2023-10-24 11:50:03

by Greg Kroah-Hartman

Subject: [PATCH] misc: phantom: make phantom_class constant

Now that the driver core allows for struct class to be in read-only
memory, we should make all 'class' structures declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at runtime.

Cc: Jiri Slaby <[email protected]>
Cc: Arnd Bergmann <[email protected]>
igned-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/misc/phantom.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/misc/phantom.c b/drivers/misc/phantom.c
index 7966a6b8b5b3..30bd7c39c261 100644
--- a/drivers/misc/phantom.c
+++ b/drivers/misc/phantom.c
@@ -35,9 +35,12 @@
#define PHB_NOT_OH 2

static DEFINE_MUTEX(phantom_mutex);
-static struct class *phantom_class;
static int phantom_major;

+static const struct class phantom_class = {
+ .name = "phantom",
+};
+
struct phantom_device {
unsigned int opened;
void __iomem *caddr;
@@ -403,7 +406,7 @@ static int phantom_probe(struct pci_dev *pdev,
goto err_irq;
}

- if (IS_ERR(device_create(phantom_class, &pdev->dev,
+ if (IS_ERR(device_create(&phantom_class, &pdev->dev,
MKDEV(phantom_major, minor), NULL,
"phantom%u", minor)))
dev_err(&pdev->dev, "can't create device\n");
@@ -436,7 +439,7 @@ static void phantom_remove(struct pci_dev *pdev)
struct phantom_device *pht = pci_get_drvdata(pdev);
unsigned int minor = MINOR(pht->cdev.dev);

- device_destroy(phantom_class, MKDEV(phantom_major, minor));
+ device_destroy(&phantom_class, MKDEV(phantom_major, minor));

cdev_del(&pht->cdev);

@@ -503,13 +506,12 @@ static int __init phantom_init(void)
int retval;
dev_t dev;

- phantom_class = class_create("phantom");
- if (IS_ERR(phantom_class)) {
- retval = PTR_ERR(phantom_class);
+ retval = class_register(&phantom_class);
+ if (retval) {
printk(KERN_ERR "phantom: can't register phantom class\n");
goto err;
}
- retval = class_create_file(phantom_class, &class_attr_version.attr);
+ retval = class_create_file(&phantom_class, &class_attr_version.attr);
if (retval) {
printk(KERN_ERR "phantom: can't create sysfs version file\n");
goto err_class;
@@ -535,9 +537,9 @@ static int __init phantom_init(void)
err_unchr:
unregister_chrdev_region(dev, PHANTOM_MAX_MINORS);
err_attr:
- class_remove_file(phantom_class, &class_attr_version.attr);
+ class_remove_file(&phantom_class, &class_attr_version.attr);
err_class:
- class_destroy(phantom_class);
+ class_unregister(&phantom_class);
err:
return retval;
}
@@ -548,8 +550,8 @@ static void __exit phantom_exit(void)

unregister_chrdev_region(MKDEV(phantom_major, 0), PHANTOM_MAX_MINORS);

- class_remove_file(phantom_class, &class_attr_version.attr);
- class_destroy(phantom_class);
+ class_remove_file(&phantom_class, &class_attr_version.attr);
+ class_unregister(&phantom_class);

pr_debug("phantom: module successfully removed\n");
}
--
2.42.0

2023-10-25 08:47:06

by Jiri Slaby

Subject: Re: [PATCH] misc: phantom: make phantom_class constant

On 24. 10. 23, 13:49, Greg Kroah-Hartman wrote:
> Now that the driver core allows for struct class to be in read-only
> memory, we should make all 'class' structures declared at build time
> placing them into read-only memory, instead of having to be dynamically
> allocated at runtime.
>
> Cc: Jiri Slaby <[email protected]>
> Cc: Arnd Bergmann <[email protected]>

The code:

Reviewed-by: Jiri Slaby <[email protected]>

> igned-off-by: Greg Kroah-Hartman <[email protected]>

But I am missing ^S here.

--
js

2023-10-25 08:53:54

by Greg Kroah-Hartman

Subject: Re: [PATCH] misc: phantom: make phantom_class constant

On Wed, Oct 25, 2023 at 10:46:26AM +0200, Jiri Slaby wrote:
> On 24. 10. 23, 13:49, Greg Kroah-Hartman wrote:
> > Now that the driver core allows for struct class to be in read-only
> > memory, we should make all 'class' structures declared at build time
> > placing them into read-only memory, instead of having to be dynamically
> > allocated at runtime.
> >
> > Cc: Jiri Slaby <[email protected]>
> > Cc: Arnd Bergmann <[email protected]>
>
> The code:
>
> Reviewed-by: Jiri Slaby <[email protected]>
>
> > igned-off-by: Greg Kroah-Hartman <[email protected]>
>
> But I am missing ^S here.

Ick, cut-and-paste error, odd. I'll fix this up when applying it.

thanks for the review,

greg k-h