1 files changed, 186 insertions, 98 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 780690dc08cd..288fe0055cd5 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -59,40 +59,158 @@ extern const int sysctl_vals[];
 #define SYSCTL_LONG_ONE		((void *)&sysctl_long_vals[1])
 #define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[2])
 
+#define SYSCTL_CONV_IDENTITY(val) (val)
+/**
+ *
+ * "dir" originates from read_iter (dir = 0) or write_iter (dir = 1)
+ * in the file_operations struct at proc/proc_sysctl.c. Its value means
+ * one of two things for sysctl:
+ * 1. SYSCTL_USER_TO_KERN(dir) Writing to an internal kernel variable from user
+ *                             space (dir > 0)
+ * 2. SYSCTL_KERN_TO_USER(dir) Writing to a user space buffer from a kernel
+ *                             variable (dir == 0).
+ */
+#define SYSCTL_USER_TO_KERN(dir) (!!(dir))
+#define SYSCTL_KERN_TO_USER(dir) (!dir)
+
+#define SYSCTL_USER_TO_KERN_INT_CONV(name, u_ptr_op)		\
+int sysctl_user_to_kern_int_conv##name(const bool *negp,	\
+				       const unsigned long *u_ptr,\
+				       int *k_ptr)		\
+{								\
+	unsigned long u = u_ptr_op(*u_ptr);			\
+	if (*negp) {						\
+		if (u > (unsigned long) INT_MAX + 1)		\
+			return -EINVAL;				\
+		WRITE_ONCE(*k_ptr, -u);				\
+	} else {						\
+		if (u > (unsigned long) INT_MAX)		\
+			return -EINVAL;				\
+		WRITE_ONCE(*k_ptr, u);				\
+	}							\
+	return 0;						\
+}
+
+#define SYSCTL_KERN_TO_USER_INT_CONV(name, k_ptr_op)		\
+int sysctl_kern_to_user_int_conv##name(bool *negp,		\
+				       unsigned long *u_ptr,	\
+				       const int *k_ptr)	\
+{								\
+	int val = READ_ONCE(*k_ptr);				\
+	if (val < 0) {						\
+		*negp = true;					\
+		*u_ptr = -k_ptr_op((unsigned long)val);		\
+	} else {						\
+		*negp = false;					\
+		*u_ptr = k_ptr_op((unsigned long)val);		\
+	}							\
+	return 0;						\
+}
+
+/**
+ * To range check on a converted value, use a temp k_ptr
+ * When checking range, value should be within (tbl->extra1, tbl->extra2)
+ */
+#define SYSCTL_INT_CONV_CUSTOM(name, user_to_kern, kern_to_user,	\
+			       k_ptr_range_check)			\
+int do_proc_int_conv##name(bool *negp, unsigned long *u_ptr, int *k_ptr,\
+			   int dir, const struct ctl_table *tbl)	\
+{									\
+	if (SYSCTL_KERN_TO_USER(dir))					\
+		return kern_to_user(negp, u_ptr, k_ptr);		\
+									\
+	if (k_ptr_range_check) {					\
+		int tmp_k, ret;						\
+		if (!tbl)						\
+			return -EINVAL;					\
+		ret = user_to_kern(negp, u_ptr, &tmp_k);		\
+		if (ret)						\
+			return ret;					\
+		if ((tbl->extra1 && *(int *)tbl->extra1 > tmp_k) ||	\
+		    (tbl->extra2 && *(int *)tbl->extra2 < tmp_k))	\
+			return -EINVAL;					\
+		WRITE_ONCE(*k_ptr, tmp_k);				\
+	} else								\
+		return user_to_kern(negp, u_ptr, k_ptr);		\
+	return 0;							\
+}
+
+#define SYSCTL_USER_TO_KERN_UINT_CONV(name, u_ptr_op)		\
+int sysctl_user_to_kern_uint_conv##name(const unsigned long *u_ptr,\
+					unsigned int *k_ptr)	\
+{								\
+	unsigned long u = u_ptr_op(*u_ptr);			\
+	if (u > UINT_MAX)					\
+		return -EINVAL;					\
+	WRITE_ONCE(*k_ptr, u);					\
+	return 0;						\
+}
+
+#define SYSCTL_UINT_CONV_CUSTOM(name, user_to_kern, kern_to_user,	\
+				k_ptr_range_check)			\
+int do_proc_uint_conv##name(unsigned long *u_ptr, unsigned int *k_ptr,	\
+			   int dir, const struct ctl_table *tbl)	\
+{									\
+	if (SYSCTL_KERN_TO_USER(dir))					\
+		return kern_to_user(u_ptr, k_ptr);			\
+									\
+	if (k_ptr_range_check) {					\
+		unsigned int tmp_k;					\
+		int ret;						\
+		if (!tbl)						\
+			return -EINVAL;					\
+		ret = user_to_kern(u_ptr, &tmp_k);			\
+		if (ret)						\
+			return ret;					\
+		if ((tbl->extra1 &&					\
+		     *(unsigned int *)tbl->extra1 > tmp_k) ||		\
+		    (tbl->extra2 &&					\
+		     *(unsigned int *)tbl->extra2 < tmp_k))		\
+			return -ERANGE;					\
+		WRITE_ONCE(*k_ptr, tmp_k);				\
+	} else								\
+		return user_to_kern(u_ptr, k_ptr);			\
+	return 0;							\
+}
+
+
 extern const unsigned long sysctl_long_vals[];
 
-typedef int proc_handler(struct ctl_table *ctl, int write, void *buffer,
+typedef int proc_handler(const struct ctl_table *ctl, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
 
-int proc_dostring(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_dobool(struct ctl_table *table, int write, void *buffer,
+int proc_dostring(const struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dobool(const struct ctl_table *table, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
-int proc_dointvec(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_douintvec(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_dointvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_douintvec_minmax(struct ctl_table *table, int write, void *buffer,
+int proc_dointvec(const struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_dointvec_minmax(const struct ctl_table *table, int dir, void *buffer,
+			 size_t *lenp, loff_t *ppos);
+int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
+		       size_t *lenp, loff_t *ppos,
+		       int (*conv)(bool *negp, unsigned long *u_ptr, int *k_ptr,
+				   int dir, const struct ctl_table *table));
+int proc_douintvec(const struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_douintvec_minmax(const struct ctl_table *table, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
-int proc_dou8vec_minmax(struct ctl_table *table, int write, void *buffer,
+int proc_douintvec_conv(const struct ctl_table *table, int write, void *buffer,
+			size_t *lenp, loff_t *ppos,
+			int (*conv)(unsigned long *lvalp, unsigned int *valp,
+				    int write, const struct ctl_table *table));
+
+int proc_dou8vec_minmax(const struct ctl_table *table, int write, void *buffer,
 			size_t *lenp, loff_t *ppos);
-int proc_dointvec_jiffies(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
-int proc_dointvec_userhz_jiffies(struct ctl_table *, int, void *, size_t *,
-		loff_t *);
-int proc_dointvec_ms_jiffies(struct ctl_table *, int, void *, size_t *,
-		loff_t *);
-int proc_doulongvec_minmax(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, void *,
-		size_t *, loff_t *);
-int proc_do_large_bitmap(struct ctl_table *, int, void *, size_t *, loff_t *);
-int proc_do_static_key(struct ctl_table *table, int write, void *buffer,
+int proc_doulongvec_minmax(const struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
+				void *buffer, size_t *lenp, loff_t *ppos,
+				unsigned long convmul, unsigned long convdiv);
+int proc_do_large_bitmap(const struct ctl_table *, int, void *, size_t *, loff_t *);
+int proc_do_static_key(const struct ctl_table *table, int write, void *buffer,
 		size_t *lenp, loff_t *ppos);
+int sysctl_kern_to_user_uint_conv(unsigned long *u_ptr, const unsigned int *k_ptr);
 
 /*
- * Register a set of sysctl names by calling register_sysctl_table
- * with an initialised array of struct ctl_table's.  An entry with 
- * NULL procname terminates the table.  table->de will be
- * set up by the registration and need not be initialised in advance.
+ * Register a set of sysctl names by calling register_sysctl
+ * with an initialised array of struct ctl_table's.
  *
  * sysctl names can be mirrored automatically under /proc/sys.  The
  * procname supplied controls /proc naming.
@@ -133,11 +251,10 @@ static inline void *proc_sys_poll_event(struct ctl_table_poll *poll)
 
 /* A sysctl table is an array of struct ctl_table: */
 struct ctl_table {
-	const char *procname;		/* Text ID for /proc/sys, or zero */
+	const char *procname;		/* Text ID for /proc/sys */
 	void *data;
 	int maxlen;
 	umode_t mode;
-	struct ctl_table *child;	/* Deprecated */
 	proc_handler *proc_handler;	/* Callback for text formatting */
 	struct ctl_table_poll *poll;
 	void *extra1;
@@ -149,12 +266,26 @@ struct ctl_node {
 	struct ctl_table_header *header;
 };
 
-/* struct ctl_table_header is used to maintain dynamic lists of
-   struct ctl_table trees. */
+/**
+ * struct ctl_table_header - maintains dynamic lists of struct ctl_table trees
+ * @ctl_table: pointer to the first element in ctl_table array
+ * @ctl_table_size: number of elements pointed by @ctl_table
+ * @used: The entry will never be touched when equal to 0.
+ * @count: Upped every time something is added to @inodes and downed every time
+ *         something is removed from inodes
+ * @nreg: When nreg drops to 0 the ctl_table_header will be unregistered.
+ * @rcu: Delays the freeing of the inode. Introduced with "unfuck proc_sysctl ->d_compare()"
+ *
+ * @type: Enumeration to differentiate between ctl target types
+ * @type.SYSCTL_TABLE_TYPE_DEFAULT: ctl target with no special considerations
+ * @type.SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY: Identifies a permanently empty dir
+ *                                            target to serve as a mount point
+ */
 struct ctl_table_header {
 	union {
 		struct {
-			struct ctl_table *ctl_table;
+			const struct ctl_table *ctl_table;
+			int ctl_table_size;
 			int used;
 			int count;
 			int nreg;
@@ -162,12 +293,16 @@ struct ctl_table_header {
 		struct rcu_head rcu;
 	};
 	struct completion *unregistering;
-	struct ctl_table *ctl_table_arg;
+	const struct ctl_table *ctl_table_arg;
 	struct ctl_table_root *root;
 	struct ctl_table_set *set;
 	struct ctl_dir *parent;
 	struct ctl_node *node;
 	struct hlist_head inodes; /* head for proc_inode->sysctl_inodes */
+	enum {
+		SYSCTL_TABLE_TYPE_DEFAULT,
+		SYSCTL_TABLE_TYPE_PERMANENTLY_EMPTY,
+	} type;
 };
 
 struct ctl_dir {
@@ -185,32 +320,15 @@ struct ctl_table_root {
 	struct ctl_table_set default_set;
 	struct ctl_table_set *(*lookup)(struct ctl_table_root *root);
 	void (*set_ownership)(struct ctl_table_header *head,
-			      struct ctl_table *table,
 			      kuid_t *uid, kgid_t *gid);
-	int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
+	int (*permissions)(struct ctl_table_header *head, const struct ctl_table *table);
 };
 
-/* struct ctl_path describes where in the hierarchy a table is added */
-struct ctl_path {
-	const char *procname;
-};
+#define register_sysctl(path, table)	\
+	register_sysctl_sz(path, table, ARRAY_SIZE(table))
 
 #ifdef CONFIG_SYSCTL
 
-#define DECLARE_SYSCTL_BASE(_name, _table)				\
-static struct ctl_table _name##_base_table[] = {			\
-	{								\
-		.procname	= #_name,				\
-		.mode		= 0555,					\
-		.child		= _table,				\
-	},								\
-	{ },								\
-}
-
-extern int __register_sysctl_base(struct ctl_table *base_table);
-
-#define register_sysctl_base(_name) __register_sysctl_base(_name##_base_table)
-
 void proc_sys_poll_notify(struct ctl_table_poll *poll);
 
 extern void setup_sysctl_set(struct ctl_table_set *p,
@@ -220,55 +338,27 @@ extern void retire_sysctl_set(struct ctl_table_set *set);
 
 struct ctl_table_header *__register_sysctl_table(
 	struct ctl_table_set *set,
-	const char *path, struct ctl_table *table);
-struct ctl_table_header *__register_sysctl_paths(
-	struct ctl_table_set *set,
-	const struct ctl_path *path, struct ctl_table *table);
-struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table);
-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);
-
+	const char *path, const struct ctl_table *table, size_t table_size);
+struct ctl_table_header *register_sysctl_sz(const char *path, const struct ctl_table *table,
+					    size_t table_size);
 void unregister_sysctl_table(struct ctl_table_header * table);
 
 extern int sysctl_init_bases(void);
-extern void __register_sysctl_init(const char *path, struct ctl_table *table,
-				 const char *table_name);
-#define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table)
+extern void __register_sysctl_init(const char *path, const struct ctl_table *table,
+				 const char *table_name, size_t table_size);
+#define register_sysctl_init(path, table)	\
+	__register_sysctl_init(path, table, #table, ARRAY_SIZE(table))
 extern struct ctl_table_header *register_sysctl_mount_point(const char *path);
 
 void do_sysctl_args(void);
-int do_proc_douintvec(struct ctl_table *table, int write,
-		      void *buffer, size_t *lenp, loff_t *ppos,
-		      int (*conv)(unsigned long *lvalp,
-				  unsigned int *valp,
-				  int write, void *data),
-		      void *data);
-
-extern int pwrsw_enabled;
+bool sysctl_is_alias(char *param);
+
 extern int unaligned_enabled;
-extern int unaligned_dump_stack;
 extern int no_unaligned_warning;
 
-extern struct ctl_table sysctl_mount_point[];
-
 #else /* CONFIG_SYSCTL */
 
-#define DECLARE_SYSCTL_BASE(_name, _table)
-
-static inline int __register_sysctl_base(struct ctl_table *base_table)
-{
-	return 0;
-}
-
-#define register_sysctl_base(table) __register_sysctl_base(table)
-
-static inline struct ctl_table_header *register_sysctl_table(struct ctl_table * table)
-{
-	return NULL;
-}
-
-static inline void register_sysctl_init(const char *path, struct ctl_table *table)
+static inline void register_sysctl_init(const char *path, const struct ctl_table *table)
 {
 }
 
@@ -277,13 +367,9 @@ static inline struct ctl_table_header *register_sysctl_mount_point(const char *p
 	return NULL;
 }
 
-static inline struct ctl_table_header *register_sysctl_paths(
-			const struct ctl_path *path, struct ctl_table *table)
-{
-	return NULL;
-}
-
-static inline struct ctl_table_header *register_sysctl(const char *path, struct ctl_table *table)
+static inline struct ctl_table_header *register_sysctl_sz(const char *path,
+							  const struct ctl_table *table,
+							  size_t table_size)
 {
 	return NULL;
 }
@@ -301,9 +387,11 @@ static inline void setup_sysctl_set(struct ctl_table_set *p,
 static inline void do_sysctl_args(void)
 {
 }
-#endif /* CONFIG_SYSCTL */
 
-int sysctl_max_threads(struct ctl_table *table, int write, void *buffer,
-		size_t *lenp, loff_t *ppos);
+static inline bool sysctl_is_alias(char *param)
+{
+	return false;
+}
+#endif /* CONFIG_SYSCTL */
 
 #endif /* _LINUX_SYSCTL_H */