From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 36D704ED196; Wed, 30 Sep 2026 16:49:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790786985; cv=none; b=PJF0Od3E3QuZ6LPO4Nw+GPMqRt3tgdDxGoPDwOdEBkNrPmLf8ccVtKFng/cwDGjE451x4u2dyvtkiLU3B2uce3Th+aYJoVApiUdrpJw/1Rn/AOlB4hLjqZY2k8zT/6eCgIag50FgyjW3AgAOMSaXSoVYEbfOXr+BQzmseXA22iU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790786985; c=relaxed/simple; bh=W5tdaglF+8Ke4HvGfvyOwh1x4Wuos164UH+B5986mLY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ElU81hjVMQoYnIEOLcan44GapmXMWJRnwgijcM+w1MRHHQ6BqezlpBKntdeXwAfSYB+cRhglOahGXxME9n0YU8XvaFRoFjtjWKGD9XCjwMBd1Nw7rix1rpTCXF42MLMhSJZrQB0RzRhSRmte56PDZGXplUalaywX0VZSIGjnCQo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W4njuUJF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="W4njuUJF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 914C01F000FF; Wed, 30 Sep 2026 16:49:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790786984; bh=3Km/wTXAC4/OWnswVqn/HYkqUi6Hp05HVust3wmesEQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=W4njuUJFJAe77YNSlGuaEYTQVUkW+aaOG0nrsPGrtV3IfpadtiUYpPuduFwHMYMQE 1bNc8r1dZAUnlB3CXCVpJemydihqY8c70V3Fd3/6/j0aVCJBLjpbp/MriJhamWheub xhetPjJO3j2qJGpRuuTq1gpmJuJ0TH8PvTM4C4fc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shay Drory , Akiva Goldberger , Tariq Toukan , Jakub Kicinski , Sasha Levin Subject: [PATCH 7.2 072/457] net/mlx5: devcom, Base component size on linked devices Date: Wed, 30 Sep 2026 17:22:57 +0200 Message-ID: <20260930152347.603232112@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152346.024115587@linuxfoundation.org> References: <20260930152346.024115587@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shay Drory [ Upstream commit d09e8f64653c93da5793c16be19330968f2a32e6 ] mlx5_devcom_comp_get_size() returns the component's kref count. That kref is bumped in mlx5_devcom_register_component() under comp_list_lock, before the comp_dev is linked onto comp_dev_list_head under comp->sem. The event broadcast (mlx5_devcom_locked_send_event()) walks that list. Hence, a caller can read the expected size, but send_event won't be sent to all peers. In the SD group registration path, this lets a member broadcast its role-election event over an incomplete list, electing a primary that never completes the group, is never marked ready, and leaves the group with a stale primary. Track the number of linked comp_devs in a dedicated counter, maintained under comp->sem together with the list add/remove, and return it from mlx5_devcom_comp_get_size(). Fixes: 9bb1ac80738a ("net/mlx5: devcom, Add component size getter") Signed-off-by: Shay Drory Reviewed-by: Akiva Goldberger Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/20260915113459.3934760-2-tariqt@nvidia.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c index 64f92427602de..75855481522b1 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/devcom.c @@ -37,6 +37,7 @@ struct mlx5_devcom_comp { struct mlx5_devcom_key key; mlx5_devcom_event_handler_t handler; struct kref ref; + int nr_devs; bool ready; struct rw_semaphore sem; struct lock_class_key lock_key; @@ -170,6 +171,7 @@ devcom_alloc_comp_dev(struct mlx5_devcom_dev *devc, down_write(&comp->sem); list_add_tail(&devcom->list, &comp->comp_dev_list_head); + WRITE_ONCE(comp->nr_devs, comp->nr_devs + 1); up_write(&comp->sem); return devcom; @@ -182,6 +184,7 @@ devcom_free_comp_dev(struct mlx5_devcom_comp_dev *devcom) down_write(&comp->sem); list_del(&devcom->list); + WRITE_ONCE(comp->nr_devs, comp->nr_devs - 1); up_write(&comp->sem); kref_put(&devcom->devc->ref, mlx5_devcom_dev_release); @@ -284,7 +287,7 @@ int mlx5_devcom_comp_get_size(struct mlx5_devcom_comp_dev *devcom) { struct mlx5_devcom_comp *comp = devcom->comp; - return kref_read(&comp->ref); + return READ_ONCE(comp->nr_devs); } int mlx5_devcom_locked_send_event(struct mlx5_devcom_comp_dev *devcom, -- 2.53.0