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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 AB81FC11D3D for ; Thu, 27 Feb 2020 17:44:38 +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 793F0246A3 for ; Thu, 27 Feb 2020 17:44:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 793F0246A3 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 9FFC26ECD7; Thu, 27 Feb 2020 17:44:37 +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 D1DAE6ECD7 for ; Thu, 27 Feb 2020 17:44:35 +0000 (UTC) Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1j7ND5-0003w2-8D; Thu, 27 Feb 2020 18:44:31 +0100 Message-ID: Subject: Re: [PATCH 17/17] drm/imx: fix drm_mode_config_cleanup race condition From: Lucas Stach To: Daniel Vetter , Marco Felsch Date: Thu, 27 Feb 2020 18:44:29 +0100 In-Reply-To: <20200227172923.GY2363188@phenom.ffwll.local> References: <20200227162125.10450-1-m.felsch@pengutronix.de> <20200227162125.10450-18-m.felsch@pengutronix.de> <20200227172923.GY2363188@phenom.ffwll.local> User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a 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: kernel@pengutronix.de, airlied@linux.ie, dri-devel@lists.freedesktop.org, rmk+kernel@armlinux.org.uk, shawnguo@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Daniel, On Do, 2020-02-27 at 18:29 +0100, Daniel Vetter wrote: > On Thu, Feb 27, 2020 at 05:21:25PM +0100, Marco Felsch wrote: > > Currently there is a race conditions if the panel can't be probed e.g. > > it is not connected [1]. There where several attempts to fix this [2,3] > > but non of them made it into mainline. > > > > The problem is the combination of the component framework and the drm > > framework, as Philipp already explained [1]. To fix this we need to > > drop the devres-kmalloc and move the plain kmalloc to let the drm > > framework free the resources upon a drm_mode_config_cleanup(). So we need > > to implement a .destroy() callback for each component. We also need to > > reorder the master.unbind() callback to ensure that the driver states > > are accessible during a component.unbind() call. This reordering also > > aligns the master.unbind() with the error-cleanup path during > > master.bind(). > > > > [1] https://www.spinics.net/lists/dri-devel/msg189388.html > > [2] https://lkml.org/lkml/2018/10/16/1148 > > [3] https://lkml.org/lkml/2019/4/2/612 > > > > Signed-off-by: Marco Felsch > > I think this collides quite badly with my managed drm device resources > patch series I'm working on. Plus once we have that, you could use > drmm_kzalloc and wouldn't need to sprinkle kfree() over everything. > > I think at least, I haven't rolled much further than just getting the > baseline stuff figured out. So if it's not super-pressing to get this > patch here landed I think it'd be better to base this on top of the drmm > series. I'm working on sending out v3, I'll cc you on the imx parts so > you'll get pinged. IMO this part of imx-drm has been broken for far too long already, so we shouldn't delay this fixes series on a complete resource management rework. Regards, Lucas > Cheers, Daniel > > > --- > > drivers/gpu/drm/imx/dw_hdmi-imx.c | 28 ++++++++++++--------- > > drivers/gpu/drm/imx/imx-drm-core.c | 3 ++- > > drivers/gpu/drm/imx/imx-ldb.c | 34 +++++++++++++++++--------- > > drivers/gpu/drm/imx/imx-tve.c | 15 +++++++++--- > > drivers/gpu/drm/imx/ipuv3-crtc.c | 28 ++++++++++++++++++--- > > drivers/gpu/drm/imx/parallel-display.c | 30 ++++++++++++++++------- > > 6 files changed, 96 insertions(+), 42 deletions(-) > > > > diff --git a/drivers/gpu/drm/imx/dw_hdmi-imx.c b/drivers/gpu/drm/imx/dw_hdmi-imx.c > > index f22cfbf9353e..86a62796c151 100644 > > --- a/drivers/gpu/drm/imx/dw_hdmi-imx.c > > +++ b/drivers/gpu/drm/imx/dw_hdmi-imx.c > > @@ -137,6 +137,12 @@ static int dw_hdmi_imx_atomic_check(struct drm_encoder *encoder, > > return 0; > > } > > > > +static void dw_hdmi_imx_encoder_destroy(struct drm_encoder *encoder) > > +{ > > + drm_encoder_cleanup(encoder); > > + kfree(enc_to_imx_hdmi(encoder)); > > +} > > + > > static const struct drm_encoder_helper_funcs dw_hdmi_imx_encoder_helper_funcs = { > > .enable = dw_hdmi_imx_encoder_enable, > > .disable = dw_hdmi_imx_encoder_disable, > > @@ -144,7 +150,7 @@ static const struct drm_encoder_helper_funcs dw_hdmi_imx_encoder_helper_funcs = > > }; > > > > static const struct drm_encoder_funcs dw_hdmi_imx_encoder_funcs = { > > - .destroy = drm_encoder_cleanup, > > + .destroy = dw_hdmi_imx_encoder_destroy, > > }; > > > > static enum drm_mode_status > > @@ -212,7 +218,7 @@ static int dw_hdmi_imx_bind(struct device *dev, struct device *master, > > if (!pdev->dev.of_node) > > return -ENODEV; > > > > - hdmi = devm_kzalloc(&pdev->dev, sizeof(*hdmi), GFP_KERNEL); > > + hdmi = kzalloc(sizeof(*hdmi), GFP_KERNEL); > > if (!hdmi) > > return -ENOMEM; > > > > @@ -228,12 +234,16 @@ static int dw_hdmi_imx_bind(struct device *dev, struct device *master, > > * not been registered yet. Defer probing, and hope that > > * the required CRTC is added later. > > */ > > - if (encoder->possible_crtcs == 0) > > + if (encoder->possible_crtcs == 0) { > > + kfree(hdmi); > > return -EPROBE_DEFER; > > + } > > > > ret = dw_hdmi_imx_parse_dt(hdmi); > > - if (ret < 0) > > + if (ret < 0) { > > + kfree(hdmi); > > return ret; > > + } > > > > drm_encoder_helper_add(encoder, &dw_hdmi_imx_encoder_helper_funcs); > > drm_encoder_init(drm, encoder, &dw_hdmi_imx_encoder_funcs, > > @@ -242,15 +252,9 @@ static int dw_hdmi_imx_bind(struct device *dev, struct device *master, > > platform_set_drvdata(pdev, hdmi); > > > > hdmi->hdmi = dw_hdmi_bind(pdev, encoder, plat_data); > > - > > - /* > > - * If dw_hdmi_bind() fails we'll never call dw_hdmi_unbind(), > > - * which would have called the encoder cleanup. Do it manually. > > - */ > > - if (IS_ERR(hdmi->hdmi)) { > > + /* Don't call kfree() here, this is done by the .destroy() handler. */ > > + if (IS_ERR(hdmi->hdmi)) > > ret = PTR_ERR(hdmi->hdmi); > > - drm_encoder_cleanup(encoder); > > - } > > > > return ret; > > } > > diff --git a/drivers/gpu/drm/imx/imx-drm-core.c b/drivers/gpu/drm/imx/imx-drm-core.c > > index 9979547ca883..feab6eb9e7e5 100644 > > --- a/drivers/gpu/drm/imx/imx-drm-core.c > > +++ b/drivers/gpu/drm/imx/imx-drm-core.c > > @@ -275,9 +275,10 @@ static void imx_drm_unbind(struct device *dev) > > > > drm_kms_helper_poll_fini(drm); > > > > + component_unbind_all(drm->dev, drm); > > + > > drm_mode_config_cleanup(drm); > > > > - component_unbind_all(drm->dev, drm); > > dev_set_drvdata(dev, NULL); > > > > drm_dev_put(drm); > > diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c > > index 5e6c1b09dbfa..4a5d31da592a 100644 > > --- a/drivers/gpu/drm/imx/imx-ldb.c > > +++ b/drivers/gpu/drm/imx/imx-ldb.c > > @@ -140,6 +140,8 @@ static void imx_ldb_connector_destroy(struct drm_connector *connector) > > i2c_put_adapter(imx_ldb_con->ddc); > > /* avoid dangling pointers */ > > imx_ldb_con->ldb_channel = NULL; > > + kfree(imx_ldb_con->edid); > > + kfree(imx_ldb_con); > > } > > > > static int imx_ldb_connector_get_modes(struct drm_connector *connector) > > @@ -184,6 +186,7 @@ static void imx_ldb_encoder_destroy(struct drm_encoder *encoder) > > drm_encoder_cleanup(encoder); > > /* avoid dangling pointers */ > > channel->ldb = NULL; > > + kfree(channel); > > } > > > > static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno, > > @@ -502,9 +505,8 @@ static int imx_ldb_panel_ddc(struct device *dev, > > edidp = of_get_property(child, "edid", > > &connector->edid_len); > > if (edidp) { > > - connector->edid = devm_kmemdup(dev, edidp, > > - connector->edid_len, > > - GFP_KERNEL); > > + connector->edid = kmemdup(edidp, connector->edid_len, > > + GFP_KERNEL); > > } else if (!channel->panel) { > > /* fallback to display-timings node */ > > ret = of_get_drm_display_mode(child, > > @@ -525,7 +527,7 @@ static int imx_ldb_setup_channel(struct device *dev, > > int channel_number) > > { > > struct imx_ldb_channel *channel; > > - struct imx_ldb_connector *imx_ldb_con; > > + struct imx_ldb_connector *imx_ldb_con = NULL; > > struct drm_encoder *encoder; > > struct drm_connector *connector = NULL; > > int bus_format; > > @@ -537,7 +539,7 @@ static int imx_ldb_setup_channel(struct device *dev, > > * 3) Register it with the DRM framework > > * 4) Attach bridge or connector to encoder > > */ > > - channel = devm_kzalloc(dev, sizeof(*channel), GFP_KERNEL); > > + channel = kzalloc(sizeof(*channel), GFP_KERNEL); > > if (!channel) > > return -ENOMEM; > > > > @@ -554,17 +556,19 @@ static int imx_ldb_setup_channel(struct device *dev, > > ldb->lvds_mux ? 4 : 2, 0, > > &channel->panel, &channel->bridge); > > if (ret && ret != -ENODEV) > > - return ret; > > + goto err_free; > > > > /* panel ddc only if there is no bridge */ > > if (!channel->bridge) { > > - imx_ldb_con = devm_kzalloc(dev, sizeof(*connector), GFP_KERNEL); > > - if (!imx_ldb_con) > > - return -ENOMEM; > > + imx_ldb_con = kzalloc(sizeof(*connector), GFP_KERNEL); > > + if (!imx_ldb_con) { > > + ret = -ENOMEM; > > + goto err_free; > > + } > > > > ret = imx_ldb_panel_ddc(dev, channel, imx_ldb_con, child); > > if (ret) > > - return ret; > > + goto err_free; > > > > imx_ldb_con->ldb_channel = channel; > > connector = &imx_ldb_con->connector; > > @@ -628,7 +632,7 @@ static int imx_ldb_setup_channel(struct device *dev, > > ret = drm_bridge_attach(encoder, channel->bridge, NULL); > > if (ret) { > > DRM_ERROR("Failed to initialize bridge with drm\n"); > > - goto err_put_ddc; > > + goto err_out; > > } > > } else { > > drm_connector_attach_encoder(connector, encoder); > > @@ -637,7 +641,7 @@ static int imx_ldb_setup_channel(struct device *dev, > > if (channel->panel) { > > ret = drm_panel_attach(channel->panel, connector); > > if (ret) > > - goto err_put_ddc; > > + goto err_out; > > } > > > > return 0; > > @@ -645,6 +649,12 @@ static int imx_ldb_setup_channel(struct device *dev, > > err_put_ddc: > > if (imx_ldb_con) > > i2c_put_adapter(imx_ldb_con->ddc); > > +err_free: > > + if (imx_ldb_con) > > + kfree(imx_ldb_con->edid); > > + kfree(imx_ldb_con); > > + kfree(channel); > > +err_out: > > return ret; > > } > > > > diff --git a/drivers/gpu/drm/imx/imx-tve.c b/drivers/gpu/drm/imx/imx-tve.c > > index a7a05c47f68b..15ff5f35ff0e 100644 > > --- a/drivers/gpu/drm/imx/imx-tve.c > > +++ b/drivers/gpu/drm/imx/imx-tve.c > > @@ -241,6 +241,7 @@ static void imx_tve_connector_destroy(struct drm_connector *connector) > > i2c_put_adapter(tvec->ddc); > > /* avoid dangling pointers */ > > tvec->tve = NULL; > > + kfree(tvec); > > } > > > > static int imx_tve_connector_get_modes(struct drm_connector *connector) > > @@ -292,6 +293,7 @@ static void imx_tve_encoder_destroy(struct drm_encoder *encoder) > > drm_encoder_cleanup(encoder); > > /* avoid dangling pointers */ > > tvee->tve = NULL; > > + kfree(tvee); > > } > > > > static void imx_tve_encoder_mode_set(struct drm_encoder *encoder, > > @@ -577,13 +579,15 @@ static int imx_tve_bind(struct device *dev, struct device *master, void *data) > > struct imx_tve_connector *tvec; > > int ret; > > > > - tvee = devm_kzalloc(dev, sizeof(*tvee), GFP_KERNEL); > > + tvee = kzalloc(sizeof(*tvee), GFP_KERNEL); > > if (!tvee) > > return -ENOMEM; > > > > - tvec = devm_kzalloc(dev, sizeof(*tvec), GFP_KERNEL); > > - if (!tvec) > > - return -ENOMEM; > > + tvec = kzalloc(sizeof(*tvec), GFP_KERNEL); > > + if (!tvec) { > > + ret = -ENOMEM; > > + goto err_free; > > + } > > > > tvee->tve = imx_tve; > > tvec->tve = imx_tve; > > @@ -602,6 +606,9 @@ static int imx_tve_bind(struct device *dev, struct device *master, void *data) > > > > err_put_ddc: > > i2c_put_adapter(tvec->ddc); > > +err_free: > > + kfree(tvec); > > + kfree(tvee); > > return ret; > > } > > > > diff --git a/drivers/gpu/drm/imx/ipuv3-crtc.c b/drivers/gpu/drm/imx/ipuv3-crtc.c > > index 63c0284f8b3c..2d24677f7fef 100644 > > --- a/drivers/gpu/drm/imx/ipuv3-crtc.c > > +++ b/drivers/gpu/drm/imx/ipuv3-crtc.c > > @@ -105,6 +105,12 @@ static void ipu_crtc_atomic_disable(struct drm_crtc *crtc, > > spin_unlock_irq(&crtc->dev->event_lock); > > } > > > > +static void imx_drm_crtc_destroy(struct drm_crtc *crtc) > > +{ > > + drm_crtc_cleanup(crtc); > > + kfree(to_ipu_crtc(crtc)); > > +} > > + > > static void imx_drm_crtc_reset(struct drm_crtc *crtc) > > { > > struct imx_crtc_state *state; > > @@ -166,7 +172,7 @@ static void ipu_disable_vblank(struct drm_crtc *crtc) > > > > static const struct drm_crtc_funcs ipu_crtc_funcs = { > > .set_config = drm_atomic_helper_set_config, > > - .destroy = drm_crtc_cleanup, > > + .destroy = imx_drm_crtc_destroy, > > .page_flip = drm_atomic_helper_page_flip, > > .reset = imx_drm_crtc_reset, > > .atomic_duplicate_state = imx_drm_crtc_duplicate_state, > > @@ -357,7 +363,8 @@ static int ipu_get_resources(struct ipu_crtc *ipu_crtc, > > } > > > > static int ipu_crtc_init(struct ipu_crtc *ipu_crtc, > > - struct ipu_client_platformdata *pdata, struct drm_device *drm) > > + struct ipu_client_platformdata *pdata, > > + struct drm_device *drm) > > { > > struct ipu_soc *ipu = dev_get_drvdata(ipu_crtc->dev->parent); > > struct drm_crtc *crtc = &ipu_crtc->base; > > @@ -437,10 +444,11 @@ static int ipu_drm_bind(struct device *dev, struct device *master, void *data) > > { > > struct ipu_client_platformdata *pdata = dev->platform_data; > > struct drm_device *drm = data; > > + struct drm_crtc *registered_crtc = NULL; > > struct ipu_crtc *ipu_crtc; > > int ret; > > > > - ipu_crtc = devm_kzalloc(dev, sizeof(*ipu_crtc), GFP_KERNEL); > > + ipu_crtc = kzalloc(sizeof(*ipu_crtc), GFP_KERNEL); > > if (!ipu_crtc) > > return -ENOMEM; > > > > @@ -448,11 +456,23 @@ static int ipu_drm_bind(struct device *dev, struct device *master, void *data) > > > > ret = ipu_crtc_init(ipu_crtc, pdata, drm); > > if (ret) > > - return ret; > > + goto err; > > > > dev_set_drvdata(dev, ipu_crtc); > > > > return 0; > > + > > +err: > > + drm_for_each_crtc(registered_crtc, drm) { > > + /* > > + * The crtc was registered with the drm core framework if we > > + * enter here. So let the core .destroy() helper cleanup the > > + * code. > > + */ > > + return ret; > > + } > > + kfree(ipu_crtc); > > + return ret; > > } > > > > static void ipu_drm_unbind(struct device *dev, struct device *master, > > diff --git a/drivers/gpu/drm/imx/parallel-display.c b/drivers/gpu/drm/imx/parallel-display.c > > index 78703b15c7cf..3e247383a498 100644 > > --- a/drivers/gpu/drm/imx/parallel-display.c > > +++ b/drivers/gpu/drm/imx/parallel-display.c > > @@ -55,6 +55,8 @@ static void imx_pd_connector_destroy(struct drm_connector *connector) > > imx_drm_connector_destroy(connector); > > /* avoid dangling pointer */ > > imxpc->imxpd = NULL; > > + kfree(imxpc->edid); > > + kfree(imxpc); > > } > > > > static int imx_pd_connector_get_modes(struct drm_connector *connector) > > @@ -102,6 +104,7 @@ static void imx_pd_encoder_destroy(struct drm_encoder *encoder) > > if (imxpd->panel) > > drm_panel_detach(imxpd->panel); > > drm_encoder_cleanup(encoder); > > + kfree(imxpd); > > } > > > > static void imx_pd_encoder_enable(struct drm_encoder *encoder) > > @@ -225,31 +228,32 @@ static int imx_pd_bind(struct device *dev, struct device *master, void *data) > > struct device_node *np = dev->of_node; > > const u8 *edidp; > > struct imx_parallel_display *imxpd; > > - struct imx_parallel_connector *imxpc; > > + struct imx_parallel_connector *imxpc = NULL; > > int ret; > > u32 bus_format = 0; > > const char *fmt; > > > > - imxpd = devm_kzalloc(dev, sizeof(*imxpd), GFP_KERNEL); > > + imxpd = kzalloc(sizeof(*imxpd), GFP_KERNEL); > > if (!imxpd) > > return -ENOMEM; > > > > /* port@1 is the output port */ > > ret = drm_of_find_panel_or_bridge(np, 1, 0, &imxpd->panel, &imxpd->bridge); > > if (ret && ret != -ENODEV) > > - return ret; > > + goto err_free; > > > > if (!imxpd->bridge) { > > - imxpc = devm_kzalloc(dev, sizeof(*imxpc), GFP_KERNEL); > > - if (!imxpc) > > - return -ENOMEM; > > + imxpc = kzalloc(sizeof(*imxpc), GFP_KERNEL); > > + if (!imxpc) { > > + ret = -ENOMEM; > > + goto err_free; > > + } > > > > imxpc->imxpd = imxpd; > > > > edidp = of_get_property(np, "edid", &imxpc->edid_len); > > if (edidp) > > - imxpc->edid = devm_kmemdup(dev, edidp, imxpc->edid_len, > > - GFP_KERNEL); > > + imxpc->edid = kmemdup(edidp, imxpc->edid_len, GFP_KERNEL); > > } > > > > ret = of_property_read_string(np, "interface-pix-fmt", &fmt); > > @@ -269,9 +273,17 @@ static int imx_pd_bind(struct device *dev, struct device *master, void *data) > > > > ret = imx_pd_register(drm, imxpd, imxpc); > > if (ret) > > - return ret; > > + goto err_free; > > > > return imx_pd_attach(drm, imxpd, imxpc); > > + > > +err_free: > > + if (imxpc) > > + kfree(imxpc->edid); > > + kfree(imxpc); > > + kfree(imxpd); > > + > > + return ret; > > } > > > > static const struct component_ops imx_pd_ops = { > > -- > > 2.20.1 > > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel