Commit 4723f16d authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Petr Pavlu
Browse files

module: sysfs: Add notes attributes through attribute_group 



A kobject is meant to manage the lifecycle of some resource.
However the module sysfs code only creates a kobject to get a
"notes" subdirectory in sysfs.
This can be achieved easier and cheaper by using a sysfs group.
Switch the notes attribute code to such a group, similar to how the
section allocation in the same file already works.

Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Reviewed-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20241227-sysfs-const-bin_attr-module-v2-5-e267275f0f37@weissschuh.net


Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
parent f47c0beb

kernel/module/sysfs.c

+28 −26
Original line number Diff line number Diff line
@@ -138,20 +138,13 @@ static void remove_sect_attrs(struct module *mod) 
 */



struct module_notes_attrs {

	struct kobject *dir;

	unsigned int notes;

	struct bin_attribute attrs[] __counted_by(notes);

	struct attribute_group grp;

	struct bin_attribute attrs[];

};



static void free_notes_attrs(struct module_notes_attrs *notes_attrs,

			     unsigned int i)

static void free_notes_attrs(struct module_notes_attrs *notes_attrs)

{

	if (notes_attrs->dir) {

		while (i-- > 0)

			sysfs_remove_bin_file(notes_attrs->dir,

					      &notes_attrs->attrs[i]);

		kobject_put(notes_attrs->dir);

	}

	kfree(notes_attrs->grp.bin_attrs);

	kfree(notes_attrs);

}
@@ -159,6 +152,7 @@ static int add_notes_attrs(struct module *mod, const struct load_info *info) 
{

	unsigned int notes, loaded, i;

	struct module_notes_attrs *notes_attrs;

	struct bin_attribute **gattr;

	struct bin_attribute *nattr;

	int ret;
@@ -177,7 +171,15 @@ static int add_notes_attrs(struct module *mod, const struct load_info *info) 
	if (!notes_attrs)

		return -ENOMEM;



	notes_attrs->notes = notes;

	gattr = kcalloc(notes + 1, sizeof(*gattr), GFP_KERNEL);

	if (!gattr) {

		kfree(notes_attrs);

		return -ENOMEM;

	}



	notes_attrs->grp.name = "notes";

	notes_attrs->grp.bin_attrs = gattr;



	nattr = &notes_attrs->attrs[0];

	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {

		if (sect_empty(&info->sechdrs[i]))
@@ -189,35 +191,35 @@ static int add_notes_attrs(struct module *mod, const struct load_info *info) 
			nattr->size = info->sechdrs[i].sh_size;

			nattr->private = (void *)info->sechdrs[i].sh_addr;

			nattr->read = sysfs_bin_attr_simple_read;

			++nattr;

			*(gattr++) = nattr++;

		}

		++loaded;

	}



	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);

	if (!notes_attrs->dir) {

		ret = -ENOMEM;

		goto out;

	}



	for (i = 0; i < notes; ++i) {

		ret = sysfs_create_bin_file(notes_attrs->dir, &notes_attrs->attrs[i]);

	ret = sysfs_create_group(&mod->mkobj.kobj, &notes_attrs->grp);

	if (ret)

		goto out;

	}



	mod->notes_attrs = notes_attrs;

	return 0;



out:

	free_notes_attrs(notes_attrs, i);

	free_notes_attrs(notes_attrs);

	return ret;

}



static void remove_notes_attrs(struct module *mod)

{

	if (mod->notes_attrs)

		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);

	if (mod->notes_attrs) {

		sysfs_remove_group(&mod->mkobj.kobj,

				   &mod->notes_attrs->grp);

		/*

		 * We are positive that no one is using any notes attrs

		 * at this point.  Deallocate immediately.

		 */

		free_notes_attrs(mod->notes_attrs);

		mod->notes_attrs = NULL;

	}

}



#else /* !CONFIG_KALLSYMS */