From patchwork Fri Jan 25 15:03:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Noralf_Tr=C3=B8nnes?= X-Patchwork-Id: 10781515 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 348F613BF for ; Fri, 25 Jan 2019 15:03:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 144792F9EC for ; Fri, 25 Jan 2019 15:03:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 084D42F9FB; Fri, 25 Jan 2019 15:03:18 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 71CA02F9EC for ; Fri, 25 Jan 2019 15:03:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 551446E611; Fri, 25 Jan 2019 15:03:15 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp.domeneshop.no (smtp.domeneshop.no [IPv6:2a01:5b40:0:3005::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 61C086E611 for ; Fri, 25 Jan 2019 15:03:14 +0000 (UTC) Received: from 211.81-166-168.customer.lyse.net ([81.166.168.211]:41974 helo=localhost.localdomain) by smtp.domeneshop.no with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.84_2) (envelope-from ) id 1gn30i-00009x-8r; Fri, 25 Jan 2019 16:03:12 +0100 From: =?utf-8?q?Noralf_Tr=C3=B8nnes?= To: dri-devel@lists.freedesktop.org Subject: [PATCH] drm/fb-helper: generic: Fix drm_fbdev_client_restore() Date: Fri, 25 Jan 2019 16:03:00 +0100 Message-Id: <20190125150300.33268-1-noralf@tronnes.org> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stable@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP If fbdev setup has failed, lastclose will give a NULL pointer deref: [ 77.794295] [drm:drm_lastclose] [ 77.794414] [drm:drm_lastclose] driver lastclose completed [ 77.794660] Unable to handle kernel NULL pointer dereference at virtual address 00000014 [ 77.809460] pgd = b376b71b [ 77.818275] [00000014] *pgd=175ba831, *pte=00000000, *ppte=00000000 [ 77.830813] Internal error: Oops: 17 [#1] ARM [ 77.840963] Modules linked in: mi0283qt mipi_dbi tinydrm raspberrypi_hwmon gpio_backlight backlight snd_bcm2835(C) bcm2835_rng rng_core [ 77.865203] CPU: 0 PID: 527 Comm: lt-modetest Tainted: G C 5.0.0-rc1+ #1 [ 77.879525] Hardware name: BCM2835 [ 77.889185] PC is at restore_fbdev_mode+0x20/0x164 [ 77.900261] LR is at drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0x9c [ 78.002446] Process lt-modetest (pid: 527, stack limit = 0x7a3d5c14) [ 78.291030] Backtrace: [ 78.300815] [] (restore_fbdev_mode) from [] (drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0x9c) [ 78.319095] r9:d8a8a288 r8:d891acf0 r7:d7697910 r6:00000000 r5:d891ac00 r4:d891ac00 [ 78.334432] [] (drm_fb_helper_restore_fbdev_mode_unlocked) from [] (drm_fbdev_client_restore+0x18/0x20) [ 78.353296] r8:d76978c0 r7:d7697910 r6:d7697950 r5:d7697800 r4:d891ac00 r3:c04f47d0 [ 78.368689] [] (drm_fbdev_client_restore) from [] (drm_client_dev_restore+0x7c/0xc0) [ 78.385982] [] (drm_client_dev_restore) from [] (drm_lastclose+0xc4/0xd4) [ 78.402332] r8:d76978c0 r7:d7471080 r6:c0e0c088 r5:d8a85e00 r4:d7697800 [ 78.416688] [] (drm_lastclose) from [] (drm_release+0xa8/0x10c) [ 78.431929] r5:d8a85e00 r4:d7697800 [ 78.442989] [] (drm_release) from [] (__fput+0x104/0x1c8) [ 78.457740] r8:d5ccea10 r7:d96cfb10 r6:00000008 r5:d74c1b90 r4:d8a8a280 [ 78.472043] [] (__fput) from [] (____fput+0x18/0x1c) [ 78.486363] r10:00000006 r9:d7722000 r8:c01011c4 r7:00000000 r6:c0ebac6c r5:d892a340 [ 78.501869] r4:d8a8a280 [ 78.512002] [] (____fput) from [] (task_work_run+0x98/0xac) [ 78.527186] [] (task_work_run) from [] (do_work_pending+0x4f8/0x570) [ 78.543238] r7:d7722030 r6:00000004 r5:d7723fb0 r4:00000000 [ 78.556825] [] (do_work_pending) from [] (slow_work_pending+0xc/0x20) [ 78.674256] ---[ end trace 70d3a60cf739be3b ]--- Fix by using drm_fb_helper_lastclose() which checks if fbdev is in use. Fixes: 9060d7f49376 ("drm/fb-helper: Finish the generic fbdev emulation") Cc: stable@vger.kernel.org Signed-off-by: Noralf Trønnes Reviewed-by: Gerd Hoffmann --- drivers/gpu/drm/drm_fb_helper.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 31fcf94bf825..c5c79986f9c5 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -3185,9 +3185,7 @@ static void drm_fbdev_client_unregister(struct drm_client_dev *client) static int drm_fbdev_client_restore(struct drm_client_dev *client) { - struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); - - drm_fb_helper_restore_fbdev_mode_unlocked(fb_helper); + drm_fb_helper_lastclose(client->dev); return 0; }