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-rw-r--r--include/linux/sysctl.h8
-rw-r--r--kernel/sysctl.c89
2 files changed, 82 insertions, 15 deletions
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 4f5047df8a9..3b6e2c9fbb2 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 8e96558cb8f..f580542333e 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);