From patchwork Mon Jul 19 14:55:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 480378 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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 74385C6377E for ; Mon, 19 Jul 2021 16:36:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58A7B613AE for ; Mon, 19 Jul 2021 16:36:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348682AbhGSPz2 (ORCPT ); Mon, 19 Jul 2021 11:55:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:49524 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350520AbhGSPvI (ORCPT ); Mon, 19 Jul 2021 11:51:08 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id CE3B76127C; Mon, 19 Jul 2021 16:29:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626712200; bh=wrAXyTUu8iaEYGFgf4AL1J9lnFaFjPOR7mr8+BQtH7s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ool7iYE8MI6vCsqKD1V8BZenb5SApiqTe3S6TYs55vie7p2yIPZvZSekUmrfJBP/T HA/1iGuHAWqI3dFXdAczA6lYi/vOSDgLqMCPg+jCnSy2WNAtTOVfucQmOumH4v88YP nIF7uzvd81EQzcDLcVaocCcIccL9LE47tyE+T9io= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?q?Martin_F=C3=A4cknitz?= , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.12 288/292] MIPS: vdso: Invalid GIC access through VDSO Date: Mon, 19 Jul 2021 16:55:50 +0200 Message-Id: <20210719144952.387046837@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144942.514164272@linuxfoundation.org> References: <20210719144942.514164272@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Martin Fäcknitz [ Upstream commit 47ce8527fbba145a7723685bc9a27d9855e06491 ] Accessing raw timers (currently only CLOCK_MONOTONIC_RAW) through VDSO doesn't return the correct time when using the GIC as clock source. The address of the GIC mapped page is in this case not calculated correctly. The GIC mapped page is calculated from the VDSO data by subtracting PAGE_SIZE: void *get_gic(const struct vdso_data *data) { return (void __iomem *)data - PAGE_SIZE; } However, the data pointer is not page aligned for raw clock sources. This is because the VDSO data for raw clock sources (CS_RAW = 1) is stored after the VDSO data for coarse clock sources (CS_HRES_COARSE = 0). Therefore, only the VDSO data for CS_HRES_COARSE is page aligned: +--------------------+ | | | vd[CS_RAW] | ---+ | vd[CS_HRES_COARSE] | | +--------------------+ | -PAGE_SIZE | | | | GIC mapped page | <--+ | | +--------------------+ When __arch_get_hw_counter() is called with &vd[CS_RAW], get_gic returns the wrong address (somewhere inside the GIC mapped page). The GIC counter values are not returned which results in an invalid time. Fixes: a7f4df4e21dd ("MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()") Signed-off-by: Martin Fäcknitz Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/include/asm/vdso/vdso.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/include/asm/vdso/vdso.h b/arch/mips/include/asm/vdso/vdso.h index 737ddfc3411c..a327ca21270e 100644 --- a/arch/mips/include/asm/vdso/vdso.h +++ b/arch/mips/include/asm/vdso/vdso.h @@ -67,7 +67,7 @@ static inline const struct vdso_data *get_vdso_data(void) static inline void __iomem *get_gic(const struct vdso_data *data) { - return (void __iomem *)data - PAGE_SIZE; + return (void __iomem *)((unsigned long)data & PAGE_MASK) - PAGE_SIZE; } #endif /* CONFIG_CLKSRC_MIPS_GIC */