From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3CDA52C80 for ; Thu, 13 Mar 2025 00:54:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741827300; cv=none; b=k1pmQC2/7MV2bGe7jcfp6/jHiQoX96bbGd3eC5eK8PcL6y5mM3X/HfV2HoY2yiUR+hrHC94bTw3dbiVFPqd0zmEfFpsseP5CzJlj6EW9qxO/1jS1U9uE7Z9yohjHICqZ+o/9aIFO8Tqr1RNQpBEAjhOkc0We8LsSnELxab0W+aA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741827300; c=relaxed/simple; bh=prKb1/vsoLZeKMb2AQiT1U6bRaw46DjeGENTzbI5K3Q=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=VxLOGgDrpulV3iyQNaUdZRkxp9+NUQUOA3wvJ6dYwSbcGaFvFJquOUGjYxH7XH10nF9XciAMnkGRr1X/33dcd7Jgzyp2CqyIpOkG+lCYneQVOkjqwk8MX28mCv6ersM0wiecz1HDQkgEkOft214tYOfFsfa9nPl4bBskYc6X9s0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LJjRguAF; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LJjRguAF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1741827298; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=UoaJonu1Ykft8honHbcoNgiIucT+lAcKoBxDQ1EsVIU=; b=LJjRguAFGzyk0tCyNWwqEk0hkX52U5aUXGUoX0FJU19rGy1NvFVtRfIzZkJo8lJFyjF7G+ L3iSEsBBurNwN3bNaOf5c5frez9HSB4evscwUM+0rPdycT611OhnRyRmYZNHqD8PThrbV8 SX7hyqsbUIEiL3/7r/nPmNV6C1SL3Io= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-553-h5hFTB0PNUGrbqzmFZNZCw-1; Wed, 12 Mar 2025 20:54:54 -0400 X-MC-Unique: h5hFTB0PNUGrbqzmFZNZCw-1 X-Mimecast-MFC-AGG-ID: h5hFTB0PNUGrbqzmFZNZCw_1741827293 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8FC76195608B; Thu, 13 Mar 2025 00:54:52 +0000 (UTC) Received: from asrivats-na.rmtustx.csb (unknown [10.2.16.186]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 46C7F1955BCB; Thu, 13 Mar 2025 00:54:49 +0000 (UTC) From: Anusha Srivatsa Subject: [PATCH RFC 0/2] drm/panel: Refcounted panel allocation Date: Wed, 12 Mar 2025 20:54:41 -0400 Message-Id: <20250312-drm-panel-v1-0-e99cd69f6136@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-B4-Tracking: v=1; b=H4sIANEs0mcC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI1MDY0ND3ZSiXN2CxLzUHN1kYyNzS0ujVEtjo1QloPqCotS0zAqwWdFKQW7 OSrG1tQAm2jMqYAAAAA== X-Change-ID: 20250311-drm-panel-c327992e932e To: Neil Armstrong , Jessica Zhang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: Luca Ceresoli , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Anusha Srivatsa X-Developer-Signature: v=1; a=ed25519-sha256; t=1741827289; l=1079; i=asrivats@redhat.com; s=20250122; h=from:subject:message-id; bh=prKb1/vsoLZeKMb2AQiT1U6bRaw46DjeGENTzbI5K3Q=; b=xjrFzIHHXSIYDjna0xcXbb6Bqj7JFBaS5Mw9FAVoKT8/aywRJzepAS5iZPGRCve271zLWFm5x VKYrR51+zZ/CBllFYT0Fk8Y0/P6zklxMKNqhPINNmo/JXDZ6DKJAMNn X-Developer-Key: i=asrivats@redhat.com; a=ed25519; pk=brnIHkBsUZEhyW6Zyn0U92AeIZ1psws/q8VFbIkf1AU= X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Primary motivation is to avoid havig a dangling pointer with panels. In a scenario where panel device no longer exists, the DRM driver has no idea of it. It can continue to try and access a panel leading to use-after-free situations. This is the initial draft more for feedback only. Once the path forward is clear, further drivers will be converted to using the API. Suggested-by: Maxime Ripard Signed-off-by: Anusha Srivatsa --- Anusha Srivatsa (2): drm/panel: Add new helpers for refcounted panel allocatons drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc() drivers/gpu/drm/drm_panel.c | 50 +++++++++++++++++++++++++++++++ drivers/gpu/drm/panel/panel-simple.c | 4 +-- include/drm/drm_panel.h | 58 ++++++++++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+), 3 deletions(-) --- base-commit: 3282422bf251db541fe07c548ca304130d37d754 change-id: 20250311-drm-panel-c327992e932e Best regards, -- Anusha Srivatsa