kernel/sysctl.c: add kdoc comments to do_proc_do{u}intvec_minmax_conv_param

Kdoc comments are added to the do_proc_dointvec_minmax_conv_param and
do_proc_douintvec_minmax_conv_param structures thare are used internally
for range checking.

The error codes returned by proc_dointvec_minmax() and
proc_douintvec_minmax() are also documented.

Link: http://lkml.kernel.org/r/1519926220-7453-3-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/sysctl.c

@@ -2511,6 +2511,15 @@ static int proc_dointvec_minmax_sysadmin(struct ctl_table *table, int write,
 }
 #endif
 
+/**
+ * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
+ * @min: pointer to minimum allowable value
+ * @max: pointer to maximum allowable value
+ *
+ * The do_proc_dointvec_minmax_conv_param structure provides the
+ * minimum and maximum values for doing range checking for those sysctl
+ * parameters that use the proc_dointvec_minmax() handler.
+ */
 struct do_proc_dointvec_minmax_conv_param {
 	int *min;
 	int *max;
@@ -2554,7 +2563,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
  * This routine will ensure the values are within the range specified by
  * table->extra1 (min) and table->extra2 (max).
  *
- * Returns 0 on success.
+ * Returns 0 on success or -EINVAL on write when the range check fails.
  */
 int proc_dointvec_minmax(struct ctl_table *table, int write,
 		  void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -2567,6 +2576,15 @@ int proc_dointvec_minmax(struct ctl_table *table, int write,
 				do_proc_dointvec_minmax_conv, &param);
 }
 
+/**
+ * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
+ * @min: pointer to minimum allowable value
+ * @max: pointer to maximum allowable value
+ *
+ * The do_proc_douintvec_minmax_conv_param structure provides the
+ * minimum and maximum values for doing range checking for those sysctl
+ * parameters that use the proc_douintvec_minmax() handler.
+ */
 struct do_proc_douintvec_minmax_conv_param {
 	unsigned int *min;
 	unsigned int *max;
@@ -2614,7 +2632,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
  * check for UINT_MAX to avoid having to support wrap around uses from
  * userspace.
  *
- * Returns 0 on success.
+ * Returns 0 on success or -ERANGE on write when the range check fails.
  */
 int proc_douintvec_minmax(struct ctl_table *table, int write,
 			  void __user *buffer, size_t *lenp, loff_t *ppos)