Merge branch 'sysctl-next' of https://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl.git

# Conflicts:
#	kernel/time/jiffies.c

1 files changed, 93 insertions, 38 deletions

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 2886fbceb5d6..e5d7226ab6f5 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -59,7 +59,7 @@ extern const int sysctl_vals[];
 #define SYSCTL_LONG_ONE		((void *)&sysctl_long_vals[1])
 #define SYSCTL_LONG_MAX		((void *)&sysctl_long_vals[2])
 
-/**
+/*
  *
  * "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
@@ -74,53 +74,108 @@ extern const int sysctl_vals[];
 
 extern const unsigned long sysctl_long_vals[];
 
-typedef int proc_handler(const struct ctl_table *ctl, int write, void *buffer,
-		size_t *lenp, loff_t *ppos);
-
-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);
+typedef int proc_handler(const struct ctl_table *ctl, int dir, void *buf,
+			 size_t *lenp, loff_t *ppos);
 
-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,
+/* proc_handler functions */
+int proc_dostring(const struct ctl_table *ctl, int dir, void *buf, size_t *lenp,
+		  loff_t *ppos);
+int proc_dobool(const struct ctl_table *ctl, int dir, void *buf, size_t *lenp,
+		loff_t *ppos);
+int proc_dointvec(const struct ctl_table *ctl, int dir, void *buf, size_t *lenp,
+		  loff_t *ppos);
+int proc_dointvec_minmax(const struct ctl_table *ctl, int dir, void *buf,
+			 size_t *lenp, loff_t *ppos);
+int proc_douintvec(const struct ctl_table *ctl, int dir, void *buf, size_t *lenp,
+		   loff_t *ppos);
+int proc_douintvec_minmax(const struct ctl_table *ctl, int dir, void *buf,
+			  size_t *lenp, loff_t *ppos);
+int proc_dou8vec_minmax(const struct ctl_table *ctl, int dir, void *buf,
+			size_t *lenp, loff_t *ppos);
+int proc_doulongvec_minmax(const struct ctl_table *ctl, int dir, void *buf,
+			   size_t *lenp, loff_t *ppos);
+int proc_do_large_bitmap(const struct ctl_table *ctl, int dir, void *buf,
 			 size_t *lenp, loff_t *ppos);
-int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
+int proc_do_static_key(const struct ctl_table *ctl, int dir, void *buf,
+		       size_t *lenp, loff_t *ppos);
+
+/*
+ * proc_handler aggregators
+ *
+ * Create a proc_handler with a custom converter. Use when the user space
+ * value is a transformation of the kernel value. Cannot be passed as
+ * proc_handlers.
+ *
+ * Example of creating your custom proc handler:
+ * int custom_converter(bool *negp, ulong *u_ptr, uint *k_ptr,
+ *                      int dir, const struct ctl_table *ctl) {...}
+ * int custom_proc_handler(const struct ctl_table *ctl, int dir,
+ *                         void *buf, size_t *lenp, loff_t *ppos
+ * { return proc_dointvec_conv(ctl, dir, buf, lenp, ppos, custom_converter); }
+ */
+int proc_dointvec_conv(const struct ctl_table *ctl, int dir, void *buf,
 		       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_int_k2u_conv_kop(ulong *u_ptr, const int *k_ptr, bool *negp,
-			  ulong (*k_ptr_op)(const ulong));
-int proc_int_u2k_conv_uop(const ulong *u_ptr, int *k_ptr, const bool *negp,
-			  ulong (*u_ptr_op)(const ulong));
+				   int dir, const struct ctl_table *ctl));
+int proc_douintvec_conv(const struct ctl_table *ctl, int dir, void *buf,
+			size_t *lenp, loff_t *ppos,
+			int (*conv)(bool *negp, ulong *u_ptr, uint *k_ptr,
+				    int dir, const struct ctl_table *ctl));
+int proc_doulongvec_conv(const struct ctl_table *ctl, int dir, void *buf,
+			 size_t *lenp, loff_t *ppos,
+			 int (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
+				     int dir, const struct ctl_table *ctl));
+
+/*
+ * bi-directional converter functions
+ *
+ * Specify the converter function for both directions (user to kernel & kernel
+ * to user). Use when you want to change the value of the variable before
+ * assignment. Used to create custom proc_handler aggregators.
+ *
+ * Example of creating your custom bi-directional converter:
+ * int custom_u2k(ulong *u_ptr, const uint *k_ptr) { ... }
+ * int custom_converter(bool *negp, ulong *u_ptr, uint *k_ptr,
+ *                      int dir, const struct ctl_table *ctl)
+ * { return proc_uint_conv(u_ptr, k_ptr, dir, ctl, true,
+ *                         custom_u2k, proc_uint_k2u_conv}
+ */
 int proc_int_conv(bool *negp, ulong *u_ptr, int *k_ptr, int dir,
 		  const struct ctl_table *tbl, bool k_ptr_range_check,
 		  int (*user_to_kern)(const bool *negp, const ulong *u_ptr, int *k_ptr),
 		  int (*kern_to_user)(bool *negp, ulong *u_ptr, const int *k_ptr));
-
-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_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_uint_k2u_conv(ulong *u_ptr, const uint *k_ptr);
-int proc_uint_u2k_conv_uop(const ulong *u_ptr, uint *k_ptr,
-			   ulong (*u_ptr_op)(const ulong));
 int proc_uint_conv(ulong *u_ptr, uint *k_ptr, int dir,
 		   const struct ctl_table *tbl, bool k_ptr_range_check,
 		   int (*user_to_kern)(const ulong *u_ptr, uint *k_ptr),
 		   int (*kern_to_user)(ulong *u_ptr, const uint *k_ptr));
+int proc_ulong_conv(ulong *u_ptr, ulong *k_ptr, int dir,
+		    const struct ctl_table *tbl, bool k_ptr_range_check,
+		    int (*user_to_kern)(const ulong *u_ptr, ulong *k_ptr),
+		    int (*kern_to_user)(ulong *u_ptr, const ulong *k_ptr));
 
-int proc_dou8vec_minmax(const struct ctl_table *table, int write, void *buffer,
-			size_t *lenp, loff_t *ppos);
-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);
+/*
+ * uni-directional converter functions
+ *
+ * Specify the converter function for one directions (user to kernel or
+ * kernel to user). Use to call the actual value conversion. Used to Create
+ * bi-directional converters.
+ *
+ * Example of creating a uni-directional converter:
+ * ulong op(const ulong val) { ... }
+ * int custom_unidir_conv(ulong *u_ptr, const uint *k_ptr)
+ * { return proc_uint_k2u_conv_kop(u_ptr, k_ptr, op); }
+ */
+int proc_int_k2u_conv_kop(ulong *u_ptr, const int *k_ptr, bool *negp,
+			  ulong (*k_ptr_op)(const ulong));
+int proc_int_u2k_conv_uop(const ulong *u_ptr, int *k_ptr, const bool *negp,
+			  ulong (*u_ptr_op)(const ulong));
+int proc_uint_k2u_conv(ulong *u_ptr, const uint *k_ptr);
+int proc_uint_u2k_conv_uop(const ulong *u_ptr, uint *k_ptr,
+			   ulong (*u_ptr_op)(const ulong));
+int proc_ulong_u2k_conv_uop(const ulong *u_ptr, ulong *k_ptr,
+			    ulong (*u_ptr_op)(const ulong));
+int proc_ulong_k2u_conv_kop(ulong *u_ptr, const ulong *k_ptr,
+			    ulong (*k_ptr_op)(const ulong));
 
 /*
  * Register a set of sysctl names by calling register_sysctl
@@ -190,9 +245,9 @@ struct ctl_node {
  * @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
+ * @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 {