From nobody Fri Apr 10 21:59:26 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAD8CC00140 for ; Wed, 24 Aug 2022 16:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238403AbiHXQOC (ORCPT ); Wed, 24 Aug 2022 12:14:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238822AbiHXQNt (ORCPT ); Wed, 24 Aug 2022 12:13:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84D538E9BA for ; Wed, 24 Aug 2022 09:13:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1661357623; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jFR3xFdwN9i2Cd3/9jTqWPHspBtbjbbUfilDsWbGEig=; b=Xq4cCVDYeP31u+xoCr4H9NyyiFotZ5t2i7uVWfvqIUeNxIU36vlsJJo9XMKhKoWiByflTk 0CfFzu0hA/VQOLIIcDxP0mmeQoiOYBLbVJq9ab3iVbljrBbqoI4dbJML6rquVgSfOIE6Ct HjnM7w9ZjgM14YOav2ei3nLsmrLObPg= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-516-BuJMf8aHNU6RR_udWq3BGg-1; Wed, 24 Aug 2022 12:13:42 -0400 X-MC-Unique: BuJMf8aHNU6RR_udWq3BGg-1 Received: by mail-ej1-f71.google.com with SMTP id hr32-20020a1709073fa000b00730a39f36ddso5306485ejc.5 for ; Wed, 24 Aug 2022 09:13:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=jFR3xFdwN9i2Cd3/9jTqWPHspBtbjbbUfilDsWbGEig=; b=dTojdmEaDbqNp3A2i2vflU3+bQ6dt10yQPqRQGMgJmfMN09cMvD5eBeEYGWnpB9nla 7NTGem2KQztG6bpfugbNzQa8O3+Aum8M+BcUmfKj4J4Nzw5dQ87SuNn1PDQgFc/rqoLA htYqkG9e/v9VoXXLgXiVF4Z2P3ailzrWO0Zv19l7tIR09Z0fKa43+P1QvSlnF/doJfsM ypRw9DIYvR8nO2gL71oBaZL862tWrDnr5nJbxmfQ0M8vlaO3clvjt/Cscu1rJNEyQnPW A6vg7kIjGRDa0S+9DnIU6Y52yTtK8aBo033pUXyW83OBWZaX0vjvHspjU5aleKdyAXzG QZaA== X-Gm-Message-State: ACgBeo2Cr2YCk3bejPXJrqcBRKX0WHobeMZK8BIeBuTbrzDEQx2M9pie ih8nrjmaUueoa6Uz8uQyoQv9tSTID0xZmnSKEdJFUVLxORE+ee9PEAQwoYhPYp1z9baqbVdSUU4 no8CiZ1hWoljeuL7bypWMyNky X-Received: by 2002:a17:906:dc90:b0:73d:670d:5975 with SMTP id cs16-20020a170906dc9000b0073d670d5975mr3262122ejc.515.1661357620171; Wed, 24 Aug 2022 09:13:40 -0700 (PDT) X-Google-Smtp-Source: AA6agR4uS8NKqFvOYpGt5/IICUeLEiPTWIJ6o1anfDey5Pn39rH290LhaS+49A2XCUc3biABKcqT4A== X-Received: by 2002:a17:906:dc90:b0:73d:670d:5975 with SMTP id cs16-20020a170906dc9000b0073d670d5975mr3262109ejc.515.1661357620000; Wed, 24 Aug 2022 09:13:40 -0700 (PDT) Received: from pollux.redhat.com ([2a02:810d:4b40:2ee8:642:1aff:fe31:a15c]) by smtp.gmail.com with ESMTPSA id j2-20020a170906410200b007308bdef04bsm1359102ejk.103.2022.08.24.09.13.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Aug 2022 09:13:39 -0700 (PDT) From: Danilo Krummrich To: daniel@ffwll.ch, airlied@linux.ie, tzimmermann@suse.de, mripard@kernel.org Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Danilo Krummrich Subject: [PATCH drm-misc-next v3 3/4] drm/vc4: crtc: protect device resources after removal Date: Wed, 24 Aug 2022 18:13:26 +0200 Message-Id: <20220824161327.330627-4-dakr@redhat.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220824161327.330627-1-dakr@redhat.com> References: <20220824161327.330627-1-dakr@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" (Hardware) resources which are bound to the driver and device lifecycle must not be accessed after the device and driver are unbound. However, the DRM device isn't freed as long as the last user closed it, hence userspace can still call into the driver. Therefore protect the critical sections which are accessing those resources with drm_dev_enter() and drm_dev_exit(). Fixes: 7cc4214c27cf ("drm/vc4: crtc: Switch to drmm_kzalloc") Signed-off-by: Danilo Krummrich --- drivers/gpu/drm/vc4/vc4_crtc.c | 41 +++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c index 2def6e2ad6f0..0108613e79d5 100644 --- a/drivers/gpu/drm/vc4/vc4_crtc.c +++ b/drivers/gpu/drm/vc4/vc4_crtc.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -295,10 +296,17 @@ struct drm_encoder *vc4_get_crtc_encoder(struct drm_c= rtc *crtc, static void vc4_crtc_pixelvalve_reset(struct drm_crtc *crtc) { struct vc4_crtc *vc4_crtc =3D to_vc4_crtc(crtc); + struct drm_device *dev =3D crtc->dev; + int idx; + + if (!drm_dev_enter(dev, &idx)) + return; =20 /* The PV needs to be disabled before it can be flushed */ CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN); CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) | PV_CONTROL_FIFO_CLR); + + drm_dev_exit(idx); } =20 static void vc4_crtc_config_pv(struct drm_crtc *crtc, struct drm_encoder *= encoder, @@ -321,6 +329,10 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc, = struct drm_encoder *encode u32 format =3D is_dsi1 ? PV_CONTROL_FORMAT_DSIV_24 : PV_CONTROL_FORMAT_24; u8 ppc =3D pv_data->pixels_per_clock; bool debug_dump_regs =3D false; + int idx; + + if (!drm_dev_enter(dev, &idx)) + return; =20 if (debug_dump_regs) { struct drm_printer p =3D drm_info_printer(&vc4_crtc->pdev->dev); @@ -410,6 +422,8 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc, s= truct drm_encoder *encode drm_crtc_index(crtc)); drm_print_regset32(&p, &vc4_crtc->regset); } + + drm_dev_exit(idx); } =20 static void require_hvs_enabled(struct drm_device *dev) @@ -430,7 +444,10 @@ static int vc4_crtc_disable(struct drm_crtc *crtc, struct vc4_crtc *vc4_crtc =3D to_vc4_crtc(crtc); struct drm_device *dev =3D crtc->dev; struct vc4_dev *vc4 =3D to_vc4_dev(dev); - int ret; + int idx, ret; + + if (!drm_dev_enter(dev, &idx)) + return -ENODEV; =20 CRTC_WRITE(PV_V_CONTROL, CRTC_READ(PV_V_CONTROL) & ~PV_VCONTROL_VIDEN); @@ -464,6 +481,8 @@ static int vc4_crtc_disable(struct drm_crtc *crtc, if (vc4_encoder && vc4_encoder->post_crtc_powerdown) vc4_encoder->post_crtc_powerdown(encoder, state); =20 + drm_dev_exit(idx); + return 0; } =20 @@ -588,10 +607,14 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *c= rtc, struct vc4_crtc *vc4_crtc =3D to_vc4_crtc(crtc); struct drm_encoder *encoder =3D vc4_get_crtc_encoder(crtc, new_state); struct vc4_encoder *vc4_encoder =3D to_vc4_encoder(encoder); + int idx; =20 drm_dbg(dev, "Enabling CRTC %s (%u) connected to Encoder %s (%u)", crtc->name, crtc->base.id, encoder->name, encoder->base.id); =20 + if (!drm_dev_enter(dev, &idx)) + return; + require_hvs_enabled(dev); =20 /* Enable vblank irq handling before crtc is started otherwise @@ -619,6 +642,8 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crt= c, =20 if (vc4_encoder->post_crtc_enable) vc4_encoder->post_crtc_enable(encoder, state); + + drm_dev_exit(idx); } =20 static enum drm_mode_status vc4_crtc_mode_valid(struct drm_crtc *crtc, @@ -711,17 +736,31 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crt= c, static int vc4_enable_vblank(struct drm_crtc *crtc) { struct vc4_crtc *vc4_crtc =3D to_vc4_crtc(crtc); + struct drm_device *dev =3D crtc->dev; + int idx; + + if (!drm_dev_enter(dev, &idx)) + return -ENODEV; =20 CRTC_WRITE(PV_INTEN, PV_INT_VFP_START); =20 + drm_dev_exit(idx); + return 0; } =20 static void vc4_disable_vblank(struct drm_crtc *crtc) { struct vc4_crtc *vc4_crtc =3D to_vc4_crtc(crtc); + struct drm_device *dev =3D crtc->dev; + int idx; + + if (!drm_dev_enter(dev, &idx)) + return; =20 CRTC_WRITE(PV_INTEN, 0); + + drm_dev_exit(idx); } =20 static void vc4_crtc_handle_page_flip(struct vc4_crtc *vc4_crtc) --=20 2.37.2