[PATCH 0/9] sysctl: Consolidate do_proc_* functions into one macro

[PATCH 0/9] sysctl: Consolidate do_proc_* functions into one macro

[Joel Granados]

What
====
Generate do_proc_{int,uint,ulong} with the new do_proc_typevec macro.
Removed small differences between each implementation and put it all
under one roof. This macro is meant for internal (to sysctl.c) static
functions; it should not be used from the outside.

Groups and document the proc handler and converter functions in
include/linux/sysctl.h. Document how to create custom converters
with examples for every converter type.

This series sits on top of [1], you can see the working branch here [2].

Why
===
Working with one instead of three slightly different implementations of
the same thing makes more sense to me for three reasons: 1. I don't have
to think about the different types separately (less context switches) and
2. One place to begin debugging proc_handler issues and 3. A fix for
one type, fixes all types.

A word on macros
================
I have mixed feelings about the use of macros here, especially because
it is such a long function. But I see it as the first step. Having this
in mainline will validate that the three types **indeed** have the same
logic (I have tested extensively, but linux-next & mainline are the
ultimate tests). Once this is established in mainline, implementing an
alternative way of parametrizing becomes easier.

A word on checkpatch
====================
* It does not like that ENOSYS is returned for the no-op functions. I'm
  just following the pattern that was initially there. Does -EINVAL
  makes more sense?
* It has a false positive on a spacing around a pointer.

Testing
=======
Ran sysctl selftest/kunit on x86_64 and 0-day.

Comments are greatly appreciated

[1] https://lore.kernel.org/20251217-jag-no-macro-conv-v1-0-6e4252687915@kernel.org
[2] https://git.kernel.org/pub/scm/linux/kernel/git/joel.granados/linux.git/log/?h=jag/dovec_consolidate

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
Joel Granados (9):
      sysctl: Move default converter assignment out of do_proc_dointvec
      sysctl: Replace do_proc_dointvec with a type-generic macro
      sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro
      sysctl: Add negp parameter to douintvec converter functions
      sysctl: Generate do_proc_douintvec with a type-generic macro
      sysctl: Rename do_proc_dotypevec macro to do_proc_typevec
      sysctl: Group proc_handler declarations and document
      sysctl: Rename proc_doulongvec_minmax_conv to proc_doulongvec_conv
      sysctl: Update API function documentation

 fs/pipe.c              |   2 +-
 include/linux/sysctl.h | 123 +++++++----
 kernel/sysctl.c        | 539 +++++++++++++++++++++++--------------------------
 kernel/time/jiffies.c  |  28 ++-
 4 files changed, 371 insertions(+), 321 deletions(-)
---
base-commit: 0616c77e5d877006efe3bea27ca195d396de08dc
change-id: 20251218-jag-dovec_consolidate-5a704f2a3f9b

Best regards,
-- 
Joel Granados <joel.granados@kernel.org>

[PATCH 1/9] sysctl: Move default converter assignment out of do_proc_dointvec

[Joel Granados]

Move the converter assignment out of do_proc_dointvec into the caller.
Both the test for NULL and the assignment are meant to stay within the
sysctl.c context. This is in preparation of using a typed macro to for
the integer proc vector function.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 kernel/sysctl.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index caee1bd8b2afc0927e0dcdd33c0db41c87518bfb..284ad6c277e8b52177cca3153acf02ff39de17f0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -591,9 +591,6 @@ static int do_proc_dointvec(const struct ctl_table *table, int dir,
 	vleft = table->maxlen / sizeof(*i);
 	left = *lenp;
 
-	if (!conv)
-		conv = do_proc_int_conv;
-
 	if (SYSCTL_USER_TO_KERN(dir)) {
 		if (proc_first_pos_non_zero_ignore(ppos, table))
 			goto out;
@@ -840,7 +837,7 @@ int proc_dobool(const struct ctl_table *table, int dir, void *buffer,
 int proc_dointvec(const struct ctl_table *table, int dir, void *buffer,
 		  size_t *lenp, loff_t *ppos)
 {
-	return do_proc_dointvec(table, dir, buffer, lenp, ppos, NULL);
+	return do_proc_dointvec(table, dir, buffer, lenp, ppos, do_proc_int_conv);
 }
 
 /**
@@ -1074,6 +1071,8 @@ int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
 		       int (*conv)(bool *negp, unsigned long *u_ptr, int *k_ptr,
 				   int dir, const struct ctl_table *table))
 {
+	if (!conv)
+		conv = do_proc_int_conv;
 	return do_proc_dointvec(table, dir, buffer, lenp, ppos, conv);
 }
 

-- 
2.50.1

[PATCH 2/9] sysctl: Replace do_proc_dointvec with a type-generic macro

[Joel Granados]

Replaces do_proc_dointvec with do_proc_dotypevec macro. For now, it only
generates the integer function, but it will bring together the logic for
int, uint and ulong proc vector functions. It is parametrized on the
kernel pointer type being processed and generates a "do_proc_do##T##vec"
(where T is the type) function. The parametrization is needed for
advancing the for loop with "++" and affects the type of the k_ptr
argument in the converter call back function. Add a comment to clarify
that the macro is **not** designed to be exported outside of sysctl.c.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 kernel/sysctl.c | 142 ++++++++++++++++++++++++++++++--------------------------
 1 file changed, 75 insertions(+), 67 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 284ad6c277e8b52177cca3153acf02ff39de17f0..66db2ac69a91ac4b200cb8906dcb76209bee28bb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -572,75 +572,83 @@ static int do_proc_int_conv_minmax(bool *negp, unsigned long *u_ptr, int *k_ptr,
 
 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
 
-static int do_proc_dointvec(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 *i, vleft, first = 1, err = 0;
-	size_t left;
-	char *p;
-
-	if (!table->data || !table->maxlen || !*lenp ||
-	    (*ppos && SYSCTL_KERN_TO_USER(dir))) {
-		*lenp = 0;
-		return 0;
-	}
-
-	i = (int *) table->data;
-	vleft = table->maxlen / sizeof(*i);
-	left = *lenp;
-
-	if (SYSCTL_USER_TO_KERN(dir)) {
-		if (proc_first_pos_non_zero_ignore(ppos, table))
-			goto out;
-
-		if (left > PAGE_SIZE - 1)
-			left = PAGE_SIZE - 1;
-		p = buffer;
-	}
-
-	for (; left && vleft--; i++, first=0) {
-		unsigned long lval;
-		bool neg;
-
-		if (SYSCTL_USER_TO_KERN(dir)) {
-			proc_skip_spaces(&p, &left);
-
-			if (!left)
-				break;
-			err = proc_get_long(&p, &left, &lval, &neg,
-					     proc_wspace_sep,
-					     sizeof(proc_wspace_sep), NULL);
-			if (err)
-				break;
-			if (conv(&neg, &lval, i, 1, table)) {
-				err = -EINVAL;
-				break;
-			}
-		} else {
-			if (conv(&neg, &lval, i, 0, table)) {
-				err = -EINVAL;
-				break;
-			}
-			if (!first)
-				proc_put_char(&buffer, &left, '\t');
-			proc_put_long(&buffer, &left, lval, neg);
-		}
-	}
-
-	if (SYSCTL_KERN_TO_USER(dir) && !first && left && !err)
-		proc_put_char(&buffer, &left, '\n');
-	if (SYSCTL_USER_TO_KERN(dir) && !err && left)
-		proc_skip_spaces(&p, &left);
-	if (SYSCTL_USER_TO_KERN(dir) && first)
-		return err ? : -EINVAL;
-	*lenp -= left;
-out:
-	*ppos += *lenp;
-	return err;
+/*
+ * Do not export this macro outside the sysctl subsys.
+ * It is meant to generate static functions only
+ */
+#define do_proc_dotypevec(T) \
+static int do_proc_do##T##vec(const struct ctl_table *table, int dir, \
+		  void *buffer, size_t *lenp, loff_t *ppos, \
+		  int (*conv)(bool *negp, ulong *u_ptr, T *k_ptr, \
+			      int dir, const struct ctl_table *table)) \
+{ \
+	T *i; \
+	int vleft, first = 1, err = 0; \
+	size_t left; \
+	char *p; \
+\
+	if (!table->data || !table->maxlen || !*lenp || \
+	    (*ppos && SYSCTL_KERN_TO_USER(dir))) { \
+		*lenp = 0; \
+		return 0; \
+	} \
+\
+	i = (typeof(i)) table->data; \
+	vleft = table->maxlen / sizeof(*i); \
+	left = *lenp; \
+\
+	if (SYSCTL_USER_TO_KERN(dir)) { \
+		if (proc_first_pos_non_zero_ignore(ppos, table)) \
+			goto out; \
+\
+		if (left > PAGE_SIZE - 1) \
+			left = PAGE_SIZE - 1; \
+		p = buffer; \
+	} \
+\
+	for (; left && vleft--; i++, first = 0) { \
+		unsigned long lval; \
+		bool neg; \
+\
+		if (SYSCTL_USER_TO_KERN(dir)) { \
+			proc_skip_spaces(&p, &left); \
+\
+			if (!left) \
+				break; \
+			err = proc_get_long(&p, &left, &lval, &neg, \
+					     proc_wspace_sep, \
+					     sizeof(proc_wspace_sep), NULL); \
+			if (err) \
+				break; \
+			if (conv(&neg, &lval, i, dir, table)) { \
+				err = -EINVAL; \
+				break; \
+			} \
+		} else { \
+			if (conv(&neg, &lval, i, dir, table)) { \
+				err = -EINVAL; \
+				break; \
+			} \
+			if (!first) \
+				proc_put_char(&buffer, &left, '\t'); \
+			proc_put_long(&buffer, &left, lval, neg); \
+		} \
+	} \
+\
+	if (SYSCTL_KERN_TO_USER(dir) && !first && left && !err) \
+		proc_put_char(&buffer, &left, '\n'); \
+	if (SYSCTL_USER_TO_KERN(dir) && !err && left) \
+		proc_skip_spaces(&p, &left); \
+	if (SYSCTL_USER_TO_KERN(dir) && first) \
+		return err ? : -EINVAL; \
+	*lenp -= left; \
+out: \
+	*ppos += *lenp; \
+	return err; \
 }
 
+do_proc_dotypevec(int)
+
 static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *u_ptr,

-- 
2.50.1

[PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro

[Joel Granados]

The existing do_proc_doulongvec_minmax conversions (based on conv{mul,div})
are replaced with a call to a converter callback that is passed by the
caller.

Replace the values (HZ, 1000l) passed to proc_doulongvec_minmax_conv in
jiffies.c with a new callback containing millisecond to jiffie
conversion (do_proc_ulong_conv_ms_jiffies). This effectively changes the
simple calculation based on HZ and 1000l to a more robust conversion
based on  {_,}_msecs_to_jiffies.

Change specifics
================
* sysctl.h API
 - Implement new ulong uni & bi-directional converters (proc_ulong_*);
   export them so they can be used in proc_doulongvec_ms_jiffies_minmax
   (jiffies.c).
 - Replace two arguments (conv{mul,div}) in proc_doulongvec_minmax_conv
   with a general converter callback function that will be forwarded to
   do_proc_doulongvec.

* do_proc_doulongvec
 - Replace the hardcoded uni-directional converters with a call to the
   call back converter function
 - Generate do_proc_doulongvec with do_proc_dotypevec macro
 - Rename do_proc_doulongvec_minmax to do_proc_doulongvec

* jiffies
 - Create uni and bi-directional converters for milliseconds to jiffies
   (sysctl_{u2k,k2u}_ulong_conv_ms, do_proc_ulong_conv_ms_jiffies)
 - Pass the new bi-directional converter to proc_doulongvec_minmax_conv.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 include/linux/sysctl.h |  11 ++-
 kernel/sysctl.c        | 182 ++++++++++++++++++++++++++++++-------------------
 kernel/time/jiffies.c  |  26 ++++++-
 3 files changed, 148 insertions(+), 71 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 2886fbceb5d635fc7e0282c7467dcf82708919fe..5c8c17f98513983a459c54eae99d1cc8bd63b011 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -117,11 +117,20 @@ int proc_dou8vec_minmax(const 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 (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
+					    int dir, const struct ctl_table *table));
 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 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));
+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));
 /*
  * Register a set of sysctl names by calling register_sysctl
  * with an initialised array of struct ctl_table's.
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 66db2ac69a91ac4b200cb8906dcb76209bee28bb..d21eeb2bca19ab927a604e8de137958eb08f82a6 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -648,6 +648,7 @@ out: \
 }
 
 do_proc_dotypevec(int)
+do_proc_dotypevec(ulong)
 
 static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
 			       size_t *lenp, loff_t *ppos,
@@ -969,87 +970,128 @@ int proc_dou8vec_minmax(const struct ctl_table *table, int dir,
 }
 EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
 
-static int do_proc_doulongvec_minmax(const struct ctl_table *table, int dir,
-				     void *buffer, size_t *lenp, loff_t *ppos,
-				     unsigned long convmul,
-				     unsigned long convdiv)
+/**
+ * proc_ulong_conv - Change user or kernel pointer based on direction
+ *
+ * @u_ptr: pointer to user variable
+ * @k_ptr: pointer to kernel variable
+ * @dir: %TRUE if this is a write to the sysctl file
+ * @tbl: the sysctl table
+ * @k_ptr_range_check: Check range for k_ptr when %TRUE
+ * @user_to_kern: Callback used to assign value from user to kernel var
+ * @kern_to_user: Callback used to assign value from kernel to user var
+ *
+ * When direction is kernel to user, then the u_ptr is modified.
+ * When direction is user to kernel, then the k_ptr is modified.
+ *
+ * Returns: 0 on success
+ */
+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))
 {
-	unsigned long *i, *min, *max;
-	int vleft, first = 1, err = 0;
-	size_t left;
-	char *p;
+	if (SYSCTL_KERN_TO_USER(dir))
+		return kern_to_user(u_ptr, k_ptr);
 
-	if (!table->data || !table->maxlen || !*lenp ||
-	    (*ppos && SYSCTL_KERN_TO_USER(dir))) {
-		*lenp = 0;
-		return 0;
-	}
+	if (k_ptr_range_check) {
+		ulong tmp_k;
+		int ret;
 
-	i = table->data;
-	min = table->extra1;
-	max = table->extra2;
-	vleft = table->maxlen / sizeof(unsigned long);
-	left = *lenp;
-
-	if (SYSCTL_USER_TO_KERN(dir)) {
-		if (proc_first_pos_non_zero_ignore(ppos, table))
-			goto out;
-
-		if (left > PAGE_SIZE - 1)
-			left = PAGE_SIZE - 1;
-		p = buffer;
-	}
+		if (!tbl)
+			return -EINVAL;
+		ret = user_to_kern(u_ptr, &tmp_k);
+		if (ret)
+			return ret;
+		if ((tbl->extra1 && *(ulong *)tbl->extra1 > tmp_k) ||
+		    (tbl->extra2 && *(ulong *)tbl->extra2 < tmp_k))
+			return -ERANGE;
+		WRITE_ONCE(*k_ptr, tmp_k);
+	} else
+		return user_to_kern(u_ptr, k_ptr);
+	return 0;
+}
 
-	for (; left && vleft--; i++, first = 0) {
-		unsigned long val;
+/**
+ * proc_ulong_u2k_conv_uop - Assign user value to a kernel pointer
+ *
+ * @u_ptr: pointer to user space variable
+ * @k_ptr: pointer to kernel variable
+ * @u_ptr_op: execute this function before assigning to k_ptr
+ *
+ * Uses WRITE_ONCE to assign value to k_ptr. Executes u_ptr_op if
+ * not NULL.
+ *
+ * returns: 0 on success.
+ */
+int proc_ulong_u2k_conv_uop(const ulong *u_ptr, ulong *k_ptr,
+			    ulong (*u_ptr_op)(const ulong))
+{
+	ulong u = u_ptr_op ? u_ptr_op(*u_ptr) : *u_ptr;
 
-		if (SYSCTL_USER_TO_KERN(dir)) {
-			bool neg;
+	WRITE_ONCE(*k_ptr, u);
+	return 0;
+}
 
-			proc_skip_spaces(&p, &left);
-			if (!left)
-				break;
+static int proc_ulong_u2k_conv(const ulong *u_ptr, ulong *k_ptr)
+{
+	return proc_ulong_u2k_conv_uop(u_ptr, k_ptr, NULL);
+}
 
-			err = proc_get_long(&p, &left, &val, &neg,
-					     proc_wspace_sep,
-					     sizeof(proc_wspace_sep), NULL);
-			if (err || neg) {
-				err = -EINVAL;
-				break;
-			}
+/**
+ * proc_ulong_k2u_conv_kop - Assign kernel value to a user space pointer
+ *
+ * @u_ptr: pointer to user space variable
+ * @k_ptr: pointer to kernel variable
+ * @k_ptr_op: Operation applied to k_ptr before assignment
+ *
+ * Uses READ_ONCE to assign value to u_ptr. Executes k_ptr_op if
+ * not NULL.
+ *
+ * returns: 0 on success.
+ */
+int proc_ulong_k2u_conv_kop(ulong *u_ptr, const ulong *k_ptr,
+			    ulong (*k_ptr_op)(const ulong))
+{
+	ulong val = k_ptr_op ? k_ptr_op(READ_ONCE(*k_ptr)) : READ_ONCE(*k_ptr);
+	*u_ptr = (ulong)val;
+	return 0;
+}
 
-			val = convmul * val / convdiv;
-			if ((min && val < *min) || (max && val > *max)) {
-				err = -EINVAL;
-				break;
-			}
-			WRITE_ONCE(*i, val);
-		} else {
-			val = convdiv * READ_ONCE(*i) / convmul;
-			if (!first)
-				proc_put_char(&buffer, &left, '\t');
-			proc_put_long(&buffer, &left, val, false);
-		}
-	}
+static int proc_ulong_k2u_conv(ulong *u_ptr, const ulong *k_ptr)
+{
+	return proc_ulong_k2u_conv_kop(u_ptr, k_ptr, NULL);
+}
 
-	if (SYSCTL_KERN_TO_USER(dir) && !first && left && !err)
-		proc_put_char(&buffer, &left, '\n');
-	if (SYSCTL_USER_TO_KERN(dir) && !err)
-		proc_skip_spaces(&p, &left);
-	if (SYSCTL_USER_TO_KERN(dir) && first)
-		return err ? : -EINVAL;
-	*lenp -= left;
-out:
-	*ppos += *lenp;
-	return err;
+static int do_proc_ulong_conv(bool *negp, ulong *u_ptr, ulong *k_ptr, int dir,
+			      const struct ctl_table *tbl)
+{
+	return proc_ulong_conv(u_ptr, k_ptr, dir, tbl, true,
+			       proc_ulong_u2k_conv, proc_ulong_k2u_conv);
 }
 
+/**
+ * proc_doulongvec_minmax_conv - read a vector of unsigned longs with a custom converter
+ *
+ * @table: the sysctl table
+ * @dir: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ * @conv: Custom converter call back
+ *
+ * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
+ * values from/to the user buffer, treated as an ASCII string. Negative
+ * strings are not allowed.
+ *
+ * Returns: 0 on success
+ */
 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 (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
+					    int dir, const struct ctl_table *table))
 {
-	return do_proc_doulongvec_minmax(table, dir, buffer, lenp, ppos,
-					 convmul, convdiv);
+	return do_proc_doulongvec(table, dir, buffer, lenp, ppos, conv);
 }
 
 /**
@@ -1071,7 +1113,8 @@ int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
 int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return proc_doulongvec_minmax_conv(table, dir, buffer, lenp, ppos, 1l, 1l);
+	return do_proc_doulongvec(table, dir, buffer, lenp, ppos,
+				  do_proc_ulong_conv);
 }
 
 int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
@@ -1310,7 +1353,8 @@ int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
 
 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 (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
+					    int dir, const struct ctl_table *table))
 {
 	return -ENOSYS;
 }
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a5c7d15fce72fd2c8c8a0e0b9e40901534152124..57ed5f363f94bd566aa53c061f20d3f4f2a05944 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -187,6 +187,24 @@ static int do_proc_int_conv_ms_jiffies_minmax(bool *negp, ulong *u_ptr,
 			     sysctl_u2k_int_conv_ms, sysctl_k2u_int_conv_ms);
 }
 
+static int sysctl_u2k_ulong_conv_ms(const ulong *u_ptr, ulong *k_ptr)
+{
+	return proc_ulong_u2k_conv_uop(u_ptr, k_ptr, sysctl_msecs_to_jiffies);
+}
+
+static int sysctl_k2u_ulong_conv_ms(ulong *u_ptr, const ulong *k_ptr)
+{
+	return proc_ulong_k2u_conv_kop(u_ptr, k_ptr, sysctl_jiffies_to_msecs);
+}
+
+static int do_proc_ulong_conv_ms_jiffies(bool *negp, ulong *u_ptr, ulong *k_ptr,
+					 int dir, const struct ctl_table *tbl)
+{
+	return proc_ulong_conv(u_ptr, k_ptr, dir, tbl, false,
+			       sysctl_u2k_ulong_conv_ms, sysctl_k2u_ulong_conv_ms);
+}
+
+
 #else // CONFIG_PROC_SYSCTL
 static int do_proc_int_conv_jiffies(bool *negp, ulong *u_ptr, int *k_ptr,
 				    int dir, const struct ctl_table *tbl)
@@ -213,6 +231,12 @@ static int do_proc_int_conv_ms_jiffies_minmax(bool *negp, ulong *u_ptr,
 {
 	return -ENOSYS;
 }
+
+static int do_proc_ulong_conv_ms_jiffies(bool *negp, ulong *u_ptr, ulong *k_ptr,
+					 int dir, const struct ctl_table *tbl)
+{
+	return -ENOSYS;
+}
 #endif
 
 /**
@@ -314,7 +338,7 @@ int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
 				      void *buffer, size_t *lenp, loff_t *ppos)
 {
 	return proc_doulongvec_minmax_conv(table, dir, buffer, lenp, ppos,
-					   HZ, 1000l);
+					   do_proc_ulong_conv_ms_jiffies);
 }
 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
 

-- 
2.50.1

Re: [PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro

[kernel test robot]

Hello,

kernel test robot noticed "blktests.block/020.fail" on:

commit: 216729bf72d98eca7a48326bb17b577c3fde9634 ("[PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro")
url: https://github.com/intel-lab-lkp/linux/commits/Joel-Granados/sysctl-Move-default-converter-assignment-out-of-do_proc_dointvec/20251219-202253
patch link: https://lore.kernel.org/all/20251219-jag-dovec_consolidate-v1-3-1413b92c6040@kernel.org/
patch subject: [PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro

in testcase: blktests
version: blktests-x86_64-b1b99d1-1_20251223
with following parameters:

	disk: 1HDD
	test: block-020



config: x86_64-rhel-9.4-func
compiler: gcc-14
test machine: 4 threads Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz (Skylake) with 32G memory

(please refer to attached dmesg/kmsg for entire log/backtrace)



If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <oliver.sang@intel.com>
| Closes: https://lore.kernel.org/oe-lkp/202512291555.395cc7b0-lkp@intel.com

2025-12-26 15:49:33 cd /lkp/benchmarks/blktests
2025-12-26 15:49:33 echo block/020
2025-12-26 15:49:33 ./check block/020
block/020 (run null-blk on different schedulers with only one hardware tag)
block/020 (run null-blk on different schedulers with only one hardware tag) [failed]
    runtime    ...  42.071s
    --- tests/block/020.out	2025-12-23 16:47:43.000000000 +0000
    +++ /lkp/benchmarks/blktests/results/nodev/block/020.out.bad	2025-12-26 15:50:16.434082831 +0000
    @@ -1,2 +1,10 @@
     Running block/020
    +iodepth: min value out of range: -16384 (1 min)
    +_fio_perf: too many terse lines
    +iodepth: min value out of range: -16384 (1 min)
    +_fio_perf: too many terse lines
    +iodepth: min value out of range: -16384 (1 min)
    +_fio_perf: too many terse lines
    ...
    (Run 'diff -u tests/block/020.out /lkp/benchmarks/blktests/results/nodev/block/020.out.bad' to see the entire diff)



The kernel config and materials to reproduce are available at:
https://download.01.org/0day-ci/archive/20251229/202512291555.395cc7b0-lkp@intel.com



-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro

[Joel Granados]

[-- Attachment #1: Type: text/plain, Size: 2587 bytes --]

On Mon, Dec 29, 2025 at 03:17:58PM +0800, kernel test robot wrote:
> 
> 
> Hello,
> 
> kernel test robot noticed "blktests.block/020.fail" on:
> 
> commit: 216729bf72d98eca7a48326bb17b577c3fde9634 ("[PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro")
> url: https://github.com/intel-lab-lkp/linux/commits/Joel-Granados/sysctl-Move-default-converter-assignment-out-of-do_proc_dointvec/20251219-202253
> patch link: https://lore.kernel.org/all/20251219-jag-dovec_consolidate-v1-3-1413b92c6040@kernel.org/
> patch subject: [PATCH 3/9] sysctl: Generate do_proc_doulongvec_minmax with do_proc_dotypevec macro
> 
> in testcase: blktests
> version: blktests-x86_64-b1b99d1-1_20251223
> with following parameters:
> 
> 	disk: 1HDD
> 	test: block-020
> 
> 
> 
> config: x86_64-rhel-9.4-func
> compiler: gcc-14
> test machine: 4 threads Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz (Skylake) with 32G memory
> 
> (please refer to attached dmesg/kmsg for entire log/backtrace)
> 
> 
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <oliver.sang@intel.com>
> | Closes: https://lore.kernel.org/oe-lkp/202512291555.395cc7b0-lkp@intel.com
> 
> 2025-12-26 15:49:33 cd /lkp/benchmarks/blktests
> 2025-12-26 15:49:33 echo block/020
> 2025-12-26 15:49:33 ./check block/020
> block/020 (run null-blk on different schedulers with only one hardware tag)
> block/020 (run null-blk on different schedulers with only one hardware tag) [failed]
>     runtime    ...  42.071s
>     --- tests/block/020.out	2025-12-23 16:47:43.000000000 +0000
>     +++ /lkp/benchmarks/blktests/results/nodev/block/020.out.bad	2025-12-26 15:50:16.434082831 +0000
>     @@ -1,2 +1,10 @@
>      Running block/020
>     +iodepth: min value out of range: -16384 (1 min)
>     +_fio_perf: too many terse lines
>     +iodepth: min value out of range: -16384 (1 min)
>     +_fio_perf: too many terse lines
>     +iodepth: min value out of range: -16384 (1 min)
>     +_fio_perf: too many terse lines
>     ...
>     (Run 'diff -u tests/block/020.out /lkp/benchmarks/blktests/results/nodev/block/020.out.bad' to see the entire diff)

This is because the value returned after reading the ulong value in
/proc/sys/fs/aio-max-nr was negative (which should not happen). This is
a particular behavior for this .config that I did not encounter in my
tests.

I have reproduced it and corrected it in V2.

Best

-- 

Joel Granados

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 659 bytes --]

[PATCH 4/9] sysctl: Add negp parameter to douintvec converter functions

[Joel Granados]

Updates all douintvec converter function signatures to include a bool
*negp parameter. This is a preparation commit required to eventually
generate do_proc_douintvec with a macro. The negp argument will be
ignored as it is not relevant for the uint type. Note that
do_proc_uint_conv_pipe_maxsz in pipe.c is also modified.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 fs/pipe.c              |  2 +-
 include/linux/sysctl.h |  2 +-
 kernel/sysctl.c        | 25 +++++++++++++------------
 3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/fs/pipe.c b/fs/pipe.c
index 22647f50b286d3bca024ee4c6de51b100ddc5402..e4a8b6d43bee873ceb1928afab9909e6cd6e4418 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1492,7 +1492,7 @@ static int u2k_pipe_maxsz(const ulong *u_ptr, uint *k_ptr)
 	return proc_uint_u2k_conv_uop(u_ptr, k_ptr, round_pipe_size_ul);
 }
 
-static int do_proc_uint_conv_pipe_maxsz(ulong *u_ptr, uint *k_ptr,
+static int do_proc_uint_conv_pipe_maxsz(bool *negp, ulong *u_ptr, uint *k_ptr,
 					int dir, const struct ctl_table *table)
 {
 	return proc_uint_conv(u_ptr, k_ptr, dir, table, true,
diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 5c8c17f98513983a459c54eae99d1cc8bd63b011..8f8e357b1f4d377a0891fbc85d34073cd30469b1 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -102,7 +102,7 @@ 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 (*conv)(bool *negp, ulong *lvalp, uint *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,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d21eeb2bca19ab927a604e8de137958eb08f82a6..8d0796b45b0101096ee395c7ed7c37f7b7199db4 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -444,7 +444,7 @@ static int proc_uint_u2k_conv(const ulong *u_ptr, uint *k_ptr)
 	return proc_uint_u2k_conv_uop(u_ptr, k_ptr, NULL);
 }
 
-static int do_proc_uint_conv(ulong *u_ptr, uint *k_ptr, int dir,
+static int do_proc_uint_conv(bool *negp, ulong *u_ptr, uint *k_ptr, int dir,
 			     const struct ctl_table *tbl)
 {
 	return proc_uint_conv(u_ptr, k_ptr, dir, tbl, false,
@@ -652,7 +652,7 @@ do_proc_dotypevec(ulong)
 
 static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
 			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(unsigned long *u_ptr,
+			       int (*conv)(bool *negp, unsigned long *u_ptr,
 					   unsigned int *k_ptr, int dir,
 					   const struct ctl_table *table))
 {
@@ -705,17 +705,18 @@ static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
 
 static int do_proc_douintvec_r(const struct ctl_table *table, void *buffer,
 			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(unsigned long *u_ptr,
+			       int (*conv)(bool *negp, unsigned long *u_ptr,
 					   unsigned int *k_ptr, int dir,
 					   const struct ctl_table *table))
 {
 	unsigned long lval;
 	int err = 0;
 	size_t left;
+	bool negp;
 
 	left = *lenp;
 
-	if (conv(&lval, (unsigned int *) table->data, 0, table)) {
+	if (conv(&negp, &lval, (unsigned int *) table->data, 0, table)) {
 		err = -EINVAL;
 		goto out;
 	}
@@ -735,9 +736,8 @@ static int do_proc_douintvec_r(const struct ctl_table *table, void *buffer,
 
 static int do_proc_douintvec(const struct ctl_table *table, int dir,
 			     void *buffer, size_t *lenp, loff_t *ppos,
-			      int (*conv)(unsigned long *u_ptr,
-					  unsigned int *k_ptr, int dir,
-					  const struct ctl_table *table))
+			     int (*conv)(bool *negp, ulong *u_ptr, uint *k_ptr,
+					 int dir, const struct ctl_table *table))
 {
 	unsigned int vleft;
 
@@ -758,9 +758,6 @@ static int do_proc_douintvec(const struct ctl_table *table, int dir,
 		return -EINVAL;
 	}
 
-	if (!conv)
-		conv = do_proc_uint_conv;
-
 	if (SYSCTL_USER_TO_KERN(dir))
 		return do_proc_douintvec_w(table, buffer, lenp, ppos, conv);
 	return do_proc_douintvec_r(table, buffer, lenp, ppos, conv);
@@ -784,9 +781,13 @@ static int do_proc_douintvec(const struct ctl_table *table, int dir,
  */
 int proc_douintvec_conv(const struct ctl_table *table, int dir, void *buffer,
 			size_t *lenp, loff_t *ppos,
-			int (*conv)(unsigned long *u_ptr, unsigned int *k_ptr,
+			int (*conv)(bool *negp, ulong *u_ptr, uint *k_ptr,
 				    int dir, const struct ctl_table *table))
 {
+
+	if (!conv)
+		conv = do_proc_uint_conv;
+
 	return do_proc_douintvec(table, dir, buffer, lenp, ppos, conv);
 }
 
@@ -1314,7 +1315,7 @@ int proc_douintvec_minmax(const struct ctl_table *table, int dir,
 
 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 (*conv)(bool *negp, ulong *lvalp, uint *valp,
 				    int write, const struct ctl_table *table))
 {
 	return -ENOSYS;

-- 
2.50.1

[PATCH 5/9] sysctl: Generate do_proc_douintvec with a type-generic macro

[Joel Granados]

Generate the behavior in do_proc_douintvec{,_w,_r} functions with
do_proc_dotypevec(uint). The originals (do_proc_douintvec{,_w,_r})
where created in the same way as do_proc_dotypevec but for individual
values (no vectors). In this commit we use the existing macro
implementation to extend do_proc_douintvec to include vectors of values.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 kernel/sysctl.c | 118 ++------------------------------------------------------
 1 file changed, 3 insertions(+), 115 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 8d0796b45b0101096ee395c7ed7c37f7b7199db4..4fa26b913f59c60a5b4fbc2d66d5d99c641eecba 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -451,8 +451,8 @@ static int do_proc_uint_conv(bool *negp, ulong *u_ptr, uint *k_ptr, int dir,
 			      proc_uint_u2k_conv, proc_uint_k2u_conv);
 }
 
-static int do_proc_uint_conv_minmax(ulong *u_ptr, uint *k_ptr, int dir,
-				    const struct ctl_table *tbl)
+static int do_proc_uint_conv_minmax(bool *negp, ulong *u_ptr, uint *k_ptr,
+				    int dir, const struct ctl_table *tbl)
 {
 	return proc_uint_conv(u_ptr, k_ptr, dir, tbl, true,
 			      proc_uint_u2k_conv, proc_uint_k2u_conv);
@@ -649,119 +649,7 @@ out: \
 
 do_proc_dotypevec(int)
 do_proc_dotypevec(ulong)
-
-static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
-			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(bool *negp, unsigned long *u_ptr,
-					   unsigned int *k_ptr, int dir,
-					   const struct ctl_table *table))
-{
-	unsigned long lval;
-	int err = 0;
-	size_t left;
-	bool neg;
-	char *p = buffer;
-
-	left = *lenp;
-
-	if (proc_first_pos_non_zero_ignore(ppos, table))
-		goto bail_early;
-
-	if (left > PAGE_SIZE - 1)
-		left = PAGE_SIZE - 1;
-
-	proc_skip_spaces(&p, &left);
-	if (!left) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	err = proc_get_long(&p, &left, &lval, &neg,
-			     proc_wspace_sep,
-			     sizeof(proc_wspace_sep), NULL);
-	if (err || neg) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	if (conv(&lval, (unsigned int *) table->data, 1, table)) {
-		err = -EINVAL;
-		goto out_free;
-	}
-
-	if (!err && left)
-		proc_skip_spaces(&p, &left);
-
-out_free:
-	if (err)
-		return -EINVAL;
-
-	return 0;
-
-bail_early:
-	*ppos += *lenp;
-	return err;
-}
-
-static int do_proc_douintvec_r(const struct ctl_table *table, void *buffer,
-			       size_t *lenp, loff_t *ppos,
-			       int (*conv)(bool *negp, unsigned long *u_ptr,
-					   unsigned int *k_ptr, int dir,
-					   const struct ctl_table *table))
-{
-	unsigned long lval;
-	int err = 0;
-	size_t left;
-	bool negp;
-
-	left = *lenp;
-
-	if (conv(&negp, &lval, (unsigned int *) table->data, 0, table)) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	proc_put_long(&buffer, &left, lval, false);
-	if (!left)
-		goto out;
-
-	proc_put_char(&buffer, &left, '\n');
-
-out:
-	*lenp -= left;
-	*ppos += *lenp;
-
-	return err;
-}
-
-static int do_proc_douintvec(const struct ctl_table *table, int dir,
-			     void *buffer, size_t *lenp, loff_t *ppos,
-			     int (*conv)(bool *negp, ulong *u_ptr, uint *k_ptr,
-					 int dir, const struct ctl_table *table))
-{
-	unsigned int vleft;
-
-	if (!table->data || !table->maxlen || !*lenp ||
-	    (*ppos && SYSCTL_KERN_TO_USER(dir))) {
-		*lenp = 0;
-		return 0;
-	}
-
-	vleft = table->maxlen / sizeof(unsigned int);
-
-	/*
-	 * Arrays are not supported, keep this simple. *Do not* add
-	 * support for them.
-	 */
-	if (vleft != 1) {
-		*lenp = 0;
-		return -EINVAL;
-	}
-
-	if (SYSCTL_USER_TO_KERN(dir))
-		return do_proc_douintvec_w(table, buffer, lenp, ppos, conv);
-	return do_proc_douintvec_r(table, buffer, lenp, ppos, conv);
-}
+do_proc_dotypevec(uint)
 
 /**
  * proc_douintvec_conv - read a vector of unsigned ints with a custom converter

-- 
2.50.1

[PATCH 6/9] sysctl: Rename do_proc_dotypevec macro to do_proc_typevec

[Joel Granados]

Remove the do..do from the proc vector functions. The redundant "do"
only adds confusion to the already large amount of functions in sysctl.c

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 kernel/sysctl.c | 37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 4fa26b913f59c60a5b4fbc2d66d5d99c641eecba..aecb46bdf4cafc134f83f2014e89a209efc8c10d 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -576,8 +576,8 @@ static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
  * Do not export this macro outside the sysctl subsys.
  * It is meant to generate static functions only
  */
-#define do_proc_dotypevec(T) \
-static int do_proc_do##T##vec(const struct ctl_table *table, int dir, \
+#define do_proc_typevec(T) \
+static int do_proc_##T##vec(const struct ctl_table *table, int dir, \
 		  void *buffer, size_t *lenp, loff_t *ppos, \
 		  int (*conv)(bool *negp, ulong *u_ptr, T *k_ptr, \
 			      int dir, const struct ctl_table *table)) \
@@ -647,9 +647,9 @@ out: \
 	return err; \
 }
 
-do_proc_dotypevec(int)
-do_proc_dotypevec(ulong)
-do_proc_dotypevec(uint)
+do_proc_typevec(int)
+do_proc_typevec(ulong)
+do_proc_typevec(uint)
 
 /**
  * proc_douintvec_conv - read a vector of unsigned ints with a custom converter
@@ -676,7 +676,7 @@ int proc_douintvec_conv(const struct ctl_table *table, int dir, void *buffer,
 	if (!conv)
 		conv = do_proc_uint_conv;
 
-	return do_proc_douintvec(table, dir, buffer, lenp, ppos, conv);
+	return do_proc_uintvec(table, dir, buffer, lenp, ppos, conv);
 }
 
 /**
@@ -735,7 +735,7 @@ int proc_dobool(const struct ctl_table *table, int dir, void *buffer,
 int proc_dointvec(const struct ctl_table *table, int dir, void *buffer,
 		  size_t *lenp, loff_t *ppos)
 {
-	return do_proc_dointvec(table, dir, buffer, lenp, ppos, do_proc_int_conv);
+	return do_proc_intvec(table, dir, buffer, lenp, ppos, do_proc_int_conv);
 }
 
 /**
@@ -754,8 +754,7 @@ int proc_dointvec(const struct ctl_table *table, int dir, void *buffer,
 int proc_douintvec(const struct ctl_table *table, int dir, void *buffer,
 		size_t *lenp, loff_t *ppos)
 {
-	return do_proc_douintvec(table, dir, buffer, lenp, ppos,
-				 do_proc_uint_conv);
+	return do_proc_uintvec(table, dir, buffer, lenp, ppos, do_proc_uint_conv);
 }
 
 /**
@@ -778,8 +777,8 @@ int proc_douintvec(const struct ctl_table *table, int dir, void *buffer,
 int proc_dointvec_minmax(const struct ctl_table *table, int dir,
 		  void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return do_proc_dointvec(table, dir, buffer, lenp, ppos,
-				do_proc_int_conv_minmax);
+	return do_proc_intvec(table, dir, buffer, lenp, ppos,
+			      do_proc_int_conv_minmax);
 }
 
 /**
@@ -805,8 +804,8 @@ int proc_dointvec_minmax(const struct ctl_table *table, int dir,
 int proc_douintvec_minmax(const struct ctl_table *table, int dir,
 			  void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return do_proc_douintvec(table, dir, buffer, lenp, ppos,
-				 do_proc_uint_conv_minmax);
+	return do_proc_uintvec(table, dir, buffer, lenp, ppos,
+			       do_proc_uint_conv_minmax);
 }
 
 /**
@@ -849,8 +848,8 @@ int proc_dou8vec_minmax(const struct ctl_table *table, int dir,
 		tmp.extra2 = (unsigned int *) &max;
 
 	val = READ_ONCE(*data);
-	res = do_proc_douintvec(&tmp, dir, buffer, lenp, ppos,
-				do_proc_uint_conv_minmax);
+	res = do_proc_uintvec(&tmp, dir, buffer, lenp, ppos,
+			      do_proc_uint_conv_minmax);
 	if (res)
 		return res;
 	if (SYSCTL_USER_TO_KERN(dir))
@@ -980,7 +979,7 @@ int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
 				int (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
 					    int dir, const struct ctl_table *table))
 {
-	return do_proc_doulongvec(table, dir, buffer, lenp, ppos, conv);
+	return do_proc_ulongvec(table, dir, buffer, lenp, ppos, conv);
 }
 
 /**
@@ -1002,8 +1001,8 @@ int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
 int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return do_proc_doulongvec(table, dir, buffer, lenp, ppos,
-				  do_proc_ulong_conv);
+	return do_proc_ulongvec(table, dir, buffer, lenp, ppos,
+				do_proc_ulong_conv);
 }
 
 int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
@@ -1013,7 +1012,7 @@ int proc_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
 {
 	if (!conv)
 		conv = do_proc_int_conv;
-	return do_proc_dointvec(table, dir, buffer, lenp, ppos, conv);
+	return do_proc_intvec(table, dir, buffer, lenp, ppos, conv);
 }
 
 /**

-- 
2.50.1

[PATCH 7/9] sysctl: Group proc_handler declarations and document

[Joel Granados]

Make four groups in the sysctl header and document each group with an
example of how to use them.
1. proc_handler : All functions that can be passed to the proc_handler
   pointer in ctl_table
2. proc handler aggregators: Functions to create proc handlers with
   custom converters
3. bi-directional converters: Functions to create read/write custom
   converters. Can be passed to proc handler aggregators
4. uni-directional converters: Functions to create read or write custom
   converters. Can be passed as args to bi-directional converters

Use just one naming convention in the declarations: 'write' becomes
'dir' and 'buffer' becomes 'buf'.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 include/linux/sysctl.h | 128 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 87 insertions(+), 41 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 8f8e357b1f4d377a0891fbc85d34073cd30469b1..ad268dfd9e79f5540a4a85a9a439819fb3172640 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -74,63 +74,109 @@ 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_dointvec_conv(const struct ctl_table *table, int dir, void *buffer,
+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_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_minmax_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)(bool *negp, ulong *lvalp, uint *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_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,
-				int (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
-					    int dir, const struct ctl_table *table));
-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 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));
 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));
+
+/*
+ * 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
  * with an initialised array of struct ctl_table's.

-- 
2.50.1

[PATCH 8/9] sysctl: Rename proc_doulongvec_minmax_conv to proc_doulongvec_conv

[Joel Granados]

Remove "_minmax" from proc_doulongvec_minmax_conv as it does not enforce
min/max limits but serves as a generic converter for unsigned long
vectors. Update function declaration in sysctl.h, definition in
sysctl.c, and caller in jiffies.c accordingly.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 include/linux/sysctl.h | 8 ++++----
 kernel/sysctl.c        | 6 +++---
 kernel/time/jiffies.c  | 4 ++--
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index ad268dfd9e79f5540a4a85a9a439819fb3172640..39cf1bf9703fc66a3c9c3360ca081b5590339caa 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -121,10 +121,10 @@ 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_minmax_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));
+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
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index aecb46bdf4cafc134f83f2014e89a209efc8c10d..3fa59ef77f931c2753584ed03006f3ff9f5a1d0e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -959,7 +959,7 @@ static int do_proc_ulong_conv(bool *negp, ulong *u_ptr, ulong *k_ptr, int dir,
 }
 
 /**
- * proc_doulongvec_minmax_conv - read a vector of unsigned longs with a custom converter
+ * proc_doulongvec_conv - read a vector of unsigned longs with a custom converter
  *
  * @table: the sysctl table
  * @dir: %TRUE if this is a write to the sysctl file
@@ -974,7 +974,7 @@ static int do_proc_ulong_conv(bool *negp, ulong *u_ptr, ulong *k_ptr, int dir,
  *
  * Returns: 0 on success
  */
-int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
+int proc_doulongvec_conv(const struct ctl_table *table, int dir,
 				void *buffer, size_t *lenp, loff_t *ppos,
 				int (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
 					    int dir, const struct ctl_table *table))
@@ -1239,7 +1239,7 @@ int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
 	return -ENOSYS;
 }
 
-int proc_doulongvec_minmax_conv(const struct ctl_table *table, int dir,
+int proc_doulongvec_conv(const struct ctl_table *table, int dir,
 				void *buffer, size_t *lenp, loff_t *ppos,
 				int (*conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
 					    int dir, const struct ctl_table *table))
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 57ed5f363f94bd566aa53c061f20d3f4f2a05944..38a654e79b731956748c5ff9b476fb2adea58d7b 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -337,8 +337,8 @@ int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
 int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
 				      void *buffer, size_t *lenp, loff_t *ppos)
 {
-	return proc_doulongvec_minmax_conv(table, dir, buffer, lenp, ppos,
-					   do_proc_ulong_conv_ms_jiffies);
+	return proc_doulongvec_conv(table, dir, buffer, lenp, ppos,
+				    do_proc_ulong_conv_ms_jiffies);
 }
 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
 

-- 
2.50.1

[PATCH 9/9] sysctl: Update API function documentation

[Joel Granados]

Add colon ":" after argument name where it is missing
Add doc for proc_int_conv and proc_dointvec_conv

Signed-off-by: Joel Granados <joel.granados@kernel.org>
---
 kernel/sysctl.c | 60 +++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 14 deletions(-)

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3fa59ef77f931c2753584ed03006f3ff9f5a1d0e..0965ea1212b4097fb21158b08007cf550815a19f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -365,7 +365,7 @@ static void proc_put_char(void **buf, size_t *size, char c)
  * not NULL. Check that the values are less than UINT_MAX to avoid
  * having to support wrap around from userspace.
  *
- * returns 0 on success.
+ * Returns: 0 on success.
  */
 int proc_uint_u2k_conv_uop(const ulong *u_ptr, uint *k_ptr,
 			   ulong (*u_ptr_op)(const ulong))
@@ -386,7 +386,7 @@ int proc_uint_u2k_conv_uop(const ulong *u_ptr, uint *k_ptr,
  *
  * Uses READ_ONCE to assign value to u_ptr.
  *
- * returns 0 on success.
+ * Returns: 0 on success.
  */
 int proc_uint_k2u_conv(ulong *u_ptr, const uint *k_ptr)
 {
@@ -460,16 +460,16 @@ static int do_proc_uint_conv_minmax(bool *negp, ulong *u_ptr, uint *k_ptr,
 
 /**
  * proc_int_k2u_conv_kop - Assign kernel value to a user space pointer
- * @u_ptr - pointer to user space variable
- * @k_ptr - pointer to kernel variable
- * @negp - assigned %TRUE if the converted kernel value is negative;
+ * @u_ptr: pointer to user space variable
+ * @k_ptr: pointer to kernel variable
+ * @negp: assigned %TRUE if the converted kernel value is negative;
  *         %FALSE otherweise
- * @k_ptr_op - execute this function before assigning to u_ptr
+ * @k_ptr_op: execute this function before assigning to u_ptr
  *
  * Uses READ_ONCE to get value from k_ptr. Executes k_ptr_op before assigning
  * to u_ptr if not NULL. Does **not** check for overflow.
  *
- * returns 0 on success.
+ * Returns: 0 on success.
  */
 int proc_int_k2u_conv_kop(ulong *u_ptr, const int *k_ptr, bool *negp,
 			  ulong (*k_ptr_op)(const ulong))
@@ -488,15 +488,15 @@ int proc_int_k2u_conv_kop(ulong *u_ptr, const int *k_ptr, bool *negp,
 
 /**
  * proc_int_u2k_conv_uop - Assign user value to a kernel pointer
- * @u_ptr - pointer to user space variable
- * @k_ptr - pointer to kernel variable
- * @negp - If %TRUE, the converted user value is made negative.
- * @u_ptr_op - execute this function before assigning to k_ptr
+ * @u_ptr: pointer to user space variable
+ * @k_ptr: pointer to kernel variable
+ * @negp: If %TRUE, the converted user value is made negative.
+ * @u_ptr_op: execute this function before assigning to k_ptr
  *
  * Uses WRITE_ONCE to assign value to k_ptr. Executes u_ptr_op if
  * not NULL. Check for overflow with UINT_MAX.
  *
- * returns 0 on success.
+ * Returns: 0 on success.
  */
 int proc_int_u2k_conv_uop(const ulong *u_ptr, int *k_ptr, const bool *negp,
 			  ulong (*u_ptr_op)(const ulong))
@@ -515,6 +515,23 @@ int proc_int_u2k_conv_uop(const ulong *u_ptr, int *k_ptr, const bool *negp,
 	return 0;
 }
 
+/**
+ * proc_int_conv - Change user or kernel pointer based on direction
+ *
+ * @negp: will be passed to uni-directional converters
+ * @u_ptr: pointer to user variable
+ * @k_ptr: pointer to kernel variable
+ * @dir: %TRUE if this is a write to the sysctl file
+ * @tbl: the sysctl table
+ * @k_ptr_range_check: Check range for k_ptr when %TRUE
+ * @user_to_kern: Callback used to assign value from user to kernel var
+ * @kern_to_user: Callback used to assign value from kernel to user var
+ *
+ * When direction is kernel to user, then the u_ptr is modified.
+ * When direction is user to kernel, then the k_ptr is modified.
+ *
+ * Returns: 0 on success
+ */
 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),
@@ -910,7 +927,7 @@ int proc_ulong_conv(ulong *u_ptr, ulong *k_ptr, int dir,
  * Uses WRITE_ONCE to assign value to k_ptr. Executes u_ptr_op if
  * not NULL.
  *
- * returns: 0 on success.
+ * Returns: 0 on success.
  */
 int proc_ulong_u2k_conv_uop(const ulong *u_ptr, ulong *k_ptr,
 			    ulong (*u_ptr_op)(const ulong))
@@ -936,7 +953,7 @@ static int proc_ulong_u2k_conv(const ulong *u_ptr, ulong *k_ptr)
  * Uses READ_ONCE to assign value to u_ptr. Executes k_ptr_op if
  * not NULL.
  *
- * returns: 0 on success.
+ * Returns: 0 on success.
  */
 int proc_ulong_k2u_conv_kop(ulong *u_ptr, const ulong *k_ptr,
 			    ulong (*k_ptr_op)(const ulong))
@@ -1005,6 +1022,21 @@ int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
 				do_proc_ulong_conv);
 }
 
+/**
+ * proc_dointvec_conv - read a vector of ints with a custom converter
+ *
+ * @table: the sysctl table
+ * @dir: %TRUE if this is a write to the sysctl file
+ * @buffer: the user buffer
+ * @lenp: the size of the user buffer
+ * @ppos: file position
+ * @conv: Custom converter call back. Defaults to do_proc_int_conv
+ *
+ * Reads/writes up to table->maxlen/sizeof(int) integer values from/to the
+ * user buffer, treated as an ASCII string.
+ *
+ * Returns: 0 on success
+ */
 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,

-- 
2.50.1