diff options
Diffstat (limited to 'samples')
| -rw-r--r-- | samples/Kconfig | 6 | ||||
| -rw-r--r-- | samples/Makefile | 3 | ||||
| -rw-r--r-- | samples/configfs/Makefile | 2 | ||||
| -rw-r--r-- | samples/configfs/configfs_sample.c | 404 |
4 files changed, 414 insertions, 1 deletions
diff --git a/samples/Kconfig b/samples/Kconfig index 224ebb4..d54f28c 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -70,4 +70,10 @@ config SAMPLE_LIVEPATCH Builds a sample live patch that replaces the procfs handler for /proc/cmdline to print "this has been live patched". +config SAMPLE_CONFIGFS + tristate "Build configfs patching sample -- loadable modules only" + depends on CONFIGFS_FS && m + help + Builds a sample configfs interface. + endif # SAMPLES diff --git a/samples/Makefile b/samples/Makefile index f00257b..48001d7 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -1,4 +1,5 @@ # Makefile for Linux samples code obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ livepatch/ \ - hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ + hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ \ + configfs/ diff --git a/samples/configfs/Makefile b/samples/configfs/Makefile new file mode 100644 index 0000000..a9afd99 --- /dev/null +++ b/samples/configfs/Makefile @@ -0,0 +1,2 @@ + +obj-$(CONFIG_SAMPLE_CONFIGFS) += configfs_sample.o diff --git a/samples/configfs/configfs_sample.c b/samples/configfs/configfs_sample.c new file mode 100644 index 0000000..1ea3311 --- /dev/null +++ b/samples/configfs/configfs_sample.c @@ -0,0 +1,404 @@ +/* + * vim: noexpandtab ts=8 sts=0 sw=8: + * + * configfs_example_macros.c - This file is a demonstration module + * containing a number of configfs subsystems. It uses the helper + * macros defined by configfs.h + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + * + * Based on sysfs: + * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel + * + * configfs Copyright (C) 2005 Oracle. All rights reserved. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include <linux/configfs.h> + + + +/* + * 01-childless + * + * This first example is a childless subsystem. It cannot create + * any config_items. It just has attributes. + * + * Note that we are enclosing the configfs_subsystem inside a container. + * This is not necessary if a subsystem has no attributes directly + * on the subsystem. See the next example, 02-simple-children, for + * such a subsystem. + */ + +struct childless { + struct configfs_subsystem subsys; + int showme; + int storeme; +}; + +static inline struct childless *to_childless(struct config_item *item) +{ + return item ? container_of(to_configfs_subsystem(to_config_group(item)), + struct childless, subsys) : NULL; +} + +static ssize_t childless_showme_show(struct config_item *item, char *page) +{ + struct childless *childless = to_childless(item); + ssize_t pos; + + pos = sprintf(page, "%d\n", childless->showme); + childless->showme++; + + return pos; +} + +static ssize_t childless_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_childless(item)->storeme); +} + +static ssize_t childless_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct childless *childless = to_childless(item); + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + childless->storeme = tmp; + + return count; +} + +static ssize_t childless_description_show(struct config_item *item, char *page) +{ + return sprintf(page, +"[01-childless]\n" +"\n" +"The childless subsystem is the simplest possible subsystem in\n" +"configfs. It does not support the creation of child config_items.\n" +"It only has a few attributes. In fact, it isn't much different\n" +"than a directory in /proc.\n"); +} + +CONFIGFS_ATTR_RO(childless_, showme); +CONFIGFS_ATTR(childless_, storeme); +CONFIGFS_ATTR_RO(childless_, description); + +static struct configfs_attribute *childless_attrs[] = { + &childless_attr_showme, + &childless_attr_storeme, + &childless_attr_description, + NULL, +}; + +static struct config_item_type childless_type = { + .ct_attrs = childless_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct childless childless_subsys = { + .subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "01-childless", + .ci_type = &childless_type, + }, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 02-simple-children + * + * This example merely has a simple one-attribute child. Note that + * there is no extra attribute structure, as the child's attribute is + * known from the get-go. Also, there is no container for the + * subsystem, as it has no attributes of its own. + */ + +struct simple_child { + struct config_item item; + int storeme; +}; + +static inline struct simple_child *to_simple_child(struct config_item *item) +{ + return item ? container_of(item, struct simple_child, item) : NULL; +} + +static ssize_t simple_child_storeme_show(struct config_item *item, char *page) +{ + return sprintf(page, "%d\n", to_simple_child(item)->storeme); +} + +static ssize_t simple_child_storeme_store(struct config_item *item, + const char *page, size_t count) +{ + struct simple_child *simple_child = to_simple_child(item); + unsigned long tmp; + char *p = (char *) page; + + tmp = simple_strtoul(p, &p, 10); + if (!p || (*p && (*p != '\n'))) + return -EINVAL; + + if (tmp > INT_MAX) + return -ERANGE; + + simple_child->storeme = tmp; + + return count; +} + +CONFIGFS_ATTR(simple_child_, storeme); + +static struct configfs_attribute *simple_child_attrs[] = { + &simple_child_attr_storeme, + NULL, +}; + +static void simple_child_release(struct config_item *item) +{ + kfree(to_simple_child(item)); +} + +static struct configfs_item_operations simple_child_item_ops = { + .release = simple_child_release, +}; + +static struct config_item_type simple_child_type = { + .ct_item_ops = &simple_child_item_ops, + .ct_attrs = simple_child_attrs, + .ct_owner = THIS_MODULE, +}; + + +struct simple_children { + struct config_group group; +}; + +static inline struct simple_children *to_simple_children(struct config_item *item) +{ + return item ? container_of(to_config_group(item), + struct simple_children, group) : NULL; +} + +static struct config_item *simple_children_make_item(struct config_group *group, + const char *name) +{ + struct simple_child *simple_child; + + simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL); + if (!simple_child) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&simple_child->item, name, + &simple_child_type); + + simple_child->storeme = 0; + + return &simple_child->item; +} + +static ssize_t simple_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[02-simple-children]\n" +"\n" +"This subsystem allows the creation of child config_items. These\n" +"items have only one attribute that is readable and writeable.\n"); +} + +CONFIGFS_ATTR_RO(simple_children_, description); + +static struct configfs_attribute *simple_children_attrs[] = { + &simple_children_attr_description, + NULL, +}; + +static void simple_children_release(struct config_item *item) +{ + kfree(to_simple_children(item)); +} + +static struct configfs_item_operations simple_children_item_ops = { + .release = simple_children_release, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations simple_children_group_ops = { + .make_item = simple_children_make_item, +}; + +static struct config_item_type simple_children_type = { + .ct_item_ops = &simple_children_item_ops, + .ct_group_ops = &simple_children_group_ops, + .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem simple_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "02-simple-children", + .ci_type = &simple_children_type, + }, + }, +}; + + +/* ----------------------------------------------------------------- */ + +/* + * 03-group-children + * + * This example reuses the simple_children group from above. However, + * the simple_children group is not the subsystem itself, it is a + * child of the subsystem. Creation of a group in the subsystem creates + * a new simple_children group. That group can then have simple_child + * children of its own. + */ + +static struct config_group *group_children_make_group( + struct config_group *group, const char *name) +{ + struct simple_children *simple_children; + + simple_children = kzalloc(sizeof(struct simple_children), + GFP_KERNEL); + if (!simple_children) + return ERR_PTR(-ENOMEM); + + config_group_init_type_name(&simple_children->group, name, + &simple_children_type); + + return &simple_children->group; +} + +static ssize_t group_children_description_show(struct config_item *item, + char *page) +{ + return sprintf(page, +"[03-group-children]\n" +"\n" +"This subsystem allows the creation of child config_groups. These\n" +"groups are like the subsystem simple-children.\n"); +} + +CONFIGFS_ATTR_RO(group_children_, description); + +static struct configfs_attribute *group_children_attrs[] = { + &group_children_attr_description, + NULL, +}; + +/* + * Note that, since no extra work is required on ->drop_item(), + * no ->drop_item() is provided. + */ +static struct configfs_group_operations group_children_group_ops = { + .make_group = group_children_make_group, +}; + +static struct config_item_type group_children_type = { + .ct_group_ops = &group_children_group_ops, + .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem group_children_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "03-group-children", + .ci_type = &group_children_type, + }, + }, +}; + +/* ----------------------------------------------------------------- */ + +/* + * We're now done with our subsystem definitions. + * For convenience in this module, here's a list of them all. It + * allows the init function to easily register them. Most modules + * will only have one subsystem, and will only call register_subsystem + * on it directly. + */ +static struct configfs_subsystem *example_subsys[] = { + &childless_subsys.subsys, + &simple_children_subsys, + &group_children_subsys, + NULL, +}; + +static int __init configfs_example_init(void) +{ + int ret; + int i; + struct configfs_subsystem *subsys; + + for (i = 0; example_subsys[i]; i++) { + subsys = example_subsys[i]; + + config_group_init(&subsys->su_group); + mutex_init(&subsys->su_mutex); + ret = configfs_register_subsystem(subsys); + if (ret) { + printk(KERN_ERR "Error %d while registering subsystem %s\n", + ret, + subsys->su_group.cg_item.ci_namebuf); + goto out_unregister; + } + } + + return 0; + +out_unregister: + for (i--; i >= 0; i--) + configfs_unregister_subsystem(example_subsys[i]); + + return ret; +} + +static void __exit configfs_example_exit(void) +{ + int i; + + for (i = 0; example_subsys[i]; i++) + configfs_unregister_subsystem(example_subsys[i]); +} + +module_init(configfs_example_init); +module_exit(configfs_example_exit); +MODULE_LICENSE("GPL"); |
