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.
75 const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
90  * enum sysctl_writes_mode - supported sysctl write modes
109 	SYSCTL_WRITES_LEGACY		= -1,
127 	size_t len;  in _proc_do_string()  local
138 			len = strlen(data);  in _proc_do_string()
139 			if (len > maxlen - 1)  in _proc_do_string()
140 				len = maxlen - 1;  in _proc_do_string()
142 			if (*ppos > len)  in _proc_do_string()
144 			len = *ppos;  in _proc_do_string()
147 			len = 0;  in _proc_do_string()
152 		while ((p - buffer) < *lenp && len < maxlen - 1) {  in _proc_do_string()
156 			data[len++] = c;  in _proc_do_string()
158 		data[len] = 0;  in _proc_do_string()
160 		len = strlen(data);  in _proc_do_string()
161 		if (len > maxlen)  in _proc_do_string()
162 			len = maxlen;  in _proc_do_string()
164 		if (*ppos > len) {  in _proc_do_string()
170 		len  -= *ppos;  in _proc_do_string()
172 		if (len > *lenp)  in _proc_do_string()
173 			len = *lenp;  in _proc_do_string()
174 		if (len)  in _proc_do_string()
175 			memcpy(buffer, data, len);  in _proc_do_string()
176 		if (len < *lenp) {  in _proc_do_string()
177 			buffer[len] = '\n';  in _proc_do_string()
178 			len++;  in _proc_do_string()
180 		*lenp = len;  in _proc_do_string()
181 		*ppos += len;  in _proc_do_string()
190 		"warning, set kernel.sysctl_writes_strict = -1\n",  in warn_sysctl_write()
191 		current->comm, table->procname);  in warn_sysctl_write()
195  * proc_first_pos_non_zero_ignore - check if first position is allowed
199  * Returns true if the first position is non-zero and the sysctl_writes_strict
221  * proc_dostring - read a string sysctl
230  * string is truncated. The copied string is %NULL-terminated.
243 	return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,  in proc_dostring()
252 		(*size)--;  in proc_skip_spaces()
262 		(*size)--;  in proc_skip_char()
268  * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
291 		return -ERANGE;  in strtoul_lenient()
304  * proc_get_long - reads an ASCII formatted integer from a user buffer
315  * the amount of bytes read. If @tr is non-NULL and a trailing
316  * character exists (size is non-zero after returning from this
324 	ssize_t len = *size;  in proc_get_long()  local
326 	if (len <= 0)  in proc_get_long()
327 		return -EINVAL;  in proc_get_long()
329 	if (len > TMPBUFLEN - 1)  in proc_get_long()
330 		len = TMPBUFLEN - 1;  in proc_get_long()
332 	memcpy(tmp, *buf, len);  in proc_get_long()
334 	tmp[len] = 0;  in proc_get_long()
336 	if (*p == '-' && *size > 1) {  in proc_get_long()
342 		return -EINVAL;  in proc_get_long()
345 		return -EINVAL;  in proc_get_long()
347 	len = p - tmp;  in proc_get_long()
352 	if (len == TMPBUFLEN - 1)  in proc_get_long()
353 		return -EINVAL;  in proc_get_long()
355 	if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))  in proc_get_long()
356 		return -EINVAL;  in proc_get_long()
358 	if (tr && (len < *size))  in proc_get_long()
361 	*buf += len;  in proc_get_long()
362 	*size -= len;  in proc_get_long()
368  * proc_put_long - converts an integer to a decimal ASCII formatted string
380 	int len;  in proc_put_long()  local
383 	sprintf(p, "%s%lu", neg ? "-" : "", val);  in proc_put_long()
384 	len = strlen(tmp);  in proc_put_long()
385 	if (len > *size)  in proc_put_long()
386 		len = *size;  in proc_put_long()
387 	memcpy(*buf, tmp, len);  in proc_put_long()
388 	*size -= len;  in proc_put_long()
389 	*buf += len;  in proc_put_long()
399 		(*size)--;  in proc_put_char()
412 				return -EINVAL;  in do_proc_dointvec_conv()
413 			WRITE_ONCE(*valp, -*lvalp);  in do_proc_dointvec_conv()
416 				return -EINVAL;  in do_proc_dointvec_conv()
423 			*lvalp = -(unsigned long)val;  in do_proc_dointvec_conv()
438 			return -EINVAL;  in do_proc_douintvec_conv()
460 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_dointvec()
466 	vleft = table->maxlen / sizeof(*i);  in __do_proc_dointvec()
476 		if (left > PAGE_SIZE - 1)  in __do_proc_dointvec()
477 			left = PAGE_SIZE - 1;  in __do_proc_dointvec()
481 	for (; left && vleft--; i++, first=0) {  in __do_proc_dointvec()
496 				err = -EINVAL;  in __do_proc_dointvec()
501 				err = -EINVAL;  in __do_proc_dointvec()
515 		return err ? : -EINVAL;  in __do_proc_dointvec()
516 	*lenp -= left;  in __do_proc_dointvec()
528 	return __do_proc_dointvec(table->data, table, write,  in do_proc_dointvec()
552 	if (left > PAGE_SIZE - 1)  in do_proc_douintvec_w()
553 		left = PAGE_SIZE - 1;  in do_proc_douintvec_w()
557 		err = -EINVAL;  in do_proc_douintvec_w()
565 		err = -EINVAL;  in do_proc_douintvec_w()
570 		err = -EINVAL;  in do_proc_douintvec_w()
579 		return -EINVAL;  in do_proc_douintvec_w()
603 		err = -EINVAL;  in do_proc_douintvec_r()
614 	*lenp -= left;  in do_proc_douintvec_r()
630 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_douintvec()
636 	vleft = table->maxlen / sizeof(*i);  in __do_proc_douintvec()
644 		return -EINVAL;  in __do_proc_douintvec()
663 	return __do_proc_douintvec(table->data, table, write,  in do_proc_douintvec()
668  * proc_dobool - read/write a bool
678  * table->data must point to a bool variable and table->maxlen must
687 	bool *data = table->data;  in proc_dobool()
691 	if (table->maxlen != sizeof(bool))  in proc_dobool()
692 		return -EINVAL;  in proc_dobool()
708  * proc_dointvec - read a vector of integers
715  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
727  * proc_douintvec - read a vector of unsigned integers
734  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
758 		return -EPERM;  in proc_taint()
775 			return -EINVAL;  in proc_taint()
790  * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
791  * @min: pointer to minimum allowable value
799 	int *min;  member
811 	 * bounds-check it before touching *valp.  in do_proc_dointvec_minmax_conv()
820 		if ((param->min && *param->min > tmp) ||  in do_proc_dointvec_minmax_conv()
821 		    (param->max && *param->max < tmp))  in do_proc_dointvec_minmax_conv()
822 			return -EINVAL;  in do_proc_dointvec_minmax_conv()
830  * proc_dointvec_minmax - read a vector of integers with min/max values
837  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
841  * table->extra1 (min) and table->extra2 (max).
843  * Returns 0 on success or -EINVAL on write when the range check fails.
849 		.min = (int *) table->extra1,  in proc_dointvec_minmax()
850 		.max = (int *) table->extra2,  in proc_dointvec_minmax()
857  * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
858  * @min: pointer to minimum allowable value
866 	unsigned int *min;  member
877 	/* write via temporary local uint for bounds-checking */  in do_proc_douintvec_minmax_conv()
885 		if ((param->min && *param->min > tmp) ||  in do_proc_douintvec_minmax_conv()
886 		    (param->max && *param->max < tmp))  in do_proc_douintvec_minmax_conv()
887 			return -ERANGE;  in do_proc_douintvec_minmax_conv()
896  * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
903  * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
908  * table->extra1 (min) and table->extra2 (max). There is a final sanity
912  * Returns 0 on success or -ERANGE on write when the range check fails.
918 		.min = (unsigned int *) table->extra1,  in proc_douintvec_minmax()
919 		.max = (unsigned int *) table->extra2,  in proc_douintvec_minmax()
926  * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
933  * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
938  * table->extra1 (min) and table->extra2 (max).
946 	unsigned int min = 0, max = 255U, val;  in proc_dou8vec_minmax()  local
947 	u8 *data = table->data;  in proc_dou8vec_minmax()
949 		.min = &min,  in proc_dou8vec_minmax()
955 	if (table->maxlen != sizeof(u8))  in proc_dou8vec_minmax()
956 		return -EINVAL;  in proc_dou8vec_minmax()
958 	if (table->extra1)  in proc_dou8vec_minmax()
959 		min = *(unsigned int *) table->extra1;  in proc_dou8vec_minmax()
960 	if (table->extra2)  in proc_dou8vec_minmax()
961 		max = *(unsigned int *) table->extra2;  in proc_dou8vec_minmax()
1003 	unsigned long *i, *min, *max;  in __do_proc_doulongvec_minmax()  local
1008 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {  in __do_proc_doulongvec_minmax()
1014 	min = table->extra1;  in __do_proc_doulongvec_minmax()
1015 	max = table->extra2;  in __do_proc_doulongvec_minmax()
1016 	vleft = table->maxlen / sizeof(unsigned long);  in __do_proc_doulongvec_minmax()
1023 		if (left > PAGE_SIZE - 1)  in __do_proc_doulongvec_minmax()
1024 			left = PAGE_SIZE - 1;  in __do_proc_doulongvec_minmax()
1028 	for (; left && vleft--; i++, first = 0) {  in __do_proc_doulongvec_minmax()
1042 				err = -EINVAL;  in __do_proc_doulongvec_minmax()
1047 			if ((min && val < *min) || (max && val > *max)) {  in __do_proc_doulongvec_minmax()
1048 				err = -EINVAL;  in __do_proc_doulongvec_minmax()
1065 		return err ? : -EINVAL;  in __do_proc_doulongvec_minmax()
1066 	*lenp -= left;  in __do_proc_doulongvec_minmax()
1076 	return __do_proc_doulongvec_minmax(table->data, table, write,  in do_proc_doulongvec_minmax()
1081  * proc_doulongvec_minmax - read a vector of long integers with min/max values
1088  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1092  * table->extra1 (min) and table->extra2 (max).
1103  * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1110  * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1115  * table->extra1 (min) and table->extra2 (max).
1135 			WRITE_ONCE(*valp, -*lvalp * HZ);  in do_proc_dointvec_jiffies_conv()
1143 			lval = -(unsigned long)val;  in do_proc_dointvec_jiffies_conv()
1160 		*valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);  in do_proc_dointvec_userhz_jiffies_conv()
1166 			lval = -(unsigned long)val;  in do_proc_dointvec_userhz_jiffies_conv()
1181 		unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);  in do_proc_dointvec_ms_jiffies_conv()
1191 			lval = -(unsigned long)val;  in do_proc_dointvec_ms_jiffies_conv()
1208 	 * bounds-check it before touching *valp.  in do_proc_dointvec_ms_jiffies_minmax_conv()
1217 		if ((param->min && *param->min > tmp) ||  in do_proc_dointvec_ms_jiffies_minmax_conv()
1218 				(param->max && *param->max < tmp))  in do_proc_dointvec_ms_jiffies_minmax_conv()
1219 			return -EINVAL;  in do_proc_dointvec_ms_jiffies_minmax_conv()
1226  * proc_dointvec_jiffies - read a vector of integers as seconds
1233  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1251 		.min = (int *) table->extra1,  in proc_dointvec_ms_jiffies_minmax()
1252 		.max = (int *) table->extra2,  in proc_dointvec_ms_jiffies_minmax()
1259  * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
1266  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1281  * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
1288  * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1318 		return -ESRCH;  in proc_do_cad_pid()
1325  * proc_do_large_bitmap - read/write from/to a large bitmap
1332  * The bitmap is stored at table->data and the bitmap length (in bits)
1333  * in table->maxlen.
1335  * We use a range comma separated format (e.g. 1,3-4,10-10) so that
1346 	unsigned long bitmap_len = table->maxlen;  in proc_do_large_bitmap()
1347 	unsigned long *bitmap = *(unsigned long **) table->data;  in proc_do_large_bitmap()
1349 	char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;  in proc_do_large_bitmap()
1360 		if (left > PAGE_SIZE - 1) {  in proc_do_large_bitmap()
1361 			left = PAGE_SIZE - 1;  in proc_do_large_bitmap()
1363 			skipped = *lenp - left;  in proc_do_large_bitmap()
1368 			return -ENOMEM;  in proc_do_large_bitmap()
1375 			/* In case we stop parsing mid-number, we can reset */  in proc_do_large_bitmap()
1381 			 * only one char is left (may be a "-"), then stop here,  in proc_do_large_bitmap()
1392 				err = -EINVAL;  in proc_do_large_bitmap()
1399 				left--;  in proc_do_large_bitmap()
1402 			if (c == '-') {  in proc_do_large_bitmap()
1419 					err = -EINVAL;  in proc_do_large_bitmap()
1424 					left--;  in proc_do_large_bitmap()
1428 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);  in proc_do_large_bitmap()
1441 						   bit_a + 1) - 1;  in proc_do_large_bitmap()
1447 				proc_put_char(&buffer, &left, '-');  in proc_do_large_bitmap()
1463 		*lenp -= left;  in proc_do_large_bitmap()
1476 	return -ENOSYS;  in proc_dostring()
1482 	return -ENOSYS;  in proc_dobool()
1488 	return -ENOSYS;  in proc_dointvec()
1494 	return -ENOSYS;  in proc_douintvec()
1500 	return -ENOSYS;  in proc_dointvec_minmax()
1506 	return -ENOSYS;  in proc_douintvec_minmax()
1512 	return -ENOSYS;  in proc_dou8vec_minmax()
1518 	return -ENOSYS;  in proc_dointvec_jiffies()
1524 	return -ENOSYS;  in proc_dointvec_ms_jiffies_minmax()
1530 	return -ENOSYS;  in proc_dointvec_userhz_jiffies()
1536 	return -ENOSYS;  in proc_dointvec_ms_jiffies()
1542 	return -ENOSYS;  in proc_doulongvec_minmax()
1548 	return -ENOSYS;  in proc_doulongvec_ms_jiffies_minmax()
1554 	return -ENOSYS;  in proc_do_large_bitmap()
1563 	struct static_key *key = (struct static_key *)table->data;  in proc_do_static_key()
1569 		.mode   = table->mode,  in proc_do_static_key()
1575 		return -EPERM;  in proc_do_static_key()
1616 		.procname	= "print-fatal-signals",
1624 		.procname	= "reboot-cmd",
1631 		.procname	= "stop-a",
1638 		.procname	= "scons-poweroff",
1647 		.procname	= "tsb-ratio",
1656 		.procname	= "soft-power",
1665 		.procname	= "unaligned-trap",
1751 		.procname	= "threads-max",
1824 		.procname	= "ignore-unaligned-usertrap",
1880  * exception granted :-)