On 7/5/24 07:35, Shay Drori wrote:
On 04/07/2024 13:41, Greg KH wrote:
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On Wed, Jul 03, 2024 at 10:38:57AM +0300, Shay Drory wrote:
+/**
+ * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ
+ * @auxdev: auxiliary bus device to add the sysfs entry.
+ * @irq: The associated interrupt number.
+ *
+ * This function should be called after auxiliary device have
successfully
+ * received the irq.
+ * The driver is responsible to add a unique irq for the auxiliary
device. The
+ * driver can invoke this function from multiple thread context
safely for
+ * unique irqs of the auxiliary devices. The driver must not invoke
this API
+ * multiple times if the irq is already added previously.
+ *
+ * Return: zero on success or an error code on failure.
+ */
+int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev,
int irq)
+{
+ struct auxiliary_irq_info *info __free(kfree) = NULL;
+ struct device *dev = &auxdev->dev;
+ char *name __free(kfree) = NULL;
+ int ret;
+
+ ret = auxiliary_irq_dir_prepare(auxdev);
+ if (ret)
+ return ret;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ sysfs_attr_init(&info->sysfs_attr.attr);
+ name = kasprintf(GFP_KERNEL, "%d", irq);
+ if (!name)
+ return -ENOMEM;
+
+ ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL);
+ if (ret)
+ return ret;
+
+ info->sysfs_attr.attr.name = name;
+ ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr,
+ auxiliary_irqs_group.name);
+ if (ret)
+ goto sysfs_add_err;
+
+ info->sysfs_attr.attr.name = no_free_ptr(name);
This assignment of a name AFTER it has been created is odd. I think I
know why you are doing this, but please make it obvious and perhaps
solve it in a cleaner way.
I am doing it since I want the name memory to be freed in case of
sysfs_add_file_to_group() fails.
I don’t see a cleaner way available with cleanup.h.
Assigning this "deep" in a sysfs structure is not ok.
when creating sysfs dynamically, there isn't a cleaner way to assign the
name memory.
The closest and exact same use case for pci irq sysfs which uses dynamic
sysfs is msi_sysfs_populate_desc().
It does not use cleanup.h but still has to assign.
I Don’t have any other ideas on how to implement it any more elegantly
with cleanup.h.
Do you prefer to assign it before sysfs_add_file_to_group() similar to
msi_sysfs_populate_desc() and avoid cleanup.h for now?
I've overlooked it earlier, sorry.
easiest solution for "general" case would be:
info->sysfs_attr.attr.name = no_free_ptr(name);
ret = sysfs_add_file_to_group(&dev->kobj,
&info->sysfs_attr.attr,
auxiliary_irqs_group.name);
if (ret) {
/* freeing manualy since auto cleanup was
* disabled by no_free_ptr() */
kfree(info->sysfs_attr.attr.name);
goto sysfs_add_err;
}
but in your case it will be cleaner to alloc the space for name
together with struct auxiliary_irq_info, by placing a char array
there, either with static size or a flex one (if such case would
be generic)
going one step further would be be to reorder struct device_attribute
and struct attribute fields to have @name as the last one and make it
a flex array - but it is perhaps for another series ;)
+void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq)
+{
+ struct auxiliary_irq_info *info __free(kfree) = xa_load(&auxdev->irqs, irq);
No verification that this is an actual entry before you dereferenced it?
Bold move...
Driver must do this for allocated irq. So xa_load cannot fail.
In previous versions we had WARN_ON to catch driver bugs, but you didn’t
like it.
I think this is fine the way it is in v9.
greg k-h
Perhaps this is more about trust boundaries?,
I would like to learn something from this case :)
