Driver core: Constify struct sysfs_ops in struct kobj_type

Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime

* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime

* potentially better optimized code as the compiler
can assume that the const data cannot be changed

* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <[e-mail]>
Acked-by: David Teigland <[e-mail]>
Acked-by: Matt Domsch <[e-mail]>
Acked-by: Maciej Sosnowski <[e-mail]>
Acked-by: Hans J. Koch <[e-mail]>
Acked-by: Pekka Enberg <[e-mail]>
Acked-by: Jens Axboe <[e-mail]>
Acked-by: Stephen Hemminger <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/kobject.txt

···
 
     struct kobj_type {
 	    void (*release)(struct kobject *);
-	    struct sysfs_ops	*sysfs_ops;
+	    const struct sysfs_ops *sysfs_ops;
 	    struct attribute	**default_attrs;
     };
 

arch/ia64/kernel/topology.c

···
 	return ret;
 }
 
-static struct sysfs_ops cache_sysfs_ops = {
+static const struct sysfs_ops cache_sysfs_ops = {
 	.show   = cache_show
 };
 

arch/powerpc/kernel/cacheinfo.c

···
 	&cache_assoc_attr,
 };
 
-static struct sysfs_ops cache_index_ops = {
+static const struct sysfs_ops cache_index_ops = {
 	.show = cache_index_show,
 };
 

arch/sh/kernel/cpu/sh4/sq.c

···
 	NULL,
 };
 
-static struct sysfs_ops sq_sysfs_ops = {
+static const struct sysfs_ops sq_sysfs_ops = {
 	.show	= sq_sysfs_show,
 	.store	= sq_sysfs_store,
 };

arch/x86/kernel/cpu/intel_cacheinfo.c

···
 	return ret;
 }
 
-static struct sysfs_ops sysfs_ops = {
+static const struct sysfs_ops sysfs_ops = {
 	.show   = show,
 	.store  = store,
 };

arch/x86/kernel/cpu/mcheck/mce_amd.c

···
 	return ret;
 }
 
-static struct sysfs_ops threshold_ops = {
+static const struct sysfs_ops threshold_ops = {
 	.show			= show,
 	.store			= store,
 };

block/blk-integrity.c

···
 	NULL,
 };
 
-static struct sysfs_ops integrity_ops = {
+static const struct sysfs_ops integrity_ops = {
 	.show	= &integrity_attr_show,
 	.store	= &integrity_attr_store,
 };

block/blk-sysfs.c

···
 	kmem_cache_free(blk_requestq_cachep, q);
 }
 
-static struct sysfs_ops queue_sysfs_ops = {
+static const struct sysfs_ops queue_sysfs_ops = {
 	.show	= queue_attr_show,
 	.store	= queue_attr_store,
 };

block/elevator.c

···
 	return error;
 }
 
-static struct sysfs_ops elv_sysfs_ops = {
+static const struct sysfs_ops elv_sysfs_ops = {
 	.show	= elv_attr_show,
 	.store	= elv_attr_store,
 };

drivers/base/bus.c

···
 	return ret;
 }
 
-static struct sysfs_ops driver_sysfs_ops = {
+static const struct sysfs_ops driver_sysfs_ops = {
 	.show	= drv_attr_show,
 	.store	= drv_attr_store,
 };
···
 	return ret;
 }
 
-static struct sysfs_ops bus_sysfs_ops = {
+static const struct sysfs_ops bus_sysfs_ops = {
 	.show	= bus_attr_show,
 	.store	= bus_attr_store,
 };

drivers/base/class.c

···
 	kfree(cp);
 }
 
-static struct sysfs_ops class_sysfs_ops = {
+static const struct sysfs_ops class_sysfs_ops = {
 	.show	= class_attr_show,
 	.store	= class_attr_store,
 };

drivers/base/core.c

···
 	return ret;
 }
 
-static struct sysfs_ops dev_sysfs_ops = {
+static const struct sysfs_ops dev_sysfs_ops = {
 	.show	= dev_attr_show,
 	.store	= dev_attr_store,
 };

drivers/base/sys.c

···
 	return -EIO;
 }
 
-static struct sysfs_ops sysfs_ops = {
+static const struct sysfs_ops sysfs_ops = {
 	.show	= sysdev_show,
 	.store	= sysdev_store,
 };
···
 	return -EIO;
 }
 
-static struct sysfs_ops sysfs_class_ops = {
+static const struct sysfs_ops sysfs_class_ops = {
 	.show	= sysdev_class_show,
 	.store	= sysdev_class_store,
 };

drivers/block/pktcdvd.c

···
 	return len;
 }
 
-static struct sysfs_ops kobj_pkt_ops = {
+static const struct sysfs_ops kobj_pkt_ops = {
 	.show = kobj_pkt_show,
 	.store = kobj_pkt_store
 };

drivers/cpufreq/cpufreq.c

···
 	complete(&policy->kobj_unregister);
 }
 
-static struct sysfs_ops sysfs_ops = {
+static const struct sysfs_ops sysfs_ops = {
 	.show	= show,
 	.store	= store,
 };

drivers/cpuidle/sysfs.c

···
 	return ret;
 }
 
-static struct sysfs_ops cpuidle_sysfs_ops = {
+static const struct sysfs_ops cpuidle_sysfs_ops = {
 	.show = cpuidle_show,
 	.store = cpuidle_store,
 };
···
 	return ret;
 }
 
-static struct sysfs_ops cpuidle_state_sysfs_ops = {
+static const struct sysfs_ops cpuidle_state_sysfs_ops = {
 	.show = cpuidle_state_show,
 };
 

drivers/dma/ioat/dma.c

···
 	return entry->show(&chan->common, page);
 }
 
-struct sysfs_ops ioat_sysfs_ops = {
+const struct sysfs_ops ioat_sysfs_ops = {
 	.show	= ioat_attr_show,
 };
 

drivers/dma/ioat/dma.h

···
 			   unsigned long *phys_complete);
 void ioat_kobject_add(struct ioatdma_device *device, struct kobj_type *type);
 void ioat_kobject_del(struct ioatdma_device *device);
-extern struct sysfs_ops ioat_sysfs_ops;
+extern const struct sysfs_ops ioat_sysfs_ops;
 extern struct ioat_sysfs_entry ioat_version_attr;
 extern struct ioat_sysfs_entry ioat_cap_attr;
 #endif /* IOATDMA_H */

drivers/edac/edac_device_sysfs.c

···
 }
 
 /* edac_dev file operations for an 'ctl_info' */
-static struct sysfs_ops device_ctl_info_ops = {
+static const struct sysfs_ops device_ctl_info_ops = {
 	.show = edac_dev_ctl_info_show,
 	.store = edac_dev_ctl_info_store
 };
···
 }
 
 /* edac_dev file operations for an 'instance' */
-static struct sysfs_ops device_instance_ops = {
+static const struct sysfs_ops device_instance_ops = {
 	.show = edac_dev_instance_show,
 	.store = edac_dev_instance_store
 };
···
 }
 
 /* edac_dev file operations for a 'block' */
-static struct sysfs_ops device_block_ops = {
+static const struct sysfs_ops device_block_ops = {
 	.show = edac_dev_block_show,
 	.store = edac_dev_block_store
 };

drivers/edac/edac_mc_sysfs.c

···
 	return -EIO;
 }
 
-static struct sysfs_ops csrowfs_ops = {
+static const struct sysfs_ops csrowfs_ops = {
 	.show = csrowdev_show,
 	.store = csrowdev_store
 };
···
 }
 
 /* Intermediate show/store table */
-static struct sysfs_ops mci_ops = {
+static const struct sysfs_ops mci_ops = {
 	.show = mcidev_show,
 	.store = mcidev_store
 };

drivers/edac/edac_pci_sysfs.c

···
 }
 
 /* fs_ops table */
-static struct sysfs_ops pci_instance_ops = {
+static const struct sysfs_ops pci_instance_ops = {
 	.show = edac_pci_instance_show,
 	.store = edac_pci_instance_store
 };
···
 	return -EIO;
 }
 
-static struct sysfs_ops edac_pci_sysfs_ops = {
+static const struct sysfs_ops edac_pci_sysfs_ops = {
 	.show = edac_pci_dev_show,
 	.store = edac_pci_dev_store
 };

drivers/firmware/edd.c

···
 	return ret;
 }
 
-static struct sysfs_ops edd_attr_ops = {
+static const struct sysfs_ops edd_attr_ops = {
 	.show = edd_attr_show,
 };
 

drivers/firmware/efivars.c

···
 	return ret;
 }
 
-static struct sysfs_ops efivar_attr_ops = {
+static const struct sysfs_ops efivar_attr_ops = {
 	.show = efivar_attr_show,
 	.store = efivar_attr_store,
 };

drivers/firmware/iscsi_ibft.c

···
 	return ret;
 }
 
-static struct sysfs_ops ibft_attr_ops = {
+static const struct sysfs_ops ibft_attr_ops = {
 	.show = ibft_show_attribute,
 };
 

drivers/firmware/memmap.c

···
 	NULL
 };
 
-static struct sysfs_ops memmap_attr_ops = {
+static const struct sysfs_ops memmap_attr_ops = {
 	.show = memmap_attr_show,
 };
 

drivers/gpu/drm/ttm/ttm_bo.c

···
 	NULL
 };
 
-static struct sysfs_ops ttm_bo_global_ops = {
+static const struct sysfs_ops ttm_bo_global_ops = {
 	.show = &ttm_bo_global_show
 };
 

drivers/gpu/drm/ttm/ttm_memory.c

···
 	NULL
 };
 
-static struct sysfs_ops ttm_mem_zone_ops = {
+static const struct sysfs_ops ttm_mem_zone_ops = {
 	.show = &ttm_mem_zone_show,
 	.store = &ttm_mem_zone_store
 };

drivers/infiniband/core/cm.c

···
 		       atomic_long_read(&group->counter[cm_attr->index]));
 }
 
-static struct sysfs_ops cm_counter_ops = {
+static const struct sysfs_ops cm_counter_ops = {
 	.show = cm_show_counter
 };
 

drivers/infiniband/core/sysfs.c

···
 	return port_attr->show(p, port_attr, buf);
 }
 
-static struct sysfs_ops port_sysfs_ops = {
+static const struct sysfs_ops port_sysfs_ops = {
 	.show = port_attr_show
 };
 

drivers/md/dm-sysfs.c

···
 	NULL,
 };
 
-static struct sysfs_ops dm_sysfs_ops = {
+static const struct sysfs_ops dm_sysfs_ops = {
 	.show	= dm_attr_show,
 };
 

drivers/md/md.c

···
 	mdk_rdev_t *rdev = container_of(ko, mdk_rdev_t, kobj);
 	kfree(rdev);
 }
-static struct sysfs_ops rdev_sysfs_ops = {
+static const struct sysfs_ops rdev_sysfs_ops = {
 	.show		= rdev_attr_show,
 	.store		= rdev_attr_store,
 };
···
 	kfree(mddev);
 }
 
-static struct sysfs_ops md_sysfs_ops = {
+static const struct sysfs_ops md_sysfs_ops = {
 	.show	= md_attr_show,
 	.store	= md_attr_store,
 };

drivers/net/ibmveth.c

···
 	NULL,
 };
 
-static struct sysfs_ops veth_pool_ops = {
+static const struct sysfs_ops veth_pool_ops = {
 	.show   = veth_pool_show,
 	.store  = veth_pool_store,
 };

drivers/net/iseries_veth.c

···
 	NULL
 };
 
-static struct sysfs_ops veth_cnx_sysfs_ops = {
+static const struct sysfs_ops veth_cnx_sysfs_ops = {
 		.show = veth_cnx_attribute_show
 };
 
···
 	NULL
 };
 
-static struct sysfs_ops veth_port_sysfs_ops = {
+static const struct sysfs_ops veth_port_sysfs_ops = {
 	.show = veth_port_attribute_show
 };
 

drivers/parisc/pdc_stable.c

···
 	return ret;
 }
 
-static struct sysfs_ops pdcspath_attr_ops = {
+static const struct sysfs_ops pdcspath_attr_ops = {
 	.show = pdcspath_attr_show,
 	.store = pdcspath_attr_store,
 };

drivers/pci/hotplug/fakephp.c

···
 }
 
 static struct kobj_type legacy_ktype = {
-	.sysfs_ops = &(struct sysfs_ops){
+	.sysfs_ops = &(const struct sysfs_ops){
 		.store = legacy_store, .show = legacy_show
 	},
 	.release = &legacy_release,

drivers/pci/slot.c

···
 	return attribute->store ? attribute->store(slot, buf, len) : -EIO;
 }
 
-static struct sysfs_ops pci_slot_sysfs_ops = {
+static const struct sysfs_ops pci_slot_sysfs_ops = {
 	.show = pci_slot_attr_show,
 	.store = pci_slot_attr_store,
 };

drivers/uio/uio.c

···
 	return entry->show(mem, buf);
 }
 
-static struct sysfs_ops map_sysfs_ops = {
+static const struct sysfs_ops map_sysfs_ops = {
 	.show = map_type_show,
 };
 
···
 	return entry->show(port, buf);
 }
 
-static struct sysfs_ops portio_sysfs_ops = {
+static const struct sysfs_ops portio_sysfs_ops = {
 	.show = portio_type_show,
 };
 

drivers/uwb/wlp/sysfs.c

···
 	return ret;
 }
 
-static
-struct sysfs_ops wss_sysfs_ops = {
+static const struct sysfs_ops wss_sysfs_ops = {
 	.show	= wlp_wss_attr_show,
 	.store	= wlp_wss_attr_store,
 };

drivers/video/omap2/dss/manager.c

···
 	return manager_attr->store(manager, buf, size);
 }
 
-static struct sysfs_ops manager_sysfs_ops = {
+static const struct sysfs_ops manager_sysfs_ops = {
 	.show = manager_attr_show,
 	.store = manager_attr_store,
 };

drivers/video/omap2/dss/overlay.c

···
 	return overlay_attr->store(overlay, buf, size);
 }
 
-static struct sysfs_ops overlay_sysfs_ops = {
+static const struct sysfs_ops overlay_sysfs_ops = {
 	.show = overlay_attr_show,
 	.store = overlay_attr_store,
 };

drivers/xen/sys-hypervisor.c

···
 	return 0;
 }
 
-static struct sysfs_ops hyp_sysfs_ops = {
+static const struct sysfs_ops hyp_sysfs_ops = {
 	.show = hyp_sysfs_show,
 	.store = hyp_sysfs_store,
 };

fs/btrfs/sysfs.c

···
 	complete(&root->kobj_unregister);
 }
 
-static struct sysfs_ops btrfs_super_attr_ops = {
+static const struct sysfs_ops btrfs_super_attr_ops = {
 	.show	= btrfs_super_attr_show,
 	.store	= btrfs_super_attr_store,
 };
 
-static struct sysfs_ops btrfs_root_attr_ops = {
+static const struct sysfs_ops btrfs_root_attr_ops = {
 	.show	= btrfs_root_attr_show,
 	.store	= btrfs_root_attr_store,
 };

fs/dlm/lockspace.c

···
 	kfree(ls);
 }
 
-static struct sysfs_ops dlm_attr_ops = {
+static const struct sysfs_ops dlm_attr_ops = {
 	.show  = dlm_attr_show,
 	.store = dlm_attr_store,
 };

fs/ext4/super.c

···
 }
 
 
-static struct sysfs_ops ext4_attr_ops = {
+static const struct sysfs_ops ext4_attr_ops = {
 	.show	= ext4_attr_show,
 	.store	= ext4_attr_store,
 };

fs/gfs2/sys.c

···
 	return a->store ? a->store(sdp, buf, len) : len;
 }
 
-static struct sysfs_ops gfs2_attr_ops = {
+static const struct sysfs_ops gfs2_attr_ops = {
 	.show  = gfs2_attr_show,
 	.store = gfs2_attr_store,
 };

fs/ocfs2/cluster/masklog.c

···
 	return mlog_mask_store(mlog_attr->mask, buf, count);
 }
 
-static struct sysfs_ops mlog_attr_ops = {
+static const struct sysfs_ops mlog_attr_ops = {
 	.show  = mlog_show,
 	.store = mlog_store,
 };

fs/sysfs/file.c

···
 	size_t			count;
 	loff_t			pos;
 	char			* page;
-	struct sysfs_ops	* ops;
+	const struct sysfs_ops	* ops;
 	struct mutex		mutex;
 	int			needs_read_fill;
 	int			event;
···
 {
 	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_ops * ops = buffer->ops;
+	const struct sysfs_ops * ops = buffer->ops;
 	int ret = 0;
 	ssize_t count;
 
···
 {
 	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_ops * ops = buffer->ops;
+	const struct sysfs_ops * ops = buffer->ops;
 	int rc;
 
 	/* need attr_sd for attr and ops, its parent for kobj */
···
 	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
 	struct sysfs_buffer *buffer;
-	struct sysfs_ops *ops;
+	const struct sysfs_ops *ops;
 	int error = -EACCES;
 	char *p;
 

include/linux/kobject.h

···
 
 struct kobj_type {
 	void (*release)(struct kobject *kobj);
-	struct sysfs_ops *sysfs_ops;
+	const struct sysfs_ops *sysfs_ops;
 	struct attribute **default_attrs;
 };
 
···
 			 const char *buf, size_t count);
 };
 
-extern struct sysfs_ops kobj_sysfs_ops;
+extern const struct sysfs_ops kobj_sysfs_ops;
 
 /**
  * struct kset - a set of kobjects of a specific type, belonging to a specific subsystem.

kernel/params.c

···
 	return ret;
 }
 
-static struct sysfs_ops module_sysfs_ops = {
+static const struct sysfs_ops module_sysfs_ops = {
 	.show = module_attr_show,
 	.store = module_attr_store,
 };

lib/kobject.c

···
 	return ret;
 }
 
-struct sysfs_ops kobj_sysfs_ops = {
+const struct sysfs_ops kobj_sysfs_ops = {
 	.show	= kobj_attr_show,
 	.store	= kobj_attr_store,
 };

mm/slub.c

···
 	kfree(s);
 }
 
-static struct sysfs_ops slab_sysfs_ops = {
+static const struct sysfs_ops slab_sysfs_ops = {
 	.show = slab_attr_show,
 	.store = slab_attr_store,
 };

net/bridge/br_private.h

···
 
 #ifdef CONFIG_SYSFS
 /* br_sysfs_if.c */
-extern struct sysfs_ops brport_sysfs_ops;
+extern const struct sysfs_ops brport_sysfs_ops;
 extern int br_sysfs_addif(struct net_bridge_port *p);
 
 /* br_sysfs_br.c */

net/bridge/br_sysfs_if.c

···
 	return ret;
 }
 
-struct sysfs_ops brport_sysfs_ops = {
+const struct sysfs_ops brport_sysfs_ops = {
 	.show = brport_show,
 	.store = brport_store,
 };

samples/kobject/kset-example.c

···
 }
 
 /* Our custom sysfs_ops that we will associate with our ktype later on */
-static struct sysfs_ops foo_sysfs_ops = {
+static const struct sysfs_ops foo_sysfs_ops = {
 	.show = foo_attr_show,
 	.store = foo_attr_store,
 };