765-1-julien.grall@arm.com> <20190613161656.20765-8-julien.grall@arm.com> <20190621153316.GC2790@e103592.cambridge.arm.com> From: Julien Grall Message-ID: <54e5e484-0268-0593-e5e7-16d7451cc849@arm.com> Date: Mon, 24 Jun 2019 17:44:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190621153316.GC2790@e103592.cambridge.arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190624_094456_603037_D75AAEB9 X-CRM114-Status: GOOD ( 17.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Anton.Kirilov@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, oleg@redhat.com, zhang.lei@jp.fujitsu.com, alex.bennee@linaro.org, linux-arm-kernel@lists.infradead.org, Daniel.Kiss@arm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Dave, I will answer the rest of the e-mail separately. On 6/21/19 4:33 PM, Dave Martin wrote: > On Thu, Jun 13, 2019 at 05:16:55PM +0100, Julien Grall wrote: >> + * state on context switch. The bit will be set again while >> + * restoring/zeroing the registers. >> */ >> - sve_user_disable(); >> + if (test_and_clear_thread_flag(TIF_SVE)) >> + set_thread_flag(TIF_SVE_NEEDS_FLUSH); > > Do we need to do this under local_bh_disable()? Does it matter? > > It looks to me like this is called when we still have interrupts > disabled, which is probably worth fixing. This may actually be a bug: > if kzalloc() causes us to sleep, we have the potential to trigger > sleeping-while-atomic splats. I am not sure to understand this. Which kzalloc do you refer to? Is it the one in sve_alloc? > > If you agree that's a bug, try to come up with a preliminary patch > that's suitable for stable. > > (I may have just misunderstood / misremembered something here.) Cheers, -- Julien Grall _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel