From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 392EC196C77; Thu, 6 Jun 2024 14:15:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683315; cv=none; b=ANXqdjf5hXMLnZT0BwG4D6noxZ2LaCAZHT4ds8Detpchl7cOHE//fIkRohFqHk8zwh+5IbMy1Z5lmpf0CIFf0KTBR37IDIF24Fy/bjYlQWhFdCGuJfQfh5RvUbbhAqmZIRD/II3Yb1veHkaERWXM0MpRhTC4SErV+Qoam5qNss4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717683315; c=relaxed/simple; bh=bWnbB5u6WVc5K+2UwOX4RtiSlSmd+d5BYDY0fc5iSS0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QORnoOKKt4ZfP5kb9cQpTOzRXvPa3VuH0+xooO8aE1fTCwv5twnD0ZJVzKvl2cl8FZ/OJ51rYrqhwAo7zUtI+T6TG7hefwLvu4ARSpjqAx7KgPDexwJn877woOhVTdVDF57LLMSgXkxm29bU247o67vEtnWqQJwW+RmN09jBvGI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zY7CMHQJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zY7CMHQJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 160A5C4AF08; Thu, 6 Jun 2024 14:15:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1717683315; bh=bWnbB5u6WVc5K+2UwOX4RtiSlSmd+d5BYDY0fc5iSS0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zY7CMHQJpBUYy7Co/6fElmd0DVC1/CsSvzGeNiW/znf6TCOP0d7o8GLc39f6jn1m+ 6+k9YOsOTXWQzluW5+pFMpcDKszHN9l0cLv7oSstkZy8GHg1LuwIZRYP/pc3NxbdH1 IScrGhMU4HnuQ8meOoUpechbfp9odFiIZ5/x5Hww= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Duoming Zhou , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 255/744] ax25: Use kernel universal linked list to implement ax25_dev_list Date: Thu, 6 Jun 2024 15:58:47 +0200 Message-ID: <20240606131740.586617046@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240606131732.440653204@linuxfoundation.org> References: <20240606131732.440653204@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Duoming Zhou [ Upstream commit a7d6e36b9ad052926ba2ecba3a59d8bb67dabcb4 ] The origin ax25_dev_list implements its own single linked list, which is complicated and error-prone. For example, when deleting the node of ax25_dev_list in ax25_dev_device_down(), we have to operate on the head node and other nodes separately. This patch uses kernel universal linked list to replace original ax25_dev_list, which make the operation of ax25_dev_list easier. We should do "dev->ax25_ptr = ax25_dev;" and "dev->ax25_ptr = NULL;" while holding the spinlock, otherwise the ax25_dev_device_up() and ax25_dev_device_down() could race. Suggested-by: Dan Carpenter Signed-off-by: Duoming Zhou Reviewed-by: Dan Carpenter Link: https://lore.kernel.org/r/85bba3af651ca0e1a519da8d0d715b949891171c.1715247018.git.duoming@zju.edu.cn Signed-off-by: Jakub Kicinski Stable-dep-of: b505e0319852 ("ax25: Fix reference count leak issues of ax25_dev") Signed-off-by: Sasha Levin --- include/net/ax25.h | 3 +-- net/ax25/ax25_dev.c | 40 +++++++++++++++------------------------- 2 files changed, 16 insertions(+), 27 deletions(-) diff --git a/include/net/ax25.h b/include/net/ax25.h index 0d939e5aee4ec..c2a85fd3f5ea4 100644 --- a/include/net/ax25.h +++ b/include/net/ax25.h @@ -216,7 +216,7 @@ typedef struct { struct ctl_table; typedef struct ax25_dev { - struct ax25_dev *next; + struct list_head list; struct net_device *dev; netdevice_tracker dev_tracker; @@ -330,7 +330,6 @@ int ax25_addr_size(const ax25_digi *); void ax25_digi_invert(const ax25_digi *, ax25_digi *); /* ax25_dev.c */ -extern ax25_dev *ax25_dev_list; extern spinlock_t ax25_dev_lock; #if IS_ENABLED(CONFIG_AX25) diff --git a/net/ax25/ax25_dev.c b/net/ax25/ax25_dev.c index 282ec581c0720..f16ee5c09d07a 100644 --- a/net/ax25/ax25_dev.c +++ b/net/ax25/ax25_dev.c @@ -22,11 +22,12 @@ #include #include #include +#include #include #include #include -ax25_dev *ax25_dev_list; +static LIST_HEAD(ax25_dev_list); DEFINE_SPINLOCK(ax25_dev_lock); ax25_dev *ax25_addr_ax25dev(ax25_address *addr) @@ -34,7 +35,7 @@ ax25_dev *ax25_addr_ax25dev(ax25_address *addr) ax25_dev *ax25_dev, *res = NULL; spin_lock_bh(&ax25_dev_lock); - for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next) + list_for_each_entry(ax25_dev, &ax25_dev_list, list) if (ax25cmp(addr, (const ax25_address *)ax25_dev->dev->dev_addr) == 0) { res = ax25_dev; ax25_dev_hold(ax25_dev); @@ -59,7 +60,6 @@ void ax25_dev_device_up(struct net_device *dev) } refcount_set(&ax25_dev->refcount, 1); - dev->ax25_ptr = ax25_dev; ax25_dev->dev = dev; netdev_hold(dev, &ax25_dev->dev_tracker, GFP_KERNEL); ax25_dev->forward = NULL; @@ -85,8 +85,8 @@ void ax25_dev_device_up(struct net_device *dev) #endif spin_lock_bh(&ax25_dev_lock); - ax25_dev->next = ax25_dev_list; - ax25_dev_list = ax25_dev; + list_add(&ax25_dev->list, &ax25_dev_list); + dev->ax25_ptr = ax25_dev; spin_unlock_bh(&ax25_dev_lock); ax25_dev_hold(ax25_dev); @@ -111,32 +111,25 @@ void ax25_dev_device_down(struct net_device *dev) /* * Remove any packet forwarding that points to this device. */ - for (s = ax25_dev_list; s != NULL; s = s->next) + list_for_each_entry(s, &ax25_dev_list, list) if (s->forward == dev) s->forward = NULL; - if ((s = ax25_dev_list) == ax25_dev) { - ax25_dev_list = s->next; - goto unlock_put; - } - - while (s != NULL && s->next != NULL) { - if (s->next == ax25_dev) { - s->next = ax25_dev->next; + list_for_each_entry(s, &ax25_dev_list, list) { + if (s == ax25_dev) { + list_del(&s->list); goto unlock_put; } - - s = s->next; } - spin_unlock_bh(&ax25_dev_lock); dev->ax25_ptr = NULL; + spin_unlock_bh(&ax25_dev_lock); ax25_dev_put(ax25_dev); return; unlock_put: + dev->ax25_ptr = NULL; spin_unlock_bh(&ax25_dev_lock); ax25_dev_put(ax25_dev); - dev->ax25_ptr = NULL; netdev_put(dev, &ax25_dev->dev_tracker); ax25_dev_put(ax25_dev); } @@ -200,16 +193,13 @@ struct net_device *ax25_fwd_dev(struct net_device *dev) */ void __exit ax25_dev_free(void) { - ax25_dev *s, *ax25_dev; + ax25_dev *s, *n; spin_lock_bh(&ax25_dev_lock); - ax25_dev = ax25_dev_list; - while (ax25_dev != NULL) { - s = ax25_dev; - netdev_put(ax25_dev->dev, &ax25_dev->dev_tracker); - ax25_dev = ax25_dev->next; + list_for_each_entry_safe(s, n, &ax25_dev_list, list) { + netdev_put(s->dev, &s->dev_tracker); + list_del(&s->list); kfree(s); } - ax25_dev_list = NULL; spin_unlock_bh(&ax25_dev_lock); } -- 2.43.0