4 * Copyright (C) 1991, 1992 Linus Torvalds
7 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
9 * Wirzenius wrote this portably, Torvalds fucked it up :-)
13 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
14 * - changed to provide snprintf and vsnprintf functions
15 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
16 * - scnprintf and vscnprintf
20 #include <linux/clk.h>
21 #include <linux/clk-provider.h>
22 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
23 #include <linux/types.h>
24 #include <linux/string.h>
25 #include <linux/ctype.h>
26 #include <linux/kernel.h>
27 #include <linux/kallsyms.h>
28 #include <linux/math64.h>
29 #include <linux/uaccess.h>
30 #include <linux/ioport.h>
31 #include <linux/dcache.h>
32 #include <linux/cred.h>
33 #include <linux/uuid.h>
35 #include <net/addrconf.h>
36 #include <linux/siphash.h>
37 #include <linux/compiler.h>
39 #include <linux/blkdev.h>
42 #include "../mm/internal.h" /* For the trace_print_flags arrays */
44 #include <asm/page.h> /* for PAGE_SIZE */
45 #include <asm/byteorder.h> /* cpu_to_le16 */
47 #include <linux/string_helpers.h>
51 * simple_strtoull - convert a string to an unsigned long long
52 * @cp: The start of the string
53 * @endp: A pointer to the end of the parsed string will be placed here
54 * @base: The number base to use
56 * This function is obsolete. Please use kstrtoull instead.
58 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
60 unsigned long long result;
63 cp = _parse_integer_fixup_radix(cp, &base);
64 rv = _parse_integer(cp, base, &result);
66 cp += (rv & ~KSTRTOX_OVERFLOW);
73 EXPORT_SYMBOL(simple_strtoull);
76 * simple_strtoul - convert a string to an unsigned long
77 * @cp: The start of the string
78 * @endp: A pointer to the end of the parsed string will be placed here
79 * @base: The number base to use
81 * This function is obsolete. Please use kstrtoul instead.
83 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
85 return simple_strtoull(cp, endp, base);
87 EXPORT_SYMBOL(simple_strtoul);
90 * simple_strtol - convert a string to a signed long
91 * @cp: The start of the string
92 * @endp: A pointer to the end of the parsed string will be placed here
93 * @base: The number base to use
95 * This function is obsolete. Please use kstrtol instead.
97 long simple_strtol(const char *cp, char **endp, unsigned int base)
100 return -simple_strtoul(cp + 1, endp, base);
102 return simple_strtoul(cp, endp, base);
104 EXPORT_SYMBOL(simple_strtol);
107 * simple_strtoll - convert a string to a signed long long
108 * @cp: The start of the string
109 * @endp: A pointer to the end of the parsed string will be placed here
110 * @base: The number base to use
112 * This function is obsolete. Please use kstrtoll instead.
114 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
117 return -simple_strtoull(cp + 1, endp, base);
119 return simple_strtoull(cp, endp, base);
121 EXPORT_SYMBOL(simple_strtoll);
123 static noinline_for_stack
124 int skip_atoi(const char **s)
129 i = i*10 + *((*s)++) - '0';
130 } while (isdigit(**s));
136 * Decimal conversion is by far the most typical, and is used for
137 * /proc and /sys data. This directly impacts e.g. top performance
138 * with many processes running. We optimize it for speed by emitting
139 * two characters at a time, using a 200 byte lookup table. This
140 * roughly halves the number of multiplications compared to computing
141 * the digits one at a time. Implementation strongly inspired by the
142 * previous version, which in turn used ideas described at
143 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
144 * from the author, Douglas W. Jones).
146 * It turns out there is precisely one 26 bit fixed-point
147 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
148 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
149 * range happens to be somewhat larger (x <= 1073741898), but that's
150 * irrelevant for our purpose.
152 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
153 * need a 32x32->64 bit multiply, so we simply use the same constant.
155 * For dividing a number in the range [100, 10^4-1] by 100, there are
156 * several options. The simplest is (x * 0x147b) >> 19, which is valid
157 * for all x <= 43698.
160 static const u16 decpair[100] = {
161 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
162 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
163 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
164 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
165 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
166 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
167 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
168 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
169 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
170 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
171 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
176 * This will print a single '0' even if r == 0, since we would
177 * immediately jump to out_r where two 0s would be written but only
178 * one of them accounted for in buf. This is needed by ip4_string
179 * below. All other callers pass a non-zero value of r.
181 static noinline_for_stack
182 char *put_dec_trunc8(char *buf, unsigned r)
190 /* 100 <= r < 10^8 */
191 q = (r * (u64)0x28f5c29) >> 32;
192 *((u16 *)buf) = decpair[r - 100*q];
199 /* 100 <= q < 10^6 */
200 r = (q * (u64)0x28f5c29) >> 32;
201 *((u16 *)buf) = decpair[q - 100*r];
208 /* 100 <= r < 10^4 */
209 q = (r * 0x147b) >> 19;
210 *((u16 *)buf) = decpair[r - 100*q];
217 *((u16 *)buf) = decpair[r];
218 buf += r < 10 ? 1 : 2;
222 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
223 static noinline_for_stack
224 char *put_dec_full8(char *buf, unsigned r)
229 q = (r * (u64)0x28f5c29) >> 32;
230 *((u16 *)buf) = decpair[r - 100*q];
234 r = (q * (u64)0x28f5c29) >> 32;
235 *((u16 *)buf) = decpair[q - 100*r];
239 q = (r * 0x147b) >> 19;
240 *((u16 *)buf) = decpair[r - 100*q];
244 *((u16 *)buf) = decpair[q];
249 static noinline_for_stack
250 char *put_dec(char *buf, unsigned long long n)
252 if (n >= 100*1000*1000)
253 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
254 /* 1 <= n <= 1.6e11 */
255 if (n >= 100*1000*1000)
256 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
258 return put_dec_trunc8(buf, n);
261 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
264 put_dec_full4(char *buf, unsigned r)
269 q = (r * 0x147b) >> 19;
270 *((u16 *)buf) = decpair[r - 100*q];
273 *((u16 *)buf) = decpair[q];
277 * Call put_dec_full4 on x % 10000, return x / 10000.
278 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
279 * holds for all x < 1,128,869,999. The largest value this
280 * helper will ever be asked to convert is 1,125,520,955.
281 * (second call in the put_dec code, assuming n is all-ones).
283 static noinline_for_stack
284 unsigned put_dec_helper4(char *buf, unsigned x)
286 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
288 put_dec_full4(buf, x - q * 10000);
292 /* Based on code by Douglas W. Jones found at
293 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
294 * (with permission from the author).
295 * Performs no 64-bit division and hence should be fast on 32-bit machines.
298 char *put_dec(char *buf, unsigned long long n)
300 uint32_t d3, d2, d1, q, h;
302 if (n < 100*1000*1000)
303 return put_dec_trunc8(buf, n);
305 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
308 d3 = (h >> 16); /* implicit "& 0xffff" */
310 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
311 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
312 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
313 q = put_dec_helper4(buf, q);
315 q += 7671 * d3 + 9496 * d2 + 6 * d1;
316 q = put_dec_helper4(buf+4, q);
318 q += 4749 * d3 + 42 * d2;
319 q = put_dec_helper4(buf+8, q);
324 buf = put_dec_trunc8(buf, q);
325 else while (buf[-1] == '0')
334 * Convert passed number to decimal string.
335 * Returns the length of string. On buffer overflow, returns 0.
337 * If speed is not important, use snprintf(). It's easy to read the code.
339 int num_to_str(char *buf, int size, unsigned long long num)
341 /* put_dec requires 2-byte alignment of the buffer. */
342 char tmp[sizeof(num) * 3] __aligned(2);
345 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
350 len = put_dec(tmp, num) - tmp;
355 for (idx = 0; idx < len; ++idx)
356 buf[idx] = tmp[len - idx - 1];
360 #define SIGN 1 /* unsigned/signed, must be 1 */
361 #define LEFT 2 /* left justified */
362 #define PLUS 4 /* show plus */
363 #define SPACE 8 /* space if plus */
364 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
365 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
366 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
369 FORMAT_TYPE_NONE, /* Just a string part */
371 FORMAT_TYPE_PRECISION,
375 FORMAT_TYPE_PERCENT_CHAR,
377 FORMAT_TYPE_LONG_LONG,
391 unsigned int type:8; /* format_type enum */
392 signed int field_width:24; /* width of output field */
393 unsigned int flags:8; /* flags to number() */
394 unsigned int base:8; /* number base, 8, 10 or 16 only */
395 signed int precision:16; /* # of digits/chars */
397 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
398 #define PRECISION_MAX ((1 << 15) - 1)
400 static noinline_for_stack
401 char *number(char *buf, char *end, unsigned long long num,
402 struct printf_spec spec)
404 /* put_dec requires 2-byte alignment of the buffer. */
405 char tmp[3 * sizeof(num)] __aligned(2);
408 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
410 bool is_zero = num == 0LL;
411 int field_width = spec.field_width;
412 int precision = spec.precision;
414 BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
416 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
417 * produces same digits or (maybe lowercased) letters */
418 locase = (spec.flags & SMALL);
419 if (spec.flags & LEFT)
420 spec.flags &= ~ZEROPAD;
422 if (spec.flags & SIGN) {
423 if ((signed long long)num < 0) {
425 num = -(signed long long)num;
427 } else if (spec.flags & PLUS) {
430 } else if (spec.flags & SPACE) {
442 /* generate full string in tmp[], in reverse order */
445 tmp[i++] = hex_asc_upper[num] | locase;
446 else if (spec.base != 10) { /* 8 or 16 */
447 int mask = spec.base - 1;
453 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
456 } else { /* base 10 */
457 i = put_dec(tmp, num) - tmp;
460 /* printing 100 using %2d gives "100", not "00" */
463 /* leading space padding */
464 field_width -= precision;
465 if (!(spec.flags & (ZEROPAD | LEFT))) {
466 while (--field_width >= 0) {
478 /* "0x" / "0" prefix */
480 if (spec.base == 16 || !is_zero) {
485 if (spec.base == 16) {
487 *buf = ('X' | locase);
491 /* zero or space padding */
492 if (!(spec.flags & LEFT)) {
493 char c = ' ' + (spec.flags & ZEROPAD);
494 BUILD_BUG_ON(' ' + ZEROPAD != '0');
495 while (--field_width >= 0) {
501 /* hmm even more zero padding? */
502 while (i <= --precision) {
507 /* actual digits of result */
513 /* trailing space padding */
514 while (--field_width >= 0) {
523 static noinline_for_stack
524 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
526 struct printf_spec spec;
528 spec.type = FORMAT_TYPE_PTR;
529 spec.field_width = 2 + 2 * size; /* 0x + hex */
530 spec.flags = SPECIAL | SMALL | ZEROPAD;
534 return number(buf, end, num, spec);
537 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
540 if (buf >= end) /* nowhere to put anything */
543 if (size <= spaces) {
544 memset(buf, ' ', size);
548 if (len > size - spaces)
550 memmove(buf + spaces, buf, len);
552 memset(buf, ' ', spaces);
556 * Handle field width padding for a string.
557 * @buf: current buffer position
558 * @n: length of string
559 * @end: end of output buffer
560 * @spec: for field width and flags
561 * Returns: new buffer position after padding.
563 static noinline_for_stack
564 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
568 if (likely(n >= spec.field_width))
570 /* we want to pad the sucker */
571 spaces = spec.field_width - n;
572 if (!(spec.flags & LEFT)) {
573 move_right(buf - n, end, n, spaces);
584 static noinline_for_stack
585 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
588 size_t lim = spec.precision;
590 if ((unsigned long)s < PAGE_SIZE)
602 return widen_string(buf, len, end, spec);
605 static noinline_for_stack
606 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
609 const char *array[4], *s;
610 const struct dentry *p;
615 case '2': case '3': case '4':
616 depth = fmt[1] - '0';
623 for (i = 0; i < depth; i++, d = p) {
624 p = READ_ONCE(d->d_parent);
625 array[i] = READ_ONCE(d->d_name.name);
634 for (n = 0; n != spec.precision; n++, buf++) {
646 return widen_string(buf, n, end, spec);
650 static noinline_for_stack
651 char *bdev_name(char *buf, char *end, struct block_device *bdev,
652 struct printf_spec spec, const char *fmt)
654 struct gendisk *hd = bdev->bd_disk;
656 buf = string(buf, end, hd->disk_name, spec);
657 if (bdev->bd_part->partno) {
658 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
663 buf = number(buf, end, bdev->bd_part->partno, spec);
669 static noinline_for_stack
670 char *symbol_string(char *buf, char *end, void *ptr,
671 struct printf_spec spec, const char *fmt)
674 #ifdef CONFIG_KALLSYMS
675 char sym[KSYM_SYMBOL_LEN];
679 ptr = __builtin_extract_return_addr(ptr);
680 value = (unsigned long)ptr;
682 #ifdef CONFIG_KALLSYMS
684 sprint_backtrace(sym, value);
685 else if (*fmt != 'f' && *fmt != 's')
686 sprint_symbol(sym, value);
688 sprint_symbol_no_offset(sym, value);
690 return string(buf, end, sym, spec);
692 return special_hex_number(buf, end, value, sizeof(void *));
696 static const struct printf_spec default_str_spec = {
701 static const struct printf_spec default_dec_spec = {
706 static noinline_for_stack
707 char *resource_string(char *buf, char *end, struct resource *res,
708 struct printf_spec spec, const char *fmt)
710 #ifndef IO_RSRC_PRINTK_SIZE
711 #define IO_RSRC_PRINTK_SIZE 6
714 #ifndef MEM_RSRC_PRINTK_SIZE
715 #define MEM_RSRC_PRINTK_SIZE 10
717 static const struct printf_spec io_spec = {
719 .field_width = IO_RSRC_PRINTK_SIZE,
721 .flags = SPECIAL | SMALL | ZEROPAD,
723 static const struct printf_spec mem_spec = {
725 .field_width = MEM_RSRC_PRINTK_SIZE,
727 .flags = SPECIAL | SMALL | ZEROPAD,
729 static const struct printf_spec bus_spec = {
733 .flags = SMALL | ZEROPAD,
735 static const struct printf_spec str_spec = {
740 static const struct printf_spec flag_spec = {
743 .flags = SPECIAL | SMALL,
746 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
747 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
748 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
749 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
750 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
751 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
752 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
753 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
755 char *p = sym, *pend = sym + sizeof(sym);
756 int decode = (fmt[0] == 'R') ? 1 : 0;
757 const struct printf_spec *specp;
760 if (res->flags & IORESOURCE_IO) {
761 p = string(p, pend, "io ", str_spec);
763 } else if (res->flags & IORESOURCE_MEM) {
764 p = string(p, pend, "mem ", str_spec);
766 } else if (res->flags & IORESOURCE_IRQ) {
767 p = string(p, pend, "irq ", str_spec);
768 specp = &default_dec_spec;
769 } else if (res->flags & IORESOURCE_DMA) {
770 p = string(p, pend, "dma ", str_spec);
771 specp = &default_dec_spec;
772 } else if (res->flags & IORESOURCE_BUS) {
773 p = string(p, pend, "bus ", str_spec);
776 p = string(p, pend, "??? ", str_spec);
780 if (decode && res->flags & IORESOURCE_UNSET) {
781 p = string(p, pend, "size ", str_spec);
782 p = number(p, pend, resource_size(res), *specp);
784 p = number(p, pend, res->start, *specp);
785 if (res->start != res->end) {
787 p = number(p, pend, res->end, *specp);
791 if (res->flags & IORESOURCE_MEM_64)
792 p = string(p, pend, " 64bit", str_spec);
793 if (res->flags & IORESOURCE_PREFETCH)
794 p = string(p, pend, " pref", str_spec);
795 if (res->flags & IORESOURCE_WINDOW)
796 p = string(p, pend, " window", str_spec);
797 if (res->flags & IORESOURCE_DISABLED)
798 p = string(p, pend, " disabled", str_spec);
800 p = string(p, pend, " flags ", str_spec);
801 p = number(p, pend, res->flags, flag_spec);
806 return string(buf, end, sym, spec);
809 static noinline_for_stack
810 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
813 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
814 negative value, fallback to the default */
817 if (spec.field_width == 0)
818 /* nothing to print */
821 if (ZERO_OR_NULL_PTR(addr))
823 return string(buf, end, NULL, spec);
840 if (spec.field_width > 0)
841 len = min_t(int, spec.field_width, 64);
843 for (i = 0; i < len; ++i) {
845 *buf = hex_asc_hi(addr[i]);
848 *buf = hex_asc_lo(addr[i]);
851 if (separator && i != len - 1) {
861 static noinline_for_stack
862 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
863 struct printf_spec spec, const char *fmt)
865 const int CHUNKSZ = 32;
866 int nr_bits = max_t(int, spec.field_width, 0);
870 /* reused to print numbers */
871 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
873 chunksz = nr_bits & (CHUNKSZ - 1);
877 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
878 for (; i >= 0; i -= CHUNKSZ) {
882 chunkmask = ((1ULL << chunksz) - 1);
883 word = i / BITS_PER_LONG;
884 bit = i % BITS_PER_LONG;
885 val = (bitmap[word] >> bit) & chunkmask;
894 spec.field_width = DIV_ROUND_UP(chunksz, 4);
895 buf = number(buf, end, val, spec);
902 static noinline_for_stack
903 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
904 struct printf_spec spec, const char *fmt)
906 int nr_bits = max_t(int, spec.field_width, 0);
907 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
911 rbot = cur = find_first_bit(bitmap, nr_bits);
912 while (cur < nr_bits) {
914 cur = find_next_bit(bitmap, nr_bits, cur + 1);
915 if (cur < nr_bits && cur <= rtop + 1)
925 buf = number(buf, end, rbot, default_dec_spec);
931 buf = number(buf, end, rtop, default_dec_spec);
939 static noinline_for_stack
940 char *mac_address_string(char *buf, char *end, u8 *addr,
941 struct printf_spec spec, const char *fmt)
943 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
947 bool reversed = false;
963 for (i = 0; i < 6; i++) {
965 p = hex_byte_pack(p, addr[5 - i]);
967 p = hex_byte_pack(p, addr[i]);
969 if (fmt[0] == 'M' && i != 5)
974 return string(buf, end, mac_addr, spec);
977 static noinline_for_stack
978 char *ip4_string(char *p, const u8 *addr, const char *fmt)
981 bool leading_zeros = (fmt[0] == 'i');
1006 for (i = 0; i < 4; i++) {
1007 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1008 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1009 if (leading_zeros) {
1015 /* reverse the digits in the quad */
1017 *p++ = temp[digits];
1027 static noinline_for_stack
1028 char *ip6_compressed_string(char *p, const char *addr)
1031 unsigned char zerolength[8];
1036 bool needcolon = false;
1038 struct in6_addr in6;
1040 memcpy(&in6, addr, sizeof(struct in6_addr));
1042 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1044 memset(zerolength, 0, sizeof(zerolength));
1051 /* find position of longest 0 run */
1052 for (i = 0; i < range; i++) {
1053 for (j = i; j < range; j++) {
1054 if (in6.s6_addr16[j] != 0)
1059 for (i = 0; i < range; i++) {
1060 if (zerolength[i] > longest) {
1061 longest = zerolength[i];
1065 if (longest == 1) /* don't compress a single 0 */
1069 for (i = 0; i < range; i++) {
1070 if (i == colonpos) {
1071 if (needcolon || i == 0)
1082 /* hex u16 without leading 0s */
1083 word = ntohs(in6.s6_addr16[i]);
1088 p = hex_byte_pack(p, hi);
1090 *p++ = hex_asc_lo(hi);
1091 p = hex_byte_pack(p, lo);
1094 p = hex_byte_pack(p, lo);
1096 *p++ = hex_asc_lo(lo);
1103 p = ip4_string(p, &in6.s6_addr[12], "I4");
1110 static noinline_for_stack
1111 char *ip6_string(char *p, const char *addr, const char *fmt)
1115 for (i = 0; i < 8; i++) {
1116 p = hex_byte_pack(p, *addr++);
1117 p = hex_byte_pack(p, *addr++);
1118 if (fmt[0] == 'I' && i != 7)
1126 static noinline_for_stack
1127 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1128 struct printf_spec spec, const char *fmt)
1130 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1132 if (fmt[0] == 'I' && fmt[2] == 'c')
1133 ip6_compressed_string(ip6_addr, addr);
1135 ip6_string(ip6_addr, addr, fmt);
1137 return string(buf, end, ip6_addr, spec);
1140 static noinline_for_stack
1141 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1142 struct printf_spec spec, const char *fmt)
1144 char ip4_addr[sizeof("255.255.255.255")];
1146 ip4_string(ip4_addr, addr, fmt);
1148 return string(buf, end, ip4_addr, spec);
1151 static noinline_for_stack
1152 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1153 struct printf_spec spec, const char *fmt)
1155 bool have_p = false, have_s = false, have_f = false, have_c = false;
1156 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1157 sizeof(":12345") + sizeof("/123456789") +
1158 sizeof("%1234567890")];
1159 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1160 const u8 *addr = (const u8 *) &sa->sin6_addr;
1161 char fmt6[2] = { fmt[0], '6' };
1165 while (isalpha(*++fmt)) {
1182 if (have_p || have_s || have_f) {
1187 if (fmt6[0] == 'I' && have_c)
1188 p = ip6_compressed_string(ip6_addr + off, addr);
1190 p = ip6_string(ip6_addr + off, addr, fmt6);
1192 if (have_p || have_s || have_f)
1197 p = number(p, pend, ntohs(sa->sin6_port), spec);
1201 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1202 IPV6_FLOWINFO_MASK), spec);
1206 p = number(p, pend, sa->sin6_scope_id, spec);
1210 return string(buf, end, ip6_addr, spec);
1213 static noinline_for_stack
1214 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1215 struct printf_spec spec, const char *fmt)
1217 bool have_p = false;
1218 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1219 char *pend = ip4_addr + sizeof(ip4_addr);
1220 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1221 char fmt4[3] = { fmt[0], '4', 0 };
1224 while (isalpha(*++fmt)) {
1238 p = ip4_string(ip4_addr, addr, fmt4);
1241 p = number(p, pend, ntohs(sa->sin_port), spec);
1245 return string(buf, end, ip4_addr, spec);
1248 static noinline_for_stack
1249 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1254 unsigned int flags = 0;
1257 if (spec.field_width == 0)
1258 return buf; /* nothing to print */
1260 if (ZERO_OR_NULL_PTR(addr))
1261 return string(buf, end, NULL, spec); /* NULL pointer */
1265 switch (fmt[count++]) {
1267 flags |= ESCAPE_ANY;
1270 flags |= ESCAPE_SPECIAL;
1273 flags |= ESCAPE_HEX;
1276 flags |= ESCAPE_NULL;
1279 flags |= ESCAPE_OCTAL;
1285 flags |= ESCAPE_SPACE;
1294 flags = ESCAPE_ANY_NP;
1296 len = spec.field_width < 0 ? 1 : spec.field_width;
1299 * string_escape_mem() writes as many characters as it can to
1300 * the given buffer, and returns the total size of the output
1301 * had the buffer been big enough.
1303 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1308 static noinline_for_stack
1309 char *uuid_string(char *buf, char *end, const u8 *addr,
1310 struct printf_spec spec, const char *fmt)
1312 char uuid[UUID_STRING_LEN + 1];
1315 const u8 *index = uuid_index;
1320 uc = true; /* fall-through */
1329 for (i = 0; i < 16; i++) {
1331 p = hex_byte_pack_upper(p, addr[index[i]]);
1333 p = hex_byte_pack(p, addr[index[i]]);
1346 return string(buf, end, uuid, spec);
1349 int kptr_restrict __read_mostly;
1351 static noinline_for_stack
1352 char *restricted_pointer(char *buf, char *end, const void *ptr,
1353 struct printf_spec spec)
1356 spec.flags |= SMALL;
1357 if (spec.field_width == -1) {
1358 spec.field_width = 2 * sizeof(ptr);
1359 spec.flags |= ZEROPAD;
1362 switch (kptr_restrict) {
1364 /* Always print %pK values */
1367 const struct cred *cred;
1370 * kptr_restrict==1 cannot be used in IRQ context
1371 * because its test for CAP_SYSLOG would be meaningless.
1373 if (in_irq() || in_serving_softirq() || in_nmi())
1374 return string(buf, end, "pK-error", spec);
1377 * Only print the real pointer value if the current
1378 * process has CAP_SYSLOG and is running with the
1379 * same credentials it started with. This is because
1380 * access to files is checked at open() time, but %pK
1381 * checks permission at read() time. We don't want to
1382 * leak pointer values if a binary opens a file using
1383 * %pK and then elevates privileges before reading it.
1385 cred = current_cred();
1386 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1387 !uid_eq(cred->euid, cred->uid) ||
1388 !gid_eq(cred->egid, cred->gid))
1394 /* Always print 0's for %pK */
1399 return number(buf, end, (unsigned long)ptr, spec);
1402 static noinline_for_stack
1403 char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1405 unsigned long long num;
1410 num = *(const netdev_features_t *)addr;
1411 size = sizeof(netdev_features_t);
1414 num = (unsigned long)addr;
1415 size = sizeof(unsigned long);
1419 return special_hex_number(buf, end, num, size);
1422 static noinline_for_stack
1423 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1425 unsigned long long num;
1430 num = *(const dma_addr_t *)addr;
1431 size = sizeof(dma_addr_t);
1435 num = *(const phys_addr_t *)addr;
1436 size = sizeof(phys_addr_t);
1440 return special_hex_number(buf, end, num, size);
1443 static noinline_for_stack
1444 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1447 if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1448 return string(buf, end, NULL, spec);
1452 return number(buf, end, clk_get_rate(clk), spec);
1456 #ifdef CONFIG_COMMON_CLK
1457 return string(buf, end, __clk_get_name(clk), spec);
1459 return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1465 char *format_flags(char *buf, char *end, unsigned long flags,
1466 const struct trace_print_flags *names)
1469 const struct printf_spec numspec = {
1470 .flags = SPECIAL|SMALL,
1476 for ( ; flags && names->name; names++) {
1478 if ((flags & mask) != mask)
1481 buf = string(buf, end, names->name, default_str_spec);
1492 buf = number(buf, end, flags, numspec);
1497 static noinline_for_stack
1498 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1500 unsigned long flags;
1501 const struct trace_print_flags *names;
1505 flags = *(unsigned long *)flags_ptr;
1506 /* Remove zone id */
1507 flags &= (1UL << NR_PAGEFLAGS) - 1;
1508 names = pageflag_names;
1511 flags = *(unsigned long *)flags_ptr;
1512 names = vmaflag_names;
1515 flags = *(gfp_t *)flags_ptr;
1516 names = gfpflag_names;
1519 WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1523 return format_flags(buf, end, flags, names);
1526 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1528 for ( ; np && depth; depth--)
1531 return kbasename(np->full_name);
1534 static noinline_for_stack
1535 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1538 const struct device_node *parent = np->parent;
1540 /* special case for root node */
1542 return string(buf, end, "/", default_str_spec);
1544 for (depth = 0; parent->parent; depth++)
1545 parent = parent->parent;
1547 for ( ; depth >= 0; depth--) {
1548 buf = string(buf, end, "/", default_str_spec);
1549 buf = string(buf, end, device_node_name_for_depth(np, depth),
1555 static noinline_for_stack
1556 char *device_node_string(char *buf, char *end, struct device_node *dn,
1557 struct printf_spec spec, const char *fmt)
1559 char tbuf[sizeof("xxxx") + 1];
1562 char *buf_start = buf;
1563 struct property *prop;
1564 bool has_mult, pass;
1565 static const struct printf_spec num_spec = {
1572 struct printf_spec str_spec = spec;
1573 str_spec.field_width = -1;
1575 if (!IS_ENABLED(CONFIG_OF))
1576 return string(buf, end, "(!OF)", spec);
1578 if ((unsigned long)dn < PAGE_SIZE)
1579 return string(buf, end, "(null)", spec);
1581 /* simple case without anything any more format specifiers */
1583 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1586 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1594 case 'f': /* full_name */
1595 buf = device_node_gen_full_name(dn, buf, end);
1597 case 'n': /* name */
1598 buf = string(buf, end, dn->name, str_spec);
1600 case 'p': /* phandle */
1601 buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1603 case 'P': /* path-spec */
1604 p = kbasename(of_node_full_name(dn));
1607 buf = string(buf, end, p, str_spec);
1609 case 'F': /* flags */
1610 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1611 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1612 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1613 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1615 buf = string(buf, end, tbuf, str_spec);
1617 case 'c': /* major compatible string */
1618 ret = of_property_read_string(dn, "compatible", &p);
1620 buf = string(buf, end, p, str_spec);
1622 case 'C': /* full compatible string */
1624 of_property_for_each_string(dn, "compatible", prop, p) {
1626 buf = string(buf, end, ",", str_spec);
1627 buf = string(buf, end, "\"", str_spec);
1628 buf = string(buf, end, p, str_spec);
1629 buf = string(buf, end, "\"", str_spec);
1639 return widen_string(buf, buf - buf_start, end, spec);
1642 static noinline_for_stack
1643 char *pointer_string(char *buf, char *end, const void *ptr,
1644 struct printf_spec spec)
1647 spec.flags |= SMALL;
1648 if (spec.field_width == -1) {
1649 spec.field_width = 2 * sizeof(ptr);
1650 spec.flags |= ZEROPAD;
1653 return number(buf, end, (unsigned long int)ptr, spec);
1656 static bool have_filled_random_ptr_key __read_mostly;
1657 static siphash_key_t ptr_key __read_mostly;
1659 static void fill_random_ptr_key(struct random_ready_callback *unused)
1661 get_random_bytes(&ptr_key, sizeof(ptr_key));
1663 * have_filled_random_ptr_key==true is dependent on get_random_bytes().
1664 * ptr_to_id() needs to see have_filled_random_ptr_key==true
1665 * after get_random_bytes() returns.
1668 WRITE_ONCE(have_filled_random_ptr_key, true);
1671 static struct random_ready_callback random_ready = {
1672 .func = fill_random_ptr_key
1675 static int __init initialize_ptr_random(void)
1677 int ret = add_random_ready_callback(&random_ready);
1681 } else if (ret == -EALREADY) {
1682 fill_random_ptr_key(&random_ready);
1688 early_initcall(initialize_ptr_random);
1690 /* Maps a pointer to a 32 bit unique identifier. */
1691 static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
1693 unsigned long hashval;
1694 const int default_width = 2 * sizeof(ptr);
1696 if (unlikely(!have_filled_random_ptr_key)) {
1697 spec.field_width = default_width;
1698 /* string length must be less than default_width */
1699 return string(buf, end, "(ptrval)", spec);
1703 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
1705 * Mask off the first 32 bits, this makes explicit that we have
1706 * modified the address (and 32 bits is plenty for a unique ID).
1708 hashval = hashval & 0xffffffff;
1710 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
1713 spec.flags |= SMALL;
1714 if (spec.field_width == -1) {
1715 spec.field_width = default_width;
1716 spec.flags |= ZEROPAD;
1720 return number(buf, end, hashval, spec);
1724 * Show a '%p' thing. A kernel extension is that the '%p' is followed
1725 * by an extra set of alphanumeric characters that are extended format
1728 * Please update scripts/checkpatch.pl when adding/removing conversion
1729 * characters. (Search for "check for vsprintf extension").
1731 * Right now we handle:
1733 * - 'F' For symbolic function descriptor pointers with offset
1734 * - 'f' For simple symbolic function names without offset
1735 * - 'S' For symbolic direct pointers with offset
1736 * - 's' For symbolic direct pointers without offset
1737 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1738 * - 'B' For backtraced symbolic direct pointers with offset
1739 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1740 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1741 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1742 * width which must be explicitly specified either as part of the
1743 * format string '%32b[l]' or through '%*b[l]', [l] selects
1744 * range-list format instead of hex format
1745 * - 'M' For a 6-byte MAC address, it prints the address in the
1746 * usual colon-separated hex notation
1747 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1748 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1749 * with a dash-separated hex notation
1750 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1751 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1752 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1753 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1755 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1756 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1757 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1758 * IPv6 omits the colons (01020304...0f)
1759 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1761 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1762 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1763 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1764 * - 'I[6S]c' for IPv6 addresses printed as specified by
1765 * http://tools.ietf.org/html/rfc5952
1766 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1767 * of the following flags (see string_escape_mem() for the
1770 * c - ESCAPE_SPECIAL
1776 * By default ESCAPE_ANY_NP is used.
1777 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1778 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1779 * Options for %pU are:
1780 * b big endian lower case hex (default)
1781 * B big endian UPPER case hex
1782 * l little endian lower case hex
1783 * L little endian UPPER case hex
1784 * big endian output byte order is:
1785 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1786 * little endian output byte order is:
1787 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1788 * - 'V' For a struct va_format which contains a format string * and va_list *,
1789 * call vsnprintf(->format, *->va_list).
1790 * Implements a "recursive vsnprintf".
1791 * Do not use this feature without some mechanism to verify the
1792 * correctness of the format string and va_list arguments.
1793 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1794 * - 'NF' For a netdev_features_t
1795 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1796 * a certain separator (' ' by default):
1800 * The maximum supported length is 64 bytes of the input. Consider
1801 * to use print_hex_dump() for the larger input.
1802 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1803 * (default assumed to be phys_addr_t, passed by reference)
1804 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1805 * - 'D[234]' Same as 'd' but for a struct file
1806 * - 'g' For block_device name (gendisk + partition number)
1807 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1808 * (legacy clock framework) of the clock
1809 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1810 * (legacy clock framework) of the clock
1811 * - 'Cr' For a clock, it prints the current rate of the clock
1812 * - 'G' For flags to be printed as a collection of symbolic strings that would
1813 * construct the specific value. Supported flags given by option:
1814 * p page flags (see struct page) given as pointer to unsigned long
1815 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1816 * v vma flags (VM_*) given as pointer to unsigned long
1817 * - 'O' For a kobject based struct. Must be one of the following:
1818 * - 'OF[fnpPcCF]' For a device tree object
1819 * Without any optional arguments prints the full_name
1820 * f device node full_name
1821 * n device node name
1822 * p device node phandle
1823 * P device node path spec (name + @unit)
1824 * F device node flags
1825 * c major compatible string
1826 * C full compatible string
1828 * - 'x' For printing the address. Equivalent to "%lx".
1830 * ** When making changes please also update:
1831 * Documentation/core-api/printk-formats.rst
1833 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1834 * function pointers are really function descriptors, which contain a
1835 * pointer to the real address.
1837 * Note: The default behaviour (unadorned %p) is to hash the address,
1838 * rendering it useful as a unique identifier.
1840 static noinline_for_stack
1841 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1842 struct printf_spec spec)
1844 const int default_width = 2 * sizeof(void *);
1846 if (!ptr && *fmt != 'K' && *fmt != 'x') {
1848 * Print (null) with the same width as a pointer so it makes
1849 * tabular output look nice.
1851 if (spec.field_width == -1)
1852 spec.field_width = default_width;
1853 return string(buf, end, "(null)", spec);
1861 ptr = dereference_symbol_descriptor(ptr);
1864 return symbol_string(buf, end, ptr, spec, fmt);
1867 return resource_string(buf, end, ptr, spec, fmt);
1869 return hex_string(buf, end, ptr, spec, fmt);
1873 return bitmap_list_string(buf, end, ptr, spec, fmt);
1875 return bitmap_string(buf, end, ptr, spec, fmt);
1877 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1878 case 'm': /* Contiguous: 000102030405 */
1880 /* [mM]R (Reverse order; Bluetooth) */
1881 return mac_address_string(buf, end, ptr, spec, fmt);
1882 case 'I': /* Formatted IP supported
1884 * 6: 0001:0203:...:0708
1885 * 6c: 1::708 or 1::1.2.3.4
1887 case 'i': /* Contiguous:
1888 * 4: 001.002.003.004
1893 return ip6_addr_string(buf, end, ptr, spec, fmt);
1895 return ip4_addr_string(buf, end, ptr, spec, fmt);
1898 struct sockaddr raw;
1899 struct sockaddr_in v4;
1900 struct sockaddr_in6 v6;
1903 switch (sa->raw.sa_family) {
1905 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1907 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1909 return string(buf, end, "(invalid address)", spec);
1914 return escaped_string(buf, end, ptr, spec, fmt);
1916 return uuid_string(buf, end, ptr, spec, fmt);
1921 va_copy(va, *((struct va_format *)ptr)->va);
1922 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1923 ((struct va_format *)ptr)->fmt, va);
1930 return restricted_pointer(buf, end, ptr, spec);
1932 return netdev_bits(buf, end, ptr, fmt);
1934 return address_val(buf, end, ptr, fmt);
1936 return dentry_name(buf, end, ptr, spec, fmt);
1938 return clock(buf, end, ptr, spec, fmt);
1940 return dentry_name(buf, end,
1941 ((const struct file *)ptr)->f_path.dentry,
1945 return bdev_name(buf, end, ptr, spec, fmt);
1949 return flags_string(buf, end, ptr, fmt);
1953 return device_node_string(buf, end, ptr, spec, fmt + 1);
1956 return pointer_string(buf, end, ptr, spec);
1959 /* default is to _not_ leak addresses, hash before printing */
1960 return ptr_to_id(buf, end, ptr, spec);
1964 * Helper function to decode printf style format.
1965 * Each call decode a token from the format and return the
1966 * number of characters read (or likely the delta where it wants
1967 * to go on the next call).
1968 * The decoded token is returned through the parameters
1970 * 'h', 'l', or 'L' for integer fields
1971 * 'z' support added 23/7/1999 S.H.
1972 * 'z' changed to 'Z' --davidm 1/25/99
1973 * 'Z' changed to 'z' --adobriyan 2017-01-25
1974 * 't' added for ptrdiff_t
1976 * @fmt: the format string
1977 * @type of the token returned
1978 * @flags: various flags such as +, -, # tokens..
1979 * @field_width: overwritten width
1980 * @base: base of the number (octal, hex, ...)
1981 * @precision: precision of a number
1982 * @qualifier: qualifier of a number (long, size_t, ...)
1984 static noinline_for_stack
1985 int format_decode(const char *fmt, struct printf_spec *spec)
1987 const char *start = fmt;
1990 /* we finished early by reading the field width */
1991 if (spec->type == FORMAT_TYPE_WIDTH) {
1992 if (spec->field_width < 0) {
1993 spec->field_width = -spec->field_width;
1994 spec->flags |= LEFT;
1996 spec->type = FORMAT_TYPE_NONE;
2000 /* we finished early by reading the precision */
2001 if (spec->type == FORMAT_TYPE_PRECISION) {
2002 if (spec->precision < 0)
2003 spec->precision = 0;
2005 spec->type = FORMAT_TYPE_NONE;
2010 spec->type = FORMAT_TYPE_NONE;
2012 for (; *fmt ; ++fmt) {
2017 /* Return the current non-format string */
2018 if (fmt != start || !*fmt)
2024 while (1) { /* this also skips first '%' */
2030 case '-': spec->flags |= LEFT; break;
2031 case '+': spec->flags |= PLUS; break;
2032 case ' ': spec->flags |= SPACE; break;
2033 case '#': spec->flags |= SPECIAL; break;
2034 case '0': spec->flags |= ZEROPAD; break;
2035 default: found = false;
2042 /* get field width */
2043 spec->field_width = -1;
2046 spec->field_width = skip_atoi(&fmt);
2047 else if (*fmt == '*') {
2048 /* it's the next argument */
2049 spec->type = FORMAT_TYPE_WIDTH;
2050 return ++fmt - start;
2054 /* get the precision */
2055 spec->precision = -1;
2058 if (isdigit(*fmt)) {
2059 spec->precision = skip_atoi(&fmt);
2060 if (spec->precision < 0)
2061 spec->precision = 0;
2062 } else if (*fmt == '*') {
2063 /* it's the next argument */
2064 spec->type = FORMAT_TYPE_PRECISION;
2065 return ++fmt - start;
2070 /* get the conversion qualifier */
2072 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2073 *fmt == 'z' || *fmt == 't') {
2075 if (unlikely(qualifier == *fmt)) {
2076 if (qualifier == 'l') {
2079 } else if (qualifier == 'h') {
2090 spec->type = FORMAT_TYPE_CHAR;
2091 return ++fmt - start;
2094 spec->type = FORMAT_TYPE_STR;
2095 return ++fmt - start;
2098 spec->type = FORMAT_TYPE_PTR;
2099 return ++fmt - start;
2102 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2103 return ++fmt - start;
2105 /* integer number formats - set up the flags and "break" */
2111 spec->flags |= SMALL;
2119 spec->flags |= SIGN;
2125 * Since %n poses a greater security risk than
2126 * utility, treat it as any other invalid or
2127 * unsupported format specifier.
2132 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2133 spec->type = FORMAT_TYPE_INVALID;
2137 if (qualifier == 'L')
2138 spec->type = FORMAT_TYPE_LONG_LONG;
2139 else if (qualifier == 'l') {
2140 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2141 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2142 } else if (qualifier == 'z') {
2143 spec->type = FORMAT_TYPE_SIZE_T;
2144 } else if (qualifier == 't') {
2145 spec->type = FORMAT_TYPE_PTRDIFF;
2146 } else if (qualifier == 'H') {
2147 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2148 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2149 } else if (qualifier == 'h') {
2150 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2151 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2153 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2154 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2157 return ++fmt - start;
2161 set_field_width(struct printf_spec *spec, int width)
2163 spec->field_width = width;
2164 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2165 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2170 set_precision(struct printf_spec *spec, int prec)
2172 spec->precision = prec;
2173 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2174 spec->precision = clamp(prec, 0, PRECISION_MAX);
2179 * vsnprintf - Format a string and place it in a buffer
2180 * @buf: The buffer to place the result into
2181 * @size: The size of the buffer, including the trailing null space
2182 * @fmt: The format string to use
2183 * @args: Arguments for the format string
2185 * This function generally follows C99 vsnprintf, but has some
2186 * extensions and a few limitations:
2188 * - ``%n`` is unsupported
2189 * - ``%p*`` is handled by pointer()
2191 * See pointer() or Documentation/core-api/printk-formats.rst for more
2192 * extensive description.
2194 * **Please update the documentation in both places when making changes**
2196 * The return value is the number of characters which would
2197 * be generated for the given input, excluding the trailing
2198 * '\0', as per ISO C99. If you want to have the exact
2199 * number of characters written into @buf as return value
2200 * (not including the trailing '\0'), use vscnprintf(). If the
2201 * return is greater than or equal to @size, the resulting
2202 * string is truncated.
2204 * If you're not already dealing with a va_list consider using snprintf().
2206 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2208 unsigned long long num;
2210 struct printf_spec spec = {0};
2212 /* Reject out-of-range values early. Large positive sizes are
2213 used for unknown buffer sizes. */
2214 if (WARN_ON_ONCE(size > INT_MAX))
2220 /* Make sure end is always >= buf */
2227 const char *old_fmt = fmt;
2228 int read = format_decode(fmt, &spec);
2232 switch (spec.type) {
2233 case FORMAT_TYPE_NONE: {
2236 if (copy > end - str)
2238 memcpy(str, old_fmt, copy);
2244 case FORMAT_TYPE_WIDTH:
2245 set_field_width(&spec, va_arg(args, int));
2248 case FORMAT_TYPE_PRECISION:
2249 set_precision(&spec, va_arg(args, int));
2252 case FORMAT_TYPE_CHAR: {
2255 if (!(spec.flags & LEFT)) {
2256 while (--spec.field_width > 0) {
2263 c = (unsigned char) va_arg(args, int);
2267 while (--spec.field_width > 0) {
2275 case FORMAT_TYPE_STR:
2276 str = string(str, end, va_arg(args, char *), spec);
2279 case FORMAT_TYPE_PTR:
2280 str = pointer(fmt, str, end, va_arg(args, void *),
2282 while (isalnum(*fmt))
2286 case FORMAT_TYPE_PERCENT_CHAR:
2292 case FORMAT_TYPE_INVALID:
2294 * Presumably the arguments passed gcc's type
2295 * checking, but there is no safe or sane way
2296 * for us to continue parsing the format and
2297 * fetching from the va_list; the remaining
2298 * specifiers and arguments would be out of
2304 switch (spec.type) {
2305 case FORMAT_TYPE_LONG_LONG:
2306 num = va_arg(args, long long);
2308 case FORMAT_TYPE_ULONG:
2309 num = va_arg(args, unsigned long);
2311 case FORMAT_TYPE_LONG:
2312 num = va_arg(args, long);
2314 case FORMAT_TYPE_SIZE_T:
2315 if (spec.flags & SIGN)
2316 num = va_arg(args, ssize_t);
2318 num = va_arg(args, size_t);
2320 case FORMAT_TYPE_PTRDIFF:
2321 num = va_arg(args, ptrdiff_t);
2323 case FORMAT_TYPE_UBYTE:
2324 num = (unsigned char) va_arg(args, int);
2326 case FORMAT_TYPE_BYTE:
2327 num = (signed char) va_arg(args, int);
2329 case FORMAT_TYPE_USHORT:
2330 num = (unsigned short) va_arg(args, int);
2332 case FORMAT_TYPE_SHORT:
2333 num = (short) va_arg(args, int);
2335 case FORMAT_TYPE_INT:
2336 num = (int) va_arg(args, int);
2339 num = va_arg(args, unsigned int);
2342 str = number(str, end, num, spec);
2354 /* the trailing null byte doesn't count towards the total */
2358 EXPORT_SYMBOL(vsnprintf);
2361 * vscnprintf - Format a string and place it in a buffer
2362 * @buf: The buffer to place the result into
2363 * @size: The size of the buffer, including the trailing null space
2364 * @fmt: The format string to use
2365 * @args: Arguments for the format string
2367 * The return value is the number of characters which have been written into
2368 * the @buf not including the trailing '\0'. If @size is == 0 the function
2371 * If you're not already dealing with a va_list consider using scnprintf().
2373 * See the vsnprintf() documentation for format string extensions over C99.
2375 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2379 i = vsnprintf(buf, size, fmt, args);
2381 if (likely(i < size))
2387 EXPORT_SYMBOL(vscnprintf);
2390 * snprintf - Format a string and place it in a buffer
2391 * @buf: The buffer to place the result into
2392 * @size: The size of the buffer, including the trailing null space
2393 * @fmt: The format string to use
2394 * @...: Arguments for the format string
2396 * The return value is the number of characters which would be
2397 * generated for the given input, excluding the trailing null,
2398 * as per ISO C99. If the return is greater than or equal to
2399 * @size, the resulting string is truncated.
2401 * See the vsnprintf() documentation for format string extensions over C99.
2403 int snprintf(char *buf, size_t size, const char *fmt, ...)
2408 va_start(args, fmt);
2409 i = vsnprintf(buf, size, fmt, args);
2414 EXPORT_SYMBOL(snprintf);
2417 * scnprintf - Format a string and place it in a buffer
2418 * @buf: The buffer to place the result into
2419 * @size: The size of the buffer, including the trailing null space
2420 * @fmt: The format string to use
2421 * @...: Arguments for the format string
2423 * The return value is the number of characters written into @buf not including
2424 * the trailing '\0'. If @size is == 0 the function returns 0.
2427 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2432 va_start(args, fmt);
2433 i = vscnprintf(buf, size, fmt, args);
2438 EXPORT_SYMBOL(scnprintf);
2441 * vsprintf - Format a string and place it in a buffer
2442 * @buf: The buffer to place the result into
2443 * @fmt: The format string to use
2444 * @args: Arguments for the format string
2446 * The function returns the number of characters written
2447 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2450 * If you're not already dealing with a va_list consider using sprintf().
2452 * See the vsnprintf() documentation for format string extensions over C99.
2454 int vsprintf(char *buf, const char *fmt, va_list args)
2456 return vsnprintf(buf, INT_MAX, fmt, args);
2458 EXPORT_SYMBOL(vsprintf);
2461 * sprintf - Format a string and place it in a buffer
2462 * @buf: The buffer to place the result into
2463 * @fmt: The format string to use
2464 * @...: Arguments for the format string
2466 * The function returns the number of characters written
2467 * into @buf. Use snprintf() or scnprintf() in order to avoid
2470 * See the vsnprintf() documentation for format string extensions over C99.
2472 int sprintf(char *buf, const char *fmt, ...)
2477 va_start(args, fmt);
2478 i = vsnprintf(buf, INT_MAX, fmt, args);
2483 EXPORT_SYMBOL(sprintf);
2485 #ifdef CONFIG_BINARY_PRINTF
2488 * vbin_printf() - VA arguments to binary data
2489 * bstr_printf() - Binary data to text string
2493 * vbin_printf - Parse a format string and place args' binary value in a buffer
2494 * @bin_buf: The buffer to place args' binary value
2495 * @size: The size of the buffer(by words(32bits), not characters)
2496 * @fmt: The format string to use
2497 * @args: Arguments for the format string
2499 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2502 * The return value is the number of words(32bits) which would be generated for
2506 * If the return value is greater than @size, the resulting bin_buf is NOT
2507 * valid for bstr_printf().
2509 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2511 struct printf_spec spec = {0};
2515 str = (char *)bin_buf;
2516 end = (char *)(bin_buf + size);
2518 #define save_arg(type) \
2520 unsigned long long value; \
2521 if (sizeof(type) == 8) { \
2522 unsigned long long val8; \
2523 str = PTR_ALIGN(str, sizeof(u32)); \
2524 val8 = va_arg(args, unsigned long long); \
2525 if (str + sizeof(type) <= end) { \
2526 *(u32 *)str = *(u32 *)&val8; \
2527 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
2531 unsigned int val4; \
2532 str = PTR_ALIGN(str, sizeof(type)); \
2533 val4 = va_arg(args, int); \
2534 if (str + sizeof(type) <= end) \
2535 *(typeof(type) *)str = (type)(long)val4; \
2536 value = (unsigned long long)val4; \
2538 str += sizeof(type); \
2543 int read = format_decode(fmt, &spec);
2547 switch (spec.type) {
2548 case FORMAT_TYPE_NONE:
2549 case FORMAT_TYPE_PERCENT_CHAR:
2551 case FORMAT_TYPE_INVALID:
2554 case FORMAT_TYPE_WIDTH:
2555 case FORMAT_TYPE_PRECISION:
2556 width = (int)save_arg(int);
2557 /* Pointers may require the width */
2559 set_field_width(&spec, width);
2562 case FORMAT_TYPE_CHAR:
2566 case FORMAT_TYPE_STR: {
2567 const char *save_str = va_arg(args, char *);
2570 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2571 || (unsigned long)save_str < PAGE_SIZE)
2572 save_str = "(null)";
2573 len = strlen(save_str) + 1;
2574 if (str + len < end)
2575 memcpy(str, save_str, len);
2580 case FORMAT_TYPE_PTR:
2581 /* Dereferenced pointers must be done now */
2583 /* Dereference of functions is still OK */
2591 if (!isalnum(*fmt)) {
2595 str = pointer(fmt, str, end, va_arg(args, void *),
2600 end[-1] = '\0'; /* Must be nul terminated */
2602 /* skip all alphanumeric pointer suffixes */
2603 while (isalnum(*fmt))
2608 switch (spec.type) {
2610 case FORMAT_TYPE_LONG_LONG:
2611 save_arg(long long);
2613 case FORMAT_TYPE_ULONG:
2614 case FORMAT_TYPE_LONG:
2615 save_arg(unsigned long);
2617 case FORMAT_TYPE_SIZE_T:
2620 case FORMAT_TYPE_PTRDIFF:
2621 save_arg(ptrdiff_t);
2623 case FORMAT_TYPE_UBYTE:
2624 case FORMAT_TYPE_BYTE:
2627 case FORMAT_TYPE_USHORT:
2628 case FORMAT_TYPE_SHORT:
2638 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2641 EXPORT_SYMBOL_GPL(vbin_printf);
2644 * bstr_printf - Format a string from binary arguments and place it in a buffer
2645 * @buf: The buffer to place the result into
2646 * @size: The size of the buffer, including the trailing null space
2647 * @fmt: The format string to use
2648 * @bin_buf: Binary arguments for the format string
2650 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2651 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2652 * a binary buffer that generated by vbin_printf.
2654 * The format follows C99 vsnprintf, but has some extensions:
2655 * see vsnprintf comment for details.
2657 * The return value is the number of characters which would
2658 * be generated for the given input, excluding the trailing
2659 * '\0', as per ISO C99. If you want to have the exact
2660 * number of characters written into @buf as return value
2661 * (not including the trailing '\0'), use vscnprintf(). If the
2662 * return is greater than or equal to @size, the resulting
2663 * string is truncated.
2665 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2667 struct printf_spec spec = {0};
2669 const char *args = (const char *)bin_buf;
2671 if (WARN_ON_ONCE(size > INT_MAX))
2677 #define get_arg(type) \
2679 typeof(type) value; \
2680 if (sizeof(type) == 8) { \
2681 args = PTR_ALIGN(args, sizeof(u32)); \
2682 *(u32 *)&value = *(u32 *)args; \
2683 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
2685 args = PTR_ALIGN(args, sizeof(type)); \
2686 value = *(typeof(type) *)args; \
2688 args += sizeof(type); \
2692 /* Make sure end is always >= buf */
2699 const char *old_fmt = fmt;
2700 int read = format_decode(fmt, &spec);
2704 switch (spec.type) {
2705 case FORMAT_TYPE_NONE: {
2708 if (copy > end - str)
2710 memcpy(str, old_fmt, copy);
2716 case FORMAT_TYPE_WIDTH:
2717 set_field_width(&spec, get_arg(int));
2720 case FORMAT_TYPE_PRECISION:
2721 set_precision(&spec, get_arg(int));
2724 case FORMAT_TYPE_CHAR: {
2727 if (!(spec.flags & LEFT)) {
2728 while (--spec.field_width > 0) {
2734 c = (unsigned char) get_arg(char);
2738 while (--spec.field_width > 0) {
2746 case FORMAT_TYPE_STR: {
2747 const char *str_arg = args;
2748 args += strlen(str_arg) + 1;
2749 str = string(str, end, (char *)str_arg, spec);
2753 case FORMAT_TYPE_PTR: {
2754 bool process = false;
2756 /* Non function dereferences were already done */
2765 if (!isalnum(*fmt)) {
2769 /* Pointer dereference was already processed */
2771 len = copy = strlen(args);
2772 if (copy > end - str)
2774 memcpy(str, args, copy);
2780 str = pointer(fmt, str, end, get_arg(void *), spec);
2782 while (isalnum(*fmt))
2787 case FORMAT_TYPE_PERCENT_CHAR:
2793 case FORMAT_TYPE_INVALID:
2797 unsigned long long num;
2799 switch (spec.type) {
2801 case FORMAT_TYPE_LONG_LONG:
2802 num = get_arg(long long);
2804 case FORMAT_TYPE_ULONG:
2805 case FORMAT_TYPE_LONG:
2806 num = get_arg(unsigned long);
2808 case FORMAT_TYPE_SIZE_T:
2809 num = get_arg(size_t);
2811 case FORMAT_TYPE_PTRDIFF:
2812 num = get_arg(ptrdiff_t);
2814 case FORMAT_TYPE_UBYTE:
2815 num = get_arg(unsigned char);
2817 case FORMAT_TYPE_BYTE:
2818 num = get_arg(signed char);
2820 case FORMAT_TYPE_USHORT:
2821 num = get_arg(unsigned short);
2823 case FORMAT_TYPE_SHORT:
2824 num = get_arg(short);
2826 case FORMAT_TYPE_UINT:
2827 num = get_arg(unsigned int);
2833 str = number(str, end, num, spec);
2835 } /* switch(spec.type) */
2848 /* the trailing null byte doesn't count towards the total */
2851 EXPORT_SYMBOL_GPL(bstr_printf);
2854 * bprintf - Parse a format string and place args' binary value in a buffer
2855 * @bin_buf: The buffer to place args' binary value
2856 * @size: The size of the buffer(by words(32bits), not characters)
2857 * @fmt: The format string to use
2858 * @...: Arguments for the format string
2860 * The function returns the number of words(u32) written
2863 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2868 va_start(args, fmt);
2869 ret = vbin_printf(bin_buf, size, fmt, args);
2874 EXPORT_SYMBOL_GPL(bprintf);
2876 #endif /* CONFIG_BINARY_PRINTF */
2879 * vsscanf - Unformat a buffer into a list of arguments
2880 * @buf: input buffer
2881 * @fmt: format of buffer
2884 int vsscanf(const char *buf, const char *fmt, va_list args)
2886 const char *str = buf;
2894 unsigned long long u;
2900 /* skip any white space in format */
2901 /* white space in format matchs any amount of
2902 * white space, including none, in the input.
2904 if (isspace(*fmt)) {
2905 fmt = skip_spaces(++fmt);
2906 str = skip_spaces(str);
2909 /* anything that is not a conversion must match exactly */
2910 if (*fmt != '%' && *fmt) {
2911 if (*fmt++ != *str++)
2920 /* skip this conversion.
2921 * advance both strings to next white space
2926 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2927 /* '%*[' not yet supported, invalid format */
2932 while (!isspace(*str) && *str)
2937 /* get field width */
2939 if (isdigit(*fmt)) {
2940 field_width = skip_atoi(&fmt);
2941 if (field_width <= 0)
2945 /* get conversion qualifier */
2947 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2950 if (unlikely(qualifier == *fmt)) {
2951 if (qualifier == 'h') {
2954 } else if (qualifier == 'l') {
2965 /* return number of characters read so far */
2966 *va_arg(args, int *) = str - buf;
2980 char *s = (char *)va_arg(args, char*);
2981 if (field_width == -1)
2985 } while (--field_width > 0 && *str);
2991 char *s = (char *)va_arg(args, char *);
2992 if (field_width == -1)
2993 field_width = SHRT_MAX;
2994 /* first, skip leading white space in buffer */
2995 str = skip_spaces(str);
2997 /* now copy until next white space */
2998 while (*str && !isspace(*str) && field_width--)
3005 * Warning: This implementation of the '[' conversion specifier
3006 * deviates from its glibc counterpart in the following ways:
3007 * (1) It does NOT support ranges i.e. '-' is NOT a special
3009 * (2) It cannot match the closing bracket ']' itself
3010 * (3) A field width is required
3011 * (4) '%*[' (discard matching input) is currently not supported
3014 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3015 * buf1, buf2, buf3);
3021 char *s = (char *)va_arg(args, char *);
3022 DECLARE_BITMAP(set, 256) = {0};
3023 unsigned int len = 0;
3024 bool negate = (*fmt == '^');
3026 /* field width is required */
3027 if (field_width == -1)
3033 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
3034 set_bit((u8)*fmt, set);
3036 /* no ']' or no character set found */
3042 bitmap_complement(set, set, 256);
3043 /* exclude null '\0' byte */
3047 /* match must be non-empty */
3048 if (!test_bit((u8)*str, set))
3051 while (test_bit((u8)*str, set) && field_width--)
3071 /* looking for '%' in str */
3076 /* invalid format; stop here */
3080 /* have some sort of integer conversion.
3081 * first, skip white space in buffer.
3083 str = skip_spaces(str);
3086 if (is_sign && digit == '-')
3090 || (base == 16 && !isxdigit(digit))
3091 || (base == 10 && !isdigit(digit))
3092 || (base == 8 && (!isdigit(digit) || digit > '7'))
3093 || (base == 0 && !isdigit(digit)))
3097 val.s = qualifier != 'L' ?
3098 simple_strtol(str, &next, base) :
3099 simple_strtoll(str, &next, base);
3101 val.u = qualifier != 'L' ?
3102 simple_strtoul(str, &next, base) :
3103 simple_strtoull(str, &next, base);
3105 if (field_width > 0 && next - str > field_width) {
3107 _parse_integer_fixup_radix(str, &base);
3108 while (next - str > field_width) {
3110 val.s = div_s64(val.s, base);
3112 val.u = div_u64(val.u, base);
3117 switch (qualifier) {
3118 case 'H': /* that's 'hh' in format */
3120 *va_arg(args, signed char *) = val.s;
3122 *va_arg(args, unsigned char *) = val.u;
3126 *va_arg(args, short *) = val.s;
3128 *va_arg(args, unsigned short *) = val.u;
3132 *va_arg(args, long *) = val.s;
3134 *va_arg(args, unsigned long *) = val.u;
3138 *va_arg(args, long long *) = val.s;
3140 *va_arg(args, unsigned long long *) = val.u;
3143 *va_arg(args, size_t *) = val.u;
3147 *va_arg(args, int *) = val.s;
3149 *va_arg(args, unsigned int *) = val.u;
3161 EXPORT_SYMBOL(vsscanf);
3164 * sscanf - Unformat a buffer into a list of arguments
3165 * @buf: input buffer
3166 * @fmt: formatting of buffer
3167 * @...: resulting arguments
3169 int sscanf(const char *buf, const char *fmt, ...)
3174 va_start(args, fmt);
3175 i = vsscanf(buf, fmt, args);
3180 EXPORT_SYMBOL(sscanf);