diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 4f5047df8a9e..3b6e2c9fbb2e 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -1059,7 +1059,15 @@ struct ctl_table_header struct completion *unregistering; }; +/* struct ctl_path describes where in the hierarchy a table is added */ +struct ctl_path { + const char *procname; + int ctl_name; +}; + struct ctl_table_header *register_sysctl_table(struct ctl_table * table); +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table); void unregister_sysctl_table(struct ctl_table_header * table); int sysctl_check_table(struct ctl_table *table); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8e96558cb8f3..f580542333eb 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1561,11 +1561,12 @@ static __init int sysctl_init(void) core_initcall(sysctl_init); /** - * register_sysctl_table - register a sysctl hierarchy + * register_sysctl_paths - register a sysctl hierarchy + * @path: The path to the directory the sysctl table is in. * @table: the top-level table structure * * Register a sysctl table hierarchy. @table should be a filled in ctl_table - * array. An entry with a ctl_name of 0 terminates the table. + * array. A completely 0 filled entry terminates the table. * * The members of the &struct ctl_table structure are used as follows: * @@ -1628,25 +1629,76 @@ core_initcall(sysctl_init); * This routine returns %NULL on a failure to register, and a pointer * to the table header on success. */ -struct ctl_table_header *register_sysctl_table(struct ctl_table * table) +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table) { - struct ctl_table_header *tmp; - tmp = kmalloc(sizeof(struct ctl_table_header), GFP_KERNEL); - if (!tmp) + struct ctl_table_header *header; + struct ctl_table *new, **prevp; + unsigned int n, npath; + + /* Count the path components */ + for (npath = 0; path[npath].ctl_name || path[npath].procname; ++npath) + ; + + /* + * For each path component, allocate a 2-element ctl_table array. + * The first array element will be filled with the sysctl entry + * for this, the second will be the sentinel (ctl_name == 0). + * + * We allocate everything in one go so that we don't have to + * worry about freeing additional memory in unregister_sysctl_table. + */ + header = kzalloc(sizeof(struct ctl_table_header) + + (2 * npath * sizeof(struct ctl_table)), GFP_KERNEL); + if (!header) return NULL; - tmp->ctl_table = table; - INIT_LIST_HEAD(&tmp->ctl_entry); - tmp->used = 0; - tmp->unregistering = NULL; - sysctl_set_parent(NULL, table); - if (sysctl_check_table(tmp->ctl_table)) { - kfree(tmp); + + new = (struct ctl_table *) (header + 1); + + /* Now connect the dots */ + prevp = &header->ctl_table; + for (n = 0; n < npath; ++n, ++path) { + /* Copy the procname */ + new->procname = path->procname; + new->ctl_name = path->ctl_name; + new->mode = 0555; + + *prevp = new; + prevp = &new->child; + + new += 2; + } + *prevp = table; + + INIT_LIST_HEAD(&header->ctl_entry); + header->used = 0; + header->unregistering = NULL; + sysctl_set_parent(NULL, header->ctl_table); + if (sysctl_check_table(header->ctl_table)) { + kfree(header); return NULL; } spin_lock(&sysctl_lock); - list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry); + list_add_tail(&header->ctl_entry, &root_table_header.ctl_entry); spin_unlock(&sysctl_lock); - return tmp; + + return header; +} + +/** + * register_sysctl_table - register a sysctl table hierarchy + * @table: the top-level table structure + * + * Register a sysctl table hierarchy. @table should be a filled in ctl_table + * array. A completely 0 filled entry terminates the table. + * + * See register_sysctl_paths for more details. + */ +struct ctl_table_header *register_sysctl_table(struct ctl_table *table) +{ + static const struct ctl_path null_path[] = { {} }; + + return register_sysctl_paths(null_path, table); } /** @@ -1675,6 +1727,12 @@ struct ctl_table_header *register_sysctl_table(struct ctl_table * table) return NULL; } +struct ctl_table_header *register_sysctl_paths(const struct ctl_path *path, + struct ctl_table *table) +{ + return NULL; +} + void unregister_sysctl_table(struct ctl_table_header * table) { } @@ -2733,6 +2791,7 @@ EXPORT_SYMBOL(proc_dostring); EXPORT_SYMBOL(proc_doulongvec_minmax); EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax); EXPORT_SYMBOL(register_sysctl_table); +EXPORT_SYMBOL(register_sysctl_paths); EXPORT_SYMBOL(sysctl_intvec); EXPORT_SYMBOL(sysctl_jiffies); EXPORT_SYMBOL(sysctl_ms_jiffies);