From patchwork Wed May 3 15:37:46 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Kristina_Mart=C5=A1enko?= X-Patchwork-Id: 9710041 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9A19860351 for ; Wed, 3 May 2017 15:59:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8B29C28662 for ; Wed, 3 May 2017 15:59:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E5EA28667; Wed, 3 May 2017 15:59:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 0374D28662 for ; Wed, 3 May 2017 15:59:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=sMdh9sPp8WlmpEuBrGHO5x1dCf5SJU22bAxoeoXmSDk=; b=MVOF4/Vf69zeyrqMnnNpNEIhl+ VQMeC/G16OF+3XNAsAZ8rODO4De/kZmVs4+d08uUnZA7DL6rs/tnhft4ho7QnNtQ6UrVddvXyFFnt 0hLn4lQh0ny6mku3M0W839Ghr6stcOYJyC/QqmTV2HD9R1TiAEHD0QtTiNGMdwAVIukQp/5HzdoJL PDbf48Rh2a65VjojYLRDaZONJI3Nx9WkW19YWbZYI7l9Gbinf/SIXP85q4c5srfuXfJ3Cs5+lqcnV hRVLNeKNCi8W9w9WgVjEQbbDkdV5HtWnX55uyCsWVumf54ChZjLuMEvyWcMRQx9jhYV08Car0SSwq MJF+0oZA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1d5wg4-0005N6-NX; Wed, 03 May 2017 15:58:56 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1d5wfY-0004UN-7m for linux-arm-kernel@bombadil.infradead.org; Wed, 03 May 2017 15:58:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5GS8iFpD4UauqWAwYQeRFkycpv3aRs0MIi0i5EyZ0Rs=; b=wXBb+Vc2rMuD1wDlMqdkgtZUA EH/6k/MKscK8wc462TxPe7fQYtrODqrfVzLIWhHIGLbMPudJtNvsJh4DSr0xrx+VUzsel7HrAq/Hr bhd5kPe28tPHB5ktrai09J7ZaUpgyqqbPPcw9i6LMS/a5DLN8xHoBnyKhN1XqMY1uPlm8E8nZQDWZ qjVoTByCpqiOarO7Gv6mjLdIn2Ow7yGjxvyj80japJJCRLC9uVxMk7dx8JfaU5uDyyjUi7bEScrG1 Lprm0XAT2UmnWc+zJ8OKTJ7aCbbEg8Dh/m+i42PrefNZOj02tZIbjjQUT+1VeGM1wbQCmJAtFRqGl rBUE/VMDA==; Received: from foss.arm.com ([217.140.101.70]) by merlin.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1d5wMz-0005jm-Ly for linux-arm-kernel@lists.infradead.org; Wed, 03 May 2017 15:39:14 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BA5401509; Wed, 3 May 2017 08:38:24 -0700 (PDT) Received: from moonbear.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 95DF93F3E1; Wed, 3 May 2017 08:38:23 -0700 (PDT) From: Kristina Martsenko To: Will Deacon , Catalin Marinas Subject: [PATCH v2 2/4] arm64: hw_breakpoint: fix watchpoint matching for tagged pointers Date: Wed, 3 May 2017 16:37:46 +0100 Message-Id: <1493825868-30872-3-git-send-email-kristina.martsenko@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1493825868-30872-1-git-send-email-kristina.martsenko@arm.com> References: <1493825868-30872-1-git-send-email-kristina.martsenko@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170503_113913_838500_8BB5E58E X-CRM114-Status: GOOD ( 14.05 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Andre Przywara , Dave Martin , linux-arm-kernel@lists.infradead.org, Marc Zyngier MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP When we take a watchpoint exception, the address that triggered the watchpoint is found in FAR_EL1. We compare it to the address of each configured watchpoint to see which one was hit. The configured watchpoint addresses are untagged, while the address in FAR_EL1 will have an address tag if the data access was done using a tagged address. The tag needs to be removed to compare the address to the watchpoints. Currently we don't remove it, and as a result can report the wrong watchpoint as being hit (specifically, always either the highest TTBR0 watchpoint or lowest TTBR1 watchpoint). This patch removes the tag. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Signed-off-by: Kristina Martsenko Acked-by: Mark Rutland --- arch/arm64/include/asm/uaccess.h | 6 +++--- arch/arm64/kernel/hw_breakpoint.c | 3 +++ 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 5308d696311b..0221029e27ff 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -106,9 +106,9 @@ static inline void set_fs(mm_segment_t fs) }) /* - * When dealing with data aborts or instruction traps we may end up with - * a tagged userland pointer. Clear the tag to get a sane pointer to pass - * on to access_ok(), for instance. + * When dealing with data aborts, watchpoints, or instruction traps we may end + * up with a tagged userland pointer. Clear the tag to get a sane pointer to + * pass on to access_ok(), for instance. */ #define untagged_addr(addr) sign_extend64(addr, 55) diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index 0296e7924240..749f81779420 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -36,6 +36,7 @@ #include #include #include +#include /* Breakpoint currently in use for each BRP. */ static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[ARM_MAX_BRP]); @@ -721,6 +722,8 @@ static u64 get_distance_from_watchpoint(unsigned long addr, u64 val, u64 wp_low, wp_high; u32 lens, lene; + addr = untagged_addr(addr); + lens = __ffs(ctrl->len); lene = __fls(ctrl->len);