1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * sysctl.c: General linux system control interface
4 *
5 * Begun 24 March 1995, Stephen Tweedie
6 * Added /proc support, Dec 1995
7 * Added bdflush entry and intvec min/max checking, 2/23/96, Tom Dyas.
8 * Added hooks for /proc/sys/net (minor, minor patch), 96/4/1, Mike Shaver.
9 * Added kernel/java-{interpreter,appletviewer}, 96/5/10, Mike Shaver.
10 * Dynamic registration fixes, Stephen Tweedie.
11 * Added kswapd-interval, ctrl-alt-del, printk stuff, 1/8/97, Chris Horn.
12 * Made sysctl support optional via CONFIG_SYSCTL, 1/10/97, Chris
13 * Horn.
14 * Added proc_doulongvec_ms_jiffies_minmax, 09/08/99, Carlos H. Bauer.
15 * Added proc_doulongvec_minmax, 09/08/99, Carlos H. Bauer.
16 * Changed linked lists to use list.h instead of lists.h, 02/24/00, Bill
17 * Wendling.
18 * The list_for_each() macro wasn't appropriate for the sysctl loop.
19 * Removed it and replaced it with older style, 03/23/00, Bill Wendling
20 */
21
22 #include <linux/module.h>
23 #include <linux/mm.h>
24 #include <linux/swap.h>
25 #include <linux/slab.h>
26 #include <linux/sysctl.h>
27 #include <linux/bitmap.h>
28 #include <linux/signal.h>
29 #include <linux/panic.h>
30 #include <linux/printk.h>
31 #include <linux/proc_fs.h>
32 #include <linux/security.h>
33 #include <linux/ctype.h>
34 #include <linux/kmemleak.h>
35 #include <linux/filter.h>
36 #include <linux/fs.h>
37 #include <linux/init.h>
38 #include <linux/kernel.h>
39 #include <linux/kobject.h>
40 #include <linux/net.h>
41 #include <linux/sysrq.h>
42 #include <linux/highuid.h>
43 #include <linux/writeback.h>
44 #include <linux/ratelimit.h>
45 #include <linux/compaction.h>
46 #include <linux/hugetlb.h>
47 #include <linux/initrd.h>
48 #include <linux/key.h>
49 #include <linux/times.h>
50 #include <linux/limits.h>
51 #include <linux/dcache.h>
52 #include <linux/syscalls.h>
53 #include <linux/vmstat.h>
54 #include <linux/nfs_fs.h>
55 #include <linux/acpi.h>
56 #include <linux/reboot.h>
57 #include <linux/ftrace.h>
58 #include <linux/perf_event.h>
59 #include <linux/oom.h>
60 #include <linux/kmod.h>
61 #include <linux/capability.h>
62 #include <linux/binfmts.h>
63 #include <linux/sched/sysctl.h>
64 #include <linux/mount.h>
65 #include <linux/userfaultfd_k.h>
66 #include <linux/pid.h>
67
68 #include "../lib/kstrtox.h"
69
70 #include <linux/uaccess.h>
71 #include <asm/processor.h>
72
73 #ifdef CONFIG_X86
74 #include <asm/nmi.h>
75 #include <asm/stacktrace.h>
76 #include <asm/io.h>
77 #endif
78 #ifdef CONFIG_SPARC
79 #include <asm/setup.h>
80 #endif
81 #ifdef CONFIG_RT_MUTEXES
82 #include <linux/rtmutex.h>
83 #endif
84
85 /* shared constants to be used in various sysctls */
86 const int sysctl_vals[] = { 0, 1, 2, 3, 4, 100, 200, 1000, 3000, INT_MAX, 65535, -1 };
87 EXPORT_SYMBOL(sysctl_vals);
88
89 const unsigned long sysctl_long_vals[] = { 0, 1, LONG_MAX };
90 EXPORT_SYMBOL_GPL(sysctl_long_vals);
91
92 #if defined(CONFIG_SYSCTL)
93
94 /* Constants used for minimum and maximum */
95
96 #ifdef CONFIG_PERF_EVENTS
97 static const int six_hundred_forty_kb = 640 * 1024;
98 #endif
99
100
101 static const int ngroups_max = NGROUPS_MAX;
102 static const int cap_last_cap = CAP_LAST_CAP;
103
104 #ifdef CONFIG_PROC_SYSCTL
105
106 /**
107 * enum sysctl_writes_mode - supported sysctl write modes
108 *
109 * @SYSCTL_WRITES_LEGACY: each write syscall must fully contain the sysctl value
110 * to be written, and multiple writes on the same sysctl file descriptor
111 * will rewrite the sysctl value, regardless of file position. No warning
112 * is issued when the initial position is not 0.
113 * @SYSCTL_WRITES_WARN: same as above but warn when the initial file position is
114 * not 0.
115 * @SYSCTL_WRITES_STRICT: writes to numeric sysctl entries must always be at
116 * file position 0 and the value must be fully contained in the buffer
117 * sent to the write syscall. If dealing with strings respect the file
118 * position, but restrict this to the max length of the buffer, anything
119 * passed the max length will be ignored. Multiple writes will append
120 * to the buffer.
121 *
122 * These write modes control how current file position affects the behavior of
123 * updating sysctl values through the proc interface on each write.
124 */
125 enum sysctl_writes_mode {
126 SYSCTL_WRITES_LEGACY = -1,
127 SYSCTL_WRITES_WARN = 0,
128 SYSCTL_WRITES_STRICT = 1,
129 };
130
131 static enum sysctl_writes_mode sysctl_writes_strict = SYSCTL_WRITES_STRICT;
132 #endif /* CONFIG_PROC_SYSCTL */
133
134 #if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
135 defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
136 int sysctl_legacy_va_layout;
137 #endif
138
139 #endif /* CONFIG_SYSCTL */
140
141 /*
142 * /proc/sys support
143 */
144
145 #ifdef CONFIG_PROC_SYSCTL
146
_proc_do_string(char * data,int maxlen,int write,char * buffer,size_t * lenp,loff_t * ppos)147 static int _proc_do_string(char *data, int maxlen, int write,
148 char *buffer, size_t *lenp, loff_t *ppos)
149 {
150 size_t len;
151 char c, *p;
152
153 if (!data || !maxlen || !*lenp) {
154 *lenp = 0;
155 return 0;
156 }
157
158 if (write) {
159 if (sysctl_writes_strict == SYSCTL_WRITES_STRICT) {
160 /* Only continue writes not past the end of buffer. */
161 len = strlen(data);
162 if (len > maxlen - 1)
163 len = maxlen - 1;
164
165 if (*ppos > len)
166 return 0;
167 len = *ppos;
168 } else {
169 /* Start writing from beginning of buffer. */
170 len = 0;
171 }
172
173 *ppos += *lenp;
174 p = buffer;
175 while ((p - buffer) < *lenp && len < maxlen - 1) {
176 c = *(p++);
177 if (c == 0 || c == '\n')
178 break;
179 data[len++] = c;
180 }
181 data[len] = 0;
182 } else {
183 len = strlen(data);
184 if (len > maxlen)
185 len = maxlen;
186
187 if (*ppos > len) {
188 *lenp = 0;
189 return 0;
190 }
191
192 data += *ppos;
193 len -= *ppos;
194
195 if (len > *lenp)
196 len = *lenp;
197 if (len)
198 memcpy(buffer, data, len);
199 if (len < *lenp) {
200 buffer[len] = '\n';
201 len++;
202 }
203 *lenp = len;
204 *ppos += len;
205 }
206 return 0;
207 }
208
warn_sysctl_write(struct ctl_table * table)209 static void warn_sysctl_write(struct ctl_table *table)
210 {
211 pr_warn_once("%s wrote to %s when file position was not 0!\n"
212 "This will not be supported in the future. To silence this\n"
213 "warning, set kernel.sysctl_writes_strict = -1\n",
214 current->comm, table->procname);
215 }
216
217 /**
218 * proc_first_pos_non_zero_ignore - check if first position is allowed
219 * @ppos: file position
220 * @table: the sysctl table
221 *
222 * Returns true if the first position is non-zero and the sysctl_writes_strict
223 * mode indicates this is not allowed for numeric input types. String proc
224 * handlers can ignore the return value.
225 */
proc_first_pos_non_zero_ignore(loff_t * ppos,struct ctl_table * table)226 static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
227 struct ctl_table *table)
228 {
229 if (!*ppos)
230 return false;
231
232 switch (sysctl_writes_strict) {
233 case SYSCTL_WRITES_STRICT:
234 return true;
235 case SYSCTL_WRITES_WARN:
236 warn_sysctl_write(table);
237 return false;
238 default:
239 return false;
240 }
241 }
242
243 /**
244 * proc_dostring - read a string sysctl
245 * @table: the sysctl table
246 * @write: %TRUE if this is a write to the sysctl file
247 * @buffer: the user buffer
248 * @lenp: the size of the user buffer
249 * @ppos: file position
250 *
251 * Reads/writes a string from/to the user buffer. If the kernel
252 * buffer provided is not large enough to hold the string, the
253 * string is truncated. The copied string is %NULL-terminated.
254 * If the string is being read by the user process, it is copied
255 * and a newline '\n' is added. It is truncated if the buffer is
256 * not large enough.
257 *
258 * Returns 0 on success.
259 */
proc_dostring(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)260 int proc_dostring(struct ctl_table *table, int write,
261 void *buffer, size_t *lenp, loff_t *ppos)
262 {
263 if (write)
264 proc_first_pos_non_zero_ignore(ppos, table);
265
266 return _proc_do_string(table->data, table->maxlen, write, buffer, lenp,
267 ppos);
268 }
269
proc_skip_spaces(char ** buf,size_t * size)270 static void proc_skip_spaces(char **buf, size_t *size)
271 {
272 while (*size) {
273 if (!isspace(**buf))
274 break;
275 (*size)--;
276 (*buf)++;
277 }
278 }
279
proc_skip_char(char ** buf,size_t * size,const char v)280 static void proc_skip_char(char **buf, size_t *size, const char v)
281 {
282 while (*size) {
283 if (**buf != v)
284 break;
285 (*size)--;
286 (*buf)++;
287 }
288 }
289
290 /**
291 * strtoul_lenient - parse an ASCII formatted integer from a buffer and only
292 * fail on overflow
293 *
294 * @cp: kernel buffer containing the string to parse
295 * @endp: pointer to store the trailing characters
296 * @base: the base to use
297 * @res: where the parsed integer will be stored
298 *
299 * In case of success 0 is returned and @res will contain the parsed integer,
300 * @endp will hold any trailing characters.
301 * This function will fail the parse on overflow. If there wasn't an overflow
302 * the function will defer the decision what characters count as invalid to the
303 * caller.
304 */
strtoul_lenient(const char * cp,char ** endp,unsigned int base,unsigned long * res)305 static int strtoul_lenient(const char *cp, char **endp, unsigned int base,
306 unsigned long *res)
307 {
308 unsigned long long result;
309 unsigned int rv;
310
311 cp = _parse_integer_fixup_radix(cp, &base);
312 rv = _parse_integer(cp, base, &result);
313 if ((rv & KSTRTOX_OVERFLOW) || (result != (unsigned long)result))
314 return -ERANGE;
315
316 cp += rv;
317
318 if (endp)
319 *endp = (char *)cp;
320
321 *res = (unsigned long)result;
322 return 0;
323 }
324
325 #define TMPBUFLEN 22
326 /**
327 * proc_get_long - reads an ASCII formatted integer from a user buffer
328 *
329 * @buf: a kernel buffer
330 * @size: size of the kernel buffer
331 * @val: this is where the number will be stored
332 * @neg: set to %TRUE if number is negative
333 * @perm_tr: a vector which contains the allowed trailers
334 * @perm_tr_len: size of the perm_tr vector
335 * @tr: pointer to store the trailer character
336 *
337 * In case of success %0 is returned and @buf and @size are updated with
338 * the amount of bytes read. If @tr is non-NULL and a trailing
339 * character exists (size is non-zero after returning from this
340 * function), @tr is updated with the trailing character.
341 */
proc_get_long(char ** buf,size_t * size,unsigned long * val,bool * neg,const char * perm_tr,unsigned perm_tr_len,char * tr)342 static int proc_get_long(char **buf, size_t *size,
343 unsigned long *val, bool *neg,
344 const char *perm_tr, unsigned perm_tr_len, char *tr)
345 {
346 char *p, tmp[TMPBUFLEN];
347 ssize_t len = *size;
348
349 if (len <= 0)
350 return -EINVAL;
351
352 if (len > TMPBUFLEN - 1)
353 len = TMPBUFLEN - 1;
354
355 memcpy(tmp, *buf, len);
356
357 tmp[len] = 0;
358 p = tmp;
359 if (*p == '-' && *size > 1) {
360 *neg = true;
361 p++;
362 } else
363 *neg = false;
364 if (!isdigit(*p))
365 return -EINVAL;
366
367 if (strtoul_lenient(p, &p, 0, val))
368 return -EINVAL;
369
370 len = p - tmp;
371
372 /* We don't know if the next char is whitespace thus we may accept
373 * invalid integers (e.g. 1234...a) or two integers instead of one
374 * (e.g. 123...1). So lets not allow such large numbers. */
375 if (len == TMPBUFLEN - 1)
376 return -EINVAL;
377
378 if (len < *size && perm_tr_len && !memchr(perm_tr, *p, perm_tr_len))
379 return -EINVAL;
380
381 if (tr && (len < *size))
382 *tr = *p;
383
384 *buf += len;
385 *size -= len;
386
387 return 0;
388 }
389
390 /**
391 * proc_put_long - converts an integer to a decimal ASCII formatted string
392 *
393 * @buf: the user buffer
394 * @size: the size of the user buffer
395 * @val: the integer to be converted
396 * @neg: sign of the number, %TRUE for negative
397 *
398 * In case of success @buf and @size are updated with the amount of bytes
399 * written.
400 */
proc_put_long(void ** buf,size_t * size,unsigned long val,bool neg)401 static void proc_put_long(void **buf, size_t *size, unsigned long val, bool neg)
402 {
403 int len;
404 char tmp[TMPBUFLEN], *p = tmp;
405
406 sprintf(p, "%s%lu", neg ? "-" : "", val);
407 len = strlen(tmp);
408 if (len > *size)
409 len = *size;
410 memcpy(*buf, tmp, len);
411 *size -= len;
412 *buf += len;
413 }
414 #undef TMPBUFLEN
415
proc_put_char(void ** buf,size_t * size,char c)416 static void proc_put_char(void **buf, size_t *size, char c)
417 {
418 if (*size) {
419 char **buffer = (char **)buf;
420 **buffer = c;
421
422 (*size)--;
423 (*buffer)++;
424 *buf = *buffer;
425 }
426 }
427
do_proc_dointvec_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)428 static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
429 int *valp,
430 int write, void *data)
431 {
432 if (write) {
433 if (*negp) {
434 if (*lvalp > (unsigned long) INT_MAX + 1)
435 return -EINVAL;
436 WRITE_ONCE(*valp, -*lvalp);
437 } else {
438 if (*lvalp > (unsigned long) INT_MAX)
439 return -EINVAL;
440 WRITE_ONCE(*valp, *lvalp);
441 }
442 } else {
443 int val = READ_ONCE(*valp);
444 if (val < 0) {
445 *negp = true;
446 *lvalp = -(unsigned long)val;
447 } else {
448 *negp = false;
449 *lvalp = (unsigned long)val;
450 }
451 }
452 return 0;
453 }
454
do_proc_douintvec_conv(unsigned long * lvalp,unsigned int * valp,int write,void * data)455 static int do_proc_douintvec_conv(unsigned long *lvalp,
456 unsigned int *valp,
457 int write, void *data)
458 {
459 if (write) {
460 if (*lvalp > UINT_MAX)
461 return -EINVAL;
462 WRITE_ONCE(*valp, *lvalp);
463 } else {
464 unsigned int val = READ_ONCE(*valp);
465 *lvalp = (unsigned long)val;
466 }
467 return 0;
468 }
469
470 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
471
__do_proc_dointvec(void * tbl_data,struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(bool * negp,unsigned long * lvalp,int * valp,int write,void * data),void * data)472 static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
473 int write, void *buffer,
474 size_t *lenp, loff_t *ppos,
475 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
476 int write, void *data),
477 void *data)
478 {
479 int *i, vleft, first = 1, err = 0;
480 size_t left;
481 char *p;
482
483 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
484 *lenp = 0;
485 return 0;
486 }
487
488 i = (int *) tbl_data;
489 vleft = table->maxlen / sizeof(*i);
490 left = *lenp;
491
492 if (!conv)
493 conv = do_proc_dointvec_conv;
494
495 if (write) {
496 if (proc_first_pos_non_zero_ignore(ppos, table))
497 goto out;
498
499 if (left > PAGE_SIZE - 1)
500 left = PAGE_SIZE - 1;
501 p = buffer;
502 }
503
504 for (; left && vleft--; i++, first=0) {
505 unsigned long lval;
506 bool neg;
507
508 if (write) {
509 proc_skip_spaces(&p, &left);
510
511 if (!left)
512 break;
513 err = proc_get_long(&p, &left, &lval, &neg,
514 proc_wspace_sep,
515 sizeof(proc_wspace_sep), NULL);
516 if (err)
517 break;
518 if (conv(&neg, &lval, i, 1, data)) {
519 err = -EINVAL;
520 break;
521 }
522 } else {
523 if (conv(&neg, &lval, i, 0, data)) {
524 err = -EINVAL;
525 break;
526 }
527 if (!first)
528 proc_put_char(&buffer, &left, '\t');
529 proc_put_long(&buffer, &left, lval, neg);
530 }
531 }
532
533 if (!write && !first && left && !err)
534 proc_put_char(&buffer, &left, '\n');
535 if (write && !err && left)
536 proc_skip_spaces(&p, &left);
537 if (write && first)
538 return err ? : -EINVAL;
539 *lenp -= left;
540 out:
541 *ppos += *lenp;
542 return err;
543 }
544
do_proc_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(bool * negp,unsigned long * lvalp,int * valp,int write,void * data),void * data)545 static int do_proc_dointvec(struct ctl_table *table, int write,
546 void *buffer, size_t *lenp, loff_t *ppos,
547 int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
548 int write, void *data),
549 void *data)
550 {
551 return __do_proc_dointvec(table->data, table, write,
552 buffer, lenp, ppos, conv, data);
553 }
554
do_proc_douintvec_w(unsigned int * tbl_data,struct ctl_table * table,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(unsigned long * lvalp,unsigned int * valp,int write,void * data),void * data)555 static int do_proc_douintvec_w(unsigned int *tbl_data,
556 struct ctl_table *table,
557 void *buffer,
558 size_t *lenp, loff_t *ppos,
559 int (*conv)(unsigned long *lvalp,
560 unsigned int *valp,
561 int write, void *data),
562 void *data)
563 {
564 unsigned long lval;
565 int err = 0;
566 size_t left;
567 bool neg;
568 char *p = buffer;
569
570 left = *lenp;
571
572 if (proc_first_pos_non_zero_ignore(ppos, table))
573 goto bail_early;
574
575 if (left > PAGE_SIZE - 1)
576 left = PAGE_SIZE - 1;
577
578 proc_skip_spaces(&p, &left);
579 if (!left) {
580 err = -EINVAL;
581 goto out_free;
582 }
583
584 err = proc_get_long(&p, &left, &lval, &neg,
585 proc_wspace_sep,
586 sizeof(proc_wspace_sep), NULL);
587 if (err || neg) {
588 err = -EINVAL;
589 goto out_free;
590 }
591
592 if (conv(&lval, tbl_data, 1, data)) {
593 err = -EINVAL;
594 goto out_free;
595 }
596
597 if (!err && left)
598 proc_skip_spaces(&p, &left);
599
600 out_free:
601 if (err)
602 return -EINVAL;
603
604 return 0;
605
606 /* This is in keeping with old __do_proc_dointvec() */
607 bail_early:
608 *ppos += *lenp;
609 return err;
610 }
611
do_proc_douintvec_r(unsigned int * tbl_data,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(unsigned long * lvalp,unsigned int * valp,int write,void * data),void * data)612 static int do_proc_douintvec_r(unsigned int *tbl_data, void *buffer,
613 size_t *lenp, loff_t *ppos,
614 int (*conv)(unsigned long *lvalp,
615 unsigned int *valp,
616 int write, void *data),
617 void *data)
618 {
619 unsigned long lval;
620 int err = 0;
621 size_t left;
622
623 left = *lenp;
624
625 if (conv(&lval, tbl_data, 0, data)) {
626 err = -EINVAL;
627 goto out;
628 }
629
630 proc_put_long(&buffer, &left, lval, false);
631 if (!left)
632 goto out;
633
634 proc_put_char(&buffer, &left, '\n');
635
636 out:
637 *lenp -= left;
638 *ppos += *lenp;
639
640 return err;
641 }
642
__do_proc_douintvec(void * tbl_data,struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(unsigned long * lvalp,unsigned int * valp,int write,void * data),void * data)643 static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
644 int write, void *buffer,
645 size_t *lenp, loff_t *ppos,
646 int (*conv)(unsigned long *lvalp,
647 unsigned int *valp,
648 int write, void *data),
649 void *data)
650 {
651 unsigned int *i, vleft;
652
653 if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
654 *lenp = 0;
655 return 0;
656 }
657
658 i = (unsigned int *) tbl_data;
659 vleft = table->maxlen / sizeof(*i);
660
661 /*
662 * Arrays are not supported, keep this simple. *Do not* add
663 * support for them.
664 */
665 if (vleft != 1) {
666 *lenp = 0;
667 return -EINVAL;
668 }
669
670 if (!conv)
671 conv = do_proc_douintvec_conv;
672
673 if (write)
674 return do_proc_douintvec_w(i, table, buffer, lenp, ppos,
675 conv, data);
676 return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
677 }
678
do_proc_douintvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,int (* conv)(unsigned long * lvalp,unsigned int * valp,int write,void * data),void * data)679 int do_proc_douintvec(struct ctl_table *table, int write,
680 void *buffer, size_t *lenp, loff_t *ppos,
681 int (*conv)(unsigned long *lvalp,
682 unsigned int *valp,
683 int write, void *data),
684 void *data)
685 {
686 return __do_proc_douintvec(table->data, table, write,
687 buffer, lenp, ppos, conv, data);
688 }
689
690 /**
691 * proc_dobool - read/write a bool
692 * @table: the sysctl table
693 * @write: %TRUE if this is a write to the sysctl file
694 * @buffer: the user buffer
695 * @lenp: the size of the user buffer
696 * @ppos: file position
697 *
698 * Reads/writes one integer value from/to the user buffer,
699 * treated as an ASCII string.
700 *
701 * table->data must point to a bool variable and table->maxlen must
702 * be sizeof(bool).
703 *
704 * Returns 0 on success.
705 */
proc_dobool(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)706 int proc_dobool(struct ctl_table *table, int write, void *buffer,
707 size_t *lenp, loff_t *ppos)
708 {
709 struct ctl_table tmp;
710 bool *data = table->data;
711 int res, val;
712
713 /* Do not support arrays yet. */
714 if (table->maxlen != sizeof(bool))
715 return -EINVAL;
716
717 tmp = *table;
718 tmp.maxlen = sizeof(val);
719 tmp.data = &val;
720
721 val = READ_ONCE(*data);
722 res = proc_dointvec(&tmp, write, buffer, lenp, ppos);
723 if (res)
724 return res;
725 if (write)
726 WRITE_ONCE(*data, val);
727 return 0;
728 }
729
730 /**
731 * proc_dointvec - read a vector of integers
732 * @table: the sysctl table
733 * @write: %TRUE if this is a write to the sysctl file
734 * @buffer: the user buffer
735 * @lenp: the size of the user buffer
736 * @ppos: file position
737 *
738 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
739 * values from/to the user buffer, treated as an ASCII string.
740 *
741 * Returns 0 on success.
742 */
proc_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)743 int proc_dointvec(struct ctl_table *table, int write, void *buffer,
744 size_t *lenp, loff_t *ppos)
745 {
746 return do_proc_dointvec(table, write, buffer, lenp, ppos, NULL, NULL);
747 }
748
749 #ifdef CONFIG_COMPACTION
proc_dointvec_minmax_warn_RT_change(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)750 static int proc_dointvec_minmax_warn_RT_change(struct ctl_table *table,
751 int write, void *buffer, size_t *lenp, loff_t *ppos)
752 {
753 int ret, old;
754
755 if (!IS_ENABLED(CONFIG_PREEMPT_RT) || !write)
756 return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
757
758 old = *(int *)table->data;
759 ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
760 if (ret)
761 return ret;
762 if (old != *(int *)table->data)
763 pr_warn_once("sysctl attribute %s changed by %s[%d]\n",
764 table->procname, current->comm,
765 task_pid_nr(current));
766 return ret;
767 }
768 #endif
769
770 /**
771 * proc_douintvec - read a vector of unsigned integers
772 * @table: the sysctl table
773 * @write: %TRUE if this is a write to the sysctl file
774 * @buffer: the user buffer
775 * @lenp: the size of the user buffer
776 * @ppos: file position
777 *
778 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
779 * values from/to the user buffer, treated as an ASCII string.
780 *
781 * Returns 0 on success.
782 */
proc_douintvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)783 int proc_douintvec(struct ctl_table *table, int write, void *buffer,
784 size_t *lenp, loff_t *ppos)
785 {
786 return do_proc_douintvec(table, write, buffer, lenp, ppos,
787 do_proc_douintvec_conv, NULL);
788 }
789
790 /*
791 * Taint values can only be increased
792 * This means we can safely use a temporary.
793 */
proc_taint(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)794 static int proc_taint(struct ctl_table *table, int write,
795 void *buffer, size_t *lenp, loff_t *ppos)
796 {
797 struct ctl_table t;
798 unsigned long tmptaint = get_taint();
799 int err;
800
801 if (write && !capable(CAP_SYS_ADMIN))
802 return -EPERM;
803
804 t = *table;
805 t.data = &tmptaint;
806 err = proc_doulongvec_minmax(&t, write, buffer, lenp, ppos);
807 if (err < 0)
808 return err;
809
810 if (write) {
811 int i;
812
813 /*
814 * If we are relying on panic_on_taint not producing
815 * false positives due to userspace input, bail out
816 * before setting the requested taint flags.
817 */
818 if (panic_on_taint_nousertaint && (tmptaint & panic_on_taint))
819 return -EINVAL;
820
821 /*
822 * Poor man's atomic or. Not worth adding a primitive
823 * to everyone's atomic.h for this
824 */
825 for (i = 0; i < TAINT_FLAGS_COUNT; i++)
826 if ((1UL << i) & tmptaint)
827 add_taint(i, LOCKDEP_STILL_OK);
828 }
829
830 return err;
831 }
832
833 /**
834 * struct do_proc_dointvec_minmax_conv_param - proc_dointvec_minmax() range checking structure
835 * @min: pointer to minimum allowable value
836 * @max: pointer to maximum allowable value
837 *
838 * The do_proc_dointvec_minmax_conv_param structure provides the
839 * minimum and maximum values for doing range checking for those sysctl
840 * parameters that use the proc_dointvec_minmax() handler.
841 */
842 struct do_proc_dointvec_minmax_conv_param {
843 int *min;
844 int *max;
845 };
846
do_proc_dointvec_minmax_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)847 static int do_proc_dointvec_minmax_conv(bool *negp, unsigned long *lvalp,
848 int *valp,
849 int write, void *data)
850 {
851 int tmp, ret;
852 struct do_proc_dointvec_minmax_conv_param *param = data;
853 /*
854 * If writing, first do so via a temporary local int so we can
855 * bounds-check it before touching *valp.
856 */
857 int *ip = write ? &tmp : valp;
858
859 ret = do_proc_dointvec_conv(negp, lvalp, ip, write, data);
860 if (ret)
861 return ret;
862
863 if (write) {
864 if ((param->min && *param->min > tmp) ||
865 (param->max && *param->max < tmp))
866 return -EINVAL;
867 WRITE_ONCE(*valp, tmp);
868 }
869
870 return 0;
871 }
872
873 /**
874 * proc_dointvec_minmax - read a vector of integers with min/max values
875 * @table: the sysctl table
876 * @write: %TRUE if this is a write to the sysctl file
877 * @buffer: the user buffer
878 * @lenp: the size of the user buffer
879 * @ppos: file position
880 *
881 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
882 * values from/to the user buffer, treated as an ASCII string.
883 *
884 * This routine will ensure the values are within the range specified by
885 * table->extra1 (min) and table->extra2 (max).
886 *
887 * Returns 0 on success or -EINVAL on write when the range check fails.
888 */
proc_dointvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)889 int proc_dointvec_minmax(struct ctl_table *table, int write,
890 void *buffer, size_t *lenp, loff_t *ppos)
891 {
892 struct do_proc_dointvec_minmax_conv_param param = {
893 .min = (int *) table->extra1,
894 .max = (int *) table->extra2,
895 };
896 return do_proc_dointvec(table, write, buffer, lenp, ppos,
897 do_proc_dointvec_minmax_conv, ¶m);
898 }
899
900 /**
901 * struct do_proc_douintvec_minmax_conv_param - proc_douintvec_minmax() range checking structure
902 * @min: pointer to minimum allowable value
903 * @max: pointer to maximum allowable value
904 *
905 * The do_proc_douintvec_minmax_conv_param structure provides the
906 * minimum and maximum values for doing range checking for those sysctl
907 * parameters that use the proc_douintvec_minmax() handler.
908 */
909 struct do_proc_douintvec_minmax_conv_param {
910 unsigned int *min;
911 unsigned int *max;
912 };
913
do_proc_douintvec_minmax_conv(unsigned long * lvalp,unsigned int * valp,int write,void * data)914 static int do_proc_douintvec_minmax_conv(unsigned long *lvalp,
915 unsigned int *valp,
916 int write, void *data)
917 {
918 int ret;
919 unsigned int tmp;
920 struct do_proc_douintvec_minmax_conv_param *param = data;
921 /* write via temporary local uint for bounds-checking */
922 unsigned int *up = write ? &tmp : valp;
923
924 ret = do_proc_douintvec_conv(lvalp, up, write, data);
925 if (ret)
926 return ret;
927
928 if (write) {
929 if ((param->min && *param->min > tmp) ||
930 (param->max && *param->max < tmp))
931 return -ERANGE;
932
933 WRITE_ONCE(*valp, tmp);
934 }
935
936 return 0;
937 }
938
939 /**
940 * proc_douintvec_minmax - read a vector of unsigned ints with min/max values
941 * @table: the sysctl table
942 * @write: %TRUE if this is a write to the sysctl file
943 * @buffer: the user buffer
944 * @lenp: the size of the user buffer
945 * @ppos: file position
946 *
947 * Reads/writes up to table->maxlen/sizeof(unsigned int) unsigned integer
948 * values from/to the user buffer, treated as an ASCII string. Negative
949 * strings are not allowed.
950 *
951 * This routine will ensure the values are within the range specified by
952 * table->extra1 (min) and table->extra2 (max). There is a final sanity
953 * check for UINT_MAX to avoid having to support wrap around uses from
954 * userspace.
955 *
956 * Returns 0 on success or -ERANGE on write when the range check fails.
957 */
proc_douintvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)958 int proc_douintvec_minmax(struct ctl_table *table, int write,
959 void *buffer, size_t *lenp, loff_t *ppos)
960 {
961 struct do_proc_douintvec_minmax_conv_param param = {
962 .min = (unsigned int *) table->extra1,
963 .max = (unsigned int *) table->extra2,
964 };
965 return do_proc_douintvec(table, write, buffer, lenp, ppos,
966 do_proc_douintvec_minmax_conv, ¶m);
967 }
968
969 /**
970 * proc_dou8vec_minmax - read a vector of unsigned chars with min/max values
971 * @table: the sysctl table
972 * @write: %TRUE if this is a write to the sysctl file
973 * @buffer: the user buffer
974 * @lenp: the size of the user buffer
975 * @ppos: file position
976 *
977 * Reads/writes up to table->maxlen/sizeof(u8) unsigned chars
978 * values from/to the user buffer, treated as an ASCII string. Negative
979 * strings are not allowed.
980 *
981 * This routine will ensure the values are within the range specified by
982 * table->extra1 (min) and table->extra2 (max).
983 *
984 * Returns 0 on success or an error on write when the range check fails.
985 */
proc_dou8vec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)986 int proc_dou8vec_minmax(struct ctl_table *table, int write,
987 void *buffer, size_t *lenp, loff_t *ppos)
988 {
989 struct ctl_table tmp;
990 unsigned int min = 0, max = 255U, val;
991 u8 *data = table->data;
992 struct do_proc_douintvec_minmax_conv_param param = {
993 .min = &min,
994 .max = &max,
995 };
996 int res;
997
998 /* Do not support arrays yet. */
999 if (table->maxlen != sizeof(u8))
1000 return -EINVAL;
1001
1002 if (table->extra1) {
1003 min = *(unsigned int *) table->extra1;
1004 if (min > 255U)
1005 return -EINVAL;
1006 }
1007 if (table->extra2) {
1008 max = *(unsigned int *) table->extra2;
1009 if (max > 255U)
1010 return -EINVAL;
1011 }
1012
1013 tmp = *table;
1014
1015 tmp.maxlen = sizeof(val);
1016 tmp.data = &val;
1017 val = READ_ONCE(*data);
1018 res = do_proc_douintvec(&tmp, write, buffer, lenp, ppos,
1019 do_proc_douintvec_minmax_conv, ¶m);
1020 if (res)
1021 return res;
1022 if (write)
1023 WRITE_ONCE(*data, val);
1024 return 0;
1025 }
1026 EXPORT_SYMBOL_GPL(proc_dou8vec_minmax);
1027
1028 #ifdef CONFIG_MAGIC_SYSRQ
sysrq_sysctl_handler(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1029 static int sysrq_sysctl_handler(struct ctl_table *table, int write,
1030 void *buffer, size_t *lenp, loff_t *ppos)
1031 {
1032 int tmp, ret;
1033
1034 tmp = sysrq_mask();
1035
1036 ret = __do_proc_dointvec(&tmp, table, write, buffer,
1037 lenp, ppos, NULL, NULL);
1038 if (ret || !write)
1039 return ret;
1040
1041 if (write)
1042 sysrq_toggle_support(tmp);
1043
1044 return 0;
1045 }
1046 #endif
1047
__do_proc_doulongvec_minmax(void * data,struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,unsigned long convmul,unsigned long convdiv)1048 static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
1049 int write, void *buffer, size_t *lenp, loff_t *ppos,
1050 unsigned long convmul, unsigned long convdiv)
1051 {
1052 unsigned long *i, *min, *max;
1053 int vleft, first = 1, err = 0;
1054 size_t left;
1055 char *p;
1056
1057 if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
1058 *lenp = 0;
1059 return 0;
1060 }
1061
1062 i = data;
1063 min = table->extra1;
1064 max = table->extra2;
1065 vleft = table->maxlen / sizeof(unsigned long);
1066 left = *lenp;
1067
1068 if (write) {
1069 if (proc_first_pos_non_zero_ignore(ppos, table))
1070 goto out;
1071
1072 if (left > PAGE_SIZE - 1)
1073 left = PAGE_SIZE - 1;
1074 p = buffer;
1075 }
1076
1077 for (; left && vleft--; i++, first = 0) {
1078 unsigned long val;
1079
1080 if (write) {
1081 bool neg;
1082
1083 proc_skip_spaces(&p, &left);
1084 if (!left)
1085 break;
1086
1087 err = proc_get_long(&p, &left, &val, &neg,
1088 proc_wspace_sep,
1089 sizeof(proc_wspace_sep), NULL);
1090 if (err || neg) {
1091 err = -EINVAL;
1092 break;
1093 }
1094
1095 val = convmul * val / convdiv;
1096 if ((min && val < *min) || (max && val > *max)) {
1097 err = -EINVAL;
1098 break;
1099 }
1100 WRITE_ONCE(*i, val);
1101 } else {
1102 val = convdiv * READ_ONCE(*i) / convmul;
1103 if (!first)
1104 proc_put_char(&buffer, &left, '\t');
1105 proc_put_long(&buffer, &left, val, false);
1106 }
1107 }
1108
1109 if (!write && !first && left && !err)
1110 proc_put_char(&buffer, &left, '\n');
1111 if (write && !err)
1112 proc_skip_spaces(&p, &left);
1113 if (write && first)
1114 return err ? : -EINVAL;
1115 *lenp -= left;
1116 out:
1117 *ppos += *lenp;
1118 return err;
1119 }
1120
do_proc_doulongvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos,unsigned long convmul,unsigned long convdiv)1121 static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
1122 void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul,
1123 unsigned long convdiv)
1124 {
1125 return __do_proc_doulongvec_minmax(table->data, table, write,
1126 buffer, lenp, ppos, convmul, convdiv);
1127 }
1128
1129 /**
1130 * proc_doulongvec_minmax - read a vector of long integers with min/max values
1131 * @table: the sysctl table
1132 * @write: %TRUE if this is a write to the sysctl file
1133 * @buffer: the user buffer
1134 * @lenp: the size of the user buffer
1135 * @ppos: file position
1136 *
1137 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1138 * values from/to the user buffer, treated as an ASCII string.
1139 *
1140 * This routine will ensure the values are within the range specified by
1141 * table->extra1 (min) and table->extra2 (max).
1142 *
1143 * Returns 0 on success.
1144 */
proc_doulongvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1145 int proc_doulongvec_minmax(struct ctl_table *table, int write,
1146 void *buffer, size_t *lenp, loff_t *ppos)
1147 {
1148 return do_proc_doulongvec_minmax(table, write, buffer, lenp, ppos, 1l, 1l);
1149 }
1150
1151 /**
1152 * proc_doulongvec_ms_jiffies_minmax - read a vector of millisecond values with min/max values
1153 * @table: the sysctl table
1154 * @write: %TRUE if this is a write to the sysctl file
1155 * @buffer: the user buffer
1156 * @lenp: the size of the user buffer
1157 * @ppos: file position
1158 *
1159 * Reads/writes up to table->maxlen/sizeof(unsigned long) unsigned long
1160 * values from/to the user buffer, treated as an ASCII string. The values
1161 * are treated as milliseconds, and converted to jiffies when they are stored.
1162 *
1163 * This routine will ensure the values are within the range specified by
1164 * table->extra1 (min) and table->extra2 (max).
1165 *
1166 * Returns 0 on success.
1167 */
proc_doulongvec_ms_jiffies_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1168 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
1169 void *buffer, size_t *lenp, loff_t *ppos)
1170 {
1171 return do_proc_doulongvec_minmax(table, write, buffer,
1172 lenp, ppos, HZ, 1000l);
1173 }
1174
1175
do_proc_dointvec_jiffies_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)1176 static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
1177 int *valp,
1178 int write, void *data)
1179 {
1180 if (write) {
1181 if (*lvalp > INT_MAX / HZ)
1182 return 1;
1183 if (*negp)
1184 WRITE_ONCE(*valp, -*lvalp * HZ);
1185 else
1186 WRITE_ONCE(*valp, *lvalp * HZ);
1187 } else {
1188 int val = READ_ONCE(*valp);
1189 unsigned long lval;
1190 if (val < 0) {
1191 *negp = true;
1192 lval = -(unsigned long)val;
1193 } else {
1194 *negp = false;
1195 lval = (unsigned long)val;
1196 }
1197 *lvalp = lval / HZ;
1198 }
1199 return 0;
1200 }
1201
do_proc_dointvec_userhz_jiffies_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)1202 static int do_proc_dointvec_userhz_jiffies_conv(bool *negp, unsigned long *lvalp,
1203 int *valp,
1204 int write, void *data)
1205 {
1206 if (write) {
1207 if (USER_HZ < HZ && *lvalp > (LONG_MAX / HZ) * USER_HZ)
1208 return 1;
1209 *valp = clock_t_to_jiffies(*negp ? -*lvalp : *lvalp);
1210 } else {
1211 int val = *valp;
1212 unsigned long lval;
1213 if (val < 0) {
1214 *negp = true;
1215 lval = -(unsigned long)val;
1216 } else {
1217 *negp = false;
1218 lval = (unsigned long)val;
1219 }
1220 *lvalp = jiffies_to_clock_t(lval);
1221 }
1222 return 0;
1223 }
1224
do_proc_dointvec_ms_jiffies_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)1225 static int do_proc_dointvec_ms_jiffies_conv(bool *negp, unsigned long *lvalp,
1226 int *valp,
1227 int write, void *data)
1228 {
1229 if (write) {
1230 unsigned long jif = msecs_to_jiffies(*negp ? -*lvalp : *lvalp);
1231
1232 if (jif > INT_MAX)
1233 return 1;
1234 WRITE_ONCE(*valp, (int)jif);
1235 } else {
1236 int val = READ_ONCE(*valp);
1237 unsigned long lval;
1238 if (val < 0) {
1239 *negp = true;
1240 lval = -(unsigned long)val;
1241 } else {
1242 *negp = false;
1243 lval = (unsigned long)val;
1244 }
1245 *lvalp = jiffies_to_msecs(lval);
1246 }
1247 return 0;
1248 }
1249
do_proc_dointvec_ms_jiffies_minmax_conv(bool * negp,unsigned long * lvalp,int * valp,int write,void * data)1250 static int do_proc_dointvec_ms_jiffies_minmax_conv(bool *negp, unsigned long *lvalp,
1251 int *valp, int write, void *data)
1252 {
1253 int tmp, ret;
1254 struct do_proc_dointvec_minmax_conv_param *param = data;
1255 /*
1256 * If writing, first do so via a temporary local int so we can
1257 * bounds-check it before touching *valp.
1258 */
1259 int *ip = write ? &tmp : valp;
1260
1261 ret = do_proc_dointvec_ms_jiffies_conv(negp, lvalp, ip, write, data);
1262 if (ret)
1263 return ret;
1264
1265 if (write) {
1266 if ((param->min && *param->min > tmp) ||
1267 (param->max && *param->max < tmp))
1268 return -EINVAL;
1269 *valp = tmp;
1270 }
1271 return 0;
1272 }
1273
1274 /**
1275 * proc_dointvec_jiffies - read a vector of integers as seconds
1276 * @table: the sysctl table
1277 * @write: %TRUE if this is a write to the sysctl file
1278 * @buffer: the user buffer
1279 * @lenp: the size of the user buffer
1280 * @ppos: file position
1281 *
1282 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1283 * values from/to the user buffer, treated as an ASCII string.
1284 * The values read are assumed to be in seconds, and are converted into
1285 * jiffies.
1286 *
1287 * Returns 0 on success.
1288 */
proc_dointvec_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1289 int proc_dointvec_jiffies(struct ctl_table *table, int write,
1290 void *buffer, size_t *lenp, loff_t *ppos)
1291 {
1292 return do_proc_dointvec(table,write,buffer,lenp,ppos,
1293 do_proc_dointvec_jiffies_conv,NULL);
1294 }
1295
proc_dointvec_ms_jiffies_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1296 int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write,
1297 void *buffer, size_t *lenp, loff_t *ppos)
1298 {
1299 struct do_proc_dointvec_minmax_conv_param param = {
1300 .min = (int *) table->extra1,
1301 .max = (int *) table->extra2,
1302 };
1303 return do_proc_dointvec(table, write, buffer, lenp, ppos,
1304 do_proc_dointvec_ms_jiffies_minmax_conv, ¶m);
1305 }
1306
1307 /**
1308 * proc_dointvec_userhz_jiffies - read a vector of integers as 1/USER_HZ seconds
1309 * @table: the sysctl table
1310 * @write: %TRUE if this is a write to the sysctl file
1311 * @buffer: the user buffer
1312 * @lenp: the size of the user buffer
1313 * @ppos: pointer to the file position
1314 *
1315 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1316 * values from/to the user buffer, treated as an ASCII string.
1317 * The values read are assumed to be in 1/USER_HZ seconds, and
1318 * are converted into jiffies.
1319 *
1320 * Returns 0 on success.
1321 */
proc_dointvec_userhz_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1322 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
1323 void *buffer, size_t *lenp, loff_t *ppos)
1324 {
1325 return do_proc_dointvec(table, write, buffer, lenp, ppos,
1326 do_proc_dointvec_userhz_jiffies_conv, NULL);
1327 }
1328
1329 /**
1330 * proc_dointvec_ms_jiffies - read a vector of integers as 1 milliseconds
1331 * @table: the sysctl table
1332 * @write: %TRUE if this is a write to the sysctl file
1333 * @buffer: the user buffer
1334 * @lenp: the size of the user buffer
1335 * @ppos: file position
1336 * @ppos: the current position in the file
1337 *
1338 * Reads/writes up to table->maxlen/sizeof(unsigned int) integer
1339 * values from/to the user buffer, treated as an ASCII string.
1340 * The values read are assumed to be in 1/1000 seconds, and
1341 * are converted into jiffies.
1342 *
1343 * Returns 0 on success.
1344 */
proc_dointvec_ms_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1345 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write, void *buffer,
1346 size_t *lenp, loff_t *ppos)
1347 {
1348 return do_proc_dointvec(table, write, buffer, lenp, ppos,
1349 do_proc_dointvec_ms_jiffies_conv, NULL);
1350 }
1351
proc_do_cad_pid(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1352 static int proc_do_cad_pid(struct ctl_table *table, int write, void *buffer,
1353 size_t *lenp, loff_t *ppos)
1354 {
1355 struct pid *new_pid;
1356 pid_t tmp;
1357 int r;
1358
1359 tmp = pid_vnr(cad_pid);
1360
1361 r = __do_proc_dointvec(&tmp, table, write, buffer,
1362 lenp, ppos, NULL, NULL);
1363 if (r || !write)
1364 return r;
1365
1366 new_pid = find_get_pid(tmp);
1367 if (!new_pid)
1368 return -ESRCH;
1369
1370 put_pid(xchg(&cad_pid, new_pid));
1371 return 0;
1372 }
1373
1374 /**
1375 * proc_do_large_bitmap - read/write from/to a large bitmap
1376 * @table: the sysctl table
1377 * @write: %TRUE if this is a write to the sysctl file
1378 * @buffer: the user buffer
1379 * @lenp: the size of the user buffer
1380 * @ppos: file position
1381 *
1382 * The bitmap is stored at table->data and the bitmap length (in bits)
1383 * in table->maxlen.
1384 *
1385 * We use a range comma separated format (e.g. 1,3-4,10-10) so that
1386 * large bitmaps may be represented in a compact manner. Writing into
1387 * the file will clear the bitmap then update it with the given input.
1388 *
1389 * Returns 0 on success.
1390 */
proc_do_large_bitmap(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1391 int proc_do_large_bitmap(struct ctl_table *table, int write,
1392 void *buffer, size_t *lenp, loff_t *ppos)
1393 {
1394 int err = 0;
1395 size_t left = *lenp;
1396 unsigned long bitmap_len = table->maxlen;
1397 unsigned long *bitmap = *(unsigned long **) table->data;
1398 unsigned long *tmp_bitmap = NULL;
1399 char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
1400
1401 if (!bitmap || !bitmap_len || !left || (*ppos && !write)) {
1402 *lenp = 0;
1403 return 0;
1404 }
1405
1406 if (write) {
1407 char *p = buffer;
1408 size_t skipped = 0;
1409
1410 if (left > PAGE_SIZE - 1) {
1411 left = PAGE_SIZE - 1;
1412 /* How much of the buffer we'll skip this pass */
1413 skipped = *lenp - left;
1414 }
1415
1416 tmp_bitmap = bitmap_zalloc(bitmap_len, GFP_KERNEL);
1417 if (!tmp_bitmap)
1418 return -ENOMEM;
1419 proc_skip_char(&p, &left, '\n');
1420 while (!err && left) {
1421 unsigned long val_a, val_b;
1422 bool neg;
1423 size_t saved_left;
1424
1425 /* In case we stop parsing mid-number, we can reset */
1426 saved_left = left;
1427 err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
1428 sizeof(tr_a), &c);
1429 /*
1430 * If we consumed the entirety of a truncated buffer or
1431 * only one char is left (may be a "-"), then stop here,
1432 * reset, & come back for more.
1433 */
1434 if ((left <= 1) && skipped) {
1435 left = saved_left;
1436 break;
1437 }
1438
1439 if (err)
1440 break;
1441 if (val_a >= bitmap_len || neg) {
1442 err = -EINVAL;
1443 break;
1444 }
1445
1446 val_b = val_a;
1447 if (left) {
1448 p++;
1449 left--;
1450 }
1451
1452 if (c == '-') {
1453 err = proc_get_long(&p, &left, &val_b,
1454 &neg, tr_b, sizeof(tr_b),
1455 &c);
1456 /*
1457 * If we consumed all of a truncated buffer or
1458 * then stop here, reset, & come back for more.
1459 */
1460 if (!left && skipped) {
1461 left = saved_left;
1462 break;
1463 }
1464
1465 if (err)
1466 break;
1467 if (val_b >= bitmap_len || neg ||
1468 val_a > val_b) {
1469 err = -EINVAL;
1470 break;
1471 }
1472 if (left) {
1473 p++;
1474 left--;
1475 }
1476 }
1477
1478 bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
1479 proc_skip_char(&p, &left, '\n');
1480 }
1481 left += skipped;
1482 } else {
1483 unsigned long bit_a, bit_b = 0;
1484 bool first = 1;
1485
1486 while (left) {
1487 bit_a = find_next_bit(bitmap, bitmap_len, bit_b);
1488 if (bit_a >= bitmap_len)
1489 break;
1490 bit_b = find_next_zero_bit(bitmap, bitmap_len,
1491 bit_a + 1) - 1;
1492
1493 if (!first)
1494 proc_put_char(&buffer, &left, ',');
1495 proc_put_long(&buffer, &left, bit_a, false);
1496 if (bit_a != bit_b) {
1497 proc_put_char(&buffer, &left, '-');
1498 proc_put_long(&buffer, &left, bit_b, false);
1499 }
1500
1501 first = 0; bit_b++;
1502 }
1503 proc_put_char(&buffer, &left, '\n');
1504 }
1505
1506 if (!err) {
1507 if (write) {
1508 if (*ppos)
1509 bitmap_or(bitmap, bitmap, tmp_bitmap, bitmap_len);
1510 else
1511 bitmap_copy(bitmap, tmp_bitmap, bitmap_len);
1512 }
1513 *lenp -= left;
1514 *ppos += *lenp;
1515 }
1516
1517 bitmap_free(tmp_bitmap);
1518 return err;
1519 }
1520
1521 #else /* CONFIG_PROC_SYSCTL */
1522
proc_dostring(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1523 int proc_dostring(struct ctl_table *table, int write,
1524 void *buffer, size_t *lenp, loff_t *ppos)
1525 {
1526 return -ENOSYS;
1527 }
1528
proc_dobool(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1529 int proc_dobool(struct ctl_table *table, int write,
1530 void *buffer, size_t *lenp, loff_t *ppos)
1531 {
1532 return -ENOSYS;
1533 }
1534
proc_dointvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1535 int proc_dointvec(struct ctl_table *table, int write,
1536 void *buffer, size_t *lenp, loff_t *ppos)
1537 {
1538 return -ENOSYS;
1539 }
1540
proc_douintvec(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1541 int proc_douintvec(struct ctl_table *table, int write,
1542 void *buffer, size_t *lenp, loff_t *ppos)
1543 {
1544 return -ENOSYS;
1545 }
1546
proc_dointvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1547 int proc_dointvec_minmax(struct ctl_table *table, int write,
1548 void *buffer, size_t *lenp, loff_t *ppos)
1549 {
1550 return -ENOSYS;
1551 }
1552
proc_douintvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1553 int proc_douintvec_minmax(struct ctl_table *table, int write,
1554 void *buffer, size_t *lenp, loff_t *ppos)
1555 {
1556 return -ENOSYS;
1557 }
1558
proc_dou8vec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1559 int proc_dou8vec_minmax(struct ctl_table *table, int write,
1560 void *buffer, size_t *lenp, loff_t *ppos)
1561 {
1562 return -ENOSYS;
1563 }
1564
proc_dointvec_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1565 int proc_dointvec_jiffies(struct ctl_table *table, int write,
1566 void *buffer, size_t *lenp, loff_t *ppos)
1567 {
1568 return -ENOSYS;
1569 }
1570
proc_dointvec_ms_jiffies_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1571 int proc_dointvec_ms_jiffies_minmax(struct ctl_table *table, int write,
1572 void *buffer, size_t *lenp, loff_t *ppos)
1573 {
1574 return -ENOSYS;
1575 }
1576
proc_dointvec_userhz_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1577 int proc_dointvec_userhz_jiffies(struct ctl_table *table, int write,
1578 void *buffer, size_t *lenp, loff_t *ppos)
1579 {
1580 return -ENOSYS;
1581 }
1582
proc_dointvec_ms_jiffies(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1583 int proc_dointvec_ms_jiffies(struct ctl_table *table, int write,
1584 void *buffer, size_t *lenp, loff_t *ppos)
1585 {
1586 return -ENOSYS;
1587 }
1588
proc_doulongvec_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1589 int proc_doulongvec_minmax(struct ctl_table *table, int write,
1590 void *buffer, size_t *lenp, loff_t *ppos)
1591 {
1592 return -ENOSYS;
1593 }
1594
proc_doulongvec_ms_jiffies_minmax(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1595 int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int write,
1596 void *buffer, size_t *lenp, loff_t *ppos)
1597 {
1598 return -ENOSYS;
1599 }
1600
proc_do_large_bitmap(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1601 int proc_do_large_bitmap(struct ctl_table *table, int write,
1602 void *buffer, size_t *lenp, loff_t *ppos)
1603 {
1604 return -ENOSYS;
1605 }
1606
1607 #endif /* CONFIG_PROC_SYSCTL */
1608
1609 #if defined(CONFIG_SYSCTL)
proc_do_static_key(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)1610 int proc_do_static_key(struct ctl_table *table, int write,
1611 void *buffer, size_t *lenp, loff_t *ppos)
1612 {
1613 struct static_key *key = (struct static_key *)table->data;
1614 static DEFINE_MUTEX(static_key_mutex);
1615 int val, ret;
1616 struct ctl_table tmp = {
1617 .data = &val,
1618 .maxlen = sizeof(val),
1619 .mode = table->mode,
1620 .extra1 = SYSCTL_ZERO,
1621 .extra2 = SYSCTL_ONE,
1622 };
1623
1624 if (write && !capable(CAP_SYS_ADMIN))
1625 return -EPERM;
1626
1627 mutex_lock(&static_key_mutex);
1628 val = static_key_enabled(key);
1629 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1630 if (write && !ret) {
1631 if (val)
1632 static_key_enable(key);
1633 else
1634 static_key_disable(key);
1635 }
1636 mutex_unlock(&static_key_mutex);
1637 return ret;
1638 }
1639
1640 static struct ctl_table kern_table[] = {
1641 {
1642 .procname = "panic",
1643 .data = &panic_timeout,
1644 .maxlen = sizeof(int),
1645 .mode = 0644,
1646 .proc_handler = proc_dointvec,
1647 },
1648 #ifdef CONFIG_PROC_SYSCTL
1649 {
1650 .procname = "tainted",
1651 .maxlen = sizeof(long),
1652 .mode = 0644,
1653 .proc_handler = proc_taint,
1654 },
1655 {
1656 .procname = "sysctl_writes_strict",
1657 .data = &sysctl_writes_strict,
1658 .maxlen = sizeof(int),
1659 .mode = 0644,
1660 .proc_handler = proc_dointvec_minmax,
1661 .extra1 = SYSCTL_NEG_ONE,
1662 .extra2 = SYSCTL_ONE,
1663 },
1664 #endif
1665 {
1666 .procname = "print-fatal-signals",
1667 .data = &print_fatal_signals,
1668 .maxlen = sizeof(int),
1669 .mode = 0644,
1670 .proc_handler = proc_dointvec,
1671 },
1672 #ifdef CONFIG_SPARC
1673 {
1674 .procname = "reboot-cmd",
1675 .data = reboot_command,
1676 .maxlen = 256,
1677 .mode = 0644,
1678 .proc_handler = proc_dostring,
1679 },
1680 {
1681 .procname = "stop-a",
1682 .data = &stop_a_enabled,
1683 .maxlen = sizeof (int),
1684 .mode = 0644,
1685 .proc_handler = proc_dointvec,
1686 },
1687 {
1688 .procname = "scons-poweroff",
1689 .data = &scons_pwroff,
1690 .maxlen = sizeof (int),
1691 .mode = 0644,
1692 .proc_handler = proc_dointvec,
1693 },
1694 #endif
1695 #ifdef CONFIG_SPARC64
1696 {
1697 .procname = "tsb-ratio",
1698 .data = &sysctl_tsb_ratio,
1699 .maxlen = sizeof (int),
1700 .mode = 0644,
1701 .proc_handler = proc_dointvec,
1702 },
1703 #endif
1704 #ifdef CONFIG_PARISC
1705 {
1706 .procname = "soft-power",
1707 .data = &pwrsw_enabled,
1708 .maxlen = sizeof (int),
1709 .mode = 0644,
1710 .proc_handler = proc_dointvec,
1711 },
1712 #endif
1713 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW
1714 {
1715 .procname = "unaligned-trap",
1716 .data = &unaligned_enabled,
1717 .maxlen = sizeof (int),
1718 .mode = 0644,
1719 .proc_handler = proc_dointvec,
1720 },
1721 #endif
1722 #ifdef CONFIG_STACK_TRACER
1723 {
1724 .procname = "stack_tracer_enabled",
1725 .data = &stack_tracer_enabled,
1726 .maxlen = sizeof(int),
1727 .mode = 0644,
1728 .proc_handler = stack_trace_sysctl,
1729 },
1730 #endif
1731 #ifdef CONFIG_TRACING
1732 {
1733 .procname = "ftrace_dump_on_oops",
1734 .data = &ftrace_dump_on_oops,
1735 .maxlen = sizeof(int),
1736 .mode = 0644,
1737 .proc_handler = proc_dointvec,
1738 },
1739 {
1740 .procname = "traceoff_on_warning",
1741 .data = &__disable_trace_on_warning,
1742 .maxlen = sizeof(__disable_trace_on_warning),
1743 .mode = 0644,
1744 .proc_handler = proc_dointvec,
1745 },
1746 {
1747 .procname = "tracepoint_printk",
1748 .data = &tracepoint_printk,
1749 .maxlen = sizeof(tracepoint_printk),
1750 .mode = 0644,
1751 .proc_handler = tracepoint_printk_sysctl,
1752 },
1753 #endif
1754 #ifdef CONFIG_MODULES
1755 {
1756 .procname = "modprobe",
1757 .data = &modprobe_path,
1758 .maxlen = KMOD_PATH_LEN,
1759 .mode = 0644,
1760 .proc_handler = proc_dostring,
1761 },
1762 {
1763 .procname = "modules_disabled",
1764 .data = &modules_disabled,
1765 .maxlen = sizeof(int),
1766 .mode = 0644,
1767 /* only handle a transition from default "0" to "1" */
1768 .proc_handler = proc_dointvec_minmax,
1769 .extra1 = SYSCTL_ONE,
1770 .extra2 = SYSCTL_ONE,
1771 },
1772 #endif
1773 #ifdef CONFIG_UEVENT_HELPER
1774 {
1775 .procname = "hotplug",
1776 .data = &uevent_helper,
1777 .maxlen = UEVENT_HELPER_PATH_LEN,
1778 .mode = 0644,
1779 .proc_handler = proc_dostring,
1780 },
1781 #endif
1782 #ifdef CONFIG_MAGIC_SYSRQ
1783 {
1784 .procname = "sysrq",
1785 .data = NULL,
1786 .maxlen = sizeof (int),
1787 .mode = 0644,
1788 .proc_handler = sysrq_sysctl_handler,
1789 },
1790 #endif
1791 #ifdef CONFIG_PROC_SYSCTL
1792 {
1793 .procname = "cad_pid",
1794 .data = NULL,
1795 .maxlen = sizeof (int),
1796 .mode = 0600,
1797 .proc_handler = proc_do_cad_pid,
1798 },
1799 #endif
1800 {
1801 .procname = "threads-max",
1802 .data = NULL,
1803 .maxlen = sizeof(int),
1804 .mode = 0644,
1805 .proc_handler = sysctl_max_threads,
1806 },
1807 {
1808 .procname = "usermodehelper",
1809 .mode = 0555,
1810 .child = usermodehelper_table,
1811 },
1812 {
1813 .procname = "overflowuid",
1814 .data = &overflowuid,
1815 .maxlen = sizeof(int),
1816 .mode = 0644,
1817 .proc_handler = proc_dointvec_minmax,
1818 .extra1 = SYSCTL_ZERO,
1819 .extra2 = SYSCTL_MAXOLDUID,
1820 },
1821 {
1822 .procname = "overflowgid",
1823 .data = &overflowgid,
1824 .maxlen = sizeof(int),
1825 .mode = 0644,
1826 .proc_handler = proc_dointvec_minmax,
1827 .extra1 = SYSCTL_ZERO,
1828 .extra2 = SYSCTL_MAXOLDUID,
1829 },
1830 #ifdef CONFIG_S390
1831 {
1832 .procname = "userprocess_debug",
1833 .data = &show_unhandled_signals,
1834 .maxlen = sizeof(int),
1835 .mode = 0644,
1836 .proc_handler = proc_dointvec,
1837 },
1838 #endif
1839 {
1840 .procname = "pid_max",
1841 .data = &pid_max,
1842 .maxlen = sizeof (int),
1843 .mode = 0644,
1844 .proc_handler = proc_dointvec_minmax,
1845 .extra1 = &pid_max_min,
1846 .extra2 = &pid_max_max,
1847 },
1848 {
1849 .procname = "panic_on_oops",
1850 .data = &panic_on_oops,
1851 .maxlen = sizeof(int),
1852 .mode = 0644,
1853 .proc_handler = proc_dointvec,
1854 },
1855 {
1856 .procname = "panic_print",
1857 .data = &panic_print,
1858 .maxlen = sizeof(unsigned long),
1859 .mode = 0644,
1860 .proc_handler = proc_doulongvec_minmax,
1861 },
1862 {
1863 .procname = "ngroups_max",
1864 .data = (void *)&ngroups_max,
1865 .maxlen = sizeof (int),
1866 .mode = 0444,
1867 .proc_handler = proc_dointvec,
1868 },
1869 {
1870 .procname = "cap_last_cap",
1871 .data = (void *)&cap_last_cap,
1872 .maxlen = sizeof(int),
1873 .mode = 0444,
1874 .proc_handler = proc_dointvec,
1875 },
1876 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86)
1877 {
1878 .procname = "unknown_nmi_panic",
1879 .data = &unknown_nmi_panic,
1880 .maxlen = sizeof (int),
1881 .mode = 0644,
1882 .proc_handler = proc_dointvec,
1883 },
1884 #endif
1885
1886 #if (defined(CONFIG_X86_32) || defined(CONFIG_PARISC)) && \
1887 defined(CONFIG_DEBUG_STACKOVERFLOW)
1888 {
1889 .procname = "panic_on_stackoverflow",
1890 .data = &sysctl_panic_on_stackoverflow,
1891 .maxlen = sizeof(int),
1892 .mode = 0644,
1893 .proc_handler = proc_dointvec,
1894 },
1895 #endif
1896 #if defined(CONFIG_X86)
1897 {
1898 .procname = "panic_on_unrecovered_nmi",
1899 .data = &panic_on_unrecovered_nmi,
1900 .maxlen = sizeof(int),
1901 .mode = 0644,
1902 .proc_handler = proc_dointvec,
1903 },
1904 {
1905 .procname = "panic_on_io_nmi",
1906 .data = &panic_on_io_nmi,
1907 .maxlen = sizeof(int),
1908 .mode = 0644,
1909 .proc_handler = proc_dointvec,
1910 },
1911 {
1912 .procname = "bootloader_type",
1913 .data = &bootloader_type,
1914 .maxlen = sizeof (int),
1915 .mode = 0444,
1916 .proc_handler = proc_dointvec,
1917 },
1918 {
1919 .procname = "bootloader_version",
1920 .data = &bootloader_version,
1921 .maxlen = sizeof (int),
1922 .mode = 0444,
1923 .proc_handler = proc_dointvec,
1924 },
1925 {
1926 .procname = "io_delay_type",
1927 .data = &io_delay_type,
1928 .maxlen = sizeof(int),
1929 .mode = 0644,
1930 .proc_handler = proc_dointvec,
1931 },
1932 #endif
1933 #if defined(CONFIG_MMU)
1934 {
1935 .procname = "randomize_va_space",
1936 .data = &randomize_va_space,
1937 .maxlen = sizeof(int),
1938 .mode = 0644,
1939 .proc_handler = proc_dointvec,
1940 },
1941 #endif
1942 #if defined(CONFIG_S390) && defined(CONFIG_SMP)
1943 {
1944 .procname = "spin_retry",
1945 .data = &spin_retry,
1946 .maxlen = sizeof (int),
1947 .mode = 0644,
1948 .proc_handler = proc_dointvec,
1949 },
1950 #endif
1951 #if defined(CONFIG_ACPI_SLEEP) && defined(CONFIG_X86)
1952 {
1953 .procname = "acpi_video_flags",
1954 .data = &acpi_realmode_flags,
1955 .maxlen = sizeof (unsigned long),
1956 .mode = 0644,
1957 .proc_handler = proc_doulongvec_minmax,
1958 },
1959 #endif
1960 #ifdef CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN
1961 {
1962 .procname = "ignore-unaligned-usertrap",
1963 .data = &no_unaligned_warning,
1964 .maxlen = sizeof (int),
1965 .mode = 0644,
1966 .proc_handler = proc_dointvec,
1967 },
1968 #endif
1969 #ifdef CONFIG_IA64
1970 {
1971 .procname = "unaligned-dump-stack",
1972 .data = &unaligned_dump_stack,
1973 .maxlen = sizeof (int),
1974 .mode = 0644,
1975 .proc_handler = proc_dointvec,
1976 },
1977 #endif
1978 #ifdef CONFIG_RT_MUTEXES
1979 {
1980 .procname = "max_lock_depth",
1981 .data = &max_lock_depth,
1982 .maxlen = sizeof(int),
1983 .mode = 0644,
1984 .proc_handler = proc_dointvec,
1985 },
1986 #endif
1987 #ifdef CONFIG_KEYS
1988 {
1989 .procname = "keys",
1990 .mode = 0555,
1991 .child = key_sysctls,
1992 },
1993 #endif
1994 #ifdef CONFIG_PERF_EVENTS
1995 /*
1996 * User-space scripts rely on the existence of this file
1997 * as a feature check for perf_events being enabled.
1998 *
1999 * So it's an ABI, do not remove!
2000 */
2001 {
2002 .procname = "perf_event_paranoid",
2003 .data = &sysctl_perf_event_paranoid,
2004 .maxlen = sizeof(sysctl_perf_event_paranoid),
2005 .mode = 0644,
2006 .proc_handler = proc_dointvec,
2007 },
2008 {
2009 .procname = "perf_event_mlock_kb",
2010 .data = &sysctl_perf_event_mlock,
2011 .maxlen = sizeof(sysctl_perf_event_mlock),
2012 .mode = 0644,
2013 .proc_handler = proc_dointvec,
2014 },
2015 {
2016 .procname = "perf_event_max_sample_rate",
2017 .data = &sysctl_perf_event_sample_rate,
2018 .maxlen = sizeof(sysctl_perf_event_sample_rate),
2019 .mode = 0644,
2020 .proc_handler = perf_proc_update_handler,
2021 .extra1 = SYSCTL_ONE,
2022 },
2023 {
2024 .procname = "perf_cpu_time_max_percent",
2025 .data = &sysctl_perf_cpu_time_max_percent,
2026 .maxlen = sizeof(sysctl_perf_cpu_time_max_percent),
2027 .mode = 0644,
2028 .proc_handler = perf_cpu_time_max_percent_handler,
2029 .extra1 = SYSCTL_ZERO,
2030 .extra2 = SYSCTL_ONE_HUNDRED,
2031 },
2032 {
2033 .procname = "perf_event_max_stack",
2034 .data = &sysctl_perf_event_max_stack,
2035 .maxlen = sizeof(sysctl_perf_event_max_stack),
2036 .mode = 0644,
2037 .proc_handler = perf_event_max_stack_handler,
2038 .extra1 = SYSCTL_ZERO,
2039 .extra2 = (void *)&six_hundred_forty_kb,
2040 },
2041 {
2042 .procname = "perf_event_max_contexts_per_stack",
2043 .data = &sysctl_perf_event_max_contexts_per_stack,
2044 .maxlen = sizeof(sysctl_perf_event_max_contexts_per_stack),
2045 .mode = 0644,
2046 .proc_handler = perf_event_max_stack_handler,
2047 .extra1 = SYSCTL_ZERO,
2048 .extra2 = SYSCTL_ONE_THOUSAND,
2049 },
2050 #endif
2051 {
2052 .procname = "panic_on_warn",
2053 .data = &panic_on_warn,
2054 .maxlen = sizeof(int),
2055 .mode = 0644,
2056 .proc_handler = proc_dointvec_minmax,
2057 .extra1 = SYSCTL_ZERO,
2058 .extra2 = SYSCTL_ONE,
2059 },
2060 #ifdef CONFIG_TREE_RCU
2061 {
2062 .procname = "panic_on_rcu_stall",
2063 .data = &sysctl_panic_on_rcu_stall,
2064 .maxlen = sizeof(sysctl_panic_on_rcu_stall),
2065 .mode = 0644,
2066 .proc_handler = proc_dointvec_minmax,
2067 .extra1 = SYSCTL_ZERO,
2068 .extra2 = SYSCTL_ONE,
2069 },
2070 {
2071 .procname = "max_rcu_stall_to_panic",
2072 .data = &sysctl_max_rcu_stall_to_panic,
2073 .maxlen = sizeof(sysctl_max_rcu_stall_to_panic),
2074 .mode = 0644,
2075 .proc_handler = proc_dointvec_minmax,
2076 .extra1 = SYSCTL_ONE,
2077 .extra2 = SYSCTL_INT_MAX,
2078 },
2079 #endif
2080 { }
2081 };
2082
2083 static struct ctl_table vm_table[] = {
2084 {
2085 .procname = "overcommit_memory",
2086 .data = &sysctl_overcommit_memory,
2087 .maxlen = sizeof(sysctl_overcommit_memory),
2088 .mode = 0644,
2089 .proc_handler = overcommit_policy_handler,
2090 .extra1 = SYSCTL_ZERO,
2091 .extra2 = SYSCTL_TWO,
2092 },
2093 {
2094 .procname = "overcommit_ratio",
2095 .data = &sysctl_overcommit_ratio,
2096 .maxlen = sizeof(sysctl_overcommit_ratio),
2097 .mode = 0644,
2098 .proc_handler = overcommit_ratio_handler,
2099 },
2100 {
2101 .procname = "overcommit_kbytes",
2102 .data = &sysctl_overcommit_kbytes,
2103 .maxlen = sizeof(sysctl_overcommit_kbytes),
2104 .mode = 0644,
2105 .proc_handler = overcommit_kbytes_handler,
2106 },
2107 {
2108 .procname = "page-cluster",
2109 .data = &page_cluster,
2110 .maxlen = sizeof(int),
2111 .mode = 0644,
2112 .proc_handler = proc_dointvec_minmax,
2113 .extra1 = SYSCTL_ZERO,
2114 .extra2 = (void *)&page_cluster_max,
2115 },
2116 {
2117 .procname = "dirtytime_expire_seconds",
2118 .data = &dirtytime_expire_interval,
2119 .maxlen = sizeof(dirtytime_expire_interval),
2120 .mode = 0644,
2121 .proc_handler = dirtytime_interval_handler,
2122 .extra1 = SYSCTL_ZERO,
2123 },
2124 {
2125 .procname = "swappiness",
2126 .data = &vm_swappiness,
2127 .maxlen = sizeof(vm_swappiness),
2128 .mode = 0644,
2129 .proc_handler = proc_dointvec_minmax,
2130 .extra1 = SYSCTL_ZERO,
2131 .extra2 = SYSCTL_TWO_HUNDRED,
2132 },
2133 #ifdef CONFIG_NUMA
2134 {
2135 .procname = "numa_stat",
2136 .data = &sysctl_vm_numa_stat,
2137 .maxlen = sizeof(int),
2138 .mode = 0644,
2139 .proc_handler = sysctl_vm_numa_stat_handler,
2140 .extra1 = SYSCTL_ZERO,
2141 .extra2 = SYSCTL_ONE,
2142 },
2143 #endif
2144 #ifdef CONFIG_HUGETLB_PAGE
2145 {
2146 .procname = "nr_hugepages",
2147 .data = NULL,
2148 .maxlen = sizeof(unsigned long),
2149 .mode = 0644,
2150 .proc_handler = hugetlb_sysctl_handler,
2151 },
2152 #ifdef CONFIG_NUMA
2153 {
2154 .procname = "nr_hugepages_mempolicy",
2155 .data = NULL,
2156 .maxlen = sizeof(unsigned long),
2157 .mode = 0644,
2158 .proc_handler = &hugetlb_mempolicy_sysctl_handler,
2159 },
2160 #endif
2161 {
2162 .procname = "hugetlb_shm_group",
2163 .data = &sysctl_hugetlb_shm_group,
2164 .maxlen = sizeof(gid_t),
2165 .mode = 0644,
2166 .proc_handler = proc_dointvec,
2167 },
2168 {
2169 .procname = "nr_overcommit_hugepages",
2170 .data = NULL,
2171 .maxlen = sizeof(unsigned long),
2172 .mode = 0644,
2173 .proc_handler = hugetlb_overcommit_handler,
2174 },
2175 #endif
2176 {
2177 .procname = "lowmem_reserve_ratio",
2178 .data = &sysctl_lowmem_reserve_ratio,
2179 .maxlen = sizeof(sysctl_lowmem_reserve_ratio),
2180 .mode = 0644,
2181 .proc_handler = lowmem_reserve_ratio_sysctl_handler,
2182 },
2183 {
2184 .procname = "drop_caches",
2185 .data = &sysctl_drop_caches,
2186 .maxlen = sizeof(int),
2187 .mode = 0200,
2188 .proc_handler = drop_caches_sysctl_handler,
2189 .extra1 = SYSCTL_ONE,
2190 .extra2 = SYSCTL_FOUR,
2191 },
2192 #ifdef CONFIG_COMPACTION
2193 {
2194 .procname = "compact_memory",
2195 .data = NULL,
2196 .maxlen = sizeof(int),
2197 .mode = 0200,
2198 .proc_handler = sysctl_compaction_handler,
2199 },
2200 {
2201 .procname = "compaction_proactiveness",
2202 .data = &sysctl_compaction_proactiveness,
2203 .maxlen = sizeof(sysctl_compaction_proactiveness),
2204 .mode = 0644,
2205 .proc_handler = compaction_proactiveness_sysctl_handler,
2206 .extra1 = SYSCTL_ZERO,
2207 .extra2 = SYSCTL_ONE_HUNDRED,
2208 },
2209 {
2210 .procname = "extfrag_threshold",
2211 .data = &sysctl_extfrag_threshold,
2212 .maxlen = sizeof(int),
2213 .mode = 0644,
2214 .proc_handler = proc_dointvec_minmax,
2215 .extra1 = SYSCTL_ZERO,
2216 .extra2 = SYSCTL_ONE_THOUSAND,
2217 },
2218 {
2219 .procname = "compact_unevictable_allowed",
2220 .data = &sysctl_compact_unevictable_allowed,
2221 .maxlen = sizeof(int),
2222 .mode = 0644,
2223 .proc_handler = proc_dointvec_minmax_warn_RT_change,
2224 .extra1 = SYSCTL_ZERO,
2225 .extra2 = SYSCTL_ONE,
2226 },
2227
2228 #endif /* CONFIG_COMPACTION */
2229 {
2230 .procname = "min_free_kbytes",
2231 .data = &min_free_kbytes,
2232 .maxlen = sizeof(min_free_kbytes),
2233 .mode = 0644,
2234 .proc_handler = min_free_kbytes_sysctl_handler,
2235 .extra1 = SYSCTL_ZERO,
2236 },
2237 {
2238 .procname = "watermark_boost_factor",
2239 .data = &watermark_boost_factor,
2240 .maxlen = sizeof(watermark_boost_factor),
2241 .mode = 0644,
2242 .proc_handler = proc_dointvec_minmax,
2243 .extra1 = SYSCTL_ZERO,
2244 },
2245 {
2246 .procname = "watermark_scale_factor",
2247 .data = &watermark_scale_factor,
2248 .maxlen = sizeof(watermark_scale_factor),
2249 .mode = 0644,
2250 .proc_handler = watermark_scale_factor_sysctl_handler,
2251 .extra1 = SYSCTL_ONE,
2252 .extra2 = SYSCTL_THREE_THOUSAND,
2253 },
2254 {
2255 .procname = "percpu_pagelist_high_fraction",
2256 .data = &percpu_pagelist_high_fraction,
2257 .maxlen = sizeof(percpu_pagelist_high_fraction),
2258 .mode = 0644,
2259 .proc_handler = percpu_pagelist_high_fraction_sysctl_handler,
2260 .extra1 = SYSCTL_ZERO,
2261 },
2262 {
2263 .procname = "page_lock_unfairness",
2264 .data = &sysctl_page_lock_unfairness,
2265 .maxlen = sizeof(sysctl_page_lock_unfairness),
2266 .mode = 0644,
2267 .proc_handler = proc_dointvec_minmax,
2268 .extra1 = SYSCTL_ZERO,
2269 },
2270 #ifdef CONFIG_MMU
2271 {
2272 .procname = "max_map_count",
2273 .data = &sysctl_max_map_count,
2274 .maxlen = sizeof(sysctl_max_map_count),
2275 .mode = 0644,
2276 .proc_handler = proc_dointvec_minmax,
2277 .extra1 = SYSCTL_ZERO,
2278 },
2279 #else
2280 {
2281 .procname = "nr_trim_pages",
2282 .data = &sysctl_nr_trim_pages,
2283 .maxlen = sizeof(sysctl_nr_trim_pages),
2284 .mode = 0644,
2285 .proc_handler = proc_dointvec_minmax,
2286 .extra1 = SYSCTL_ZERO,
2287 },
2288 #endif
2289 {
2290 .procname = "vfs_cache_pressure",
2291 .data = &sysctl_vfs_cache_pressure,
2292 .maxlen = sizeof(sysctl_vfs_cache_pressure),
2293 .mode = 0644,
2294 .proc_handler = proc_dointvec_minmax,
2295 .extra1 = SYSCTL_ZERO,
2296 },
2297 #if defined(HAVE_ARCH_PICK_MMAP_LAYOUT) || \
2298 defined(CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT)
2299 {
2300 .procname = "legacy_va_layout",
2301 .data = &sysctl_legacy_va_layout,
2302 .maxlen = sizeof(sysctl_legacy_va_layout),
2303 .mode = 0644,
2304 .proc_handler = proc_dointvec_minmax,
2305 .extra1 = SYSCTL_ZERO,
2306 },
2307 #endif
2308 #ifdef CONFIG_NUMA
2309 {
2310 .procname = "zone_reclaim_mode",
2311 .data = &node_reclaim_mode,
2312 .maxlen = sizeof(node_reclaim_mode),
2313 .mode = 0644,
2314 .proc_handler = proc_dointvec_minmax,
2315 .extra1 = SYSCTL_ZERO,
2316 },
2317 {
2318 .procname = "min_unmapped_ratio",
2319 .data = &sysctl_min_unmapped_ratio,
2320 .maxlen = sizeof(sysctl_min_unmapped_ratio),
2321 .mode = 0644,
2322 .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
2323 .extra1 = SYSCTL_ZERO,
2324 .extra2 = SYSCTL_ONE_HUNDRED,
2325 },
2326 {
2327 .procname = "min_slab_ratio",
2328 .data = &sysctl_min_slab_ratio,
2329 .maxlen = sizeof(sysctl_min_slab_ratio),
2330 .mode = 0644,
2331 .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
2332 .extra1 = SYSCTL_ZERO,
2333 .extra2 = SYSCTL_ONE_HUNDRED,
2334 },
2335 #endif
2336 #ifdef CONFIG_SMP
2337 {
2338 .procname = "stat_interval",
2339 .data = &sysctl_stat_interval,
2340 .maxlen = sizeof(sysctl_stat_interval),
2341 .mode = 0644,
2342 .proc_handler = proc_dointvec_jiffies,
2343 },
2344 {
2345 .procname = "stat_refresh",
2346 .data = NULL,
2347 .maxlen = 0,
2348 .mode = 0600,
2349 .proc_handler = vmstat_refresh,
2350 },
2351 #endif
2352 #ifdef CONFIG_MMU
2353 {
2354 .procname = "mmap_min_addr",
2355 .data = &dac_mmap_min_addr,
2356 .maxlen = sizeof(unsigned long),
2357 .mode = 0644,
2358 .proc_handler = mmap_min_addr_handler,
2359 },
2360 #endif
2361 #ifdef CONFIG_NUMA
2362 {
2363 .procname = "numa_zonelist_order",
2364 .data = &numa_zonelist_order,
2365 .maxlen = NUMA_ZONELIST_ORDER_LEN,
2366 .mode = 0644,
2367 .proc_handler = numa_zonelist_order_handler,
2368 },
2369 #endif
2370 #if (defined(CONFIG_X86_32) && !defined(CONFIG_UML))|| \
2371 (defined(CONFIG_SUPERH) && defined(CONFIG_VSYSCALL))
2372 {
2373 .procname = "vdso_enabled",
2374 #ifdef CONFIG_X86_32
2375 .data = &vdso32_enabled,
2376 .maxlen = sizeof(vdso32_enabled),
2377 #else
2378 .data = &vdso_enabled,
2379 .maxlen = sizeof(vdso_enabled),
2380 #endif
2381 .mode = 0644,
2382 .proc_handler = proc_dointvec,
2383 .extra1 = SYSCTL_ZERO,
2384 },
2385 #endif
2386 #ifdef CONFIG_MEMORY_FAILURE
2387 {
2388 .procname = "memory_failure_early_kill",
2389 .data = &sysctl_memory_failure_early_kill,
2390 .maxlen = sizeof(sysctl_memory_failure_early_kill),
2391 .mode = 0644,
2392 .proc_handler = proc_dointvec_minmax,
2393 .extra1 = SYSCTL_ZERO,
2394 .extra2 = SYSCTL_ONE,
2395 },
2396 {
2397 .procname = "memory_failure_recovery",
2398 .data = &sysctl_memory_failure_recovery,
2399 .maxlen = sizeof(sysctl_memory_failure_recovery),
2400 .mode = 0644,
2401 .proc_handler = proc_dointvec_minmax,
2402 .extra1 = SYSCTL_ZERO,
2403 .extra2 = SYSCTL_ONE,
2404 },
2405 #endif
2406 {
2407 .procname = "user_reserve_kbytes",
2408 .data = &sysctl_user_reserve_kbytes,
2409 .maxlen = sizeof(sysctl_user_reserve_kbytes),
2410 .mode = 0644,
2411 .proc_handler = proc_doulongvec_minmax,
2412 },
2413 {
2414 .procname = "admin_reserve_kbytes",
2415 .data = &sysctl_admin_reserve_kbytes,
2416 .maxlen = sizeof(sysctl_admin_reserve_kbytes),
2417 .mode = 0644,
2418 .proc_handler = proc_doulongvec_minmax,
2419 },
2420 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
2421 {
2422 .procname = "mmap_rnd_bits",
2423 .data = &mmap_rnd_bits,
2424 .maxlen = sizeof(mmap_rnd_bits),
2425 .mode = 0600,
2426 .proc_handler = proc_dointvec_minmax,
2427 .extra1 = (void *)&mmap_rnd_bits_min,
2428 .extra2 = (void *)&mmap_rnd_bits_max,
2429 },
2430 #endif
2431 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
2432 {
2433 .procname = "mmap_rnd_compat_bits",
2434 .data = &mmap_rnd_compat_bits,
2435 .maxlen = sizeof(mmap_rnd_compat_bits),
2436 .mode = 0600,
2437 .proc_handler = proc_dointvec_minmax,
2438 .extra1 = (void *)&mmap_rnd_compat_bits_min,
2439 .extra2 = (void *)&mmap_rnd_compat_bits_max,
2440 },
2441 #endif
2442 #ifdef CONFIG_USERFAULTFD
2443 {
2444 .procname = "unprivileged_userfaultfd",
2445 .data = &sysctl_unprivileged_userfaultfd,
2446 .maxlen = sizeof(sysctl_unprivileged_userfaultfd),
2447 .mode = 0644,
2448 .proc_handler = proc_dointvec_minmax,
2449 .extra1 = SYSCTL_ZERO,
2450 .extra2 = SYSCTL_ONE,
2451 },
2452 #endif
2453 { }
2454 };
2455
2456 static struct ctl_table debug_table[] = {
2457 #ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
2458 {
2459 .procname = "exception-trace",
2460 .data = &show_unhandled_signals,
2461 .maxlen = sizeof(int),
2462 .mode = 0644,
2463 .proc_handler = proc_dointvec
2464 },
2465 #endif
2466 { }
2467 };
2468
2469 static struct ctl_table dev_table[] = {
2470 { }
2471 };
2472
2473 DECLARE_SYSCTL_BASE(kernel, kern_table);
2474 DECLARE_SYSCTL_BASE(vm, vm_table);
2475 DECLARE_SYSCTL_BASE(debug, debug_table);
2476 DECLARE_SYSCTL_BASE(dev, dev_table);
2477
sysctl_init_bases(void)2478 int __init sysctl_init_bases(void)
2479 {
2480 register_sysctl_base(kernel);
2481 register_sysctl_base(vm);
2482 register_sysctl_base(debug);
2483 register_sysctl_base(dev);
2484
2485 return 0;
2486 }
2487 #endif /* CONFIG_SYSCTL */
2488 /*
2489 * No sense putting this after each symbol definition, twice,
2490 * exception granted :-)
2491 */
2492 EXPORT_SYMBOL(proc_dobool);
2493 EXPORT_SYMBOL(proc_dointvec);
2494 EXPORT_SYMBOL(proc_douintvec);
2495 EXPORT_SYMBOL(proc_dointvec_jiffies);
2496 EXPORT_SYMBOL(proc_dointvec_minmax);
2497 EXPORT_SYMBOL_GPL(proc_douintvec_minmax);
2498 EXPORT_SYMBOL(proc_dointvec_userhz_jiffies);
2499 EXPORT_SYMBOL(proc_dointvec_ms_jiffies);
2500 EXPORT_SYMBOL(proc_dostring);
2501 EXPORT_SYMBOL(proc_doulongvec_minmax);
2502 EXPORT_SYMBOL(proc_doulongvec_ms_jiffies_minmax);
2503 EXPORT_SYMBOL(proc_do_large_bitmap);
2504