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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 B3BFEC49ED7 for ; Fri, 20 Sep 2019 14:37:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94D2620B7C for ; Fri, 20 Sep 2019 14:37:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392784AbfITOhc (ORCPT ); Fri, 20 Sep 2019 10:37:32 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35788 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388031AbfITOZA (ORCPT ); Fri, 20 Sep 2019 10:25:00 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqE-0004x6-1e; Fri, 20 Sep 2019 15:24:58 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqC-0007qo-UQ; Fri, 20 Sep 2019 15:24:56 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "John Garry" , "Kefeng Wang" , "Guenter Roeck" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 028/132] hwmon: (f71805f) Use request_muxed_region for Super-IO accesses In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guenter Roeck commit 73e6ff71a7ea924fb7121d576a2d41e3be3fc6b5 upstream. Super-IO accesses may fail on a system with no or unmapped LPC bus. Unable to handle kernel paging request at virtual address ffffffbffee0002e pgd = ffffffc1d68d4000 [ffffffbffee0002e] *pgd=0000000000000000, *pud=0000000000000000 Internal error: Oops: 94000046 [#1] PREEMPT SMP Modules linked in: f71805f(+) hwmon CPU: 3 PID: 1659 Comm: insmod Not tainted 4.5.0+ #88 Hardware name: linux,dummy-virt (DT) task: ffffffc1f6665400 ti: ffffffc1d6418000 task.ti: ffffffc1d6418000 PC is at f71805f_find+0x6c/0x358 [f71805f] Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: e53004e20a58e ("hwmon: New f71805f driver") Reported-by: Kefeng Wang Reported-by: John Garry Cc: John Garry Acked-by: John Garry Signed-off-by: Guenter Roeck Signed-off-by: Ben Hutchings --- drivers/hwmon/f71805f.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) --- a/drivers/hwmon/f71805f.c +++ b/drivers/hwmon/f71805f.c @@ -96,17 +96,23 @@ superio_select(int base, int ld) outb(ld, base + 1); } -static inline void +static inline int superio_enter(int base) { + if (!request_muxed_region(base, 2, DRVNAME)) + return -EBUSY; + outb(0x87, base); outb(0x87, base); + + return 0; } static inline void superio_exit(int base) { outb(0xaa, base); + release_region(base, 2); } /* @@ -1562,7 +1568,7 @@ exit: static int __init f71805f_find(int sioaddr, unsigned short *address, struct f71805f_sio_data *sio_data) { - int err = -ENODEV; + int err; u16 devid; static const char * const names[] = { @@ -1570,8 +1576,11 @@ static int __init f71805f_find(int sioad "F71872F/FG or F71806F/FG", }; - superio_enter(sioaddr); + err = superio_enter(sioaddr); + if (err) + return err; + err = -ENODEV; devid = superio_inw(sioaddr, SIO_REG_MANID); if (devid != SIO_FINTEK_ID) goto exit;