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Message-Id: <20251013-jag-sysctl_conv-v1-4-4dc35ceae733@kernel.org>
Date: Mon, 13 Oct 2025 15:24:54 +0200
From: Joel Granados <joel.granados@...nel.org>
To: Alexander Viro <viro@...iv.linux.org.uk>,
Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
Kees Cook <kees@...nel.org>
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
Joel Granados <joel.granados@...nel.org>
Subject: [PATCH 4/8] sysctl: Indicate the direction of operation with macro
names
Replace the "write" integer parameter with SYSCTL_USER_TO_KERN() and
SYSCTL_KERN_TO_USER() that clearly indicate data flow direction in
sysctl operations.
"write" originates in proc_sysctl.c (proc_sys_{read,write}) and can take
one of two values: "0" or "1" when called from proc_sys_read and
proc_sys_write respectively. When write has a value of zero, data is
"written" to a user space buffer from a kernel variable (usually
ctl_table->data). Whereas when write has a value greater than zero, data
is "written" to an internal kernel variable from a user space buffer.
Remove this ambiguity by introducing macros that clearly indicate the
direction of the "write".
The write mode names in sysctl_writes_mode are left unchanged as these
directly relate to the sysctl_write_strict file in /proc/sys where the
word "write" unambiguously refers to writing to a file.
Signed-off-by: Joel Granados <joel.granados@...nel.org>
---
kernel/sysctl.c | 252 ++++++++++++++++++++++++++++++--------------------------
1 file changed, 136 insertions(+), 116 deletions(-)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9b042d81fd1c6a32f60e2834a98d48c1bc348de0..69148fe7359994b85c076b7b6750792b2d1c751e 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -30,6 +30,19 @@ EXPORT_SYMBOL(sysctl_vals);
const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
EXPORT_SYMBOL_GPL(sysctl_long_vals);
+/**
+ *
+ * "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
+ * one of two things for sysctl:
+ * 1. SYSCTL_USER_TO_KERN(dir) Writing to an internal kernel variable from user
+ * space (dir > 0)
+ * 2. SYSCTL_KERN_TO_USER(dir) Writing to a user space buffer from a kernel
+ * variable (dir == 0).
+ */
+#define SYSCTL_USER_TO_KERN(dir) (!!(dir))
+#define SYSCTL_KERN_TO_USER(dir) (!dir)
+
#if defined(CONFIG_SYSCTL)
/* Constants used for minimum and maximum */
@@ -55,7 +68,8 @@ static const int cap_last_cap = CAP_LAST_CAP;
* to the buffer.
*
* These write modes control how current file position affects the behavior of
- * updating sysctl values through the proc interface on each write.
+ * updating internal kernel (SYSCTL_USER_TO_KERN) sysctl values through the proc
+ * interface on each write.
*/
enum sysctl_writes_mode {
SYSCTL_WRITES_LEGACY = -1,
@@ -73,7 +87,7 @@ static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT;
#ifdef CONFIG_PROC_SYSCTL
-static int _proc_do_string(char *data, int maxlen, int write,
+static int _proc_do_string(char *data, int maxlen, int dir,
char *buffer, size_t *lenp, loff_t *ppos)
{
size_t len;
@@ -84,7 +98,7 @@ static int _proc_do_string(char *data, int maxlen, int write,
return 0;
}
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
/* Only continue writes not past the end of buffer. */
len = strlen(data);
@@ -172,7 +186,7 @@ static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
/**
* proc_dostring - read a string sysctl
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -186,13 +200,13 @@ static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
*
* Returns 0 on success.
*/
-int proc_dostring(const struct ctl_table *table, int write,
+int proc_dostring(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- if (write)
+ if (SYSCTL_USER_TO_KERN(dir))
proc_first_pos_non_zero_ignore(ppos, table);
- return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,
+ return _proc_do_string(table->data, table->maxlen, dir, buffer, lenp,
ppos);
}
@@ -355,10 +369,10 @@ static void proc_put_char(void **buf, size_t *size, char c)
}
static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (*negp) {
if (*lvalp > (unsigned long) INT_MAX + 1)
return -EINVAL;
@@ -382,10 +396,10 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
}
static int do_proc_douintvec_conv(unsigned long *lvalp,
- unsigned int *valp, int write,
+ unsigned int *valp, int dir,
const struct ctl_table *table)
{
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (*lvalp > UINT_MAX)
return -EINVAL;
WRITE_ONCE(*valp, *lvalp);
@@ -399,16 +413,17 @@ static int do_proc_douintvec_conv(unsigned long *lvalp,
static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
-static int do_proc_dointvec(const struct ctl_table *table, int write,
+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 *lvalp, int *valp,
- int write, const struct ctl_table *table))
+ 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 && !write)) {
+ if (!table->data || !table->maxlen || !*lenp ||
+ (*ppos && SYSCTL_KERN_TO_USER(dir))) {
*lenp = 0;
return 0;
}
@@ -420,7 +435,7 @@ static int do_proc_dointvec(const struct ctl_table *table, int write,
if (!conv)
conv = do_proc_dointvec_conv;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (proc_first_pos_non_zero_ignore(ppos, table))
goto out;
@@ -433,7 +448,7 @@ static int do_proc_dointvec(const struct ctl_table *table, int write,
unsigned long lval;
bool neg;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
proc_skip_spaces(&p, &left);
if (!left)
@@ -458,11 +473,11 @@ static int do_proc_dointvec(const struct ctl_table *table, int write,
}
}
- if (!write && !first && left && !err)
+ if (SYSCTL_KERN_TO_USER(dir) && !first && left && !err)
proc_put_char(&buffer, &left, '\n');
- if (write && !err && left)
+ if (SYSCTL_USER_TO_KERN(dir) && !err && left)
proc_skip_spaces(&p, &left);
- if (write && first)
+ if (SYSCTL_USER_TO_KERN(dir) && first)
return err ? : -EINVAL;
*lenp -= left;
out:
@@ -473,7 +488,7 @@ static int do_proc_dointvec(const struct ctl_table *table, int write,
static int do_proc_douintvec_w(const struct ctl_table *table, void *buffer,
size_t *lenp, loff_t *ppos,
int (*conv)(unsigned long *lvalp,
- unsigned int *valp, int write,
+ unsigned int *valp, int dir,
const struct ctl_table *table))
{
unsigned long lval;
@@ -526,7 +541,7 @@ 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 *lvalp,
- unsigned int *valp, int write,
+ unsigned int *valp, int dir,
const struct ctl_table *table))
{
unsigned long lval;
@@ -553,14 +568,15 @@ static int do_proc_douintvec_r(const struct ctl_table *table, void *buffer,
return err;
}
-int do_proc_douintvec(const struct ctl_table *table, int write, void *buffer,
+int do_proc_douintvec(const struct ctl_table *table, int dir, void *buffer,
size_t *lenp, loff_t *ppos,
int (*conv)(unsigned long *lvalp, unsigned int *valp,
- int write, const struct ctl_table *table))
+ int dir, const struct ctl_table *table))
{
unsigned int vleft;
- if (!table->data || !table->maxlen || !*lenp || (*ppos && !write)) {
+ if (!table->data || !table->maxlen || !*lenp ||
+ (*ppos && SYSCTL_KERN_TO_USER(dir))) {
*lenp = 0;
return 0;
}
@@ -579,7 +595,7 @@ int do_proc_douintvec(const struct ctl_table *table, int write, void *buffer,
if (!conv)
conv = do_proc_douintvec_conv;
- if (write)
+ 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);
}
@@ -587,7 +603,7 @@ int do_proc_douintvec(const struct ctl_table *table, int write, void *buffer,
/**
* proc_dobool - read/write a bool
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -600,7 +616,7 @@ int do_proc_douintvec(const struct ctl_table *table, int write, void *buffer,
*
* Returns 0 on success.
*/
-int proc_dobool(const struct ctl_table *table, int write, void *buffer,
+int proc_dobool(const struct ctl_table *table, int dir, void *buffer,
size_t *lenp, loff_t *ppos)
{
struct ctl_table tmp;
@@ -616,10 +632,10 @@ int proc_dobool(const struct ctl_table *table, int write, void *buffer,
tmp.data = &val;
val = READ_ONCE(*data);
- res = proc_dointvec(&tmp, write, buffer, lenp, ppos);
+ res = proc_dointvec(&tmp, dir, buffer, lenp, ppos);
if (res)
return res;
- if (write)
+ if (SYSCTL_USER_TO_KERN(dir))
WRITE_ONCE(*data, val);
return 0;
}
@@ -627,7 +643,7 @@ int proc_dobool(const struct ctl_table *table, int write, void *buffer,
/**
* proc_dointvec - read a vector of integers
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -637,16 +653,16 @@ int proc_dobool(const struct ctl_table *table, int write, void *buffer,
*
* Returns 0 on success.
*/
-int proc_dointvec(const struct ctl_table *table, int write, 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, write, buffer, lenp, ppos, NULL);
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos, NULL);
}
/**
* proc_douintvec - read a vector of unsigned integers
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -656,15 +672,15 @@ int proc_dointvec(const struct ctl_table *table, int write, void *buffer,
*
* Returns 0 on success.
*/
-int proc_douintvec(const struct ctl_table *table, int write, 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, write, buffer, lenp, ppos,
+ return do_proc_douintvec(table, dir, buffer, lenp, ppos,
do_proc_douintvec_conv);
}
static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
int tmp, ret, *min, *max;
@@ -672,13 +688,13 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
* If writing, first do so via a temporary local int so we can
* bounds-check it before touching *valp.
*/
- int *ip = write ? &tmp : valp;
+ int *ip = SYSCTL_USER_TO_KERN(dir) ? &tmp : valp;
- ret = do_proc_dointvec_conv(negp, lvalp, ip, write, table);
+ ret = do_proc_dointvec_conv(negp, lvalp, ip, dir, table);
if (ret)
return ret;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
min = (int *) table->extra1;
max = (int *) table->extra2;
if ((min && *min > tmp) || (max && *max < tmp))
@@ -692,7 +708,7 @@ static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
/**
* proc_dointvec_minmax - read a vector of integers with min/max values
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -703,29 +719,30 @@ 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 or -EINVAL on write when the range check fails.
+ * Returns 0 on success or -EINVAL when the range check fails and
+ * SYSCTL_USER_TO_KERN(dir) == true
*/
-int proc_dointvec_minmax(const struct ctl_table *table, int write,
+int proc_dointvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_dointvec(table, write, buffer, lenp, ppos,
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos,
do_proc_dointvec_minmax_conv);
}
static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
- unsigned int *valp, int write,
+ unsigned int *valp, int dir,
const struct ctl_table *table)
{
int ret;
unsigned int tmp, *min, *max;
- /* write via temporary local uint for bounds-checking */
- unsigned int *up = write ? &tmp : valp;
+ /* When writing to the kernel use a temp local uint for bounds-checking */
+ unsigned int *up = SYSCTL_USER_TO_KERN(dir) ? &tmp : valp;
- ret = do_proc_douintvec_conv(lvalp, up, write, table);
+ ret = do_proc_douintvec_conv(lvalp, up, dir, table);
if (ret)
return ret;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
min = (unsigned int *) table->extra1;
max = (unsigned int *) table->extra2;
if ((min && *min > tmp) || (max && *max < tmp))
@@ -740,7 +757,7 @@ static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
/**
* proc_douintvec_minmax - read a vector of unsigned ints with min/max values
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -754,19 +771,20 @@ 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 or -ERANGE on write when the range check fails.
+ * Returns 0 on success or -ERANGE when range check failes and
+ * SYSCTL_USER_TO_KERN(dir) == true
*/
-int proc_douintvec_minmax(const struct ctl_table *table, int write,
+int proc_douintvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_douintvec(table, write, buffer, lenp, ppos,
+ return do_proc_douintvec(table, dir, buffer, lenp, ppos,
do_proc_douintvec_minmax_conv);
}
/**
* proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -778,9 +796,10 @@ int proc_douintvec_minmax(const struct ctl_table *table, int write,
* This routine will ensure the values are within the range specified by
* table->extra1 (min) and table->extra2 (max).
*
- * Returns 0 on success or an error on write when the range check fails.
+ * Returns 0 on success or an error on SYSCTL_USER_TO_KERN(dir) == true
+ * and the range check fails.
*/
-int proc_dou8vec_minmax(const struct ctl_table *table, int write,
+int proc_dou8vec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table tmp;
@@ -802,17 +821,17 @@ int proc_dou8vec_minmax(const struct ctl_table *table, int write,
tmp.extra2 = (unsigned int *) &max;
val = READ_ONCE(*data);
- res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
+ res = do_proc_douintvec(&tmp, dir, buffer, lenp, ppos,
do_proc_douintvec_minmax_conv);
if (res)
return res;
- if (write)
+ if (SYSCTL_USER_TO_KERN(dir))
WRITE_ONCE(*data, val);
return 0;
}
EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
-static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
+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)
@@ -822,7 +841,8 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
size_t left;
char *p;
- if (!table->data || !table->maxlen || !*lenp || (*ppos && !write)) {
+ if (!table->data || !table->maxlen || !*lenp ||
+ (*ppos && SYSCTL_KERN_TO_USER(dir))) {
*lenp = 0;
return 0;
}
@@ -833,7 +853,7 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
vleft = table->maxlen / sizeof(unsigned long);
left = *lenp;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (proc_first_pos_non_zero_ignore(ppos, table))
goto out;
@@ -845,7 +865,7 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
for (; left && vleft--; i++, first = 0) {
unsigned long val;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
bool neg;
proc_skip_spaces(&p, &left);
@@ -874,11 +894,11 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
}
}
- if (!write && !first && left && !err)
+ if (SYSCTL_KERN_TO_USER(dir) && !first && left && !err)
proc_put_char(&buffer, &left, '\n');
- if (write && !err)
+ if (SYSCTL_USER_TO_KERN(dir) && !err)
proc_skip_spaces(&p, &left);
- if (write && first)
+ if (SYSCTL_USER_TO_KERN(dir) && first)
return err ? : -EINVAL;
*lenp -= left;
out:
@@ -889,7 +909,7 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
/**
* proc_doulongvec_minmax - read a vector of long integers with min/max values
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -902,16 +922,16 @@ static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
*
* Returns 0 on success.
*/
-int proc_doulongvec_minmax(const struct ctl_table *table, int write,
+int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
+ return do_proc_doulongvec_minmax(table, dir, buffer, lenp, ppos, 1l, 1l);
}
/**
* proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -925,19 +945,19 @@ int proc_doulongvec_minmax(const struct ctl_table *table, int write,
*
* Returns 0 on success.
*/
-int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int write,
+int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_doulongvec_minmax(table, write, buffer,
- lenp, ppos, HZ, 1000l);
+ return do_proc_doulongvec_minmax(table, dir, buffer,
+ lenp, ppos, HZ, 1000l);
}
static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (*lvalp > INT_MAX / HZ)
return 1;
if (*negp)
@@ -960,10 +980,10 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
}
static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
return 1;
*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
@@ -983,10 +1003,10 @@ static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp
}
static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
if (jif > INT_MAX)
@@ -1008,7 +1028,7 @@ static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
}
static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lvalp,
- int *valp, int write,
+ int *valp, int dir,
const struct ctl_table *table)
{
int tmp, ret, *min, *max;
@@ -1016,13 +1036,13 @@ static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lv
* If writing, first do so via a temporary local int so we can
* bounds-check it before touching *valp.
*/
- int *ip = write ? &tmp : valp;
+ int *ip = SYSCTL_USER_TO_KERN(dir) ? &tmp : valp;
- ret = do_proc_dointvec_ms_jiffies_conv(negp, lvalp, ip, write, table);
+ ret = do_proc_dointvec_ms_jiffies_conv(negp, lvalp, ip, dir, table);
if (ret)
return ret;
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
min = (int *) table->extra1;
max = (int *) table->extra2;
if ((min && *min > tmp) || (max && *max < tmp))
@@ -1035,7 +1055,7 @@ static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lv
/**
* proc_dointvec_jiffies - read a vector of integers as seconds
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -1047,24 +1067,24 @@ static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lv
*
* Returns 0 on success.
*/
-int proc_dointvec_jiffies(const struct ctl_table *table, int write,
+int proc_dointvec_jiffies(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_dointvec(table,write,buffer,lenp,ppos,
- do_proc_dointvec_jiffies_conv);
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos,
+ do_proc_dointvec_jiffies_conv);
}
-int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int write,
+int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_dointvec(table, write, buffer, lenp, ppos,
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos,
do_proc_dointvec_ms_jiffies_minmax_conv);
}
/**
* proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @dir: %TRUE if this is a write to the sysctl file
* @buffer: the user buffer
* @lenp: the size of the user buffer
* @ppos: pointer to the file position
@@ -1076,17 +1096,17 @@ int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int write,
*
* Returns 0 on success.
*/
-int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int write,
+int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
- return do_proc_dointvec(table, write, buffer, lenp, ppos,
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos,
do_proc_dointvec_userhz_jiffies_conv);
}
/**
* proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @dir: %TRUE if this is a write to the sysctl file
* @buffer: the user buffer
* @lenp: the size of the user buffer
* @ppos: the current position in the file
@@ -1098,17 +1118,17 @@ int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int write,
*
* Returns 0 on success.
*/
-int proc_dointvec_ms_jiffies(const struct ctl_table *table, int write, void *buffer,
+int proc_dointvec_ms_jiffies(const struct ctl_table *table, int dir, void *buffer,
size_t *lenp, loff_t *ppos)
{
- return do_proc_dointvec(table, write, buffer, lenp, ppos,
+ return do_proc_dointvec(table, dir, buffer, lenp, ppos,
do_proc_dointvec_ms_jiffies_conv);
}
/**
* proc_do_large_bitmap - read/write from/to a large bitmap
* @table: the sysctl table
- * @write: %TRUE if this is a write to the sysctl file
+ * @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
@@ -1122,7 +1142,7 @@ int proc_dointvec_ms_jiffies(const struct ctl_table *table, int write, void *buf
*
* Returns 0 on success.
*/
-int proc_do_large_bitmap(const struct ctl_table *table, int write,
+int proc_do_large_bitmap(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
int err = 0;
@@ -1132,12 +1152,12 @@ int proc_do_large_bitmap(const struct ctl_table *table, int write,
unsigned long *tmp_bitmap = NULL;
char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
- if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
+ if (!bitmap || !bitmap_len || !left || (*ppos && SYSCTL_KERN_TO_USER(dir))) {
*lenp = 0;
return 0;
}
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
char *p = buffer;
size_t skipped = 0;
@@ -1238,7 +1258,7 @@ int proc_do_large_bitmap(const struct ctl_table *table, int write,
}
if (!err) {
- if (write) {
+ if (SYSCTL_USER_TO_KERN(dir)) {
if (*ppos)
bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
else
@@ -1254,85 +1274,85 @@ int proc_do_large_bitmap(const struct ctl_table *table, int write,
#else /* CONFIG_PROC_SYSCTL */
-int proc_dostring(const struct ctl_table *table, int write,
+int proc_dostring(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dobool(const struct ctl_table *table, int write,
+int proc_dobool(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec(const struct ctl_table *table, int write,
+int proc_dointvec(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_douintvec(const struct ctl_table *table, int write,
+int proc_douintvec(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec_minmax(const struct ctl_table *table, int write,
+int proc_dointvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_douintvec_minmax(const struct ctl_table *table, int write,
+int proc_douintvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dou8vec_minmax(const struct ctl_table *table, int write,
+int proc_dou8vec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec_jiffies(const struct ctl_table *table, int write,
+int proc_dointvec_jiffies(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int write,
+int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int write,
+int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_dointvec_ms_jiffies(const struct ctl_table *table, int write,
+int proc_dointvec_ms_jiffies(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_doulongvec_minmax(const struct ctl_table *table, int write,
+int proc_doulongvec_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int write,
+int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
}
-int proc_do_large_bitmap(const struct ctl_table *table, int write,
+int proc_do_large_bitmap(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
return -ENOSYS;
@@ -1341,7 +1361,7 @@ int proc_do_large_bitmap(const struct ctl_table *table, int write,
#endif /* CONFIG_PROC_SYSCTL */
#if defined(CONFIG_SYSCTL)
-int proc_do_static_key(const struct ctl_table *table, int write,
+int proc_do_static_key(const struct ctl_table *table, int dir,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct static_key *key = (struct static_key *)table->data;
@@ -1355,13 +1375,13 @@ int proc_do_static_key(const struct ctl_table *table, int write,
.extra2 = SYSCTL_ONE,
};
- if (write && !capable(CAP_SYS_ADMIN))
+ if (SYSCTL_USER_TO_KERN(dir) && !capable(CAP_SYS_ADMIN))
return -EPERM;
mutex_lock(&static_key_mutex);
val = static_key_enabled(key);
- ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
- if (write && !ret) {
+ ret = proc_dointvec_minmax(&tmp, dir, buffer, lenp, ppos);
+ if (SYSCTL_USER_TO_KERN(dir) && !ret) {
if (val)
static_key_enable(key);
else
--
2.50.1
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