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=-18.8 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, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 84E79C433E0 for ; Thu, 25 Feb 2021 10:16:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 423A964F0C for ; Thu, 25 Feb 2021 10:16:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233743AbhBYKQR (ORCPT ); Thu, 25 Feb 2021 05:16:17 -0500 Received: from mail.kernel.org ([198.145.29.99]:35148 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233541AbhBYJ7g (ORCPT ); Thu, 25 Feb 2021 04:59:36 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B570264F1F; Thu, 25 Feb 2021 09:55:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614246926; bh=gZ+N1I5HIHR1YRe2mHJvMFBSNe9GgX/g1+pp2iLjckw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jfaYBUnMvjfWX5781owUJg6hAOF1KxN1co3Ocv2F6dPgNWMcQ0lh6lWTw9oxqO5Rm ivEmn0dKU9CNvkXYL55BmUOaLaTkTmgsG08L82U3V49Zap9/qrTKj5hJqs3MRAfG8+ 6WrwWGJ8/iiTfKQMztdxn8Ul3YY+VUtXIEJXH1RU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Quanyang Wang , Daniel Vetter , Sasha Levin Subject: [PATCH 5.10 18/23] drm/xlnx: fix kmemleak by sending vblank_event in atomic_disable Date: Thu, 25 Feb 2021 10:53:49 +0100 Message-Id: <20210225092517.401977784@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210225092516.531932232@linuxfoundation.org> References: <20210225092516.531932232@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Quanyang Wang [ Upstream commit a7e02f7796c163ac8297b30223bf24bade9f8a50 ] When running xrandr to change resolution of DP, the kmemleak as below can be observed: unreferenced object 0xffff00080a351000 (size 256): comm "Xorg", pid 248, jiffies 4294899614 (age 19.960s) hex dump (first 32 bytes): 98 a0 bc 01 08 00 ff ff 01 00 00 00 00 00 00 00 ................ ff ff ff ff 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000e0bd0f69>] kmemleak_alloc+0x30/0x40 [<00000000cde2f318>] kmem_cache_alloc+0x3d4/0x588 [<0000000088ea9bd7>] drm_atomic_helper_setup_commit+0x84/0x5f8 [<000000002290a264>] drm_atomic_helper_commit+0x58/0x388 [<00000000f6ea78c3>] drm_atomic_commit+0x4c/0x60 [<00000000c8e0725e>] drm_atomic_connector_commit_dpms+0xe8/0x110 [<0000000020ade187>] drm_mode_obj_set_property_ioctl+0x1b0/0x450 [<00000000918206d6>] drm_connector_property_set_ioctl+0x3c/0x68 [<000000008d51e7a5>] drm_ioctl_kernel+0xc4/0x118 [<000000002a819b75>] drm_ioctl+0x214/0x448 [<000000008ca4e588>] __arm64_sys_ioctl+0xa8/0xf0 [<0000000034e15a35>] el0_svc_common.constprop.0+0x74/0x190 [<000000001b93d916>] do_el0_svc+0x24/0x90 [<00000000ce9230e0>] el0_svc+0x14/0x20 [<00000000e3607d82>] el0_sync_handler+0xb0/0xb8 [<000000003e79c15f>] el0_sync+0x174/0x180 This is because there is a scenario that a drm_crtc_commit commit is allocated but not freed. The drm subsystem require/release references to a CRTC commit by calling drm_crtc_commit_get/put, and when drm_crtc_commit_put find that commit.ref.refcount is zero, it will call __drm_crtc_commit_free to free this CRTC commit. Among these drm_crtc_commit_get/put pairs, there is a drm_crtc_commit_get in drm_atomic_helper_setup_commit as below: ... new_crtc_state->event->base.completion = &commit->flip_done; new_crtc_state->event->base.completion_release = release_crtc_commit; drm_crtc_commit_get(commit); ... This reference to the CRTC commit should be released at the function release_crtc_commit by calling e->completion_release(e->completion) in drm_send_event_locked. So we need to call drm_send_event_locked at two places: handling vblank event in the irq handler and the crtc disable helper. But in zynqmp_disp_crtc_atomic_disable, it only marks the flip is done and not call drm_crtc_commit_put. This result that the refcount of this commit is always non-zero and this commit will never be freed. Since the function drm_crtc_send_vblank_event has operations both sending a flip_done signal and releasing reference to the CRTC commit, let's use it instead. Signed-off-by: Quanyang Wang Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210202064121.173362-1-quanyang.wang@windriver.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/xlnx/zynqmp_disp.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/xlnx/zynqmp_disp.c b/drivers/gpu/drm/xlnx/zynqmp_disp.c index 98bd48f13fd11..8cd8af35cfaac 100644 --- a/drivers/gpu/drm/xlnx/zynqmp_disp.c +++ b/drivers/gpu/drm/xlnx/zynqmp_disp.c @@ -1398,19 +1398,11 @@ static void zynqmp_disp_enable(struct zynqmp_disp *disp) */ static void zynqmp_disp_disable(struct zynqmp_disp *disp) { - struct drm_crtc *crtc = &disp->crtc; - zynqmp_disp_audio_disable(&disp->audio); zynqmp_disp_avbuf_disable_audio(&disp->avbuf); zynqmp_disp_avbuf_disable_channels(&disp->avbuf); zynqmp_disp_avbuf_disable(&disp->avbuf); - - /* Mark the flip is done as crtc is disabled anyway */ - if (crtc->state->event) { - complete_all(crtc->state->event->base.completion); - crtc->state->event = NULL; - } } static inline struct zynqmp_disp *crtc_to_disp(struct drm_crtc *crtc) @@ -1499,6 +1491,13 @@ zynqmp_disp_crtc_atomic_disable(struct drm_crtc *crtc, drm_crtc_vblank_off(&disp->crtc); + spin_lock_irq(&crtc->dev->event_lock); + if (crtc->state->event) { + drm_crtc_send_vblank_event(crtc, crtc->state->event); + crtc->state->event = NULL; + } + spin_unlock_irq(&crtc->dev->event_lock); + clk_disable_unprepare(disp->pclk); pm_runtime_put_sync(disp->dev); } -- 2.27.0