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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 8953FC433DF for ; Wed, 17 Jun 2020 09:53:19 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 658552078D for ; Wed, 17 Jun 2020 09:53:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 658552078D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D8AB46E5BE; Wed, 17 Jun 2020 09:53:18 +0000 (UTC) Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8B779898EA for ; Wed, 17 Jun 2020 09:53:17 +0000 (UTC) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=localhost) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1jlUks-0003EN-LW; Wed, 17 Jun 2020 11:53:14 +0200 Message-ID: Subject: Re: [PATCH v2] drm/etnaviv: fix ref count leak via pm_runtime_get_sync From: Lucas Stach To: Navid Emamdoost , Russell King , Christian Gmeiner , David Airlie , Daniel Vetter , etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Date: Wed, 17 Jun 2020 11:53:08 +0200 In-Reply-To: <20200615061220.68711-1-navid.emamdoost@gmail.com> References: <20200615061220.68711-1-navid.emamdoost@gmail.com> User-Agent: Evolution 3.36.2 (3.36.2-1.fc32) MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mccamant@cs.umn.edu, andy.shevchenko@gmail.com, emamd001@umn.edu, kjlu@umn.edu, wu000273@umn.edu Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Navid, Am Montag, den 15.06.2020, 01:12 -0500 schrieb Navid Emamdoost: > in etnaviv_gpu_submit, etnaviv_gpu_recover_hang, etnaviv_gpu_debugfs, > and etnaviv_gpu_init the call to pm_runtime_get_sync increments the > counter even in case of failure, leading to incorrect ref count. > In case of failure, decrement the ref count before returning. While that change is correct with the current API, may I ask the question why the way this API works is considered reasonable? A API call that fails, but still changes internal state and expects the caller to clean up the mess it not really what I would consider fool- proof API design. Is there a specific reason why it is done this way and not handled internally? Regards, Lucas > Signed-off-by: Navid Emamdoost > --- > Changes in v2: > - replace pm_runtime_put with pm_runtime_put_noidle > --- > drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c > index a31eeff2b297..7c9f3f9ba123 100644 > --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c > +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c > @@ -722,7 +722,7 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu) > ret = pm_runtime_get_sync(gpu->dev); > if (ret < 0) { > dev_err(gpu->dev, "Failed to enable GPU power domain\n"); > - return ret; > + goto pm_put; > } > > etnaviv_hw_identify(gpu); > @@ -819,6 +819,7 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu) > > fail: > pm_runtime_mark_last_busy(gpu->dev); > +pm_put: > pm_runtime_put_autosuspend(gpu->dev); > > return ret; > @@ -859,7 +860,7 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m) > > ret = pm_runtime_get_sync(gpu->dev); > if (ret < 0) > - return ret; > + goto pm_put; > > dma_lo = gpu_read(gpu, VIVS_FE_DMA_LOW); > dma_hi = gpu_read(gpu, VIVS_FE_DMA_HIGH); > @@ -1003,6 +1004,7 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m) > ret = 0; > > pm_runtime_mark_last_busy(gpu->dev); > +pm_put: > pm_runtime_put_autosuspend(gpu->dev); > > return ret; > @@ -1016,7 +1018,7 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu) > dev_err(gpu->dev, "recover hung GPU!\n"); > > if (pm_runtime_get_sync(gpu->dev) < 0) > - return; > + goto pm_put; > > mutex_lock(&gpu->lock); > > @@ -1035,6 +1037,7 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu) > > mutex_unlock(&gpu->lock); > pm_runtime_mark_last_busy(gpu->dev); > +pm_put: > pm_runtime_put_autosuspend(gpu->dev); > } > > @@ -1308,8 +1311,10 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit) > > if (!submit->runtime_resumed) { > ret = pm_runtime_get_sync(gpu->dev); > - if (ret < 0) > + if (ret < 0) { > + pm_runtime_put_noidle(gpu->dev); > return NULL; > + } > submit->runtime_resumed = true; > } > > @@ -1326,6 +1331,7 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit) > ret = event_alloc(gpu, nr_events, event); > if (ret) { > DRM_ERROR("no free events\n"); > + pm_runtime_put_noidle(gpu->dev); > return NULL; > } > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel