linux-kernel - [PATCH 2/2] vfio/mbochs: make mbochs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240301-class_cleanup-vfio-v1-2-9236d69083f5@marliere.net>
Date: Fri, 01 Mar 2024 14:51:48 -0300
From: "Ricardo B. Marliere" <ricardo@...liere.net>
To: Kirti Wankhede <kwankhede@...dia.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
 "Ricardo B. Marliere" <ricardo@...liere.net>
Subject: [PATCH 2/2] vfio/mbochs: make mbochs_class constant

Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the mbochs_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@...liere.net>
---
 samples/vfio-mdev/mbochs.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 93405264ff23..9062598ea03d 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -133,7 +133,9 @@ static struct mdev_type *mbochs_mdev_types[] = {
 };
 
 static dev_t		mbochs_devt;
-static struct class	*mbochs_class;
+static const struct class mbochs_class = {
+	.name = MBOCHS_CLASS_NAME,
+};
 static struct cdev	mbochs_cdev;
 static struct device	mbochs_dev;
 static struct mdev_parent mbochs_parent;
@@ -1422,13 +1424,10 @@ static int __init mbochs_dev_init(void)
 	if (ret)
 		goto err_cdev;
 
-	mbochs_class = class_create(MBOCHS_CLASS_NAME);
-	if (IS_ERR(mbochs_class)) {
-		pr_err("Error: failed to register mbochs_dev class\n");
-		ret = PTR_ERR(mbochs_class);
+	ret = class_register(&mbochs_class);
+	if (ret)
 		goto err_driver;
-	}
-	mbochs_dev.class = mbochs_class;
+	mbochs_dev.class = &mbochs_class;
 	mbochs_dev.release = mbochs_device_release;
 	dev_set_name(&mbochs_dev, "%s", MBOCHS_NAME);
 
@@ -1448,7 +1447,7 @@ static int __init mbochs_dev_init(void)
 	device_del(&mbochs_dev);
 err_put:
 	put_device(&mbochs_dev);
-	class_destroy(mbochs_class);
+	class_unregister(&mbochs_class);
 err_driver:
 	mdev_unregister_driver(&mbochs_driver);
 err_cdev:
@@ -1466,8 +1465,7 @@ static void __exit mbochs_dev_exit(void)
 	mdev_unregister_driver(&mbochs_driver);
 	cdev_del(&mbochs_cdev);
 	unregister_chrdev_region(mbochs_devt, MINORMASK + 1);
-	class_destroy(mbochs_class);
-	mbochs_class = NULL;
+	class_unregister(&mbochs_class);
 }
 
 MODULE_IMPORT_NS(DMA_BUF);

-- 
2.43.0