1 // SPDX-License-Identifier: GPL-2.0-only
26 const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
29 const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
41  * enum sysctl_writes_mode - supported sysctl write modes
43  * @SYSCTL_WRITES_LEGACY: each write syscall must fully contain the sysctl value
51  *	sent to the write syscall. If dealing with strings respect the file
56  * These write modes control how current file position affects the behavior of
58  * interface on each write.
61 	SYSCTL_WRITES_LEGACY		= -1,
63 	SYSCTL_WRITES_STRICT		= 1,
91 			if (len > maxlen - 1)  in _proc_do_string()
92 				len = maxlen - 1;  in _proc_do_string()
104 		while ((p - buffer) < *lenp && len < maxlen - 1) {  in _proc_do_string()
122 		len  -= *ppos;  in _proc_do_string()
142 		"warning, set kernel.sysctl_writes_strict = -1\n",  in warn_sysctl_write()
143 		current->comm, table->procname);  in warn_sysctl_write()
147  * proc_first_pos_non_zero_ignore - check if first position is allowed
151  * Returns true if the first position is non-zero and the sysctl_writes_strict
173  * proc_dostring - read a string sysctl
175  * @dir: %TRUE if this is a write to the sysctl file
182  * string is truncated. The copied string is %NULL-terminated.
195 	return _proc_do_string(table->data, table->maxlen, dir, buffer, lenp,  in proc_dostring()
204 		(*size)--;  in proc_skip_spaces()
214 		(*size)--;  in proc_skip_char()
220  * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
243 		return -ERANGE;  in strtoul_lenient()
256  * proc_get_long - reads an ASCII formatted integer from a user buffer
267  * the amount of bytes read. If @tr is non-NULL and a trailing
268  * character exists (size is non-zero after returning from this
279 		return -EINVAL;  in proc_get_long()
281 	if (len > TMPBUFLEN - 1)  in proc_get_long()
282 		len = TMPBUFLEN - 1;  in proc_get_long()
288 	if (*p == '-' && *size > 1) {  in proc_get_long()
294 		return -EINVAL;  in proc_get_long()
297 		return -EINVAL;  in proc_get_long()
299 	len = p - tmp;  in proc_get_long()
303 	 * (e.g. 123...1). So lets not allow such large numbers. */  in proc_get_long()
304 	if (len == TMPBUFLEN - 1)  in proc_get_long()
305 		return -EINVAL;  in proc_get_long()
308 		return -EINVAL;  in proc_get_long()
314 	*size -= len;  in proc_get_long()
320  * proc_put_long - converts an integer to a decimal ASCII formatted string
335 	sprintf(p, "%s%lu", neg ? "-" : "", val);  in proc_put_long()
340 	*size -= len;  in proc_put_long()
351 		(*size)--;  in proc_put_char()
358  * proc_uint_u2k_conv_uop - Assign user value to a kernel pointer
376 		return -EINVAL;  in proc_uint_u2k_conv_uop()
382  * proc_uint_k2u_conv - Assign kernel value to a user space pointer
399  * proc_uint_conv - Change user or kernel pointer based on direction
403  * @dir: %TRUE if this is a write to the sysctl file
427 			return -EINVAL;  in proc_uint_conv()
431 		if ((tbl->extra1 &&  in proc_uint_conv()
432 		     *(uint *)tbl->extra1 > tmp_k) ||  in proc_uint_conv()
433 		    (tbl->extra2 &&  in proc_uint_conv()
434 		     *(uint *)tbl->extra2 < tmp_k))  in proc_uint_conv()
435 			return -ERANGE;  in proc_uint_conv()
462  * proc_int_k2u_conv_kop - Assign kernel value to a user space pointer
481 		*u_ptr = k_ptr_op ? -k_ptr_op((ulong)val) : -(ulong)val;  in proc_int_k2u_conv_kop()
490  * proc_int_u2k_conv_uop - Assign user value to a kernel pointer
507 		if (u > (ulong) INT_MAX + 1)  in proc_int_u2k_conv_uop()
508 			return -EINVAL;  in proc_int_u2k_conv_uop()
509 		WRITE_ONCE(*k_ptr, -u);  in proc_int_u2k_conv_uop()
512 			return -EINVAL;  in proc_int_u2k_conv_uop()
530 			return -EINVAL;  in proc_int_conv()
534 		if ((tbl->extra1 && *(int *)tbl->extra1 > tmp_k) ||  in proc_int_conv()
535 		    (tbl->extra2 && *(int *)tbl->extra2 < tmp_k))  in proc_int_conv()
536 			return -EINVAL;  in proc_int_conv()
580 	int *i, vleft, first = 1, err = 0;  in do_proc_dointvec()
584 	if (!table->data || !table->maxlen || !*lenp ||  in do_proc_dointvec()
590 	i = (int *) table->data;  in do_proc_dointvec()
591 	vleft = table->maxlen / sizeof(*i);  in do_proc_dointvec()
601 		if (left > PAGE_SIZE - 1)  in do_proc_dointvec()
602 			left = PAGE_SIZE - 1;  in do_proc_dointvec()
606 	for (; left && vleft--; i++, first=0) {  in do_proc_dointvec()
620 			if (conv(&neg, &lval, i, 1, table)) {  in do_proc_dointvec()
621 				err = -EINVAL;  in do_proc_dointvec()
626 				err = -EINVAL;  in do_proc_dointvec()
640 		return err ? : -EINVAL;  in do_proc_dointvec()
641 	*lenp -= left;  in do_proc_dointvec()
664 	if (left > PAGE_SIZE - 1)  in do_proc_douintvec_w()
665 		left = PAGE_SIZE - 1;  in do_proc_douintvec_w()
669 		err = -EINVAL;  in do_proc_douintvec_w()
677 		err = -EINVAL;  in do_proc_douintvec_w()
681 	if (conv(&lval, (unsigned int *) table->data, 1, table)) {  in do_proc_douintvec_w()
682 		err = -EINVAL;  in do_proc_douintvec_w()
691 		return -EINVAL;  in do_proc_douintvec_w()
712 	if (conv(&lval, (unsigned int *) table->data, 0, table)) {  in do_proc_douintvec_r()
713 		err = -EINVAL;  in do_proc_douintvec_r()
724 	*lenp -= left;  in do_proc_douintvec_r()
738 	if (!table->data || !table->maxlen || !*lenp ||  in do_proc_douintvec()
744 	vleft = table->maxlen / sizeof(unsigned int);  in do_proc_douintvec()
750 	if (vleft != 1) {  in do_proc_douintvec()
752 		return -EINVAL;  in do_proc_douintvec()
764  * proc_douintvec_conv - read a vector of unsigned ints with a custom converter
767  * @dir: %TRUE if this is a write to the sysctl file
773  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
788  * proc_dobool - read/write a bool
790  * @dir: %TRUE if this is a write to the sysctl file
798  * table->data must point to a bool variable and table->maxlen must
807 	bool *data = table->data;  in proc_dobool()
811 	if (table->maxlen != sizeof(bool))  in proc_dobool()
812 		return -EINVAL;  in proc_dobool()
828  * proc_dointvec - read a vector of integers
830  * @dir: %TRUE if this is a write to the sysctl file
835  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
847  * proc_douintvec - read a vector of unsigned integers
849  * @dir: %TRUE if this is a write to the sysctl file
854  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
867  * proc_dointvec_minmax - read a vector of integers with min/max values
869  * @dir: %TRUE if this is a write to the sysctl file
874  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
878  * table->extra1 (min) and table->extra2 (max).
880  * Returns 0 on success or -EINVAL when the range check fails and
891  * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
893  * @dir: %TRUE if this is a write to the sysctl file
898  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
903  * are within the range specified by table->extra1 (min) and table->extra2
907  * Returns 0 on success or -ERANGE when range check failes and
918  * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
920  * @dir: %TRUE if this is a write to the sysctl file
925  * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
930  * table->extra1 (min) and table->extra2 (max).
940 	u8 *data = table->data;  in proc_dou8vec_minmax()
944 	if (table->maxlen != sizeof(u8))  in proc_dou8vec_minmax()
945 		return -EINVAL;  in proc_dou8vec_minmax()
973 	int vleft, first = 1, err = 0;  in do_proc_doulongvec_minmax()
977 	if (!table->data || !table->maxlen || !*lenp ||  in do_proc_doulongvec_minmax()
983 	i = table->data;  in do_proc_doulongvec_minmax()
984 	min = table->extra1;  in do_proc_doulongvec_minmax()
985 	max = table->extra2;  in do_proc_doulongvec_minmax()
986 	vleft = table->maxlen / sizeof(unsigned long);  in do_proc_doulongvec_minmax()
993 		if (left > PAGE_SIZE - 1)  in do_proc_doulongvec_minmax()
994 			left = PAGE_SIZE - 1;  in do_proc_doulongvec_minmax()
998 	for (; left && vleft--; i++, first = 0) {  in do_proc_doulongvec_minmax()
1012 				err = -EINVAL;  in do_proc_doulongvec_minmax()
1018 				err = -EINVAL;  in do_proc_doulongvec_minmax()
1035 		return err ? : -EINVAL;  in do_proc_doulongvec_minmax()
1036 	*lenp -= left;  in do_proc_doulongvec_minmax()
1051  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1053  * @dir: %TRUE if this is a write to the sysctl file
1058  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1062  * table->extra1 (min) and table->extra2 (max).
1069 	return proc_doulongvec_minmax_conv(table, dir, buffer, lenp, ppos, 1l, 1l);  in proc_doulongvec_minmax()
1073  * proc_dointvec_conv - read a vector of ints with a custom converter
1075  * @dir: %TRUE if this is a write to the sysctl file
1081  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
1097  * proc_do_large_bitmap - read/write from/to a large bitmap
1099  * @dir: %TRUE if this is a write to the sysctl file
1104  * The bitmap is stored at table->data and the bitmap length (in bits)
1105  * in table->maxlen.
1107  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
1118 	unsigned long bitmap_len = table->maxlen;  in proc_do_large_bitmap()
1119 	unsigned long *bitmap = *(unsigned long **) table->data;  in proc_do_large_bitmap()
1121 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c = 0;  in proc_do_large_bitmap()
1132 		if (left > PAGE_SIZE - 1) {  in proc_do_large_bitmap()
1133 			left = PAGE_SIZE - 1;  in proc_do_large_bitmap()
1135 			skipped = *lenp - left;  in proc_do_large_bitmap()
1140 			return -ENOMEM;  in proc_do_large_bitmap()
1147 			/* In case we stop parsing mid-number, we can reset */  in proc_do_large_bitmap()
1153 			 * only one char is left (may be a "-"), then stop here,  in proc_do_large_bitmap()
1156 			if ((left <= 1) && skipped) {  in proc_do_large_bitmap()
1164 				err = -EINVAL;  in proc_do_large_bitmap()
1171 				left--;  in proc_do_large_bitmap()
1174 			if (c == '-') {  in proc_do_large_bitmap()
1191 					err = -EINVAL;  in proc_do_large_bitmap()
1196 					left--;  in proc_do_large_bitmap()
1200 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);  in proc_do_large_bitmap()
1206 		bool first = 1;  in proc_do_large_bitmap()
1213 						   bit_a + 1) - 1;  in proc_do_large_bitmap()
1219 				proc_put_char(&buffer, &left, '-');  in proc_do_large_bitmap()
1235 		*lenp -= left;  in proc_do_large_bitmap()
1248 	return -ENOSYS;  in proc_dostring()
1254 	return -ENOSYS;  in proc_dobool()
1260 	return -ENOSYS;  in proc_dointvec()
1266 	return -ENOSYS;  in proc_douintvec()
1272 	return -ENOSYS;  in proc_dointvec_minmax()
1278 	return -ENOSYS;  in proc_douintvec_minmax()
1281 int proc_douintvec_conv(const struct ctl_table *table, int write, void *buffer,  in proc_douintvec_conv()  argument
1284 				    int write, const struct ctl_table *table))  in proc_douintvec_conv()
1286 	return -ENOSYS;  in proc_douintvec_conv()
1291 	return -ENOSYS;  in proc_uint_k2u_conv()
1297 	return -ENOSYS;  in proc_uint_u2k_conv_uop()
1305 	return -ENOSYS;  in proc_uint_conv()
1311 	return -ENOSYS;  in proc_dou8vec_minmax()
1317 	return -ENOSYS;  in proc_doulongvec_minmax()
1324 	return -ENOSYS;  in proc_doulongvec_minmax_conv()
1332 	return -ENOSYS;  in proc_dointvec_conv()
1338 	return -ENOSYS;  in proc_do_large_bitmap()
1347 	struct static_key *key = (struct static_key *)table->data;  in proc_do_static_key()
1353 		.mode   = table->mode,  in proc_do_static_key()
1359 		return -EPERM;  in proc_do_static_key()
1402 		.procname	= "unaligned-trap",
1411 		.procname	= "ignore-unaligned-usertrap",
1429  * exception granted :-)