Commit ef153851 authored by Joel Granados's avatar Joel Granados
Browse files

sysctl: Replace unidirectional INT converter macros with functions 



Replace SYSCTL_USER_TO_KERN_INT_CONV and SYSCTL_KERN_TO_USER_INT_CONV
macros with function implementing the same logic.This makes debugging
easier and aligns with the functions preference described in
coding-style.rst. Update all jiffies converters to use explicit function
implementations instead of macro-generated versions.

Signed-off-by: default avatarJoel Granados <joel.granados@kernel.org>
parent b3af263b

include/linux/sysctl.h

+7 −49
Original line number Diff line number Diff line
@@ -74,40 +74,6 @@ extern const int sysctl_vals[]; 
#define SYSCTL_KERN_TO_USER(dir) (!dir)



#ifdef CONFIG_PROC_SYSCTL

#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)
@@ -135,22 +101,8 @@ int do_proc_int_conv##name(bool *negp, unsigned long *u_ptr, int *k_ptr,\ 
		return user_to_kern(negp, u_ptr, k_ptr);		\

	return 0;							\

}

#else // CONFIG_PROC_SYSCTL

#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)		\

{								\

	return -ENOSYS;						\

}



#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)	\

{								\

	return -ENOSYS;						\

}

#else // CONFIG_PROC_SYSCTL



#define SYSCTL_INT_CONV_CUSTOM(name, user_to_kern, kern_to_user,	\

			       k_ptr_range_check)			\
@@ -170,6 +122,7 @@ typedef int proc_handler(const struct ctl_table *ctl, 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(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);
@@ -177,6 +130,11 @@ 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_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_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);

kernel/sysctl.c

+67 −2
Original line number Diff line number Diff line
@@ -458,8 +458,73 @@ static int do_proc_uint_conv_minmax(ulong *u_ptr, uint *k_ptr, int dir, 
			      proc_uint_u2k_conv, proc_uint_k2u_conv);

}



static SYSCTL_USER_TO_KERN_INT_CONV(, SYSCTL_CONV_IDENTITY)

static SYSCTL_KERN_TO_USER_INT_CONV(, SYSCTL_CONV_IDENTITY)

/**

 * 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;

 *        %FALSE otherweise

 * @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.

 */

int proc_int_k2u_conv_kop(ulong *u_ptr, const int *k_ptr, bool *negp,

			  ulong (*k_ptr_op)(const ulong))

{

	int val = READ_ONCE(*k_ptr);



	if (val < 0) {

		*negp = true;

		*u_ptr = k_ptr_op ? -k_ptr_op((ulong)val) : -(ulong)val;

	} else {

		*negp = false;

		*u_ptr = k_ptr_op ? k_ptr_op((ulong)val) : (ulong) val;

	}

	return 0;

}



/**

 * 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

 *

 * 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.

 */

int proc_int_u2k_conv_uop(const ulong *u_ptr, int *k_ptr, const bool *negp,

			  ulong (*u_ptr_op)(const ulong))

{

	ulong u = u_ptr_op ? u_ptr_op(*u_ptr) : *u_ptr;



	if (*negp) {

		if (u > (ulong) INT_MAX + 1)

			return -EINVAL;

		WRITE_ONCE(*k_ptr, -u);

	} else {

		if (u > (ulong) INT_MAX)

			return -EINVAL;

		WRITE_ONCE(*k_ptr, u);

	}

	return 0;

}



static int sysctl_user_to_kern_int_conv(const bool *negp, const ulong *u_ptr,

					int *k_ptr)

{

	return proc_int_u2k_conv_uop(u_ptr, k_ptr, negp, NULL);

}



static int sysctl_kern_to_user_int_conv(bool *negp, ulong *u_ptr, const int *k_ptr)

{

	return proc_int_k2u_conv_kop(u_ptr, k_ptr, negp, NULL);

}



static SYSCTL_INT_CONV_CUSTOM(, sysctl_user_to_kern_int_conv,

			      sysctl_kern_to_user_int_conv, false)

kernel/time/jiffies.c

+93 −18
Original line number Diff line number Diff line
@@ -100,26 +100,101 @@ void __init register_refined_jiffies(long cycles_per_second) 
	__clocksource_register(&refined_jiffies);

}



#define SYSCTL_CONV_MULT_HZ(val) ((val) * HZ)

#define SYSCTL_CONV_DIV_HZ(val) ((val) / HZ)



static SYSCTL_USER_TO_KERN_INT_CONV(_hz, SYSCTL_CONV_MULT_HZ)

static SYSCTL_KERN_TO_USER_INT_CONV(_hz, SYSCTL_CONV_DIV_HZ)

static SYSCTL_USER_TO_KERN_INT_CONV(_userhz, clock_t_to_jiffies)

static SYSCTL_KERN_TO_USER_INT_CONV(_userhz, jiffies_to_clock_t)

static SYSCTL_USER_TO_KERN_INT_CONV(_ms, msecs_to_jiffies)

static SYSCTL_KERN_TO_USER_INT_CONV(_ms, jiffies_to_msecs)



static SYSCTL_INT_CONV_CUSTOM(_jiffies, sysctl_user_to_kern_int_conv_hz,

			      sysctl_kern_to_user_int_conv_hz, false)

#ifdef CONFIG_PROC_SYSCTL

static ulong mult_hz(const ulong val)

{

	return val * HZ;

}



static ulong div_hz(const ulong val)

{

	return val / HZ;

}



static int sysctl_u2k_int_conv_hz(const bool *negp, const ulong *u_ptr, int *k_ptr)

{

	return proc_int_u2k_conv_uop(u_ptr, k_ptr, negp, mult_hz);

}



static int sysctl_k2u_int_conv_hz(bool *negp, ulong *u_ptr, const int *k_ptr)

{

	return proc_int_k2u_conv_kop(u_ptr, k_ptr, negp, div_hz);

}



static int sysctl_u2k_int_conv_userhz(const bool *negp, const ulong *u_ptr, int *k_ptr)

{

	return proc_int_u2k_conv_uop(u_ptr, k_ptr, negp, clock_t_to_jiffies);

}



static ulong sysctl_jiffies_to_clock_t(const ulong val)

{

	return jiffies_to_clock_t(val);

}



static int sysctl_k2u_int_conv_userhz(bool *negp, ulong *u_ptr, const int *k_ptr)

{

	return proc_int_k2u_conv_kop(u_ptr, k_ptr, negp, sysctl_jiffies_to_clock_t);

}



static ulong sysctl_msecs_to_jiffies(const ulong val)

{

	return msecs_to_jiffies(val);

}



static int sysctl_u2k_int_conv_ms(const bool *negp, const ulong *u_ptr, int *k_ptr)

{

	return proc_int_u2k_conv_uop(u_ptr, k_ptr, negp, sysctl_msecs_to_jiffies);

}



static ulong sysctl_jiffies_to_msecs(const ulong val)

{

	return jiffies_to_msecs(val);

}



static int sysctl_k2u_int_conv_ms(bool *negp, ulong *u_ptr, const int *k_ptr)

{

	return proc_int_k2u_conv_kop(u_ptr, k_ptr, negp, sysctl_jiffies_to_msecs);

}





static SYSCTL_INT_CONV_CUSTOM(_jiffies, sysctl_u2k_int_conv_hz,

			      sysctl_k2u_int_conv_hz, false)

static SYSCTL_INT_CONV_CUSTOM(_userhz_jiffies,

			      sysctl_user_to_kern_int_conv_userhz,

			      sysctl_kern_to_user_int_conv_userhz, false)

static SYSCTL_INT_CONV_CUSTOM(_ms_jiffies, sysctl_user_to_kern_int_conv_ms,

			      sysctl_kern_to_user_int_conv_ms, false)

			      sysctl_u2k_int_conv_userhz,

			      sysctl_k2u_int_conv_userhz, false)

static SYSCTL_INT_CONV_CUSTOM(_ms_jiffies, sysctl_u2k_int_conv_ms,

			      sysctl_k2u_int_conv_ms, false)

static SYSCTL_INT_CONV_CUSTOM(_ms_jiffies_minmax,

			      sysctl_user_to_kern_int_conv_ms,

			      sysctl_kern_to_user_int_conv_ms, true)

			      sysctl_u2k_int_conv_ms,

			      sysctl_k2u_int_conv_ms, true)



#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)

{

	return -ENOSYS;

}



static int do_proc_int_conv_userhz_jiffies(bool *negp, ulong *u_ptr,

					   int *k_ptr, int dir,

					   const struct ctl_table *tbl)

{

	return -ENOSYS;

}



static int do_proc_int_conv_ms_jiffies(bool *negp, ulong *u_ptr, int *k_ptr,

				       int dir, const struct ctl_table *tbl)

{

	return -ENOSYS;

}



static int do_proc_int_conv_ms_jiffies_minmax(bool *negp, ulong *u_ptr,

					      int *k_ptr, int dir,

					      const struct ctl_table *tbl)

{

	return -ENOSYS;

}

#endif



/**

 * proc_dointvec_jiffies - read a vector of integers as seconds