From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 6D0EF31ED6A for ; Thu, 11 Dec 2025 19:49:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765482578; cv=none; b=sHOrs4WViwfTlL+RhqludLwDlZ+lZPqBLVHK5Hu1rCblJnFkt7Iw/1zqEO3jmoLtKZH5goaiDkSgSkU9hfLMk+XuVZKIj0tzdgwy313BoZBJbb08VWSlUDP8+KUPcRdxu2sgAbsUrnI0h/iQQGsDrwNavrdkrhUhOOAymUsFNL0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765482578; c=relaxed/simple; bh=dn9uonTdxtBrLTc1sw3QKohXkVb0YW4FMCPFwY7sAZg=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eO9J8B+yXsyj4IHzdaUI7e+RFBQ7Xb08neze7PMFzmzxMkgQgxfwAGJAkVK295yWVIb3Cqfvn5dY0DigsQ/f/XlrYRxERB87sQUqn2YxvxQ94yV36+QJMfs5BYZSErhhgq7NzuhMs/3x2a5SkPZK7Yu1YFpLoqx1A1bPM7RJjRE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=Kwty78d1; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="Kwty78d1" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1765482575; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jIoDvXdjZ3/MYVyn7uIyimWQTnMk+lOUAkbaFH7qygo=; b=Kwty78d1OUyDiTrCjFbHvJs3DyJ+Lk5we132UqvkWidcIdYKokEILFHAGZmrid1dZ90sGf EUnyB4ciiWL8ikRRzAx8ADZ5aMYPa3S8bnay7v4vMtJHCPe6cZLNtZEXzVxa1s32C7mXVv 8oMZ8EApucOjeMuhp451V4+8tQGJ2NA= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-352-3YWi1aKwNjKgq5qr7s-9Cg-1; Thu, 11 Dec 2025 14:49:31 -0500 X-MC-Unique: 3YWi1aKwNjKgq5qr7s-9Cg-1 X-Mimecast-MFC-AGG-ID: 3YWi1aKwNjKgq5qr7s-9Cg_1765482567 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B5C0818011DF; Thu, 11 Dec 2025 19:49:27 +0000 (UTC) Received: from p16v.luc.cera.cz (unknown [10.45.224.252]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 81AED1956056; Thu, 11 Dec 2025 19:49:19 +0000 (UTC) From: Ivan Vecera To: netdev@vger.kernel.org, Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Vadim Fedorenko , Arkadiusz Kubalewski , Grzegorz Nitka , Jiri Pirko , Petr Oros , Michal Schmidt , Prathosh Satish , Tony Nguyen , Przemek Kitszel , Saeed Mahameed , Leon Romanovsky , Tariq Toukan , Mark Bloch , Richard Cochran , Jonathan Lemon , Simon Horman , Alexander Lobakin , Willem de Bruijn , Stefan Wahren , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-rdma@vger.kernel.org Subject: [PATCH RFC net-next 09/13] dpll: Prevent duplicate registrations Date: Thu, 11 Dec 2025 20:47:52 +0100 Message-ID: <20251211194756.234043-10-ivecera@redhat.com> In-Reply-To: <20251211194756.234043-1-ivecera@redhat.com> References: <20251211194756.234043-1-ivecera@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Modify the internal registration helpers dpll_xa_ref_{dpll,pin}_add() to reject duplicate registration attempts. Previously, if a caller attempted to register the same pin multiple times (with the same ops, priv, and cookie) on the same device, the core silently increments the reference count and return success. This behavior is incorrect because if the caller makes these duplicate registrations then for the first one dpll_pin_registration is allocated and for others the associated dpll_pin_ref.refcount is incremented. During the first unregistration the associated dpll_pin_registration is freed and for others WARN is fired. Fix this by updating the logic to return `-EEXIST` if a matching registration is found to enforce a strict "register once" policy. Signed-off-by: Ivan Vecera --- drivers/dpll/dpll_core.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/dpll/dpll_core.c b/drivers/dpll/dpll_core.c index f4a4e17fb9b6c..f9b60be8962a5 100644 --- a/drivers/dpll/dpll_core.c +++ b/drivers/dpll/dpll_core.c @@ -160,10 +160,8 @@ dpll_xa_ref_pin_add(struct xarray *xa_pins, struct dpll_pin *pin, if (ref->pin != pin) continue; reg = dpll_pin_registration_find(ref, ops, priv, cookie); - if (reg) { - refcount_inc(&ref->refcount); - return 0; - } + if (reg) + return -EEXIST; ref_exists = true; break; } @@ -243,10 +241,8 @@ dpll_xa_ref_dpll_add(struct xarray *xa_dplls, struct dpll_device *dpll, if (ref->dpll != dpll) continue; reg = dpll_pin_registration_find(ref, ops, priv, cookie); - if (reg) { - refcount_inc(&ref->refcount); - return 0; - } + if (reg) + return -EEXIST; ref_exists = true; break; } -- 2.51.2