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/sections.h> /* for dereference_function_descriptor() */
46 #include <asm/byteorder.h> /* cpu_to_le16 */
48 #include <linux/string_helpers.h>
52 * simple_strtoull - convert a string to an unsigned long long
53 * @cp: The start of the string
54 * @endp: A pointer to the end of the parsed string will be placed here
55 * @base: The number base to use
57 * This function is obsolete. Please use kstrtoull instead.
59 unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
61 unsigned long long result;
64 cp = _parse_integer_fixup_radix(cp, &base);
65 rv = _parse_integer(cp, base, &result);
67 cp += (rv & ~KSTRTOX_OVERFLOW);
74 EXPORT_SYMBOL(simple_strtoull);
77 * simple_strtoul - convert a string to an unsigned long
78 * @cp: The start of the string
79 * @endp: A pointer to the end of the parsed string will be placed here
80 * @base: The number base to use
82 * This function is obsolete. Please use kstrtoul instead.
84 unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base)
86 return simple_strtoull(cp, endp, base);
88 EXPORT_SYMBOL(simple_strtoul);
91 * simple_strtol - convert a string to a signed long
92 * @cp: The start of the string
93 * @endp: A pointer to the end of the parsed string will be placed here
94 * @base: The number base to use
96 * This function is obsolete. Please use kstrtol instead.
98 long simple_strtol(const char *cp, char **endp, unsigned int base)
101 return -simple_strtoul(cp + 1, endp, base);
103 return simple_strtoul(cp, endp, base);
105 EXPORT_SYMBOL(simple_strtol);
108 * simple_strtoll - convert a string to a signed long long
109 * @cp: The start of the string
110 * @endp: A pointer to the end of the parsed string will be placed here
111 * @base: The number base to use
113 * This function is obsolete. Please use kstrtoll instead.
115 long long simple_strtoll(const char *cp, char **endp, unsigned int base)
118 return -simple_strtoull(cp + 1, endp, base);
120 return simple_strtoull(cp, endp, base);
122 EXPORT_SYMBOL(simple_strtoll);
124 static noinline_for_stack
125 int skip_atoi(const char **s)
130 i = i*10 + *((*s)++) - '0';
131 } while (isdigit(**s));
137 * Decimal conversion is by far the most typical, and is used for
138 * /proc and /sys data. This directly impacts e.g. top performance
139 * with many processes running. We optimize it for speed by emitting
140 * two characters at a time, using a 200 byte lookup table. This
141 * roughly halves the number of multiplications compared to computing
142 * the digits one at a time. Implementation strongly inspired by the
143 * previous version, which in turn used ideas described at
144 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
145 * from the author, Douglas W. Jones).
147 * It turns out there is precisely one 26 bit fixed-point
148 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
149 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
150 * range happens to be somewhat larger (x <= 1073741898), but that's
151 * irrelevant for our purpose.
153 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
154 * need a 32x32->64 bit multiply, so we simply use the same constant.
156 * For dividing a number in the range [100, 10^4-1] by 100, there are
157 * several options. The simplest is (x * 0x147b) >> 19, which is valid
158 * for all x <= 43698.
161 static const u16 decpair[100] = {
162 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
163 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
164 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
165 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
166 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
167 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
168 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
169 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
170 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
171 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
172 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
177 * This will print a single '0' even if r == 0, since we would
178 * immediately jump to out_r where two 0s would be written but only
179 * one of them accounted for in buf. This is needed by ip4_string
180 * below. All other callers pass a non-zero value of r.
182 static noinline_for_stack
183 char *put_dec_trunc8(char *buf, unsigned r)
191 /* 100 <= r < 10^8 */
192 q = (r * (u64)0x28f5c29) >> 32;
193 *((u16 *)buf) = decpair[r - 100*q];
200 /* 100 <= q < 10^6 */
201 r = (q * (u64)0x28f5c29) >> 32;
202 *((u16 *)buf) = decpair[q - 100*r];
209 /* 100 <= r < 10^4 */
210 q = (r * 0x147b) >> 19;
211 *((u16 *)buf) = decpair[r - 100*q];
218 *((u16 *)buf) = decpair[r];
219 buf += r < 10 ? 1 : 2;
223 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
224 static noinline_for_stack
225 char *put_dec_full8(char *buf, unsigned r)
230 q = (r * (u64)0x28f5c29) >> 32;
231 *((u16 *)buf) = decpair[r - 100*q];
235 r = (q * (u64)0x28f5c29) >> 32;
236 *((u16 *)buf) = decpair[q - 100*r];
240 q = (r * 0x147b) >> 19;
241 *((u16 *)buf) = decpair[r - 100*q];
245 *((u16 *)buf) = decpair[q];
250 static noinline_for_stack
251 char *put_dec(char *buf, unsigned long long n)
253 if (n >= 100*1000*1000)
254 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
255 /* 1 <= n <= 1.6e11 */
256 if (n >= 100*1000*1000)
257 buf = put_dec_full8(buf, do_div(n, 100*1000*1000));
259 return put_dec_trunc8(buf, n);
262 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
265 put_dec_full4(char *buf, unsigned r)
270 q = (r * 0x147b) >> 19;
271 *((u16 *)buf) = decpair[r - 100*q];
274 *((u16 *)buf) = decpair[q];
278 * Call put_dec_full4 on x % 10000, return x / 10000.
279 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
280 * holds for all x < 1,128,869,999. The largest value this
281 * helper will ever be asked to convert is 1,125,520,955.
282 * (second call in the put_dec code, assuming n is all-ones).
284 static noinline_for_stack
285 unsigned put_dec_helper4(char *buf, unsigned x)
287 uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43;
289 put_dec_full4(buf, x - q * 10000);
293 /* Based on code by Douglas W. Jones found at
294 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
295 * (with permission from the author).
296 * Performs no 64-bit division and hence should be fast on 32-bit machines.
299 char *put_dec(char *buf, unsigned long long n)
301 uint32_t d3, d2, d1, q, h;
303 if (n < 100*1000*1000)
304 return put_dec_trunc8(buf, n);
306 d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */
309 d3 = (h >> 16); /* implicit "& 0xffff" */
311 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
312 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
313 q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff);
314 q = put_dec_helper4(buf, q);
316 q += 7671 * d3 + 9496 * d2 + 6 * d1;
317 q = put_dec_helper4(buf+4, q);
319 q += 4749 * d3 + 42 * d2;
320 q = put_dec_helper4(buf+8, q);
325 buf = put_dec_trunc8(buf, q);
326 else while (buf[-1] == '0')
335 * Convert passed number to decimal string.
336 * Returns the length of string. On buffer overflow, returns 0.
338 * If speed is not important, use snprintf(). It's easy to read the code.
340 int num_to_str(char *buf, int size, unsigned long long num)
342 /* put_dec requires 2-byte alignment of the buffer. */
343 char tmp[sizeof(num) * 3] __aligned(2);
346 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
351 len = put_dec(tmp, num) - tmp;
356 for (idx = 0; idx < len; ++idx)
357 buf[idx] = tmp[len - idx - 1];
361 #define SIGN 1 /* unsigned/signed, must be 1 */
362 #define LEFT 2 /* left justified */
363 #define PLUS 4 /* show plus */
364 #define SPACE 8 /* space if plus */
365 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
366 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
367 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
370 FORMAT_TYPE_NONE, /* Just a string part */
372 FORMAT_TYPE_PRECISION,
376 FORMAT_TYPE_PERCENT_CHAR,
378 FORMAT_TYPE_LONG_LONG,
392 unsigned int type:8; /* format_type enum */
393 signed int field_width:24; /* width of output field */
394 unsigned int flags:8; /* flags to number() */
395 unsigned int base:8; /* number base, 8, 10 or 16 only */
396 signed int precision:16; /* # of digits/chars */
398 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
399 #define PRECISION_MAX ((1 << 15) - 1)
401 static noinline_for_stack
402 char *number(char *buf, char *end, unsigned long long num,
403 struct printf_spec spec)
405 /* put_dec requires 2-byte alignment of the buffer. */
406 char tmp[3 * sizeof(num)] __aligned(2);
409 int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10);
411 bool is_zero = num == 0LL;
412 int field_width = spec.field_width;
413 int precision = spec.precision;
415 BUILD_BUG_ON(sizeof(struct printf_spec) != 8);
417 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
418 * produces same digits or (maybe lowercased) letters */
419 locase = (spec.flags & SMALL);
420 if (spec.flags & LEFT)
421 spec.flags &= ~ZEROPAD;
423 if (spec.flags & SIGN) {
424 if ((signed long long)num < 0) {
426 num = -(signed long long)num;
428 } else if (spec.flags & PLUS) {
431 } else if (spec.flags & SPACE) {
443 /* generate full string in tmp[], in reverse order */
446 tmp[i++] = hex_asc_upper[num] | locase;
447 else if (spec.base != 10) { /* 8 or 16 */
448 int mask = spec.base - 1;
454 tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase);
457 } else { /* base 10 */
458 i = put_dec(tmp, num) - tmp;
461 /* printing 100 using %2d gives "100", not "00" */
464 /* leading space padding */
465 field_width -= precision;
466 if (!(spec.flags & (ZEROPAD | LEFT))) {
467 while (--field_width >= 0) {
479 /* "0x" / "0" prefix */
481 if (spec.base == 16 || !is_zero) {
486 if (spec.base == 16) {
488 *buf = ('X' | locase);
492 /* zero or space padding */
493 if (!(spec.flags & LEFT)) {
494 char c = ' ' + (spec.flags & ZEROPAD);
495 BUILD_BUG_ON(' ' + ZEROPAD != '0');
496 while (--field_width >= 0) {
502 /* hmm even more zero padding? */
503 while (i <= --precision) {
508 /* actual digits of result */
514 /* trailing space padding */
515 while (--field_width >= 0) {
524 static noinline_for_stack
525 char *special_hex_number(char *buf, char *end, unsigned long long num, int size)
527 struct printf_spec spec;
529 spec.type = FORMAT_TYPE_PTR;
530 spec.field_width = 2 + 2 * size; /* 0x + hex */
531 spec.flags = SPECIAL | SMALL | ZEROPAD;
535 return number(buf, end, num, spec);
538 static void move_right(char *buf, char *end, unsigned len, unsigned spaces)
541 if (buf >= end) /* nowhere to put anything */
544 if (size <= spaces) {
545 memset(buf, ' ', size);
549 if (len > size - spaces)
551 memmove(buf + spaces, buf, len);
553 memset(buf, ' ', spaces);
557 * Handle field width padding for a string.
558 * @buf: current buffer position
559 * @n: length of string
560 * @end: end of output buffer
561 * @spec: for field width and flags
562 * Returns: new buffer position after padding.
564 static noinline_for_stack
565 char *widen_string(char *buf, int n, char *end, struct printf_spec spec)
569 if (likely(n >= spec.field_width))
571 /* we want to pad the sucker */
572 spaces = spec.field_width - n;
573 if (!(spec.flags & LEFT)) {
574 move_right(buf - n, end, n, spaces);
585 static noinline_for_stack
586 char *string(char *buf, char *end, const char *s, struct printf_spec spec)
589 size_t lim = spec.precision;
591 if ((unsigned long)s < PAGE_SIZE)
603 return widen_string(buf, len, end, spec);
606 static noinline_for_stack
607 char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
610 const char *array[4], *s;
611 const struct dentry *p;
616 case '2': case '3': case '4':
617 depth = fmt[1] - '0';
624 for (i = 0; i < depth; i++, d = p) {
625 p = READ_ONCE(d->d_parent);
626 array[i] = READ_ONCE(d->d_name.name);
635 for (n = 0; n != spec.precision; n++, buf++) {
647 return widen_string(buf, n, end, spec);
651 static noinline_for_stack
652 char *bdev_name(char *buf, char *end, struct block_device *bdev,
653 struct printf_spec spec, const char *fmt)
655 struct gendisk *hd = bdev->bd_disk;
657 buf = string(buf, end, hd->disk_name, spec);
658 if (bdev->bd_part->partno) {
659 if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) {
664 buf = number(buf, end, bdev->bd_part->partno, spec);
670 static noinline_for_stack
671 char *symbol_string(char *buf, char *end, void *ptr,
672 struct printf_spec spec, const char *fmt)
675 #ifdef CONFIG_KALLSYMS
676 char sym[KSYM_SYMBOL_LEN];
680 ptr = __builtin_extract_return_addr(ptr);
681 value = (unsigned long)ptr;
683 #ifdef CONFIG_KALLSYMS
685 sprint_backtrace(sym, value);
686 else if (*fmt != 'f' && *fmt != 's')
687 sprint_symbol(sym, value);
689 sprint_symbol_no_offset(sym, value);
691 return string(buf, end, sym, spec);
693 return special_hex_number(buf, end, value, sizeof(void *));
697 static noinline_for_stack
698 char *resource_string(char *buf, char *end, struct resource *res,
699 struct printf_spec spec, const char *fmt)
701 #ifndef IO_RSRC_PRINTK_SIZE
702 #define IO_RSRC_PRINTK_SIZE 6
705 #ifndef MEM_RSRC_PRINTK_SIZE
706 #define MEM_RSRC_PRINTK_SIZE 10
708 static const struct printf_spec io_spec = {
710 .field_width = IO_RSRC_PRINTK_SIZE,
712 .flags = SPECIAL | SMALL | ZEROPAD,
714 static const struct printf_spec mem_spec = {
716 .field_width = MEM_RSRC_PRINTK_SIZE,
718 .flags = SPECIAL | SMALL | ZEROPAD,
720 static const struct printf_spec bus_spec = {
724 .flags = SMALL | ZEROPAD,
726 static const struct printf_spec dec_spec = {
731 static const struct printf_spec str_spec = {
736 static const struct printf_spec flag_spec = {
739 .flags = SPECIAL | SMALL,
742 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
743 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
744 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
745 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
746 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
747 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
748 char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE,
749 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)];
751 char *p = sym, *pend = sym + sizeof(sym);
752 int decode = (fmt[0] == 'R') ? 1 : 0;
753 const struct printf_spec *specp;
756 if (res->flags & IORESOURCE_IO) {
757 p = string(p, pend, "io ", str_spec);
759 } else if (res->flags & IORESOURCE_MEM) {
760 p = string(p, pend, "mem ", str_spec);
762 } else if (res->flags & IORESOURCE_IRQ) {
763 p = string(p, pend, "irq ", str_spec);
765 } else if (res->flags & IORESOURCE_DMA) {
766 p = string(p, pend, "dma ", str_spec);
768 } else if (res->flags & IORESOURCE_BUS) {
769 p = string(p, pend, "bus ", str_spec);
772 p = string(p, pend, "??? ", str_spec);
776 if (decode && res->flags & IORESOURCE_UNSET) {
777 p = string(p, pend, "size ", str_spec);
778 p = number(p, pend, resource_size(res), *specp);
780 p = number(p, pend, res->start, *specp);
781 if (res->start != res->end) {
783 p = number(p, pend, res->end, *specp);
787 if (res->flags & IORESOURCE_MEM_64)
788 p = string(p, pend, " 64bit", str_spec);
789 if (res->flags & IORESOURCE_PREFETCH)
790 p = string(p, pend, " pref", str_spec);
791 if (res->flags & IORESOURCE_WINDOW)
792 p = string(p, pend, " window", str_spec);
793 if (res->flags & IORESOURCE_DISABLED)
794 p = string(p, pend, " disabled", str_spec);
796 p = string(p, pend, " flags ", str_spec);
797 p = number(p, pend, res->flags, flag_spec);
802 return string(buf, end, sym, spec);
805 static noinline_for_stack
806 char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
809 int i, len = 1; /* if we pass '%ph[CDN]', field width remains
810 negative value, fallback to the default */
813 if (spec.field_width == 0)
814 /* nothing to print */
817 if (ZERO_OR_NULL_PTR(addr))
819 return string(buf, end, NULL, spec);
836 if (spec.field_width > 0)
837 len = min_t(int, spec.field_width, 64);
839 for (i = 0; i < len; ++i) {
841 *buf = hex_asc_hi(addr[i]);
844 *buf = hex_asc_lo(addr[i]);
847 if (separator && i != len - 1) {
857 static noinline_for_stack
858 char *bitmap_string(char *buf, char *end, unsigned long *bitmap,
859 struct printf_spec spec, const char *fmt)
861 const int CHUNKSZ = 32;
862 int nr_bits = max_t(int, spec.field_width, 0);
866 /* reused to print numbers */
867 spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 };
869 chunksz = nr_bits & (CHUNKSZ - 1);
873 i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ;
874 for (; i >= 0; i -= CHUNKSZ) {
878 chunkmask = ((1ULL << chunksz) - 1);
879 word = i / BITS_PER_LONG;
880 bit = i % BITS_PER_LONG;
881 val = (bitmap[word] >> bit) & chunkmask;
890 spec.field_width = DIV_ROUND_UP(chunksz, 4);
891 buf = number(buf, end, val, spec);
898 static noinline_for_stack
899 char *bitmap_list_string(char *buf, char *end, unsigned long *bitmap,
900 struct printf_spec spec, const char *fmt)
902 int nr_bits = max_t(int, spec.field_width, 0);
903 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
907 /* reused to print numbers */
908 spec = (struct printf_spec){ .base = 10 };
910 rbot = cur = find_first_bit(bitmap, nr_bits);
911 while (cur < nr_bits) {
913 cur = find_next_bit(bitmap, nr_bits, cur + 1);
914 if (cur < nr_bits && cur <= rtop + 1)
924 buf = number(buf, end, rbot, spec);
930 buf = number(buf, end, rtop, spec);
938 static noinline_for_stack
939 char *mac_address_string(char *buf, char *end, u8 *addr,
940 struct printf_spec spec, const char *fmt)
942 char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
946 bool reversed = false;
962 for (i = 0; i < 6; i++) {
964 p = hex_byte_pack(p, addr[5 - i]);
966 p = hex_byte_pack(p, addr[i]);
968 if (fmt[0] == 'M' && i != 5)
973 return string(buf, end, mac_addr, spec);
976 static noinline_for_stack
977 char *ip4_string(char *p, const u8 *addr, const char *fmt)
980 bool leading_zeros = (fmt[0] == 'i');
1005 for (i = 0; i < 4; i++) {
1006 char temp[4] __aligned(2); /* hold each IP quad in reverse order */
1007 int digits = put_dec_trunc8(temp, addr[index]) - temp;
1008 if (leading_zeros) {
1014 /* reverse the digits in the quad */
1016 *p++ = temp[digits];
1026 static noinline_for_stack
1027 char *ip6_compressed_string(char *p, const char *addr)
1030 unsigned char zerolength[8];
1035 bool needcolon = false;
1037 struct in6_addr in6;
1039 memcpy(&in6, addr, sizeof(struct in6_addr));
1041 useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6);
1043 memset(zerolength, 0, sizeof(zerolength));
1050 /* find position of longest 0 run */
1051 for (i = 0; i < range; i++) {
1052 for (j = i; j < range; j++) {
1053 if (in6.s6_addr16[j] != 0)
1058 for (i = 0; i < range; i++) {
1059 if (zerolength[i] > longest) {
1060 longest = zerolength[i];
1064 if (longest == 1) /* don't compress a single 0 */
1068 for (i = 0; i < range; i++) {
1069 if (i == colonpos) {
1070 if (needcolon || i == 0)
1081 /* hex u16 without leading 0s */
1082 word = ntohs(in6.s6_addr16[i]);
1087 p = hex_byte_pack(p, hi);
1089 *p++ = hex_asc_lo(hi);
1090 p = hex_byte_pack(p, lo);
1093 p = hex_byte_pack(p, lo);
1095 *p++ = hex_asc_lo(lo);
1102 p = ip4_string(p, &in6.s6_addr[12], "I4");
1109 static noinline_for_stack
1110 char *ip6_string(char *p, const char *addr, const char *fmt)
1114 for (i = 0; i < 8; i++) {
1115 p = hex_byte_pack(p, *addr++);
1116 p = hex_byte_pack(p, *addr++);
1117 if (fmt[0] == 'I' && i != 7)
1125 static noinline_for_stack
1126 char *ip6_addr_string(char *buf, char *end, const u8 *addr,
1127 struct printf_spec spec, const char *fmt)
1129 char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1131 if (fmt[0] == 'I' && fmt[2] == 'c')
1132 ip6_compressed_string(ip6_addr, addr);
1134 ip6_string(ip6_addr, addr, fmt);
1136 return string(buf, end, ip6_addr, spec);
1139 static noinline_for_stack
1140 char *ip4_addr_string(char *buf, char *end, const u8 *addr,
1141 struct printf_spec spec, const char *fmt)
1143 char ip4_addr[sizeof("255.255.255.255")];
1145 ip4_string(ip4_addr, addr, fmt);
1147 return string(buf, end, ip4_addr, spec);
1150 static noinline_for_stack
1151 char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa,
1152 struct printf_spec spec, const char *fmt)
1154 bool have_p = false, have_s = false, have_f = false, have_c = false;
1155 char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1156 sizeof(":12345") + sizeof("/123456789") +
1157 sizeof("%1234567890")];
1158 char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr);
1159 const u8 *addr = (const u8 *) &sa->sin6_addr;
1160 char fmt6[2] = { fmt[0], '6' };
1164 while (isalpha(*++fmt)) {
1181 if (have_p || have_s || have_f) {
1186 if (fmt6[0] == 'I' && have_c)
1187 p = ip6_compressed_string(ip6_addr + off, addr);
1189 p = ip6_string(ip6_addr + off, addr, fmt6);
1191 if (have_p || have_s || have_f)
1196 p = number(p, pend, ntohs(sa->sin6_port), spec);
1200 p = number(p, pend, ntohl(sa->sin6_flowinfo &
1201 IPV6_FLOWINFO_MASK), spec);
1205 p = number(p, pend, sa->sin6_scope_id, spec);
1209 return string(buf, end, ip6_addr, spec);
1212 static noinline_for_stack
1213 char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa,
1214 struct printf_spec spec, const char *fmt)
1216 bool have_p = false;
1217 char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")];
1218 char *pend = ip4_addr + sizeof(ip4_addr);
1219 const u8 *addr = (const u8 *) &sa->sin_addr.s_addr;
1220 char fmt4[3] = { fmt[0], '4', 0 };
1223 while (isalpha(*++fmt)) {
1237 p = ip4_string(ip4_addr, addr, fmt4);
1240 p = number(p, pend, ntohs(sa->sin_port), spec);
1244 return string(buf, end, ip4_addr, spec);
1247 static noinline_for_stack
1248 char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec,
1253 unsigned int flags = 0;
1256 if (spec.field_width == 0)
1257 return buf; /* nothing to print */
1259 if (ZERO_OR_NULL_PTR(addr))
1260 return string(buf, end, NULL, spec); /* NULL pointer */
1264 switch (fmt[count++]) {
1266 flags |= ESCAPE_ANY;
1269 flags |= ESCAPE_SPECIAL;
1272 flags |= ESCAPE_HEX;
1275 flags |= ESCAPE_NULL;
1278 flags |= ESCAPE_OCTAL;
1284 flags |= ESCAPE_SPACE;
1293 flags = ESCAPE_ANY_NP;
1295 len = spec.field_width < 0 ? 1 : spec.field_width;
1298 * string_escape_mem() writes as many characters as it can to
1299 * the given buffer, and returns the total size of the output
1300 * had the buffer been big enough.
1302 buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL);
1307 static noinline_for_stack
1308 char *uuid_string(char *buf, char *end, const u8 *addr,
1309 struct printf_spec spec, const char *fmt)
1311 char uuid[UUID_STRING_LEN + 1];
1314 const u8 *index = uuid_index;
1319 uc = true; /* fall-through */
1328 for (i = 0; i < 16; i++) {
1330 p = hex_byte_pack_upper(p, addr[index[i]]);
1332 p = hex_byte_pack(p, addr[index[i]]);
1345 return string(buf, end, uuid, spec);
1348 int kptr_restrict __read_mostly;
1350 static noinline_for_stack
1351 char *restricted_pointer(char *buf, char *end, const void *ptr,
1352 struct printf_spec spec)
1355 spec.flags |= SMALL;
1356 if (spec.field_width == -1) {
1357 spec.field_width = 2 * sizeof(ptr);
1358 spec.flags |= ZEROPAD;
1361 switch (kptr_restrict) {
1363 /* Always print %pK values */
1366 const struct cred *cred;
1369 * kptr_restrict==1 cannot be used in IRQ context
1370 * because its test for CAP_SYSLOG would be meaningless.
1372 if (in_irq() || in_serving_softirq() || in_nmi())
1373 return string(buf, end, "pK-error", spec);
1376 * Only print the real pointer value if the current
1377 * process has CAP_SYSLOG and is running with the
1378 * same credentials it started with. This is because
1379 * access to files is checked at open() time, but %pK
1380 * checks permission at read() time. We don't want to
1381 * leak pointer values if a binary opens a file using
1382 * %pK and then elevates privileges before reading it.
1384 cred = current_cred();
1385 if (!has_capability_noaudit(current, CAP_SYSLOG) ||
1386 !uid_eq(cred->euid, cred->uid) ||
1387 !gid_eq(cred->egid, cred->gid))
1393 /* Always print 0's for %pK */
1398 return number(buf, end, (unsigned long)ptr, spec);
1401 static noinline_for_stack
1402 char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt)
1404 unsigned long long num;
1409 num = *(const netdev_features_t *)addr;
1410 size = sizeof(netdev_features_t);
1413 num = (unsigned long)addr;
1414 size = sizeof(unsigned long);
1418 return special_hex_number(buf, end, num, size);
1421 static noinline_for_stack
1422 char *address_val(char *buf, char *end, const void *addr, const char *fmt)
1424 unsigned long long num;
1429 num = *(const dma_addr_t *)addr;
1430 size = sizeof(dma_addr_t);
1434 num = *(const phys_addr_t *)addr;
1435 size = sizeof(phys_addr_t);
1439 return special_hex_number(buf, end, num, size);
1442 static noinline_for_stack
1443 char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
1446 if (!IS_ENABLED(CONFIG_HAVE_CLK) || !clk)
1447 return string(buf, end, NULL, spec);
1451 return number(buf, end, clk_get_rate(clk), spec);
1455 #ifdef CONFIG_COMMON_CLK
1456 return string(buf, end, __clk_get_name(clk), spec);
1458 return special_hex_number(buf, end, (unsigned long)clk, sizeof(unsigned long));
1464 char *format_flags(char *buf, char *end, unsigned long flags,
1465 const struct trace_print_flags *names)
1468 const struct printf_spec strspec = {
1472 const struct printf_spec numspec = {
1473 .flags = SPECIAL|SMALL,
1479 for ( ; flags && names->name; names++) {
1481 if ((flags & mask) != mask)
1484 buf = string(buf, end, names->name, strspec);
1495 buf = number(buf, end, flags, numspec);
1500 static noinline_for_stack
1501 char *flags_string(char *buf, char *end, void *flags_ptr, const char *fmt)
1503 unsigned long flags;
1504 const struct trace_print_flags *names;
1508 flags = *(unsigned long *)flags_ptr;
1509 /* Remove zone id */
1510 flags &= (1UL << NR_PAGEFLAGS) - 1;
1511 names = pageflag_names;
1514 flags = *(unsigned long *)flags_ptr;
1515 names = vmaflag_names;
1518 flags = *(gfp_t *)flags_ptr;
1519 names = gfpflag_names;
1522 WARN_ONCE(1, "Unsupported flags modifier: %c\n", fmt[1]);
1526 return format_flags(buf, end, flags, names);
1529 static const char *device_node_name_for_depth(const struct device_node *np, int depth)
1531 for ( ; np && depth; depth--)
1534 return kbasename(np->full_name);
1537 static noinline_for_stack
1538 char *device_node_gen_full_name(const struct device_node *np, char *buf, char *end)
1541 const struct device_node *parent = np->parent;
1542 static const struct printf_spec strspec = {
1547 /* special case for root node */
1549 return string(buf, end, "/", strspec);
1551 for (depth = 0; parent->parent; depth++)
1552 parent = parent->parent;
1554 for ( ; depth >= 0; depth--) {
1555 buf = string(buf, end, "/", strspec);
1556 buf = string(buf, end, device_node_name_for_depth(np, depth),
1562 static noinline_for_stack
1563 char *device_node_string(char *buf, char *end, struct device_node *dn,
1564 struct printf_spec spec, const char *fmt)
1566 char tbuf[sizeof("xxxx") + 1];
1569 char *buf_start = buf;
1570 struct property *prop;
1571 bool has_mult, pass;
1572 static const struct printf_spec num_spec = {
1579 struct printf_spec str_spec = spec;
1580 str_spec.field_width = -1;
1582 if (!IS_ENABLED(CONFIG_OF))
1583 return string(buf, end, "(!OF)", spec);
1585 if ((unsigned long)dn < PAGE_SIZE)
1586 return string(buf, end, "(null)", spec);
1588 /* simple case without anything any more format specifiers */
1590 if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0)
1593 for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) {
1601 case 'f': /* full_name */
1602 buf = device_node_gen_full_name(dn, buf, end);
1604 case 'n': /* name */
1605 buf = string(buf, end, dn->name, str_spec);
1607 case 'p': /* phandle */
1608 buf = number(buf, end, (unsigned int)dn->phandle, num_spec);
1610 case 'P': /* path-spec */
1611 p = kbasename(of_node_full_name(dn));
1614 buf = string(buf, end, p, str_spec);
1616 case 'F': /* flags */
1617 tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-';
1618 tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-';
1619 tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-';
1620 tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-';
1622 buf = string(buf, end, tbuf, str_spec);
1624 case 'c': /* major compatible string */
1625 ret = of_property_read_string(dn, "compatible", &p);
1627 buf = string(buf, end, p, str_spec);
1629 case 'C': /* full compatible string */
1631 of_property_for_each_string(dn, "compatible", prop, p) {
1633 buf = string(buf, end, ",", str_spec);
1634 buf = string(buf, end, "\"", str_spec);
1635 buf = string(buf, end, p, str_spec);
1636 buf = string(buf, end, "\"", str_spec);
1646 return widen_string(buf, buf - buf_start, end, spec);
1649 static noinline_for_stack
1650 char *pointer_string(char *buf, char *end, const void *ptr,
1651 struct printf_spec spec)
1654 spec.flags |= SMALL;
1655 if (spec.field_width == -1) {
1656 spec.field_width = 2 * sizeof(ptr);
1657 spec.flags |= ZEROPAD;
1660 return number(buf, end, (unsigned long int)ptr, spec);
1663 static bool have_filled_random_ptr_key __read_mostly;
1664 static siphash_key_t ptr_key __read_mostly;
1666 static void fill_random_ptr_key(struct random_ready_callback *unused)
1668 get_random_bytes(&ptr_key, sizeof(ptr_key));
1670 * have_filled_random_ptr_key==true is dependent on get_random_bytes().
1671 * ptr_to_id() needs to see have_filled_random_ptr_key==true
1672 * after get_random_bytes() returns.
1675 WRITE_ONCE(have_filled_random_ptr_key, true);
1678 static struct random_ready_callback random_ready = {
1679 .func = fill_random_ptr_key
1682 static int __init initialize_ptr_random(void)
1684 int ret = add_random_ready_callback(&random_ready);
1688 } else if (ret == -EALREADY) {
1689 fill_random_ptr_key(&random_ready);
1695 early_initcall(initialize_ptr_random);
1697 /* Maps a pointer to a 32 bit unique identifier. */
1698 static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec spec)
1700 unsigned long hashval;
1701 const int default_width = 2 * sizeof(ptr);
1703 if (unlikely(!have_filled_random_ptr_key)) {
1704 spec.field_width = default_width;
1705 /* string length must be less than default_width */
1706 return string(buf, end, "(ptrval)", spec);
1710 hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
1712 * Mask off the first 32 bits, this makes explicit that we have
1713 * modified the address (and 32 bits is plenty for a unique ID).
1715 hashval = hashval & 0xffffffff;
1717 hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
1720 spec.flags |= SMALL;
1721 if (spec.field_width == -1) {
1722 spec.field_width = default_width;
1723 spec.flags |= ZEROPAD;
1727 return number(buf, end, hashval, spec);
1731 * Show a '%p' thing. A kernel extension is that the '%p' is followed
1732 * by an extra set of alphanumeric characters that are extended format
1735 * Please update scripts/checkpatch.pl when adding/removing conversion
1736 * characters. (Search for "check for vsprintf extension").
1738 * Right now we handle:
1740 * - 'F' For symbolic function descriptor pointers with offset
1741 * - 'f' For simple symbolic function names without offset
1742 * - 'S' For symbolic direct pointers with offset
1743 * - 's' For symbolic direct pointers without offset
1744 * - '[FfSs]R' as above with __builtin_extract_return_addr() translation
1745 * - 'B' For backtraced symbolic direct pointers with offset
1746 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
1747 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
1748 * - 'b[l]' For a bitmap, the number of bits is determined by the field
1749 * width which must be explicitly specified either as part of the
1750 * format string '%32b[l]' or through '%*b[l]', [l] selects
1751 * range-list format instead of hex format
1752 * - 'M' For a 6-byte MAC address, it prints the address in the
1753 * usual colon-separated hex notation
1754 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
1755 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
1756 * with a dash-separated hex notation
1757 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
1758 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
1759 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
1760 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
1762 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1763 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1764 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
1765 * IPv6 omits the colons (01020304...0f)
1766 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
1768 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
1769 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
1770 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
1771 * - 'I[6S]c' for IPv6 addresses printed as specified by
1772 * http://tools.ietf.org/html/rfc5952
1773 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
1774 * of the following flags (see string_escape_mem() for the
1777 * c - ESCAPE_SPECIAL
1783 * By default ESCAPE_ANY_NP is used.
1784 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
1785 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
1786 * Options for %pU are:
1787 * b big endian lower case hex (default)
1788 * B big endian UPPER case hex
1789 * l little endian lower case hex
1790 * L little endian UPPER case hex
1791 * big endian output byte order is:
1792 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
1793 * little endian output byte order is:
1794 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
1795 * - 'V' For a struct va_format which contains a format string * and va_list *,
1796 * call vsnprintf(->format, *->va_list).
1797 * Implements a "recursive vsnprintf".
1798 * Do not use this feature without some mechanism to verify the
1799 * correctness of the format string and va_list arguments.
1800 * - 'K' For a kernel pointer that should be hidden from unprivileged users
1801 * - 'NF' For a netdev_features_t
1802 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
1803 * a certain separator (' ' by default):
1807 * The maximum supported length is 64 bytes of the input. Consider
1808 * to use print_hex_dump() for the larger input.
1809 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
1810 * (default assumed to be phys_addr_t, passed by reference)
1811 * - 'd[234]' For a dentry name (optionally 2-4 last components)
1812 * - 'D[234]' Same as 'd' but for a struct file
1813 * - 'g' For block_device name (gendisk + partition number)
1814 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
1815 * (legacy clock framework) of the clock
1816 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
1817 * (legacy clock framework) of the clock
1818 * - 'Cr' For a clock, it prints the current rate of the clock
1819 * - 'G' For flags to be printed as a collection of symbolic strings that would
1820 * construct the specific value. Supported flags given by option:
1821 * p page flags (see struct page) given as pointer to unsigned long
1822 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
1823 * v vma flags (VM_*) given as pointer to unsigned long
1824 * - 'O' For a kobject based struct. Must be one of the following:
1825 * - 'OF[fnpPcCF]' For a device tree object
1826 * Without any optional arguments prints the full_name
1827 * f device node full_name
1828 * n device node name
1829 * p device node phandle
1830 * P device node path spec (name + @unit)
1831 * F device node flags
1832 * c major compatible string
1833 * C full compatible string
1835 * - 'x' For printing the address. Equivalent to "%lx".
1837 * ** When making changes please also update:
1838 * Documentation/core-api/printk-formats.rst
1840 * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
1841 * function pointers are really function descriptors, which contain a
1842 * pointer to the real address.
1844 * Note: The default behaviour (unadorned %p) is to hash the address,
1845 * rendering it useful as a unique identifier.
1847 static noinline_for_stack
1848 char *pointer(const char *fmt, char *buf, char *end, void *ptr,
1849 struct printf_spec spec)
1851 const int default_width = 2 * sizeof(void *);
1853 if (!ptr && *fmt != 'K') {
1855 * Print (null) with the same width as a pointer so it makes
1856 * tabular output look nice.
1858 if (spec.field_width == -1)
1859 spec.field_width = default_width;
1860 return string(buf, end, "(null)", spec);
1866 ptr = dereference_function_descriptor(ptr);
1871 return symbol_string(buf, end, ptr, spec, fmt);
1874 return resource_string(buf, end, ptr, spec, fmt);
1876 return hex_string(buf, end, ptr, spec, fmt);
1880 return bitmap_list_string(buf, end, ptr, spec, fmt);
1882 return bitmap_string(buf, end, ptr, spec, fmt);
1884 case 'M': /* Colon separated: 00:01:02:03:04:05 */
1885 case 'm': /* Contiguous: 000102030405 */
1887 /* [mM]R (Reverse order; Bluetooth) */
1888 return mac_address_string(buf, end, ptr, spec, fmt);
1889 case 'I': /* Formatted IP supported
1891 * 6: 0001:0203:...:0708
1892 * 6c: 1::708 or 1::1.2.3.4
1894 case 'i': /* Contiguous:
1895 * 4: 001.002.003.004
1900 return ip6_addr_string(buf, end, ptr, spec, fmt);
1902 return ip4_addr_string(buf, end, ptr, spec, fmt);
1905 struct sockaddr raw;
1906 struct sockaddr_in v4;
1907 struct sockaddr_in6 v6;
1910 switch (sa->raw.sa_family) {
1912 return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt);
1914 return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt);
1916 return string(buf, end, "(invalid address)", spec);
1921 return escaped_string(buf, end, ptr, spec, fmt);
1923 return uuid_string(buf, end, ptr, spec, fmt);
1928 va_copy(va, *((struct va_format *)ptr)->va);
1929 buf += vsnprintf(buf, end > buf ? end - buf : 0,
1930 ((struct va_format *)ptr)->fmt, va);
1937 return restricted_pointer(buf, end, ptr, spec);
1939 return netdev_bits(buf, end, ptr, fmt);
1941 return address_val(buf, end, ptr, fmt);
1943 return dentry_name(buf, end, ptr, spec, fmt);
1945 return clock(buf, end, ptr, spec, fmt);
1947 return dentry_name(buf, end,
1948 ((const struct file *)ptr)->f_path.dentry,
1952 return bdev_name(buf, end, ptr, spec, fmt);
1956 return flags_string(buf, end, ptr, fmt);
1960 return device_node_string(buf, end, ptr, spec, fmt + 1);
1963 return pointer_string(buf, end, ptr, spec);
1966 /* default is to _not_ leak addresses, hash before printing */
1967 return ptr_to_id(buf, end, ptr, spec);
1971 * Helper function to decode printf style format.
1972 * Each call decode a token from the format and return the
1973 * number of characters read (or likely the delta where it wants
1974 * to go on the next call).
1975 * The decoded token is returned through the parameters
1977 * 'h', 'l', or 'L' for integer fields
1978 * 'z' support added 23/7/1999 S.H.
1979 * 'z' changed to 'Z' --davidm 1/25/99
1980 * 'Z' changed to 'z' --adobriyan 2017-01-25
1981 * 't' added for ptrdiff_t
1983 * @fmt: the format string
1984 * @type of the token returned
1985 * @flags: various flags such as +, -, # tokens..
1986 * @field_width: overwritten width
1987 * @base: base of the number (octal, hex, ...)
1988 * @precision: precision of a number
1989 * @qualifier: qualifier of a number (long, size_t, ...)
1991 static noinline_for_stack
1992 int format_decode(const char *fmt, struct printf_spec *spec)
1994 const char *start = fmt;
1997 /* we finished early by reading the field width */
1998 if (spec->type == FORMAT_TYPE_WIDTH) {
1999 if (spec->field_width < 0) {
2000 spec->field_width = -spec->field_width;
2001 spec->flags |= LEFT;
2003 spec->type = FORMAT_TYPE_NONE;
2007 /* we finished early by reading the precision */
2008 if (spec->type == FORMAT_TYPE_PRECISION) {
2009 if (spec->precision < 0)
2010 spec->precision = 0;
2012 spec->type = FORMAT_TYPE_NONE;
2017 spec->type = FORMAT_TYPE_NONE;
2019 for (; *fmt ; ++fmt) {
2024 /* Return the current non-format string */
2025 if (fmt != start || !*fmt)
2031 while (1) { /* this also skips first '%' */
2037 case '-': spec->flags |= LEFT; break;
2038 case '+': spec->flags |= PLUS; break;
2039 case ' ': spec->flags |= SPACE; break;
2040 case '#': spec->flags |= SPECIAL; break;
2041 case '0': spec->flags |= ZEROPAD; break;
2042 default: found = false;
2049 /* get field width */
2050 spec->field_width = -1;
2053 spec->field_width = skip_atoi(&fmt);
2054 else if (*fmt == '*') {
2055 /* it's the next argument */
2056 spec->type = FORMAT_TYPE_WIDTH;
2057 return ++fmt - start;
2061 /* get the precision */
2062 spec->precision = -1;
2065 if (isdigit(*fmt)) {
2066 spec->precision = skip_atoi(&fmt);
2067 if (spec->precision < 0)
2068 spec->precision = 0;
2069 } else if (*fmt == '*') {
2070 /* it's the next argument */
2071 spec->type = FORMAT_TYPE_PRECISION;
2072 return ++fmt - start;
2077 /* get the conversion qualifier */
2079 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2080 *fmt == 'z' || *fmt == 't') {
2082 if (unlikely(qualifier == *fmt)) {
2083 if (qualifier == 'l') {
2086 } else if (qualifier == 'h') {
2097 spec->type = FORMAT_TYPE_CHAR;
2098 return ++fmt - start;
2101 spec->type = FORMAT_TYPE_STR;
2102 return ++fmt - start;
2105 spec->type = FORMAT_TYPE_PTR;
2106 return ++fmt - start;
2109 spec->type = FORMAT_TYPE_PERCENT_CHAR;
2110 return ++fmt - start;
2112 /* integer number formats - set up the flags and "break" */
2118 spec->flags |= SMALL;
2126 spec->flags |= SIGN;
2132 * Since %n poses a greater security risk than
2133 * utility, treat it as any other invalid or
2134 * unsupported format specifier.
2139 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt);
2140 spec->type = FORMAT_TYPE_INVALID;
2144 if (qualifier == 'L')
2145 spec->type = FORMAT_TYPE_LONG_LONG;
2146 else if (qualifier == 'l') {
2147 BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG);
2148 spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN);
2149 } else if (qualifier == 'z') {
2150 spec->type = FORMAT_TYPE_SIZE_T;
2151 } else if (qualifier == 't') {
2152 spec->type = FORMAT_TYPE_PTRDIFF;
2153 } else if (qualifier == 'H') {
2154 BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE);
2155 spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN);
2156 } else if (qualifier == 'h') {
2157 BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT);
2158 spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN);
2160 BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT);
2161 spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN);
2164 return ++fmt - start;
2168 set_field_width(struct printf_spec *spec, int width)
2170 spec->field_width = width;
2171 if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) {
2172 spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX);
2177 set_precision(struct printf_spec *spec, int prec)
2179 spec->precision = prec;
2180 if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) {
2181 spec->precision = clamp(prec, 0, PRECISION_MAX);
2186 * vsnprintf - Format a string and place it in a buffer
2187 * @buf: The buffer to place the result into
2188 * @size: The size of the buffer, including the trailing null space
2189 * @fmt: The format string to use
2190 * @args: Arguments for the format string
2192 * This function generally follows C99 vsnprintf, but has some
2193 * extensions and a few limitations:
2195 * - ``%n`` is unsupported
2196 * - ``%p*`` is handled by pointer()
2198 * See pointer() or Documentation/core-api/printk-formats.rst for more
2199 * extensive description.
2201 * **Please update the documentation in both places when making changes**
2203 * The return value is the number of characters which would
2204 * be generated for the given input, excluding the trailing
2205 * '\0', as per ISO C99. If you want to have the exact
2206 * number of characters written into @buf as return value
2207 * (not including the trailing '\0'), use vscnprintf(). If the
2208 * return is greater than or equal to @size, the resulting
2209 * string is truncated.
2211 * If you're not already dealing with a va_list consider using snprintf().
2213 int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
2215 unsigned long long num;
2217 struct printf_spec spec = {0};
2219 /* Reject out-of-range values early. Large positive sizes are
2220 used for unknown buffer sizes. */
2221 if (WARN_ON_ONCE(size > INT_MAX))
2227 /* Make sure end is always >= buf */
2234 const char *old_fmt = fmt;
2235 int read = format_decode(fmt, &spec);
2239 switch (spec.type) {
2240 case FORMAT_TYPE_NONE: {
2243 if (copy > end - str)
2245 memcpy(str, old_fmt, copy);
2251 case FORMAT_TYPE_WIDTH:
2252 set_field_width(&spec, va_arg(args, int));
2255 case FORMAT_TYPE_PRECISION:
2256 set_precision(&spec, va_arg(args, int));
2259 case FORMAT_TYPE_CHAR: {
2262 if (!(spec.flags & LEFT)) {
2263 while (--spec.field_width > 0) {
2270 c = (unsigned char) va_arg(args, int);
2274 while (--spec.field_width > 0) {
2282 case FORMAT_TYPE_STR:
2283 str = string(str, end, va_arg(args, char *), spec);
2286 case FORMAT_TYPE_PTR:
2287 str = pointer(fmt, str, end, va_arg(args, void *),
2289 while (isalnum(*fmt))
2293 case FORMAT_TYPE_PERCENT_CHAR:
2299 case FORMAT_TYPE_INVALID:
2301 * Presumably the arguments passed gcc's type
2302 * checking, but there is no safe or sane way
2303 * for us to continue parsing the format and
2304 * fetching from the va_list; the remaining
2305 * specifiers and arguments would be out of
2311 switch (spec.type) {
2312 case FORMAT_TYPE_LONG_LONG:
2313 num = va_arg(args, long long);
2315 case FORMAT_TYPE_ULONG:
2316 num = va_arg(args, unsigned long);
2318 case FORMAT_TYPE_LONG:
2319 num = va_arg(args, long);
2321 case FORMAT_TYPE_SIZE_T:
2322 if (spec.flags & SIGN)
2323 num = va_arg(args, ssize_t);
2325 num = va_arg(args, size_t);
2327 case FORMAT_TYPE_PTRDIFF:
2328 num = va_arg(args, ptrdiff_t);
2330 case FORMAT_TYPE_UBYTE:
2331 num = (unsigned char) va_arg(args, int);
2333 case FORMAT_TYPE_BYTE:
2334 num = (signed char) va_arg(args, int);
2336 case FORMAT_TYPE_USHORT:
2337 num = (unsigned short) va_arg(args, int);
2339 case FORMAT_TYPE_SHORT:
2340 num = (short) va_arg(args, int);
2342 case FORMAT_TYPE_INT:
2343 num = (int) va_arg(args, int);
2346 num = va_arg(args, unsigned int);
2349 str = number(str, end, num, spec);
2361 /* the trailing null byte doesn't count towards the total */
2365 EXPORT_SYMBOL(vsnprintf);
2368 * vscnprintf - Format a string and place it in a buffer
2369 * @buf: The buffer to place the result into
2370 * @size: The size of the buffer, including the trailing null space
2371 * @fmt: The format string to use
2372 * @args: Arguments for the format string
2374 * The return value is the number of characters which have been written into
2375 * the @buf not including the trailing '\0'. If @size is == 0 the function
2378 * If you're not already dealing with a va_list consider using scnprintf().
2380 * See the vsnprintf() documentation for format string extensions over C99.
2382 int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
2386 i = vsnprintf(buf, size, fmt, args);
2388 if (likely(i < size))
2394 EXPORT_SYMBOL(vscnprintf);
2397 * snprintf - Format a string and place it in a buffer
2398 * @buf: The buffer to place the result into
2399 * @size: The size of the buffer, including the trailing null space
2400 * @fmt: The format string to use
2401 * @...: Arguments for the format string
2403 * The return value is the number of characters which would be
2404 * generated for the given input, excluding the trailing null,
2405 * as per ISO C99. If the return is greater than or equal to
2406 * @size, the resulting string is truncated.
2408 * See the vsnprintf() documentation for format string extensions over C99.
2410 int snprintf(char *buf, size_t size, const char *fmt, ...)
2415 va_start(args, fmt);
2416 i = vsnprintf(buf, size, fmt, args);
2421 EXPORT_SYMBOL(snprintf);
2424 * scnprintf - Format a string and place it in a buffer
2425 * @buf: The buffer to place the result into
2426 * @size: The size of the buffer, including the trailing null space
2427 * @fmt: The format string to use
2428 * @...: Arguments for the format string
2430 * The return value is the number of characters written into @buf not including
2431 * the trailing '\0'. If @size is == 0 the function returns 0.
2434 int scnprintf(char *buf, size_t size, const char *fmt, ...)
2439 va_start(args, fmt);
2440 i = vscnprintf(buf, size, fmt, args);
2445 EXPORT_SYMBOL(scnprintf);
2448 * vsprintf - Format a string and place it in a buffer
2449 * @buf: The buffer to place the result into
2450 * @fmt: The format string to use
2451 * @args: Arguments for the format string
2453 * The function returns the number of characters written
2454 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2457 * If you're not already dealing with a va_list consider using sprintf().
2459 * See the vsnprintf() documentation for format string extensions over C99.
2461 int vsprintf(char *buf, const char *fmt, va_list args)
2463 return vsnprintf(buf, INT_MAX, fmt, args);
2465 EXPORT_SYMBOL(vsprintf);
2468 * sprintf - Format a string and place it in a buffer
2469 * @buf: The buffer to place the result into
2470 * @fmt: The format string to use
2471 * @...: Arguments for the format string
2473 * The function returns the number of characters written
2474 * into @buf. Use snprintf() or scnprintf() in order to avoid
2477 * See the vsnprintf() documentation for format string extensions over C99.
2479 int sprintf(char *buf, const char *fmt, ...)
2484 va_start(args, fmt);
2485 i = vsnprintf(buf, INT_MAX, fmt, args);
2490 EXPORT_SYMBOL(sprintf);
2492 #ifdef CONFIG_BINARY_PRINTF
2495 * vbin_printf() - VA arguments to binary data
2496 * bstr_printf() - Binary data to text string
2500 * vbin_printf - Parse a format string and place args' binary value in a buffer
2501 * @bin_buf: The buffer to place args' binary value
2502 * @size: The size of the buffer(by words(32bits), not characters)
2503 * @fmt: The format string to use
2504 * @args: Arguments for the format string
2506 * The format follows C99 vsnprintf, except %n is ignored, and its argument
2509 * The return value is the number of words(32bits) which would be generated for
2513 * If the return value is greater than @size, the resulting bin_buf is NOT
2514 * valid for bstr_printf().
2516 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args)
2518 struct printf_spec spec = {0};
2521 str = (char *)bin_buf;
2522 end = (char *)(bin_buf + size);
2524 #define save_arg(type) \
2526 if (sizeof(type) == 8) { \
2527 unsigned long long value; \
2528 str = PTR_ALIGN(str, sizeof(u32)); \
2529 value = va_arg(args, unsigned long long); \
2530 if (str + sizeof(type) <= end) { \
2531 *(u32 *)str = *(u32 *)&value; \
2532 *(u32 *)(str + 4) = *((u32 *)&value + 1); \
2535 unsigned long value; \
2536 str = PTR_ALIGN(str, sizeof(type)); \
2537 value = va_arg(args, int); \
2538 if (str + sizeof(type) <= end) \
2539 *(typeof(type) *)str = (type)value; \
2541 str += sizeof(type); \
2545 int read = format_decode(fmt, &spec);
2549 switch (spec.type) {
2550 case FORMAT_TYPE_NONE:
2551 case FORMAT_TYPE_PERCENT_CHAR:
2553 case FORMAT_TYPE_INVALID:
2556 case FORMAT_TYPE_WIDTH:
2557 case FORMAT_TYPE_PRECISION:
2561 case FORMAT_TYPE_CHAR:
2565 case FORMAT_TYPE_STR: {
2566 const char *save_str = va_arg(args, char *);
2569 if ((unsigned long)save_str > (unsigned long)-PAGE_SIZE
2570 || (unsigned long)save_str < PAGE_SIZE)
2571 save_str = "(null)";
2572 len = strlen(save_str) + 1;
2573 if (str + len < end)
2574 memcpy(str, save_str, len);
2579 case FORMAT_TYPE_PTR:
2581 /* skip all alphanumeric pointer suffixes */
2582 while (isalnum(*fmt))
2587 switch (spec.type) {
2589 case FORMAT_TYPE_LONG_LONG:
2590 save_arg(long long);
2592 case FORMAT_TYPE_ULONG:
2593 case FORMAT_TYPE_LONG:
2594 save_arg(unsigned long);
2596 case FORMAT_TYPE_SIZE_T:
2599 case FORMAT_TYPE_PTRDIFF:
2600 save_arg(ptrdiff_t);
2602 case FORMAT_TYPE_UBYTE:
2603 case FORMAT_TYPE_BYTE:
2606 case FORMAT_TYPE_USHORT:
2607 case FORMAT_TYPE_SHORT:
2617 return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf;
2620 EXPORT_SYMBOL_GPL(vbin_printf);
2623 * bstr_printf - Format a string from binary arguments and place it in a buffer
2624 * @buf: The buffer to place the result into
2625 * @size: The size of the buffer, including the trailing null space
2626 * @fmt: The format string to use
2627 * @bin_buf: Binary arguments for the format string
2629 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
2630 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
2631 * a binary buffer that generated by vbin_printf.
2633 * The format follows C99 vsnprintf, but has some extensions:
2634 * see vsnprintf comment for details.
2636 * The return value is the number of characters which would
2637 * be generated for the given input, excluding the trailing
2638 * '\0', as per ISO C99. If you want to have the exact
2639 * number of characters written into @buf as return value
2640 * (not including the trailing '\0'), use vscnprintf(). If the
2641 * return is greater than or equal to @size, the resulting
2642 * string is truncated.
2644 int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf)
2646 struct printf_spec spec = {0};
2648 const char *args = (const char *)bin_buf;
2650 if (WARN_ON_ONCE(size > INT_MAX))
2656 #define get_arg(type) \
2658 typeof(type) value; \
2659 if (sizeof(type) == 8) { \
2660 args = PTR_ALIGN(args, sizeof(u32)); \
2661 *(u32 *)&value = *(u32 *)args; \
2662 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
2664 args = PTR_ALIGN(args, sizeof(type)); \
2665 value = *(typeof(type) *)args; \
2667 args += sizeof(type); \
2671 /* Make sure end is always >= buf */
2678 const char *old_fmt = fmt;
2679 int read = format_decode(fmt, &spec);
2683 switch (spec.type) {
2684 case FORMAT_TYPE_NONE: {
2687 if (copy > end - str)
2689 memcpy(str, old_fmt, copy);
2695 case FORMAT_TYPE_WIDTH:
2696 set_field_width(&spec, get_arg(int));
2699 case FORMAT_TYPE_PRECISION:
2700 set_precision(&spec, get_arg(int));
2703 case FORMAT_TYPE_CHAR: {
2706 if (!(spec.flags & LEFT)) {
2707 while (--spec.field_width > 0) {
2713 c = (unsigned char) get_arg(char);
2717 while (--spec.field_width > 0) {
2725 case FORMAT_TYPE_STR: {
2726 const char *str_arg = args;
2727 args += strlen(str_arg) + 1;
2728 str = string(str, end, (char *)str_arg, spec);
2732 case FORMAT_TYPE_PTR:
2733 str = pointer(fmt, str, end, get_arg(void *), spec);
2734 while (isalnum(*fmt))
2738 case FORMAT_TYPE_PERCENT_CHAR:
2744 case FORMAT_TYPE_INVALID:
2748 unsigned long long num;
2750 switch (spec.type) {
2752 case FORMAT_TYPE_LONG_LONG:
2753 num = get_arg(long long);
2755 case FORMAT_TYPE_ULONG:
2756 case FORMAT_TYPE_LONG:
2757 num = get_arg(unsigned long);
2759 case FORMAT_TYPE_SIZE_T:
2760 num = get_arg(size_t);
2762 case FORMAT_TYPE_PTRDIFF:
2763 num = get_arg(ptrdiff_t);
2765 case FORMAT_TYPE_UBYTE:
2766 num = get_arg(unsigned char);
2768 case FORMAT_TYPE_BYTE:
2769 num = get_arg(signed char);
2771 case FORMAT_TYPE_USHORT:
2772 num = get_arg(unsigned short);
2774 case FORMAT_TYPE_SHORT:
2775 num = get_arg(short);
2777 case FORMAT_TYPE_UINT:
2778 num = get_arg(unsigned int);
2784 str = number(str, end, num, spec);
2786 } /* switch(spec.type) */
2799 /* the trailing null byte doesn't count towards the total */
2802 EXPORT_SYMBOL_GPL(bstr_printf);
2805 * bprintf - Parse a format string and place args' binary value in a buffer
2806 * @bin_buf: The buffer to place args' binary value
2807 * @size: The size of the buffer(by words(32bits), not characters)
2808 * @fmt: The format string to use
2809 * @...: Arguments for the format string
2811 * The function returns the number of words(u32) written
2814 int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...)
2819 va_start(args, fmt);
2820 ret = vbin_printf(bin_buf, size, fmt, args);
2825 EXPORT_SYMBOL_GPL(bprintf);
2827 #endif /* CONFIG_BINARY_PRINTF */
2830 * vsscanf - Unformat a buffer into a list of arguments
2831 * @buf: input buffer
2832 * @fmt: format of buffer
2835 int vsscanf(const char *buf, const char *fmt, va_list args)
2837 const char *str = buf;
2845 unsigned long long u;
2851 /* skip any white space in format */
2852 /* white space in format matchs any amount of
2853 * white space, including none, in the input.
2855 if (isspace(*fmt)) {
2856 fmt = skip_spaces(++fmt);
2857 str = skip_spaces(str);
2860 /* anything that is not a conversion must match exactly */
2861 if (*fmt != '%' && *fmt) {
2862 if (*fmt++ != *str++)
2871 /* skip this conversion.
2872 * advance both strings to next white space
2877 while (!isspace(*fmt) && *fmt != '%' && *fmt) {
2878 /* '%*[' not yet supported, invalid format */
2883 while (!isspace(*str) && *str)
2888 /* get field width */
2890 if (isdigit(*fmt)) {
2891 field_width = skip_atoi(&fmt);
2892 if (field_width <= 0)
2896 /* get conversion qualifier */
2898 if (*fmt == 'h' || _tolower(*fmt) == 'l' ||
2901 if (unlikely(qualifier == *fmt)) {
2902 if (qualifier == 'h') {
2905 } else if (qualifier == 'l') {
2916 /* return number of characters read so far */
2917 *va_arg(args, int *) = str - buf;
2931 char *s = (char *)va_arg(args, char*);
2932 if (field_width == -1)
2936 } while (--field_width > 0 && *str);
2942 char *s = (char *)va_arg(args, char *);
2943 if (field_width == -1)
2944 field_width = SHRT_MAX;
2945 /* first, skip leading white space in buffer */
2946 str = skip_spaces(str);
2948 /* now copy until next white space */
2949 while (*str && !isspace(*str) && field_width--)
2956 * Warning: This implementation of the '[' conversion specifier
2957 * deviates from its glibc counterpart in the following ways:
2958 * (1) It does NOT support ranges i.e. '-' is NOT a special
2960 * (2) It cannot match the closing bracket ']' itself
2961 * (3) A field width is required
2962 * (4) '%*[' (discard matching input) is currently not supported
2965 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
2966 * buf1, buf2, buf3);
2972 char *s = (char *)va_arg(args, char *);
2973 DECLARE_BITMAP(set, 256) = {0};
2974 unsigned int len = 0;
2975 bool negate = (*fmt == '^');
2977 /* field width is required */
2978 if (field_width == -1)
2984 for ( ; *fmt && *fmt != ']'; ++fmt, ++len)
2985 set_bit((u8)*fmt, set);
2987 /* no ']' or no character set found */
2993 bitmap_complement(set, set, 256);
2994 /* exclude null '\0' byte */
2998 /* match must be non-empty */
2999 if (!test_bit((u8)*str, set))
3002 while (test_bit((u8)*str, set) && field_width--)
3022 /* looking for '%' in str */
3027 /* invalid format; stop here */
3031 /* have some sort of integer conversion.
3032 * first, skip white space in buffer.
3034 str = skip_spaces(str);
3037 if (is_sign && digit == '-')
3041 || (base == 16 && !isxdigit(digit))
3042 || (base == 10 && !isdigit(digit))
3043 || (base == 8 && (!isdigit(digit) || digit > '7'))
3044 || (base == 0 && !isdigit(digit)))
3048 val.s = qualifier != 'L' ?
3049 simple_strtol(str, &next, base) :
3050 simple_strtoll(str, &next, base);
3052 val.u = qualifier != 'L' ?
3053 simple_strtoul(str, &next, base) :
3054 simple_strtoull(str, &next, base);
3056 if (field_width > 0 && next - str > field_width) {
3058 _parse_integer_fixup_radix(str, &base);
3059 while (next - str > field_width) {
3061 val.s = div_s64(val.s, base);
3063 val.u = div_u64(val.u, base);
3068 switch (qualifier) {
3069 case 'H': /* that's 'hh' in format */
3071 *va_arg(args, signed char *) = val.s;
3073 *va_arg(args, unsigned char *) = val.u;
3077 *va_arg(args, short *) = val.s;
3079 *va_arg(args, unsigned short *) = val.u;
3083 *va_arg(args, long *) = val.s;
3085 *va_arg(args, unsigned long *) = val.u;
3089 *va_arg(args, long long *) = val.s;
3091 *va_arg(args, unsigned long long *) = val.u;
3094 *va_arg(args, size_t *) = val.u;
3098 *va_arg(args, int *) = val.s;
3100 *va_arg(args, unsigned int *) = val.u;
3112 EXPORT_SYMBOL(vsscanf);
3115 * sscanf - Unformat a buffer into a list of arguments
3116 * @buf: input buffer
3117 * @fmt: formatting of buffer
3118 * @...: resulting arguments
3120 int sscanf(const char *buf, const char *fmt, ...)
3125 va_start(args, fmt);
3126 i = vsscanf(buf, fmt, args);
3131 EXPORT_SYMBOL(sscanf);