1 // SPDX-License-Identifier: GPL-2.0-only
7  * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
9  * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
11  * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
85 const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
106  * enum sysctl_writes_mode - supported sysctl write modes
125 	SYSCTL_WRITES_LEGACY		= -1,
149 	size_t len;  in _proc_do_string()  local
160 			len = strlen(data);  in _proc_do_string()
161 			if (len > maxlen - 1)  in _proc_do_string()
162 				len = maxlen - 1;  in _proc_do_string()
164 			if (*ppos > len)  in _proc_do_string()
166 			len = *ppos;  in _proc_do_string()
169 			len = 0;  in _proc_do_string()
174 		while ((p - buffer) < *lenp && len < maxlen - 1) {  in _proc_do_string()
178 			data[len++] = c;  in _proc_do_string()
180 		data[len] = 0;  in _proc_do_string()
182 		len = strlen(data);  in _proc_do_string()
183 		if (len > maxlen)  in _proc_do_string()
184 			len = maxlen;  in _proc_do_string()
186 		if (*ppos > len) {  in _proc_do_string()
192 		len  -= *ppos;  in _proc_do_string()
194 		if (len > *lenp)  in _proc_do_string()
195 			len = *lenp;  in _proc_do_string()
196 		if (len)  in _proc_do_string()
197 			memcpy(buffer, data, len);  in _proc_do_string()
198 		if (len < *lenp) {  in _proc_do_string()
199 			buffer[len] = '\n';  in _proc_do_string()
200 			len++;  in _proc_do_string()
202 		*lenp = len;  in _proc_do_string()
203 		*ppos += len;  in _proc_do_string()
212 		"warning, set kernel.sysctl_writes_strict = -1\n",  in warn_sysctl_write()
213 		current->comm, table->procname);  in warn_sysctl_write()
217  * proc_first_pos_non_zero_ignore - check if first position is allowed
221  * Returns true if the first position is non-zero and the sysctl_writes_strict
243  * proc_dostring - read a string sysctl
252  * string is truncated. The copied string is %NULL-terminated.
265 	return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,  in proc_dostring()
274 		(*size)--;  in proc_skip_spaces()
284 		(*size)--;  in proc_skip_char()
290  * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
313 		return -ERANGE;  in strtoul_lenient()
326  * proc_get_long - reads an ASCII formatted integer from a user buffer
337  * the amount of bytes read. If @tr is non-NULL and a trailing
338  * character exists (size is non-zero after returning from this
346 	ssize_t len = *size;  in proc_get_long()  local
348 	if (len <= 0)  in proc_get_long()
349 		return -EINVAL;  in proc_get_long()
351 	if (len > TMPBUFLEN - 1)  in proc_get_long()
352 		len = TMPBUFLEN - 1;  in proc_get_long()
354 	memcpy(tmp, *buf, len);  in proc_get_long()
356 	tmp[len] = 0;  in proc_get_long()
358 	if (*p == '-' && *size > 1) {  in proc_get_long()
364 		return -EINVAL;  in proc_get_long()
367 		return -EINVAL;  in proc_get_long()
369 	len = p - tmp;  in proc_get_long()
374 	if (len == TMPBUFLEN - 1)  in proc_get_long()
375 		return -EINVAL;  in proc_get_long()
377 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))  in proc_get_long()
378 		return -EINVAL;  in proc_get_long()
380 	if (tr && (len < *size))  in proc_get_long()
383 	*buf += len;  in proc_get_long()
384 	*size -= len;  in proc_get_long()
390  * proc_put_long - converts an integer to a decimal ASCII formatted string
402 	int len;  in proc_put_long()  local
405 	sprintf(p, "%s%lu", neg ? "-" : "", val);  in proc_put_long()
406 	len = strlen(tmp);  in proc_put_long()
407 	if (len > *size)  in proc_put_long()
408 		len = *size;  in proc_put_long()
409 	memcpy(*buf, tmp, len);  in proc_put_long()
410 	*size -= len;  in proc_put_long()
411 	*buf += len;  in proc_put_long()
421 		(*size)--;  in proc_put_char()
434 				return -EINVAL;  in do_proc_dointvec_conv()
435 			WRITE_ONCE(*valp, -*lvalp);  in do_proc_dointvec_conv()
438 				return -EINVAL;  in do_proc_dointvec_conv()
445 			*lvalp = -(unsigned long)val;  in do_proc_dointvec_conv()
460 			return -EINVAL;  in do_proc_douintvec_conv()
482 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_dointvec()
488 	vleft = table->maxlen / sizeof(*i);  in __do_proc_dointvec()
498 		if (left > PAGE_SIZE - 1)  in __do_proc_dointvec()
499 			left = PAGE_SIZE - 1;  in __do_proc_dointvec()
503 	for (; left && vleft--; i++, first=0) {  in __do_proc_dointvec()
518 				err = -EINVAL;  in __do_proc_dointvec()
523 				err = -EINVAL;  in __do_proc_dointvec()
537 		return err ? : -EINVAL;  in __do_proc_dointvec()
538 	*lenp -= left;  in __do_proc_dointvec()
550 	return __do_proc_dointvec(table->data, table, write,  in do_proc_dointvec()
574 	if (left > PAGE_SIZE - 1)  in do_proc_douintvec_w()
575 		left = PAGE_SIZE - 1;  in do_proc_douintvec_w()
579 		err = -EINVAL;  in do_proc_douintvec_w()
587 		err = -EINVAL;  in do_proc_douintvec_w()
592 		err = -EINVAL;  in do_proc_douintvec_w()
601 		return -EINVAL;  in do_proc_douintvec_w()
625 		err = -EINVAL;  in do_proc_douintvec_r()
636 	*lenp -= left;  in do_proc_douintvec_r()
652 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_douintvec()
658 	vleft = table->maxlen / sizeof(*i);  in __do_proc_douintvec()
666 		return -EINVAL;  in __do_proc_douintvec()
685 	return __do_proc_douintvec(table->data, table, write,  in do_proc_douintvec()
690  * proc_dobool - read/write a bool
700  * table->data must point to a bool variable and table->maxlen must
709 	bool *data = table->data;  in proc_dobool()
713 	if (table->maxlen != sizeof(bool))  in proc_dobool()
714 		return -EINVAL;  in proc_dobool()
730  * proc_dointvec - read a vector of integers
737  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
749  * proc_douintvec - read a vector of unsigned integers
756  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
780 		return -EPERM;  in proc_taint()
797 			return -EINVAL;  in proc_taint()
812  * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
813  * @min: pointer to minimum allowable value
821 	int *min;  member
833 	 * bounds-check it before touching *valp.  in do_proc_dointvec_minmax_conv()
842 		if ((param->min && *param->min > tmp) ||  in do_proc_dointvec_minmax_conv()
843 		    (param->max && *param->max < tmp))  in do_proc_dointvec_minmax_conv()
844 			return -EINVAL;  in do_proc_dointvec_minmax_conv()
852  * proc_dointvec_minmax - read a vector of integers with min/max values
859  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
863  * table->extra1 (min) and table->extra2 (max).
865  * Returns 0 on success or -EINVAL on write when the range check fails.
871 		.min = (int *) table->extra1,  in proc_dointvec_minmax()
872 		.max = (int *) table->extra2,  in proc_dointvec_minmax()
879  * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
880  * @min: pointer to minimum allowable value
888 	unsigned int *min;  member
899 	/* write via temporary local uint for bounds-checking */  in do_proc_douintvec_minmax_conv()
907 		if ((param->min && *param->min > tmp) ||  in do_proc_douintvec_minmax_conv()
908 		    (param->max && *param->max < tmp))  in do_proc_douintvec_minmax_conv()
909 			return -ERANGE;  in do_proc_douintvec_minmax_conv()
918  * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
925  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
930  * table->extra1 (min) and table->extra2 (max). There is a final sanity
934  * Returns 0 on success or -ERANGE on write when the range check fails.
940 		.min = (unsigned int *) table->extra1,  in proc_douintvec_minmax()
941 		.max = (unsigned int *) table->extra2,  in proc_douintvec_minmax()
948  * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
955  * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
960  * table->extra1 (min) and table->extra2 (max).
968 	unsigned int min = 0, max = 255U, val;  in proc_dou8vec_minmax()  local
969 	u8 *data = table->data;  in proc_dou8vec_minmax()
971 		.min = &min,  in proc_dou8vec_minmax()
977 	if (table->maxlen != sizeof(u8))  in proc_dou8vec_minmax()
978 		return -EINVAL;  in proc_dou8vec_minmax()
980 	if (table->extra1)  in proc_dou8vec_minmax()
981 		min = *(unsigned int *) table->extra1;  in proc_dou8vec_minmax()
982 	if (table->extra2)  in proc_dou8vec_minmax()
983 		max = *(unsigned int *) table->extra2;  in proc_dou8vec_minmax()
1025 	unsigned long *i, *min, *max;  in __do_proc_doulongvec_minmax()  local
1030 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_doulongvec_minmax()
1036 	min = table->extra1;  in __do_proc_doulongvec_minmax()
1037 	max = table->extra2;  in __do_proc_doulongvec_minmax()
1038 	vleft = table->maxlen / sizeof(unsigned long);  in __do_proc_doulongvec_minmax()
1045 		if (left > PAGE_SIZE - 1)  in __do_proc_doulongvec_minmax()
1046 			left = PAGE_SIZE - 1;  in __do_proc_doulongvec_minmax()
1050 	for (; left && vleft--; i++, first = 0) {  in __do_proc_doulongvec_minmax()
1064 				err = -EINVAL;  in __do_proc_doulongvec_minmax()
1069 			if ((min && val < *min) || (max && val > *max)) {  in __do_proc_doulongvec_minmax()
1070 				err = -EINVAL;  in __do_proc_doulongvec_minmax()
1087 		return err ? : -EINVAL;  in __do_proc_doulongvec_minmax()
1088 	*lenp -= left;  in __do_proc_doulongvec_minmax()
1098 	return __do_proc_doulongvec_minmax(table->data, table, write,  in do_proc_doulongvec_minmax()
1103  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1110  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1114  * table->extra1 (min) and table->extra2 (max).
1125  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1132  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1137  * table->extra1 (min) and table->extra2 (max).
1157 			WRITE_ONCE(*valp, -*lvalp * HZ);  in do_proc_dointvec_jiffies_conv()
1165 			lval = -(unsigned long)val;  in do_proc_dointvec_jiffies_conv()
1182 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);  in do_proc_dointvec_userhz_jiffies_conv()
1188 			lval = -(unsigned long)val;  in do_proc_dointvec_userhz_jiffies_conv()
1203 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);  in do_proc_dointvec_ms_jiffies_conv()
1213 			lval = -(unsigned long)val;  in do_proc_dointvec_ms_jiffies_conv()
1230 	 * bounds-check it before touching *valp.  in do_proc_dointvec_ms_jiffies_minmax_conv()
1239 		if ((param->min && *param->min > tmp) ||  in do_proc_dointvec_ms_jiffies_minmax_conv()
1240 				(param->max && *param->max < tmp))  in do_proc_dointvec_ms_jiffies_minmax_conv()
1241 			return -EINVAL;  in do_proc_dointvec_ms_jiffies_minmax_conv()
1248  * proc_dointvec_jiffies - read a vector of integers as seconds
1255  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1273 		.min = (int *) table->extra1,  in proc_dointvec_ms_jiffies_minmax()
1274 		.max = (int *) table->extra2,  in proc_dointvec_ms_jiffies_minmax()
1281  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
1288  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1303  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
1310  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1340 		return -ESRCH;  in proc_do_cad_pid()
1347  * proc_do_large_bitmap - read/write from/to a large bitmap
1354  * The bitmap is stored at table->data and the bitmap length (in bits)
1355  * in table->maxlen.
1357  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
1368 	unsigned long bitmap_len = table->maxlen;  in proc_do_large_bitmap()
1369 	unsigned long *bitmap = *(unsigned long **) table->data;  in proc_do_large_bitmap()
1371 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;  in proc_do_large_bitmap()
1382 		if (left > PAGE_SIZE - 1) {  in proc_do_large_bitmap()
1383 			left = PAGE_SIZE - 1;  in proc_do_large_bitmap()
1385 			skipped = *lenp - left;  in proc_do_large_bitmap()
1390 			return -ENOMEM;  in proc_do_large_bitmap()
1397 			/* In case we stop parsing mid-number, we can reset */  in proc_do_large_bitmap()
1403 			 * only one char is left (may be a "-"), then stop here,  in proc_do_large_bitmap()
1414 				err = -EINVAL;  in proc_do_large_bitmap()
1421 				left--;  in proc_do_large_bitmap()
1424 			if (c == '-') {  in proc_do_large_bitmap()
1441 					err = -EINVAL;  in proc_do_large_bitmap()
1446 					left--;  in proc_do_large_bitmap()
1450 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);  in proc_do_large_bitmap()
1463 						   bit_a + 1) - 1;  in proc_do_large_bitmap()
1469 				proc_put_char(&buffer, &left, '-');  in proc_do_large_bitmap()
1485 		*lenp -= left;  in proc_do_large_bitmap()
1498 	return -ENOSYS;  in proc_dostring()
1504 	return -ENOSYS;  in proc_dobool()
1510 	return -ENOSYS;  in proc_dointvec()
1516 	return -ENOSYS;  in proc_douintvec()
1522 	return -ENOSYS;  in proc_dointvec_minmax()
1528 	return -ENOSYS;  in proc_douintvec_minmax()
1534 	return -ENOSYS;  in proc_dou8vec_minmax()
1540 	return -ENOSYS;  in proc_dointvec_jiffies()
1546 	return -ENOSYS;  in proc_dointvec_ms_jiffies_minmax()
1552 	return -ENOSYS;  in proc_dointvec_userhz_jiffies()
1558 	return -ENOSYS;  in proc_dointvec_ms_jiffies()
1564 	return -ENOSYS;  in proc_doulongvec_minmax()
1570 	return -ENOSYS;  in proc_doulongvec_ms_jiffies_minmax()
1576 	return -ENOSYS;  in proc_do_large_bitmap()
1585 	struct static_key *key = (struct static_key *)table->data;  in proc_do_static_key()
1591 		.mode   = table->mode,  in proc_do_static_key()
1597 		return -EPERM;  in proc_do_static_key()
1638 		.procname	= "print-fatal-signals",
1646 		.procname	= "reboot-cmd",
1653 		.procname	= "stop-a",
1660 		.procname	= "scons-poweroff",
1669 		.procname	= "tsb-ratio",
1678 		.procname	= "soft-power",
1687 		.procname	= "unaligned-trap",
1773 		.procname	= "threads-max",
1920 		.procname	= "ignore-unaligned-usertrap",
1938 	 * User-space scripts rely on the existence of this file
2049 		.procname	= "page-cluster",
2239  * exception granted :-)