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=-15.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 84A48C4743E for ; Fri, 4 Jun 2021 17:18:56 +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 4BAAE6140F for ; Fri, 4 Jun 2021 17:18:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BAAE6140F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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.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=XIVct5tj/QLzg6rJU3Y43x9b5XhPuXBHJk9hteSGlCE=; b=Bd0AKcvj/7D8Rg OOiCgIwCrvmw35RUH/c74X+VbweRKWeInS3tp8GxGPIMq1DUVcesEYFahcQwI7SjSKxrGxEA/Bz49 sYHi1QqZZZdpg912xBY7bcm8zxB/IGPg+Bxcs3dtZikbbLp3qDmRqPiBXqNClPh0HPWeV1eyHTGzV 36i3cKvsqVI4VFmf2R2q1E6qTUg3JwyPbX9L5JWynbMEDw7huZvYwJSlQBzdH1dYd0gI7HBChONsH 2SGpVXw3+2fiZitGKzPez51J9zM2IOjtKWstPW9EDEyQGc7npOzSzd2FaQDItvAdWS//XawpzGbwA MJKs1DJW6fRosW6VQDLA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lpDRY-00EbVt-D1; Fri, 04 Jun 2021 17:17:14 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lpDQv-00EbDZ-Ja for linux-arm-kernel@lists.infradead.org; Fri, 04 Jun 2021 17:16:35 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 292AF613FF; Fri, 4 Jun 2021 17:16:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1622826993; bh=dxwAAtcMVU4R34YhFt6+rpjbd+lANSBPmyKtwnOFGus=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XqZrzdrM2ZlUPP2WDo8Zusc1+vl1jLfxbNombBq+KmVsoMgbacdtULwqyjpO9LcEc qCCPrPvwDqmfUc0q8+Qj/MyR3Mz0y/lCwwGZO3pGlK9H5ic32okMaqayvWPcGMfD5M 1Wgnw5nFg4+mbgWU+HyZfOcJEYiRmKn9d5njXlFBfOxEhUjlgNrLq+rSg4md3db+QZ s8c76w0skr/uak1EBwT2W8GESPmNjWdazvLFeud28X8vWh4AS0fvFhAY1UJbENNcIn pDmlj7+z71FM/kwfLw1hxIWlmPVetjYrA7DZGNR8fBNT8ChtJ2M5Agb+n1Mw8VcnDt 3Kb0LSCC0/Ldw== Date: Fri, 4 Jun 2021 18:16:28 +0100 From: Will Deacon To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, james.morse@arm.com, joey.gouly@arm.com, maz@kernel.org Subject: Re: [PATCH v3 19/20] arm64: entry: don't instrument entry code with KCOV Message-ID: <20210604171628.GE3416@willie-the-truck> References: <20210525183302.56293-1-mark.rutland@arm.com> <20210525183302.56293-20-mark.rutland@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210525183302.56293-20-mark.rutland@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210604_101633_721458_7E3B3081 X-CRM114-Status: GOOD ( 17.99 ) 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 Tue, May 25, 2021 at 07:33:01PM +0100, Mark Rutland wrote: > The code in entry-common.c runs at exception entry and return > boundaries, where portions of the kernel environment aren't available. > For example, RCU may not be watching, and lockdep state may be > out-of-sync with the hardware. Due to this, it is not sound to > instrument this code. > > We generally avoid instrumentation by marking the entry functions as > `noinstr`, but currently this doesn't inhibit KCOV instrumentation. > Prevent this by disabling KCOV for the entire compilation unit. > > Signed-off-by: Mark Rutland > Cc: Catalin Marinas > Cc: James Morse > Cc: Marc Zyngier > Cc: Will Deacon > --- > arch/arm64/kernel/Makefile | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > index 6cc97730790e..294063032428 100644 > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -14,6 +14,8 @@ CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE) > CFLAGS_REMOVE_syscall.o = -fstack-protector -fstack-protector-strong > CFLAGS_syscall.o += -fno-stack-protector Can you stick a comment here please? Just summarising what you have in the commit message would be handy. Thanks, Will > +KCOV_INSTRUMENT_entry.o := n _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel