sysctl: Replace do_proc_do{int,ulong,uint}vec with do_proc_vec

Make do_proc_vec static and parametrize by proc_vec_type enum which
defines the type being processed and selects which converter is "live".
Signed-ness and size are calculated based on proc_vec_type and
table->data is now walked as raw bytes and advanced by the element size;
the converter still performs the actual typed load/store. Pass converter
as a union to avoid a cast from void*. The public
proc_do{int,uint,ulong}vec_conv() prototypes and all converter
signatures in kernel/, fs/ and the header are therefore unchanged.

Remove do_proc_doulongvec_minmax. proc_doulongvec_minmax_conv uses a
converter callback passed by the caller instead of conversions based on
conv{mul,div}. Create uni and bi-direction converters for milliseconds
to jiffies in proc_doulongvec_ms_jiffies_minmax; which is the only user
of proc_doulongvec_minmax_conv.

Replace do_proc_douintvec{,_w,_r} functions with a call to do_proc_vec.
Disallow vectors for uint by returning -EINVAL when more than one
element is detected.

Signed-off-by: Joel Granados <joel.granados@kernel.org>
This commit is contained in:
Joel Granados
2026-08-05 15:28:23 +02:00
parent 0ec31e033f
commit b96b5c6708
3 changed files with 255 additions and 216 deletions
+10 -1
View File
@@ -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.
+218 -212
View File
@@ -572,14 +572,80 @@ 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))
/*
* Element type processed by do_proc_vec(). The tag selects the element size
* and signedness, and it selects which member of union proc_vec_conv is live.
*/
enum proc_vec_type {
PROC_VEC_INT,
PROC_VEC_UINT,
PROC_VEC_ULONG,
};
/*
* Converter passed to do_proc_vec(). Only the member matching the
* enum proc_vec_type tag is ever read, so every dispatch stays fully typed and
* no void * converter pointer is needed.
*/
union proc_vec_conv {
int (*int_conv)(bool *negp, ulong *u_ptr, int *k_ptr,
int dir, const struct ctl_table *table);
int (*uint_conv)(bool *negp, ulong *u_ptr, uint *k_ptr,
int dir, const struct ctl_table *table);
int (*ulong_conv)(bool *negp, ulong *u_ptr, ulong *k_ptr,
int dir, const struct ctl_table *table);
};
/*
* Dispatch to the converter member selected by @type. @k_ptr walks
* table->data as raw bytes and is cast back to the element type here.
*/
static int proc_vec_conv(enum proc_vec_type type, union proc_vec_conv conv,
bool *negp, ulong *u_ptr, char *k_ptr, int dir,
const struct ctl_table *table)
{
int *i, vleft, first = 1, err = 0;
size_t left;
char *p;
switch (type) {
case PROC_VEC_INT:
return conv.int_conv(negp, u_ptr, (int *)k_ptr, dir, table);
case PROC_VEC_UINT:
return conv.uint_conv(negp, u_ptr, (uint *)k_ptr, dir, table);
case PROC_VEC_ULONG:
return conv.ulong_conv(negp, u_ptr, (ulong *)k_ptr, dir, table);
}
return -EINVAL;
}
/*
* Read/write a vector of @type elements. The element size and signedness are
* derived from @type, so a single runtime function replaces the per-type
* variants. table->data is walked as raw bytes (@i) advanced by @size; the
* converter performs the actual typed load/store.
*/
static int do_proc_vec(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos,
enum proc_vec_type type, union proc_vec_conv conv)
{
int vleft, first = 1, err = 0;
size_t left, size;
bool is_unsigned;
char *i, *p;
switch (type) {
case PROC_VEC_INT:
size = sizeof(int);
is_unsigned = false;
break;
case PROC_VEC_UINT:
size = sizeof(uint);
is_unsigned = true;
break;
case PROC_VEC_ULONG:
size = sizeof(ulong);
is_unsigned = true;
break;
default:
return -EINVAL;
}
if (!table->data || !table->maxlen || !*lenp ||
(*ppos && SYSCTL_KERN_TO_USER(dir))) {
@@ -587,10 +653,14 @@ static int do_proc_dointvec(const struct ctl_table *table, int dir,
return 0;
}
i = (int *) table->data;
vleft = table->maxlen / sizeof(*i);
i = table->data;
vleft = table->maxlen / size;
left = *lenp;
/* uint arrays are not supported, *Do not* add support for them. */
if (type == PROC_VEC_UINT && vleft != 1)
return -EINVAL;
if (SYSCTL_USER_TO_KERN(dir)) {
if (proc_first_pos_non_zero_ignore(ppos, table))
goto out;
@@ -600,9 +670,9 @@ static int do_proc_dointvec(const struct ctl_table *table, int dir,
p = buffer;
}
for (; left && vleft--; i++, first=0) {
for (; left && vleft--; i += size, first = 0) {
unsigned long lval;
bool neg;
bool neg = false;
if (SYSCTL_USER_TO_KERN(dir)) {
proc_skip_spaces(&p, &left);
@@ -612,14 +682,16 @@ static int do_proc_dointvec(const struct ctl_table *table, int dir,
err = proc_get_long(&p, &left, &lval, &neg,
proc_wspace_sep,
sizeof(proc_wspace_sep), NULL);
if (!err && neg && is_unsigned)
err = -EINVAL;
if (err)
break;
if (conv(&neg, &lval, i, 1, table)) {
if (proc_vec_conv(type, conv, &neg, &lval, i, dir, table)) {
err = -EINVAL;
break;
}
} else {
if (conv(&neg, &lval, i, 0, table)) {
if (proc_vec_conv(type, conv, &neg, &lval, i, dir, table)) {
err = -EINVAL;
break;
}
@@ -641,119 +713,6 @@ out:
return err;
}
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(&neg, &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);
}
/**
* proc_douintvec_conv - read a vector of unsigned ints with a custom converter
*
@@ -779,7 +738,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_UINT,
(union proc_vec_conv){ .uint_conv = conv });
}
/**
@@ -838,7 +798,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_INT,
(union proc_vec_conv){ .int_conv = do_proc_int_conv });
}
/**
@@ -857,8 +818,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_UINT,
(union proc_vec_conv){ .uint_conv = do_proc_uint_conv });
}
/**
@@ -881,8 +842,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_INT,
(union proc_vec_conv){ .int_conv = do_proc_int_conv_minmax });
}
/**
@@ -908,8 +869,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_UINT,
(union proc_vec_conv){ .uint_conv = do_proc_uint_conv_minmax });
}
/**
@@ -952,8 +913,8 @@ 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_vec(&tmp, dir, buffer, lenp, ppos, PROC_VEC_UINT,
(union proc_vec_conv){ .uint_conv = do_proc_uint_conv_minmax });
if (res)
return res;
if (SYSCTL_USER_TO_KERN(dir))
@@ -962,87 +923,129 @@ 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;
if (k_ptr_range_check) {
ulong tmp_k;
int ret;
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;
}
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;
}
for (; left && vleft--; i++, first = 0) {
unsigned long val;
if (SYSCTL_USER_TO_KERN(dir)) {
bool neg;
proc_skip_spaces(&p, &left);
if (!left)
break;
err = proc_get_long(&p, &left, &val, &neg,
proc_wspace_sep,
sizeof(proc_wspace_sep), NULL);
if (err || neg) {
err = -EINVAL;
break;
}
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);
}
}
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;
}
/**
* 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;
WRITE_ONCE(*k_ptr, u);
return 0;
}
static int proc_ulong_u2k_conv(const ulong *u_ptr, ulong *k_ptr)
{
return proc_ulong_u2k_conv_uop(u_ptr, k_ptr, NULL);
}
/**
* 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;
}
static int proc_ulong_k2u_conv(ulong *u_ptr, const ulong *k_ptr)
{
return proc_ulong_k2u_conv_kop(u_ptr, k_ptr, NULL);
}
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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_ULONG,
(union proc_vec_conv){ .ulong_conv = conv });
}
/**
@@ -1064,7 +1067,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_ULONG,
(union proc_vec_conv){ .ulong_conv = do_proc_ulong_conv });
}
/**
@@ -1090,7 +1094,8 @@ 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_vec(table, dir, buffer, lenp, ppos, PROC_VEC_INT,
(union proc_vec_conv){ .int_conv = conv });
}
/**
@@ -1319,7 +1324,8 @@ 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;
}
+25 -1
View File
@@ -185,6 +185,24 @@ 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)
@@ -211,6 +229,12 @@ 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
/**
@@ -310,7 +334,7 @@ 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);