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=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 F0D08C2BBD1 for ; Thu, 17 Sep 2020 14:05:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 485232223D for ; Thu, 17 Sep 2020 14:05:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Dmjwb72l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 485232223D 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+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=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject: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=SM2gGvi8/3kJ+F5rx6sk1JnqcP57wkh+SNTxQqdW3hY=; b=Dmjwb72lpL5aM2+/3Sfr/f4NY eAxhTYwWTyoWLOQC+IYWHJw/S3rtNwpHn9z+WA1HXpSQl/qWkdxeo3hmqXvUFZhtskobhEPEqwBIe itDctXgxaspEEooZUzmPtzo+pk/t6zy9d+NRL/XT81oQDsCLcNSKUEUpTOCA5oh7uk7Os+Pu5HXgv gO/zDpR76kFBmuDdwzwRoaVzG1b8eGfOByEN+kIzfzWbRJZt7KOBy4zHLB19uc6HL4UXKBz8XIEm8 5bcNo0ExRbF7TqJFVUe2MelvEOeakUKZbhtIOZowzU0sAp2/BzyfrA8R1STNSEpXC4VPfx6+qJj1P VNr/pnPzQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIuVn-0008CC-4L; Thu, 17 Sep 2020 14:03:47 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIuVk-0008BJ-1C for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2020 14:03:44 +0000 Received: from gaia (unknown [31.124.44.166]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 785E62065C; Thu, 17 Sep 2020 14:03:40 +0000 (UTC) Date: Thu, 17 Sep 2020 15:03:37 +0100 From: Catalin Marinas To: Andrey Konovalov Subject: Re: [PATCH v2 24/37] arm64: mte: Add in-kernel tag fault handler Message-ID: <20200917140337.GC10662@gaia> References: <7866d9e6f11f12f1bad42c895bf4947addba71c2.1600204505.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7866d9e6f11f12f1bad42c895bf4947addba71c2.1600204505.git.andreyknvl@google.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-20200917_100344_147561_14C255AD X-CRM114-Status: GOOD ( 20.84 ) 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: linux-arm-kernel@lists.infradead.org, Marco Elver , Elena Petrova , Kevin Brodsky , Will Deacon , Branislav Rankov , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko , Evgenii Stepanov , Andrey Ryabinin , Andrew Morton , Vincenzo Frascino , Dmitry Vyukov 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, Sep 15, 2020 at 11:16:06PM +0200, Andrey Konovalov wrote: > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index a3bd189602df..cdc23662691c 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -294,6 +295,18 @@ static void die_kernel_fault(const char *msg, unsigned long addr, > do_exit(SIGKILL); > } > > +static void report_tag_fault(unsigned long addr, unsigned int esr, > + struct pt_regs *regs) > +{ > + bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; > + > + pr_alert("Memory Tagging Extension Fault in %pS\n", (void *)regs->pc); > + pr_alert(" %s at address %lx\n", is_write ? "Write" : "Read", addr); > + pr_alert(" Pointer tag: [%02x], memory tag: [%02x]\n", > + mte_get_ptr_tag(addr), > + mte_get_mem_tag((void *)addr)); > +} > + > static void __do_kernel_fault(unsigned long addr, unsigned int esr, > struct pt_regs *regs) > { > @@ -641,10 +654,31 @@ static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) > return 0; > } > > +static void do_tag_recovery(unsigned long addr, unsigned int esr, > + struct pt_regs *regs) > +{ > + report_tag_fault(addr, esr, regs); I'd only report this once since we expect it to be disabled lazily on the other CPUs (i.e. just use a "static bool reported" to keep track). > + > + /* > + * Disable Memory Tagging Extension Tag Checking on the local CPU Too verbose, just say MTE tag checking, people reading this code should have learnt already what MTE stands for ;). > + * for the current EL. > + * It will be done lazily on the other CPUs when they will hit a > + * tag fault. > + */ > + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_NONE); > + isb(); > +} > + > + > static int do_tag_check_fault(unsigned long addr, unsigned int esr, > struct pt_regs *regs) > { > - do_bad_area(addr, esr, regs); > + /* The tag check fault (TCF) is per TTBR */ > + if (is_ttbr0_addr(addr)) > + do_bad_area(addr, esr, regs); > + else > + do_tag_recovery(addr, esr, regs); This part looks fine now. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel