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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 7399EC76188 for ; Fri, 19 Jul 2019 04:08:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D8D8218CA for ; Fri, 19 Jul 2019 04:08:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509304; bh=U0e1hfcszPJLc7pIVa6axSW23a8D+Vk7pOBpIP1Z8SI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FRNzFPJCGgXPwAV/kZY4hVIQ2TpRnIbI+VRW423pK3NrB8tMfsutpayV2CbZ6fzYR Cg4i8FuS7rq21ECyJyIEfmDXgg0LWiuj+rytti6wodn7cdzvP7HjuiI2NVVi8l9y1I 1awfIfjVV6JDbg+h7eXnKToJwFpjG7GDMKol1tLU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733056AbfGSEIW (ORCPT ); Fri, 19 Jul 2019 00:08:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:42442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732970AbfGSEIP (ORCPT ); Fri, 19 Jul 2019 00:08:15 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BFBCE2082E; Fri, 19 Jul 2019 04:08:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563509294; bh=U0e1hfcszPJLc7pIVa6axSW23a8D+Vk7pOBpIP1Z8SI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xgTde1aWedT764FgkoMqkmzAH6DrMpZQYGfBK+abI9gV+aZ16tjzoX1sqAMb2GsuV UWCREZtuPcAsrEZoSRkEe3osGLRHgPtmW1V+NWWf22YXgD+LNBrhEtQ1wCidfenXgi UlIKt5OqBYcl+Wp3CtMUT2QBmOmRgkwh1LpjlLeo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Daniel Vetter , Rodrigo Siqueira , Tomeu Vizoso , Emil Velikov , Benjamin Gaignard , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Daniel Vetter , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.19 020/101] drm/crc-debugfs: User irqsafe spinlock in drm_crtc_add_crc_entry Date: Fri, 19 Jul 2019 00:06:11 -0400 Message-Id: <20190719040732.17285-20-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190719040732.17285-1-sashal@kernel.org> References: <20190719040732.17285-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Vetter [ Upstream commit 1882018a70e06376234133e69ede9dd743b4dbd9 ] We can be called from any context, we need to be prepared. Noticed this while hacking on vkms, which calls this function from a normal worker. Which really upsets lockdep. Cc: Rodrigo Siqueira Cc: Tomeu Vizoso Cc: Emil Velikov Cc: Benjamin Gaignard Reviewed-by: Benjamin Gaignard Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20190605194556.16744-1-daniel.vetter@ffwll.ch Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_debugfs_crc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index 99961192bf03..a334a82fcb36 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -379,8 +379,9 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, struct drm_crtc_crc *crc = &crtc->crc; struct drm_crtc_crc_entry *entry; int head, tail; + unsigned long flags; - spin_lock(&crc->lock); + spin_lock_irqsave(&crc->lock, flags); /* Caller may not have noticed yet that userspace has stopped reading */ if (!crc->entries) { @@ -411,7 +412,7 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1); crc->head = head; - spin_unlock(&crc->lock); + spin_unlock_irqrestore(&crc->lock, flags); wake_up_interruptible(&crc->wq); -- 2.20.1