1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1991, 1992 Linus Torvalds
8 /* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
10 * Wirzenius wrote this portably, Torvalds fucked it up :-)
14 * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
15 * - changed to provide snprintf and vsnprintf functions
16 * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
17 * - scnprintf and vscnprintf
20 #include <linux/stdarg.h>
21 #include <linux/build_bug.h>
22 #include <linux/clk.h>
23 #include <linux/clk-provider.h>
24 #include <linux/errname.h>
25 #include <linux/module.h> /* for KSYM_SYMBOL_LEN */
26 #include <linux/types.h>
27 #include <linux/string.h>
28 #include <linux/ctype.h>
29 #include <linux/kernel.h>
30 #include <linux/kallsyms.h>
31 #include <linux/math64.h>
32 #include <linux/uaccess.h>
33 #include <linux/ioport.h>
34 #include <linux/dcache.h>
35 #include <linux/cred.h>
36 #include <linux/rtc.h>
37 #include <linux/time.h>
38 #include <linux/uuid.h>
40 #include <net/addrconf.h>
41 #include <linux/siphash.h>
42 #include <linux/compiler.h>
43 #include <linux/property.h>
45 #include <linux/blkdev.h>
48 #include "../mm/internal.h" /* For the trace_print_flags arrays */
50 #include <asm/page.h> /* for PAGE_SIZE */
51 #include <asm/byteorder.h> /* cpu_to_le16 */
52 #include <asm/unaligned.h>
54 #include <linux/string_helpers.h>
57 /* Disable pointer hashing if requested */
58 bool no_hash_pointers __ro_after_init
;
59 EXPORT_SYMBOL_GPL(no_hash_pointers
);
61 static noinline
unsigned long long simple_strntoull(const char *startp
, size_t max_chars
, char **endp
, unsigned int base
)
64 unsigned long long result
= 0ULL;
68 cp
= _parse_integer_fixup_radix(startp
, &base
);
69 prefix_chars
= cp
- startp
;
70 if (prefix_chars
< max_chars
) {
71 rv
= _parse_integer_limit(cp
, base
, &result
, max_chars
- prefix_chars
);
73 cp
+= (rv
& ~KSTRTOX_OVERFLOW
);
75 /* Field too short for prefix + digit, skip over without converting */
76 cp
= startp
+ max_chars
;
86 * simple_strtoull - convert a string to an unsigned long long
87 * @cp: The start of the string
88 * @endp: A pointer to the end of the parsed string will be placed here
89 * @base: The number base to use
91 * This function has caveats. Please use kstrtoull instead.
94 unsigned long long simple_strtoull(const char *cp
, char **endp
, unsigned int base
)
96 return simple_strntoull(cp
, INT_MAX
, endp
, base
);
98 EXPORT_SYMBOL(simple_strtoull
);
101 * simple_strtoul - convert a string to an unsigned long
102 * @cp: The start of the string
103 * @endp: A pointer to the end of the parsed string will be placed here
104 * @base: The number base to use
106 * This function has caveats. Please use kstrtoul instead.
108 unsigned long simple_strtoul(const char *cp
, char **endp
, unsigned int base
)
110 return simple_strtoull(cp
, endp
, base
);
112 EXPORT_SYMBOL(simple_strtoul
);
115 * simple_strtol - convert a string to a signed long
116 * @cp: The start of the string
117 * @endp: A pointer to the end of the parsed string will be placed here
118 * @base: The number base to use
120 * This function has caveats. Please use kstrtol instead.
122 long simple_strtol(const char *cp
, char **endp
, unsigned int base
)
125 return -simple_strtoul(cp
+ 1, endp
, base
);
127 return simple_strtoul(cp
, endp
, base
);
129 EXPORT_SYMBOL(simple_strtol
);
131 static long long simple_strntoll(const char *cp
, size_t max_chars
, char **endp
,
135 * simple_strntoull() safely handles receiving max_chars==0 in the
136 * case cp[0] == '-' && max_chars == 1.
137 * If max_chars == 0 we can drop through and pass it to simple_strntoull()
138 * and the content of *cp is irrelevant.
140 if (*cp
== '-' && max_chars
> 0)
141 return -simple_strntoull(cp
+ 1, max_chars
- 1, endp
, base
);
143 return simple_strntoull(cp
, max_chars
, endp
, base
);
147 * simple_strtoll - convert a string to a signed long long
148 * @cp: The start of the string
149 * @endp: A pointer to the end of the parsed string will be placed here
150 * @base: The number base to use
152 * This function has caveats. Please use kstrtoll instead.
154 long long simple_strtoll(const char *cp
, char **endp
, unsigned int base
)
156 return simple_strntoll(cp
, INT_MAX
, endp
, base
);
158 EXPORT_SYMBOL(simple_strtoll
);
160 static noinline_for_stack
161 int skip_atoi(const char **s
)
166 i
= i
*10 + *((*s
)++) - '0';
167 } while (isdigit(**s
));
173 * Decimal conversion is by far the most typical, and is used for
174 * /proc and /sys data. This directly impacts e.g. top performance
175 * with many processes running. We optimize it for speed by emitting
176 * two characters at a time, using a 200 byte lookup table. This
177 * roughly halves the number of multiplications compared to computing
178 * the digits one at a time. Implementation strongly inspired by the
179 * previous version, which in turn used ideas described at
180 * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission
181 * from the author, Douglas W. Jones).
183 * It turns out there is precisely one 26 bit fixed-point
184 * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32
185 * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual
186 * range happens to be somewhat larger (x <= 1073741898), but that's
187 * irrelevant for our purpose.
189 * For dividing a number in the range [10^4, 10^6-1] by 100, we still
190 * need a 32x32->64 bit multiply, so we simply use the same constant.
192 * For dividing a number in the range [100, 10^4-1] by 100, there are
193 * several options. The simplest is (x * 0x147b) >> 19, which is valid
194 * for all x <= 43698.
197 static const u16 decpair
[100] = {
198 #define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030)
199 _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9),
200 _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19),
201 _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29),
202 _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39),
203 _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49),
204 _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59),
205 _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69),
206 _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79),
207 _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89),
208 _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99),
213 * This will print a single '0' even if r == 0, since we would
214 * immediately jump to out_r where two 0s would be written but only
215 * one of them accounted for in buf. This is needed by ip4_string
216 * below. All other callers pass a non-zero value of r.
218 static noinline_for_stack
219 char *put_dec_trunc8(char *buf
, unsigned r
)
227 /* 100 <= r < 10^8 */
228 q
= (r
* (u64
)0x28f5c29) >> 32;
229 *((u16
*)buf
) = decpair
[r
- 100*q
];
236 /* 100 <= q < 10^6 */
237 r
= (q
* (u64
)0x28f5c29) >> 32;
238 *((u16
*)buf
) = decpair
[q
- 100*r
];
245 /* 100 <= r < 10^4 */
246 q
= (r
* 0x147b) >> 19;
247 *((u16
*)buf
) = decpair
[r
- 100*q
];
254 *((u16
*)buf
) = decpair
[r
];
255 buf
+= r
< 10 ? 1 : 2;
259 #if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64
260 static noinline_for_stack
261 char *put_dec_full8(char *buf
, unsigned r
)
266 q
= (r
* (u64
)0x28f5c29) >> 32;
267 *((u16
*)buf
) = decpair
[r
- 100*q
];
271 r
= (q
* (u64
)0x28f5c29) >> 32;
272 *((u16
*)buf
) = decpair
[q
- 100*r
];
276 q
= (r
* 0x147b) >> 19;
277 *((u16
*)buf
) = decpair
[r
- 100*q
];
281 *((u16
*)buf
) = decpair
[q
];
286 static noinline_for_stack
287 char *put_dec(char *buf
, unsigned long long n
)
289 if (n
>= 100*1000*1000)
290 buf
= put_dec_full8(buf
, do_div(n
, 100*1000*1000));
291 /* 1 <= n <= 1.6e11 */
292 if (n
>= 100*1000*1000)
293 buf
= put_dec_full8(buf
, do_div(n
, 100*1000*1000));
295 return put_dec_trunc8(buf
, n
);
298 #elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64
301 put_dec_full4(char *buf
, unsigned r
)
306 q
= (r
* 0x147b) >> 19;
307 *((u16
*)buf
) = decpair
[r
- 100*q
];
310 *((u16
*)buf
) = decpair
[q
];
314 * Call put_dec_full4 on x % 10000, return x / 10000.
315 * The approximation x/10000 == (x * 0x346DC5D7) >> 43
316 * holds for all x < 1,128,869,999. The largest value this
317 * helper will ever be asked to convert is 1,125,520,955.
318 * (second call in the put_dec code, assuming n is all-ones).
320 static noinline_for_stack
321 unsigned put_dec_helper4(char *buf
, unsigned x
)
323 uint32_t q
= (x
* (uint64_t)0x346DC5D7) >> 43;
325 put_dec_full4(buf
, x
- q
* 10000);
329 /* Based on code by Douglas W. Jones found at
330 * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour>
331 * (with permission from the author).
332 * Performs no 64-bit division and hence should be fast on 32-bit machines.
335 char *put_dec(char *buf
, unsigned long long n
)
337 uint32_t d3
, d2
, d1
, q
, h
;
339 if (n
< 100*1000*1000)
340 return put_dec_trunc8(buf
, n
);
342 d1
= ((uint32_t)n
>> 16); /* implicit "& 0xffff" */
345 d3
= (h
>> 16); /* implicit "& 0xffff" */
347 /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0
348 = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */
349 q
= 656 * d3
+ 7296 * d2
+ 5536 * d1
+ ((uint32_t)n
& 0xffff);
350 q
= put_dec_helper4(buf
, q
);
352 q
+= 7671 * d3
+ 9496 * d2
+ 6 * d1
;
353 q
= put_dec_helper4(buf
+4, q
);
355 q
+= 4749 * d3
+ 42 * d2
;
356 q
= put_dec_helper4(buf
+8, q
);
361 buf
= put_dec_trunc8(buf
, q
);
362 else while (buf
[-1] == '0')
371 * Convert passed number to decimal string.
372 * Returns the length of string. On buffer overflow, returns 0.
374 * If speed is not important, use snprintf(). It's easy to read the code.
376 int num_to_str(char *buf
, int size
, unsigned long long num
, unsigned int width
)
378 /* put_dec requires 2-byte alignment of the buffer. */
379 char tmp
[sizeof(num
) * 3] __aligned(2);
382 /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */
387 len
= put_dec(tmp
, num
) - tmp
;
390 if (len
> size
|| width
> size
)
395 for (idx
= 0; idx
< width
; idx
++)
401 for (idx
= 0; idx
< len
; ++idx
)
402 buf
[idx
+ width
] = tmp
[len
- idx
- 1];
407 #define SIGN 1 /* unsigned/signed, must be 1 */
408 #define LEFT 2 /* left justified */
409 #define PLUS 4 /* show plus */
410 #define SPACE 8 /* space if plus */
411 #define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */
412 #define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */
413 #define SPECIAL 64 /* prefix hex with "0x", octal with "0" */
415 static_assert(ZEROPAD
== ('0' - ' '));
416 static_assert(SMALL
== ' ');
419 FORMAT_TYPE_NONE
, /* Just a string part */
421 FORMAT_TYPE_PRECISION
,
425 FORMAT_TYPE_PERCENT_CHAR
,
427 FORMAT_TYPE_LONG_LONG
,
441 unsigned int type
:8; /* format_type enum */
442 signed int field_width
:24; /* width of output field */
443 unsigned int flags
:8; /* flags to number() */
444 unsigned int base
:8; /* number base, 8, 10 or 16 only */
445 signed int precision
:16; /* # of digits/chars */
447 static_assert(sizeof(struct printf_spec
) == 8);
449 #define FIELD_WIDTH_MAX ((1 << 23) - 1)
450 #define PRECISION_MAX ((1 << 15) - 1)
452 static noinline_for_stack
453 char *number(char *buf
, char *end
, unsigned long long num
,
454 struct printf_spec spec
)
456 /* put_dec requires 2-byte alignment of the buffer. */
457 char tmp
[3 * sizeof(num
)] __aligned(2);
460 int need_pfx
= ((spec
.flags
& SPECIAL
) && spec
.base
!= 10);
462 bool is_zero
= num
== 0LL;
463 int field_width
= spec
.field_width
;
464 int precision
= spec
.precision
;
466 /* locase = 0 or 0x20. ORing digits or letters with 'locase'
467 * produces same digits or (maybe lowercased) letters */
468 locase
= (spec
.flags
& SMALL
);
469 if (spec
.flags
& LEFT
)
470 spec
.flags
&= ~ZEROPAD
;
472 if (spec
.flags
& SIGN
) {
473 if ((signed long long)num
< 0) {
475 num
= -(signed long long)num
;
477 } else if (spec
.flags
& PLUS
) {
480 } else if (spec
.flags
& SPACE
) {
492 /* generate full string in tmp[], in reverse order */
495 tmp
[i
++] = hex_asc_upper
[num
] | locase
;
496 else if (spec
.base
!= 10) { /* 8 or 16 */
497 int mask
= spec
.base
- 1;
503 tmp
[i
++] = (hex_asc_upper
[((unsigned char)num
) & mask
] | locase
);
506 } else { /* base 10 */
507 i
= put_dec(tmp
, num
) - tmp
;
510 /* printing 100 using %2d gives "100", not "00" */
513 /* leading space padding */
514 field_width
-= precision
;
515 if (!(spec
.flags
& (ZEROPAD
| LEFT
))) {
516 while (--field_width
>= 0) {
528 /* "0x" / "0" prefix */
530 if (spec
.base
== 16 || !is_zero
) {
535 if (spec
.base
== 16) {
537 *buf
= ('X' | locase
);
541 /* zero or space padding */
542 if (!(spec
.flags
& LEFT
)) {
543 char c
= ' ' + (spec
.flags
& ZEROPAD
);
545 while (--field_width
>= 0) {
551 /* hmm even more zero padding? */
552 while (i
<= --precision
) {
557 /* actual digits of result */
563 /* trailing space padding */
564 while (--field_width
>= 0) {
573 static noinline_for_stack
574 char *special_hex_number(char *buf
, char *end
, unsigned long long num
, int size
)
576 struct printf_spec spec
;
578 spec
.type
= FORMAT_TYPE_PTR
;
579 spec
.field_width
= 2 + 2 * size
; /* 0x + hex */
580 spec
.flags
= SPECIAL
| SMALL
| ZEROPAD
;
584 return number(buf
, end
, num
, spec
);
587 static void move_right(char *buf
, char *end
, unsigned len
, unsigned spaces
)
590 if (buf
>= end
) /* nowhere to put anything */
593 if (size
<= spaces
) {
594 memset(buf
, ' ', size
);
598 if (len
> size
- spaces
)
600 memmove(buf
+ spaces
, buf
, len
);
602 memset(buf
, ' ', spaces
);
606 * Handle field width padding for a string.
607 * @buf: current buffer position
608 * @n: length of string
609 * @end: end of output buffer
610 * @spec: for field width and flags
611 * Returns: new buffer position after padding.
613 static noinline_for_stack
614 char *widen_string(char *buf
, int n
, char *end
, struct printf_spec spec
)
618 if (likely(n
>= spec
.field_width
))
620 /* we want to pad the sucker */
621 spaces
= spec
.field_width
- n
;
622 if (!(spec
.flags
& LEFT
)) {
623 move_right(buf
- n
, end
, n
, spaces
);
634 /* Handle string from a well known address. */
635 static char *string_nocheck(char *buf
, char *end
, const char *s
,
636 struct printf_spec spec
)
639 int lim
= spec
.precision
;
650 return widen_string(buf
, len
, end
, spec
);
653 static char *err_ptr(char *buf
, char *end
, void *ptr
,
654 struct printf_spec spec
)
656 int err
= PTR_ERR(ptr
);
657 const char *sym
= errname(err
);
660 return string_nocheck(buf
, end
, sym
, spec
);
663 * Somebody passed ERR_PTR(-1234) or some other non-existing
664 * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to
665 * printing it as its decimal representation.
669 return number(buf
, end
, err
, spec
);
672 /* Be careful: error messages must fit into the given buffer. */
673 static char *error_string(char *buf
, char *end
, const char *s
,
674 struct printf_spec spec
)
677 * Hard limit to avoid a completely insane messages. It actually
678 * works pretty well because most error messages are in
679 * the many pointer format modifiers.
681 if (spec
.precision
== -1)
682 spec
.precision
= 2 * sizeof(void *);
684 return string_nocheck(buf
, end
, s
, spec
);
688 * Do not call any complex external code here. Nested printk()/vsprintf()
689 * might cause infinite loops. Failures might break printk() and would
692 static const char *check_pointer_msg(const void *ptr
)
697 if ((unsigned long)ptr
< PAGE_SIZE
|| IS_ERR_VALUE(ptr
))
703 static int check_pointer(char **buf
, char *end
, const void *ptr
,
704 struct printf_spec spec
)
708 err_msg
= check_pointer_msg(ptr
);
710 *buf
= error_string(*buf
, end
, err_msg
, spec
);
717 static noinline_for_stack
718 char *string(char *buf
, char *end
, const char *s
,
719 struct printf_spec spec
)
721 if (check_pointer(&buf
, end
, s
, spec
))
724 return string_nocheck(buf
, end
, s
, spec
);
727 static char *pointer_string(char *buf
, char *end
,
729 struct printf_spec spec
)
733 if (spec
.field_width
== -1) {
734 spec
.field_width
= 2 * sizeof(ptr
);
735 spec
.flags
|= ZEROPAD
;
738 return number(buf
, end
, (unsigned long int)ptr
, spec
);
741 /* Make pointers available for printing early in the boot sequence. */
742 static int debug_boot_weak_hash __ro_after_init
;
744 static int __init
debug_boot_weak_hash_enable(char *str
)
746 debug_boot_weak_hash
= 1;
747 pr_info("debug_boot_weak_hash enabled\n");
750 early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable
);
752 static DEFINE_STATIC_KEY_TRUE(not_filled_random_ptr_key
);
753 static siphash_key_t ptr_key __read_mostly
;
755 static void enable_ptr_key_workfn(struct work_struct
*work
)
757 get_random_bytes(&ptr_key
, sizeof(ptr_key
));
758 /* Needs to run from preemptible context */
759 static_branch_disable(¬_filled_random_ptr_key
);
762 static DECLARE_WORK(enable_ptr_key_work
, enable_ptr_key_workfn
);
764 static int fill_random_ptr_key(struct notifier_block
*nb
,
765 unsigned long action
, void *data
)
767 /* This may be in an interrupt handler. */
768 queue_work(system_unbound_wq
, &enable_ptr_key_work
);
772 static struct notifier_block random_ready
= {
773 .notifier_call
= fill_random_ptr_key
776 static int __init
initialize_ptr_random(void)
778 int key_size
= sizeof(ptr_key
);
781 /* Use hw RNG if available. */
782 if (get_random_bytes_arch(&ptr_key
, key_size
) == key_size
) {
783 static_branch_disable(¬_filled_random_ptr_key
);
787 ret
= register_random_ready_notifier(&random_ready
);
790 } else if (ret
== -EALREADY
) {
791 /* This is in preemptible context */
792 enable_ptr_key_workfn(&enable_ptr_key_work
);
798 early_initcall(initialize_ptr_random
);
800 /* Maps a pointer to a 32 bit unique identifier. */
801 static inline int __ptr_to_hashval(const void *ptr
, unsigned long *hashval_out
)
803 unsigned long hashval
;
805 if (static_branch_unlikely(¬_filled_random_ptr_key
))
809 hashval
= (unsigned long)siphash_1u64((u64
)ptr
, &ptr_key
);
811 * Mask off the first 32 bits, this makes explicit that we have
812 * modified the address (and 32 bits is plenty for a unique ID).
814 hashval
= hashval
& 0xffffffff;
816 hashval
= (unsigned long)siphash_1u32((u32
)ptr
, &ptr_key
);
818 *hashval_out
= hashval
;
822 int ptr_to_hashval(const void *ptr
, unsigned long *hashval_out
)
824 return __ptr_to_hashval(ptr
, hashval_out
);
827 static char *ptr_to_id(char *buf
, char *end
, const void *ptr
,
828 struct printf_spec spec
)
830 const char *str
= sizeof(ptr
) == 8 ? "(____ptrval____)" : "(ptrval)";
831 unsigned long hashval
;
835 * Print the real pointer value for NULL and error pointers,
836 * as they are not actual addresses.
838 if (IS_ERR_OR_NULL(ptr
))
839 return pointer_string(buf
, end
, ptr
, spec
);
841 /* When debugging early boot use non-cryptographically secure hash. */
842 if (unlikely(debug_boot_weak_hash
)) {
843 hashval
= hash_long((unsigned long)ptr
, 32);
844 return pointer_string(buf
, end
, (const void *)hashval
, spec
);
847 ret
= __ptr_to_hashval(ptr
, &hashval
);
849 spec
.field_width
= 2 * sizeof(ptr
);
850 /* string length must be less than default_width */
851 return error_string(buf
, end
, str
, spec
);
854 return pointer_string(buf
, end
, (const void *)hashval
, spec
);
857 static char *default_pointer(char *buf
, char *end
, const void *ptr
,
858 struct printf_spec spec
)
861 * default is to _not_ leak addresses, so hash before printing,
862 * unless no_hash_pointers is specified on the command line.
864 if (unlikely(no_hash_pointers
))
865 return pointer_string(buf
, end
, ptr
, spec
);
867 return ptr_to_id(buf
, end
, ptr
, spec
);
870 int kptr_restrict __read_mostly
;
872 static noinline_for_stack
873 char *restricted_pointer(char *buf
, char *end
, const void *ptr
,
874 struct printf_spec spec
)
876 switch (kptr_restrict
) {
878 /* Handle as %p, hash and do _not_ leak addresses. */
879 return default_pointer(buf
, end
, ptr
, spec
);
881 const struct cred
*cred
;
884 * kptr_restrict==1 cannot be used in IRQ context
885 * because its test for CAP_SYSLOG would be meaningless.
887 if (in_irq() || in_serving_softirq() || in_nmi()) {
888 if (spec
.field_width
== -1)
889 spec
.field_width
= 2 * sizeof(ptr
);
890 return error_string(buf
, end
, "pK-error", spec
);
894 * Only print the real pointer value if the current
895 * process has CAP_SYSLOG and is running with the
896 * same credentials it started with. This is because
897 * access to files is checked at open() time, but %pK
898 * checks permission at read() time. We don't want to
899 * leak pointer values if a binary opens a file using
900 * %pK and then elevates privileges before reading it.
902 cred
= current_cred();
903 if (!has_capability_noaudit(current
, CAP_SYSLOG
) ||
904 !uid_eq(cred
->euid
, cred
->uid
) ||
905 !gid_eq(cred
->egid
, cred
->gid
))
911 /* Always print 0's for %pK */
916 return pointer_string(buf
, end
, ptr
, spec
);
919 static noinline_for_stack
920 char *dentry_name(char *buf
, char *end
, const struct dentry
*d
, struct printf_spec spec
,
923 const char *array
[4], *s
;
924 const struct dentry
*p
;
929 case '2': case '3': case '4':
930 depth
= fmt
[1] - '0';
937 for (i
= 0; i
< depth
; i
++, d
= p
) {
938 if (check_pointer(&buf
, end
, d
, spec
)) {
943 p
= READ_ONCE(d
->d_parent
);
944 array
[i
] = READ_ONCE(d
->d_name
.name
);
953 for (n
= 0; n
!= spec
.precision
; n
++, buf
++) {
965 return widen_string(buf
, n
, end
, spec
);
968 static noinline_for_stack
969 char *file_dentry_name(char *buf
, char *end
, const struct file
*f
,
970 struct printf_spec spec
, const char *fmt
)
972 if (check_pointer(&buf
, end
, f
, spec
))
975 return dentry_name(buf
, end
, f
->f_path
.dentry
, spec
, fmt
);
978 static noinline_for_stack
979 char *bdev_name(char *buf
, char *end
, struct block_device
*bdev
,
980 struct printf_spec spec
, const char *fmt
)
984 if (check_pointer(&buf
, end
, bdev
, spec
))
988 buf
= string(buf
, end
, hd
->disk_name
, spec
);
989 if (bdev
->bd_partno
) {
990 if (isdigit(hd
->disk_name
[strlen(hd
->disk_name
)-1])) {
995 buf
= number(buf
, end
, bdev
->bd_partno
, spec
);
1001 static noinline_for_stack
1002 char *symbol_string(char *buf
, char *end
, void *ptr
,
1003 struct printf_spec spec
, const char *fmt
)
1005 unsigned long value
;
1006 #ifdef CONFIG_KALLSYMS
1007 char sym
[KSYM_SYMBOL_LEN
];
1011 ptr
= __builtin_extract_return_addr(ptr
);
1012 value
= (unsigned long)ptr
;
1014 #ifdef CONFIG_KALLSYMS
1015 if (*fmt
== 'B' && fmt
[1] == 'b')
1016 sprint_backtrace_build_id(sym
, value
);
1017 else if (*fmt
== 'B')
1018 sprint_backtrace(sym
, value
);
1019 else if (*fmt
== 'S' && (fmt
[1] == 'b' || (fmt
[1] == 'R' && fmt
[2] == 'b')))
1020 sprint_symbol_build_id(sym
, value
);
1021 else if (*fmt
!= 's')
1022 sprint_symbol(sym
, value
);
1024 sprint_symbol_no_offset(sym
, value
);
1026 return string_nocheck(buf
, end
, sym
, spec
);
1028 return special_hex_number(buf
, end
, value
, sizeof(void *));
1032 static const struct printf_spec default_str_spec
= {
1037 static const struct printf_spec default_flag_spec
= {
1040 .flags
= SPECIAL
| SMALL
,
1043 static const struct printf_spec default_dec_spec
= {
1048 static const struct printf_spec default_dec02_spec
= {
1055 static const struct printf_spec default_dec04_spec
= {
1062 static noinline_for_stack
1063 char *resource_string(char *buf
, char *end
, struct resource
*res
,
1064 struct printf_spec spec
, const char *fmt
)
1066 #ifndef IO_RSRC_PRINTK_SIZE
1067 #define IO_RSRC_PRINTK_SIZE 6
1070 #ifndef MEM_RSRC_PRINTK_SIZE
1071 #define MEM_RSRC_PRINTK_SIZE 10
1073 static const struct printf_spec io_spec
= {
1075 .field_width
= IO_RSRC_PRINTK_SIZE
,
1077 .flags
= SPECIAL
| SMALL
| ZEROPAD
,
1079 static const struct printf_spec mem_spec
= {
1081 .field_width
= MEM_RSRC_PRINTK_SIZE
,
1083 .flags
= SPECIAL
| SMALL
| ZEROPAD
,
1085 static const struct printf_spec bus_spec
= {
1089 .flags
= SMALL
| ZEROPAD
,
1091 static const struct printf_spec str_spec
= {
1097 /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8)
1098 * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */
1099 #define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4)
1100 #define FLAG_BUF_SIZE (2 * sizeof(res->flags))
1101 #define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]")
1102 #define RAW_BUF_SIZE sizeof("[mem - flags 0x]")
1103 char sym
[max(2*RSRC_BUF_SIZE
+ DECODED_BUF_SIZE
,
1104 2*RSRC_BUF_SIZE
+ FLAG_BUF_SIZE
+ RAW_BUF_SIZE
)];
1106 char *p
= sym
, *pend
= sym
+ sizeof(sym
);
1107 int decode
= (fmt
[0] == 'R') ? 1 : 0;
1108 const struct printf_spec
*specp
;
1110 if (check_pointer(&buf
, end
, res
, spec
))
1114 if (res
->flags
& IORESOURCE_IO
) {
1115 p
= string_nocheck(p
, pend
, "io ", str_spec
);
1117 } else if (res
->flags
& IORESOURCE_MEM
) {
1118 p
= string_nocheck(p
, pend
, "mem ", str_spec
);
1120 } else if (res
->flags
& IORESOURCE_IRQ
) {
1121 p
= string_nocheck(p
, pend
, "irq ", str_spec
);
1122 specp
= &default_dec_spec
;
1123 } else if (res
->flags
& IORESOURCE_DMA
) {
1124 p
= string_nocheck(p
, pend
, "dma ", str_spec
);
1125 specp
= &default_dec_spec
;
1126 } else if (res
->flags
& IORESOURCE_BUS
) {
1127 p
= string_nocheck(p
, pend
, "bus ", str_spec
);
1130 p
= string_nocheck(p
, pend
, "??? ", str_spec
);
1134 if (decode
&& res
->flags
& IORESOURCE_UNSET
) {
1135 p
= string_nocheck(p
, pend
, "size ", str_spec
);
1136 p
= number(p
, pend
, resource_size(res
), *specp
);
1138 p
= number(p
, pend
, res
->start
, *specp
);
1139 if (res
->start
!= res
->end
) {
1141 p
= number(p
, pend
, res
->end
, *specp
);
1145 if (res
->flags
& IORESOURCE_MEM_64
)
1146 p
= string_nocheck(p
, pend
, " 64bit", str_spec
);
1147 if (res
->flags
& IORESOURCE_PREFETCH
)
1148 p
= string_nocheck(p
, pend
, " pref", str_spec
);
1149 if (res
->flags
& IORESOURCE_WINDOW
)
1150 p
= string_nocheck(p
, pend
, " window", str_spec
);
1151 if (res
->flags
& IORESOURCE_DISABLED
)
1152 p
= string_nocheck(p
, pend
, " disabled", str_spec
);
1154 p
= string_nocheck(p
, pend
, " flags ", str_spec
);
1155 p
= number(p
, pend
, res
->flags
, default_flag_spec
);
1160 return string_nocheck(buf
, end
, sym
, spec
);
1163 static noinline_for_stack
1164 char *hex_string(char *buf
, char *end
, u8
*addr
, struct printf_spec spec
,
1167 int i
, len
= 1; /* if we pass '%ph[CDN]', field width remains
1168 negative value, fallback to the default */
1171 if (spec
.field_width
== 0)
1172 /* nothing to print */
1175 if (check_pointer(&buf
, end
, addr
, spec
))
1193 if (spec
.field_width
> 0)
1194 len
= min_t(int, spec
.field_width
, 64);
1196 for (i
= 0; i
< len
; ++i
) {
1198 *buf
= hex_asc_hi(addr
[i
]);
1201 *buf
= hex_asc_lo(addr
[i
]);
1204 if (separator
&& i
!= len
- 1) {
1214 static noinline_for_stack
1215 char *bitmap_string(char *buf
, char *end
, unsigned long *bitmap
,
1216 struct printf_spec spec
, const char *fmt
)
1218 const int CHUNKSZ
= 32;
1219 int nr_bits
= max_t(int, spec
.field_width
, 0);
1223 if (check_pointer(&buf
, end
, bitmap
, spec
))
1226 /* reused to print numbers */
1227 spec
= (struct printf_spec
){ .flags
= SMALL
| ZEROPAD
, .base
= 16 };
1229 chunksz
= nr_bits
& (CHUNKSZ
- 1);
1233 i
= ALIGN(nr_bits
, CHUNKSZ
) - CHUNKSZ
;
1234 for (; i
>= 0; i
-= CHUNKSZ
) {
1238 chunkmask
= ((1ULL << chunksz
) - 1);
1239 word
= i
/ BITS_PER_LONG
;
1240 bit
= i
% BITS_PER_LONG
;
1241 val
= (bitmap
[word
] >> bit
) & chunkmask
;
1250 spec
.field_width
= DIV_ROUND_UP(chunksz
, 4);
1251 buf
= number(buf
, end
, val
, spec
);
1258 static noinline_for_stack
1259 char *bitmap_list_string(char *buf
, char *end
, unsigned long *bitmap
,
1260 struct printf_spec spec
, const char *fmt
)
1262 int nr_bits
= max_t(int, spec
.field_width
, 0);
1263 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
1264 int cur
, rbot
, rtop
;
1267 if (check_pointer(&buf
, end
, bitmap
, spec
))
1270 rbot
= cur
= find_first_bit(bitmap
, nr_bits
);
1271 while (cur
< nr_bits
) {
1273 cur
= find_next_bit(bitmap
, nr_bits
, cur
+ 1);
1274 if (cur
< nr_bits
&& cur
<= rtop
+ 1)
1284 buf
= number(buf
, end
, rbot
, default_dec_spec
);
1290 buf
= number(buf
, end
, rtop
, default_dec_spec
);
1298 static noinline_for_stack
1299 char *mac_address_string(char *buf
, char *end
, u8
*addr
,
1300 struct printf_spec spec
, const char *fmt
)
1302 char mac_addr
[sizeof("xx:xx:xx:xx:xx:xx")];
1306 bool reversed
= false;
1308 if (check_pointer(&buf
, end
, addr
, spec
))
1325 for (i
= 0; i
< 6; i
++) {
1327 p
= hex_byte_pack(p
, addr
[5 - i
]);
1329 p
= hex_byte_pack(p
, addr
[i
]);
1331 if (fmt
[0] == 'M' && i
!= 5)
1336 return string_nocheck(buf
, end
, mac_addr
, spec
);
1339 static noinline_for_stack
1340 char *ip4_string(char *p
, const u8
*addr
, const char *fmt
)
1343 bool leading_zeros
= (fmt
[0] == 'i');
1368 for (i
= 0; i
< 4; i
++) {
1369 char temp
[4] __aligned(2); /* hold each IP quad in reverse order */
1370 int digits
= put_dec_trunc8(temp
, addr
[index
]) - temp
;
1371 if (leading_zeros
) {
1377 /* reverse the digits in the quad */
1379 *p
++ = temp
[digits
];
1389 static noinline_for_stack
1390 char *ip6_compressed_string(char *p
, const char *addr
)
1393 unsigned char zerolength
[8];
1398 bool needcolon
= false;
1400 struct in6_addr in6
;
1402 memcpy(&in6
, addr
, sizeof(struct in6_addr
));
1404 useIPv4
= ipv6_addr_v4mapped(&in6
) || ipv6_addr_is_isatap(&in6
);
1406 memset(zerolength
, 0, sizeof(zerolength
));
1413 /* find position of longest 0 run */
1414 for (i
= 0; i
< range
; i
++) {
1415 for (j
= i
; j
< range
; j
++) {
1416 if (in6
.s6_addr16
[j
] != 0)
1421 for (i
= 0; i
< range
; i
++) {
1422 if (zerolength
[i
] > longest
) {
1423 longest
= zerolength
[i
];
1427 if (longest
== 1) /* don't compress a single 0 */
1431 for (i
= 0; i
< range
; i
++) {
1432 if (i
== colonpos
) {
1433 if (needcolon
|| i
== 0)
1444 /* hex u16 without leading 0s */
1445 word
= ntohs(in6
.s6_addr16
[i
]);
1450 p
= hex_byte_pack(p
, hi
);
1452 *p
++ = hex_asc_lo(hi
);
1453 p
= hex_byte_pack(p
, lo
);
1456 p
= hex_byte_pack(p
, lo
);
1458 *p
++ = hex_asc_lo(lo
);
1465 p
= ip4_string(p
, &in6
.s6_addr
[12], "I4");
1472 static noinline_for_stack
1473 char *ip6_string(char *p
, const char *addr
, const char *fmt
)
1477 for (i
= 0; i
< 8; i
++) {
1478 p
= hex_byte_pack(p
, *addr
++);
1479 p
= hex_byte_pack(p
, *addr
++);
1480 if (fmt
[0] == 'I' && i
!= 7)
1488 static noinline_for_stack
1489 char *ip6_addr_string(char *buf
, char *end
, const u8
*addr
,
1490 struct printf_spec spec
, const char *fmt
)
1492 char ip6_addr
[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")];
1494 if (fmt
[0] == 'I' && fmt
[2] == 'c')
1495 ip6_compressed_string(ip6_addr
, addr
);
1497 ip6_string(ip6_addr
, addr
, fmt
);
1499 return string_nocheck(buf
, end
, ip6_addr
, spec
);
1502 static noinline_for_stack
1503 char *ip4_addr_string(char *buf
, char *end
, const u8
*addr
,
1504 struct printf_spec spec
, const char *fmt
)
1506 char ip4_addr
[sizeof("255.255.255.255")];
1508 ip4_string(ip4_addr
, addr
, fmt
);
1510 return string_nocheck(buf
, end
, ip4_addr
, spec
);
1513 static noinline_for_stack
1514 char *ip6_addr_string_sa(char *buf
, char *end
, const struct sockaddr_in6
*sa
,
1515 struct printf_spec spec
, const char *fmt
)
1517 bool have_p
= false, have_s
= false, have_f
= false, have_c
= false;
1518 char ip6_addr
[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") +
1519 sizeof(":12345") + sizeof("/123456789") +
1520 sizeof("%1234567890")];
1521 char *p
= ip6_addr
, *pend
= ip6_addr
+ sizeof(ip6_addr
);
1522 const u8
*addr
= (const u8
*) &sa
->sin6_addr
;
1523 char fmt6
[2] = { fmt
[0], '6' };
1527 while (isalpha(*++fmt
)) {
1544 if (have_p
|| have_s
|| have_f
) {
1549 if (fmt6
[0] == 'I' && have_c
)
1550 p
= ip6_compressed_string(ip6_addr
+ off
, addr
);
1552 p
= ip6_string(ip6_addr
+ off
, addr
, fmt6
);
1554 if (have_p
|| have_s
|| have_f
)
1559 p
= number(p
, pend
, ntohs(sa
->sin6_port
), spec
);
1563 p
= number(p
, pend
, ntohl(sa
->sin6_flowinfo
&
1564 IPV6_FLOWINFO_MASK
), spec
);
1568 p
= number(p
, pend
, sa
->sin6_scope_id
, spec
);
1572 return string_nocheck(buf
, end
, ip6_addr
, spec
);
1575 static noinline_for_stack
1576 char *ip4_addr_string_sa(char *buf
, char *end
, const struct sockaddr_in
*sa
,
1577 struct printf_spec spec
, const char *fmt
)
1579 bool have_p
= false;
1580 char *p
, ip4_addr
[sizeof("255.255.255.255") + sizeof(":12345")];
1581 char *pend
= ip4_addr
+ sizeof(ip4_addr
);
1582 const u8
*addr
= (const u8
*) &sa
->sin_addr
.s_addr
;
1583 char fmt4
[3] = { fmt
[0], '4', 0 };
1586 while (isalpha(*++fmt
)) {
1600 p
= ip4_string(ip4_addr
, addr
, fmt4
);
1603 p
= number(p
, pend
, ntohs(sa
->sin_port
), spec
);
1607 return string_nocheck(buf
, end
, ip4_addr
, spec
);
1610 static noinline_for_stack
1611 char *ip_addr_string(char *buf
, char *end
, const void *ptr
,
1612 struct printf_spec spec
, const char *fmt
)
1616 if (check_pointer(&buf
, end
, ptr
, spec
))
1621 return ip6_addr_string(buf
, end
, ptr
, spec
, fmt
);
1623 return ip4_addr_string(buf
, end
, ptr
, spec
, fmt
);
1626 struct sockaddr raw
;
1627 struct sockaddr_in v4
;
1628 struct sockaddr_in6 v6
;
1631 switch (sa
->raw
.sa_family
) {
1633 return ip4_addr_string_sa(buf
, end
, &sa
->v4
, spec
, fmt
);
1635 return ip6_addr_string_sa(buf
, end
, &sa
->v6
, spec
, fmt
);
1637 return error_string(buf
, end
, "(einval)", spec
);
1641 err_fmt_msg
= fmt
[0] == 'i' ? "(%pi?)" : "(%pI?)";
1642 return error_string(buf
, end
, err_fmt_msg
, spec
);
1645 static noinline_for_stack
1646 char *escaped_string(char *buf
, char *end
, u8
*addr
, struct printf_spec spec
,
1651 unsigned int flags
= 0;
1654 if (spec
.field_width
== 0)
1655 return buf
; /* nothing to print */
1657 if (check_pointer(&buf
, end
, addr
, spec
))
1661 switch (fmt
[count
++]) {
1663 flags
|= ESCAPE_ANY
;
1666 flags
|= ESCAPE_SPECIAL
;
1669 flags
|= ESCAPE_HEX
;
1672 flags
|= ESCAPE_NULL
;
1675 flags
|= ESCAPE_OCTAL
;
1681 flags
|= ESCAPE_SPACE
;
1690 flags
= ESCAPE_ANY_NP
;
1692 len
= spec
.field_width
< 0 ? 1 : spec
.field_width
;
1695 * string_escape_mem() writes as many characters as it can to
1696 * the given buffer, and returns the total size of the output
1697 * had the buffer been big enough.
1699 buf
+= string_escape_mem(addr
, len
, buf
, buf
< end
? end
- buf
: 0, flags
, NULL
);
1704 static char *va_format(char *buf
, char *end
, struct va_format
*va_fmt
,
1705 struct printf_spec spec
, const char *fmt
)
1709 if (check_pointer(&buf
, end
, va_fmt
, spec
))
1712 va_copy(va
, *va_fmt
->va
);
1713 buf
+= vsnprintf(buf
, end
> buf
? end
- buf
: 0, va_fmt
->fmt
, va
);
1719 static noinline_for_stack
1720 char *uuid_string(char *buf
, char *end
, const u8
*addr
,
1721 struct printf_spec spec
, const char *fmt
)
1723 char uuid
[UUID_STRING_LEN
+ 1];
1726 const u8
*index
= uuid_index
;
1729 if (check_pointer(&buf
, end
, addr
, spec
))
1744 for (i
= 0; i
< 16; i
++) {
1746 p
= hex_byte_pack_upper(p
, addr
[index
[i
]]);
1748 p
= hex_byte_pack(p
, addr
[index
[i
]]);
1761 return string_nocheck(buf
, end
, uuid
, spec
);
1764 static noinline_for_stack
1765 char *netdev_bits(char *buf
, char *end
, const void *addr
,
1766 struct printf_spec spec
, const char *fmt
)
1768 unsigned long long num
;
1771 if (check_pointer(&buf
, end
, addr
, spec
))
1776 num
= *(const netdev_features_t
*)addr
;
1777 size
= sizeof(netdev_features_t
);
1780 return error_string(buf
, end
, "(%pN?)", spec
);
1783 return special_hex_number(buf
, end
, num
, size
);
1786 static noinline_for_stack
1787 char *fourcc_string(char *buf
, char *end
, const u32
*fourcc
,
1788 struct printf_spec spec
, const char *fmt
)
1790 char output
[sizeof("0123 little-endian (0x01234567)")];
1795 if (fmt
[1] != 'c' || fmt
[2] != 'c')
1796 return error_string(buf
, end
, "(%p4?)", spec
);
1798 if (check_pointer(&buf
, end
, fourcc
, spec
))
1801 orig
= get_unaligned(fourcc
);
1802 val
= orig
& ~BIT(31);
1804 for (i
= 0; i
< sizeof(u32
); i
++) {
1805 unsigned char c
= val
>> (i
* 8);
1807 /* Print non-control ASCII characters as-is, dot otherwise */
1808 *p
++ = isascii(c
) && isprint(c
) ? c
: '.';
1811 strcpy(p
, orig
& BIT(31) ? " big-endian" : " little-endian");
1816 p
= special_hex_number(p
, output
+ sizeof(output
) - 2, orig
, sizeof(u32
));
1820 return string(buf
, end
, output
, spec
);
1823 static noinline_for_stack
1824 char *address_val(char *buf
, char *end
, const void *addr
,
1825 struct printf_spec spec
, const char *fmt
)
1827 unsigned long long num
;
1830 if (check_pointer(&buf
, end
, addr
, spec
))
1835 num
= *(const dma_addr_t
*)addr
;
1836 size
= sizeof(dma_addr_t
);
1840 num
= *(const phys_addr_t
*)addr
;
1841 size
= sizeof(phys_addr_t
);
1845 return special_hex_number(buf
, end
, num
, size
);
1848 static noinline_for_stack
1849 char *date_str(char *buf
, char *end
, const struct rtc_time
*tm
, bool r
)
1851 int year
= tm
->tm_year
+ (r
? 0 : 1900);
1852 int mon
= tm
->tm_mon
+ (r
? 0 : 1);
1854 buf
= number(buf
, end
, year
, default_dec04_spec
);
1859 buf
= number(buf
, end
, mon
, default_dec02_spec
);
1864 return number(buf
, end
, tm
->tm_mday
, default_dec02_spec
);
1867 static noinline_for_stack
1868 char *time_str(char *buf
, char *end
, const struct rtc_time
*tm
, bool r
)
1870 buf
= number(buf
, end
, tm
->tm_hour
, default_dec02_spec
);
1875 buf
= number(buf
, end
, tm
->tm_min
, default_dec02_spec
);
1880 return number(buf
, end
, tm
->tm_sec
, default_dec02_spec
);
1883 static noinline_for_stack
1884 char *rtc_str(char *buf
, char *end
, const struct rtc_time
*tm
,
1885 struct printf_spec spec
, const char *fmt
)
1887 bool have_t
= true, have_d
= true;
1888 bool raw
= false, iso8601_separator
= true;
1892 if (check_pointer(&buf
, end
, tm
, spec
))
1895 switch (fmt
[count
]) {
1907 switch (fmt
[count
++]) {
1912 iso8601_separator
= false;
1921 buf
= date_str(buf
, end
, tm
, raw
);
1922 if (have_d
&& have_t
) {
1924 *buf
= iso8601_separator
? 'T' : ' ';
1928 buf
= time_str(buf
, end
, tm
, raw
);
1933 static noinline_for_stack
1934 char *time64_str(char *buf
, char *end
, const time64_t time
,
1935 struct printf_spec spec
, const char *fmt
)
1937 struct rtc_time rtc_time
;
1940 time64_to_tm(time
, 0, &tm
);
1942 rtc_time
.tm_sec
= tm
.tm_sec
;
1943 rtc_time
.tm_min
= tm
.tm_min
;
1944 rtc_time
.tm_hour
= tm
.tm_hour
;
1945 rtc_time
.tm_mday
= tm
.tm_mday
;
1946 rtc_time
.tm_mon
= tm
.tm_mon
;
1947 rtc_time
.tm_year
= tm
.tm_year
;
1948 rtc_time
.tm_wday
= tm
.tm_wday
;
1949 rtc_time
.tm_yday
= tm
.tm_yday
;
1951 rtc_time
.tm_isdst
= 0;
1953 return rtc_str(buf
, end
, &rtc_time
, spec
, fmt
);
1956 static noinline_for_stack
1957 char *time_and_date(char *buf
, char *end
, void *ptr
, struct printf_spec spec
,
1962 return rtc_str(buf
, end
, (const struct rtc_time
*)ptr
, spec
, fmt
);
1964 return time64_str(buf
, end
, *(const time64_t
*)ptr
, spec
, fmt
);
1966 return error_string(buf
, end
, "(%pt?)", spec
);
1970 static noinline_for_stack
1971 char *clock(char *buf
, char *end
, struct clk
*clk
, struct printf_spec spec
,
1974 if (!IS_ENABLED(CONFIG_HAVE_CLK
))
1975 return error_string(buf
, end
, "(%pC?)", spec
);
1977 if (check_pointer(&buf
, end
, clk
, spec
))
1983 #ifdef CONFIG_COMMON_CLK
1984 return string(buf
, end
, __clk_get_name(clk
), spec
);
1986 return ptr_to_id(buf
, end
, clk
, spec
);
1992 char *format_flags(char *buf
, char *end
, unsigned long flags
,
1993 const struct trace_print_flags
*names
)
1997 for ( ; flags
&& names
->name
; names
++) {
1999 if ((flags
& mask
) != mask
)
2002 buf
= string(buf
, end
, names
->name
, default_str_spec
);
2013 buf
= number(buf
, end
, flags
, default_flag_spec
);
2018 struct page_flags_fields
{
2022 const struct printf_spec
*spec
;
2026 static const struct page_flags_fields pff
[] = {
2027 {SECTIONS_WIDTH
, SECTIONS_PGSHIFT
, SECTIONS_MASK
,
2028 &default_dec_spec
, "section"},
2029 {NODES_WIDTH
, NODES_PGSHIFT
, NODES_MASK
,
2030 &default_dec_spec
, "node"},
2031 {ZONES_WIDTH
, ZONES_PGSHIFT
, ZONES_MASK
,
2032 &default_dec_spec
, "zone"},
2033 {LAST_CPUPID_WIDTH
, LAST_CPUPID_PGSHIFT
, LAST_CPUPID_MASK
,
2034 &default_flag_spec
, "lastcpupid"},
2035 {KASAN_TAG_WIDTH
, KASAN_TAG_PGSHIFT
, KASAN_TAG_MASK
,
2036 &default_flag_spec
, "kasantag"},
2040 char *format_page_flags(char *buf
, char *end
, unsigned long flags
)
2042 unsigned long main_flags
= flags
& PAGEFLAGS_MASK
;
2043 bool append
= false;
2046 /* Page flags from the main area. */
2048 buf
= format_flags(buf
, end
, main_flags
, pageflag_names
);
2052 /* Page flags from the fields area */
2053 for (i
= 0; i
< ARRAY_SIZE(pff
); i
++) {
2054 /* Skip undefined fields. */
2058 /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */
2065 buf
= string(buf
, end
, pff
[i
].name
, default_str_spec
);
2069 buf
= number(buf
, end
, (flags
>> pff
[i
].shift
) & pff
[i
].mask
,
2078 static noinline_for_stack
2079 char *flags_string(char *buf
, char *end
, void *flags_ptr
,
2080 struct printf_spec spec
, const char *fmt
)
2082 unsigned long flags
;
2083 const struct trace_print_flags
*names
;
2085 if (check_pointer(&buf
, end
, flags_ptr
, spec
))
2090 return format_page_flags(buf
, end
, *(unsigned long *)flags_ptr
);
2092 flags
= *(unsigned long *)flags_ptr
;
2093 names
= vmaflag_names
;
2096 flags
= (__force
unsigned long)(*(gfp_t
*)flags_ptr
);
2097 names
= gfpflag_names
;
2100 return error_string(buf
, end
, "(%pG?)", spec
);
2103 return format_flags(buf
, end
, flags
, names
);
2106 static noinline_for_stack
2107 char *fwnode_full_name_string(struct fwnode_handle
*fwnode
, char *buf
,
2112 /* Loop starting from the root node to the current node. */
2113 for (depth
= fwnode_count_parents(fwnode
); depth
>= 0; depth
--) {
2114 struct fwnode_handle
*__fwnode
=
2115 fwnode_get_nth_parent(fwnode
, depth
);
2117 buf
= string(buf
, end
, fwnode_get_name_prefix(__fwnode
),
2119 buf
= string(buf
, end
, fwnode_get_name(__fwnode
),
2122 fwnode_handle_put(__fwnode
);
2128 static noinline_for_stack
2129 char *device_node_string(char *buf
, char *end
, struct device_node
*dn
,
2130 struct printf_spec spec
, const char *fmt
)
2132 char tbuf
[sizeof("xxxx") + 1];
2135 char *buf_start
= buf
;
2136 struct property
*prop
;
2137 bool has_mult
, pass
;
2139 struct printf_spec str_spec
= spec
;
2140 str_spec
.field_width
= -1;
2143 return error_string(buf
, end
, "(%pO?)", spec
);
2145 if (!IS_ENABLED(CONFIG_OF
))
2146 return error_string(buf
, end
, "(%pOF?)", spec
);
2148 if (check_pointer(&buf
, end
, dn
, spec
))
2151 /* simple case without anything any more format specifiers */
2153 if (fmt
[0] == '\0' || strcspn(fmt
,"fnpPFcC") > 0)
2156 for (pass
= false; strspn(fmt
,"fnpPFcC"); fmt
++, pass
= true) {
2165 case 'f': /* full_name */
2166 buf
= fwnode_full_name_string(of_fwnode_handle(dn
), buf
,
2169 case 'n': /* name */
2170 p
= fwnode_get_name(of_fwnode_handle(dn
));
2171 precision
= str_spec
.precision
;
2172 str_spec
.precision
= strchrnul(p
, '@') - p
;
2173 buf
= string(buf
, end
, p
, str_spec
);
2174 str_spec
.precision
= precision
;
2176 case 'p': /* phandle */
2177 buf
= number(buf
, end
, (unsigned int)dn
->phandle
, default_dec_spec
);
2179 case 'P': /* path-spec */
2180 p
= fwnode_get_name(of_fwnode_handle(dn
));
2183 buf
= string(buf
, end
, p
, str_spec
);
2185 case 'F': /* flags */
2186 tbuf
[0] = of_node_check_flag(dn
, OF_DYNAMIC
) ? 'D' : '-';
2187 tbuf
[1] = of_node_check_flag(dn
, OF_DETACHED
) ? 'd' : '-';
2188 tbuf
[2] = of_node_check_flag(dn
, OF_POPULATED
) ? 'P' : '-';
2189 tbuf
[3] = of_node_check_flag(dn
, OF_POPULATED_BUS
) ? 'B' : '-';
2191 buf
= string_nocheck(buf
, end
, tbuf
, str_spec
);
2193 case 'c': /* major compatible string */
2194 ret
= of_property_read_string(dn
, "compatible", &p
);
2196 buf
= string(buf
, end
, p
, str_spec
);
2198 case 'C': /* full compatible string */
2200 of_property_for_each_string(dn
, "compatible", prop
, p
) {
2202 buf
= string_nocheck(buf
, end
, ",", str_spec
);
2203 buf
= string_nocheck(buf
, end
, "\"", str_spec
);
2204 buf
= string(buf
, end
, p
, str_spec
);
2205 buf
= string_nocheck(buf
, end
, "\"", str_spec
);
2215 return widen_string(buf
, buf
- buf_start
, end
, spec
);
2218 static noinline_for_stack
2219 char *fwnode_string(char *buf
, char *end
, struct fwnode_handle
*fwnode
,
2220 struct printf_spec spec
, const char *fmt
)
2222 struct printf_spec str_spec
= spec
;
2223 char *buf_start
= buf
;
2225 str_spec
.field_width
= -1;
2228 return error_string(buf
, end
, "(%pf?)", spec
);
2230 if (check_pointer(&buf
, end
, fwnode
, spec
))
2236 case 'P': /* name */
2237 buf
= string(buf
, end
, fwnode_get_name(fwnode
), str_spec
);
2239 case 'f': /* full_name */
2241 buf
= fwnode_full_name_string(fwnode
, buf
, end
);
2245 return widen_string(buf
, buf
- buf_start
, end
, spec
);
2248 int __init
no_hash_pointers_enable(char *str
)
2250 if (no_hash_pointers
)
2253 no_hash_pointers
= true;
2255 pr_warn("**********************************************************\n");
2256 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2258 pr_warn("** This system shows unhashed kernel memory addresses **\n");
2259 pr_warn("** via the console, logs, and other interfaces. This **\n");
2260 pr_warn("** might reduce the security of your system. **\n");
2262 pr_warn("** If you see this message and you are not debugging **\n");
2263 pr_warn("** the kernel, report this immediately to your system **\n");
2264 pr_warn("** administrator! **\n");
2266 pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n");
2267 pr_warn("**********************************************************\n");
2271 early_param("no_hash_pointers", no_hash_pointers_enable
);
2274 * Show a '%p' thing. A kernel extension is that the '%p' is followed
2275 * by an extra set of alphanumeric characters that are extended format
2278 * Please update scripts/checkpatch.pl when adding/removing conversion
2279 * characters. (Search for "check for vsprintf extension").
2281 * Right now we handle:
2283 * - 'S' For symbolic direct pointers (or function descriptors) with offset
2284 * - 's' For symbolic direct pointers (or function descriptors) without offset
2285 * - '[Ss]R' as above with __builtin_extract_return_addr() translation
2286 * - 'S[R]b' as above with module build ID (for use in backtraces)
2287 * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of
2288 * %ps and %pS. Be careful when re-using these specifiers.
2289 * - 'B' For backtraced symbolic direct pointers with offset
2290 * - 'Bb' as above with module build ID (for use in backtraces)
2291 * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref]
2292 * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201]
2293 * - 'b[l]' For a bitmap, the number of bits is determined by the field
2294 * width which must be explicitly specified either as part of the
2295 * format string '%32b[l]' or through '%*b[l]', [l] selects
2296 * range-list format instead of hex format
2297 * - 'M' For a 6-byte MAC address, it prints the address in the
2298 * usual colon-separated hex notation
2299 * - 'm' For a 6-byte MAC address, it prints the hex address without colons
2300 * - 'MF' For a 6-byte MAC FDDI address, it prints the address
2301 * with a dash-separated hex notation
2302 * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth)
2303 * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way
2304 * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4)
2305 * IPv6 uses colon separated network-order 16 bit hex with leading 0's
2307 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2308 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2309 * - 'i' [46] for 'raw' IPv4/IPv6 addresses
2310 * IPv6 omits the colons (01020304...0f)
2311 * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006)
2313 * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to
2314 * [4] or [6] and is able to print port [p], flowinfo [f], scope [s]
2315 * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order
2316 * - 'I[6S]c' for IPv6 addresses printed as specified by
2317 * https://tools.ietf.org/html/rfc5952
2318 * - 'E[achnops]' For an escaped buffer, where rules are defined by combination
2319 * of the following flags (see string_escape_mem() for the
2322 * c - ESCAPE_SPECIAL
2328 * By default ESCAPE_ANY_NP is used.
2329 * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form
2330 * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
2331 * Options for %pU are:
2332 * b big endian lower case hex (default)
2333 * B big endian UPPER case hex
2334 * l little endian lower case hex
2335 * L little endian UPPER case hex
2336 * big endian output byte order is:
2337 * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15]
2338 * little endian output byte order is:
2339 * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15]
2340 * - 'V' For a struct va_format which contains a format string * and va_list *,
2341 * call vsnprintf(->format, *->va_list).
2342 * Implements a "recursive vsnprintf".
2343 * Do not use this feature without some mechanism to verify the
2344 * correctness of the format string and va_list arguments.
2345 * - 'K' For a kernel pointer that should be hidden from unprivileged users.
2346 * Use only for procfs, sysfs and similar files, not printk(); please
2347 * read the documentation (path below) first.
2348 * - 'NF' For a netdev_features_t
2349 * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value.
2350 * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with
2351 * a certain separator (' ' by default):
2355 * The maximum supported length is 64 bytes of the input. Consider
2356 * to use print_hex_dump() for the larger input.
2357 * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives
2358 * (default assumed to be phys_addr_t, passed by reference)
2359 * - 'd[234]' For a dentry name (optionally 2-4 last components)
2360 * - 'D[234]' Same as 'd' but for a struct file
2361 * - 'g' For block_device name (gendisk + partition number)
2362 * - 't[RT][dt][r][s]' For time and date as represented by:
2365 * - 'C' For a clock, it prints the name (Common Clock Framework) or address
2366 * (legacy clock framework) of the clock
2367 * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address
2368 * (legacy clock framework) of the clock
2369 * - 'G' For flags to be printed as a collection of symbolic strings that would
2370 * construct the specific value. Supported flags given by option:
2371 * p page flags (see struct page) given as pointer to unsigned long
2372 * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t
2373 * v vma flags (VM_*) given as pointer to unsigned long
2374 * - 'OF[fnpPcCF]' For a device tree object
2375 * Without any optional arguments prints the full_name
2376 * f device node full_name
2377 * n device node name
2378 * p device node phandle
2379 * P device node path spec (name + @unit)
2380 * F device node flags
2381 * c major compatible string
2382 * C full compatible string
2383 * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer
2384 * Without an option prints the full name of the node
2386 * P node name, including a possible unit address
2387 * - 'x' For printing the address unmodified. Equivalent to "%lx".
2388 * Please read the documentation (path below) before using!
2389 * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of
2390 * bpf_trace_printk() where [ku] prefix specifies either kernel (k)
2391 * or user (u) memory to probe, and:
2392 * s a string, equivalent to "%s" on direct vsnprintf() use
2394 * ** When making changes please also update:
2395 * Documentation/core-api/printk-formats.rst
2397 * Note: The default behaviour (unadorned %p) is to hash the address,
2398 * rendering it useful as a unique identifier.
2400 static noinline_for_stack
2401 char *pointer(const char *fmt
, char *buf
, char *end
, void *ptr
,
2402 struct printf_spec spec
)
2407 ptr
= dereference_symbol_descriptor(ptr
);
2410 return symbol_string(buf
, end
, ptr
, spec
, fmt
);
2413 return resource_string(buf
, end
, ptr
, spec
, fmt
);
2415 return hex_string(buf
, end
, ptr
, spec
, fmt
);
2419 return bitmap_list_string(buf
, end
, ptr
, spec
, fmt
);
2421 return bitmap_string(buf
, end
, ptr
, spec
, fmt
);
2423 case 'M': /* Colon separated: 00:01:02:03:04:05 */
2424 case 'm': /* Contiguous: 000102030405 */
2426 /* [mM]R (Reverse order; Bluetooth) */
2427 return mac_address_string(buf
, end
, ptr
, spec
, fmt
);
2428 case 'I': /* Formatted IP supported
2430 * 6: 0001:0203:...:0708
2431 * 6c: 1::708 or 1::1.2.3.4
2433 case 'i': /* Contiguous:
2434 * 4: 001.002.003.004
2437 return ip_addr_string(buf
, end
, ptr
, spec
, fmt
);
2439 return escaped_string(buf
, end
, ptr
, spec
, fmt
);
2441 return uuid_string(buf
, end
, ptr
, spec
, fmt
);
2443 return va_format(buf
, end
, ptr
, spec
, fmt
);
2445 return restricted_pointer(buf
, end
, ptr
, spec
);
2447 return netdev_bits(buf
, end
, ptr
, spec
, fmt
);
2449 return fourcc_string(buf
, end
, ptr
, spec
, fmt
);
2451 return address_val(buf
, end
, ptr
, spec
, fmt
);
2453 return dentry_name(buf
, end
, ptr
, spec
, fmt
);
2455 return time_and_date(buf
, end
, ptr
, spec
, fmt
);
2457 return clock(buf
, end
, ptr
, spec
, fmt
);
2459 return file_dentry_name(buf
, end
, ptr
, spec
, fmt
);
2462 return bdev_name(buf
, end
, ptr
, spec
, fmt
);
2466 return flags_string(buf
, end
, ptr
, spec
, fmt
);
2468 return device_node_string(buf
, end
, ptr
, spec
, fmt
+ 1);
2470 return fwnode_string(buf
, end
, ptr
, spec
, fmt
+ 1);
2472 return pointer_string(buf
, end
, ptr
, spec
);
2474 /* %pe with a non-ERR_PTR gets treated as plain %p */
2476 return default_pointer(buf
, end
, ptr
, spec
);
2477 return err_ptr(buf
, end
, ptr
, spec
);
2482 return string(buf
, end
, ptr
, spec
);
2484 return error_string(buf
, end
, "(einval)", spec
);
2487 return default_pointer(buf
, end
, ptr
, spec
);
2492 * Helper function to decode printf style format.
2493 * Each call decode a token from the format and return the
2494 * number of characters read (or likely the delta where it wants
2495 * to go on the next call).
2496 * The decoded token is returned through the parameters
2498 * 'h', 'l', or 'L' for integer fields
2499 * 'z' support added 23/7/1999 S.H.
2500 * 'z' changed to 'Z' --davidm 1/25/99
2501 * 'Z' changed to 'z' --adobriyan 2017-01-25
2502 * 't' added for ptrdiff_t
2504 * @fmt: the format string
2505 * @type of the token returned
2506 * @flags: various flags such as +, -, # tokens..
2507 * @field_width: overwritten width
2508 * @base: base of the number (octal, hex, ...)
2509 * @precision: precision of a number
2510 * @qualifier: qualifier of a number (long, size_t, ...)
2512 static noinline_for_stack
2513 int format_decode(const char *fmt
, struct printf_spec
*spec
)
2515 const char *start
= fmt
;
2518 /* we finished early by reading the field width */
2519 if (spec
->type
== FORMAT_TYPE_WIDTH
) {
2520 if (spec
->field_width
< 0) {
2521 spec
->field_width
= -spec
->field_width
;
2522 spec
->flags
|= LEFT
;
2524 spec
->type
= FORMAT_TYPE_NONE
;
2528 /* we finished early by reading the precision */
2529 if (spec
->type
== FORMAT_TYPE_PRECISION
) {
2530 if (spec
->precision
< 0)
2531 spec
->precision
= 0;
2533 spec
->type
= FORMAT_TYPE_NONE
;
2538 spec
->type
= FORMAT_TYPE_NONE
;
2540 for (; *fmt
; ++fmt
) {
2545 /* Return the current non-format string */
2546 if (fmt
!= start
|| !*fmt
)
2552 while (1) { /* this also skips first '%' */
2558 case '-': spec
->flags
|= LEFT
; break;
2559 case '+': spec
->flags
|= PLUS
; break;
2560 case ' ': spec
->flags
|= SPACE
; break;
2561 case '#': spec
->flags
|= SPECIAL
; break;
2562 case '0': spec
->flags
|= ZEROPAD
; break;
2563 default: found
= false;
2570 /* get field width */
2571 spec
->field_width
= -1;
2574 spec
->field_width
= skip_atoi(&fmt
);
2575 else if (*fmt
== '*') {
2576 /* it's the next argument */
2577 spec
->type
= FORMAT_TYPE_WIDTH
;
2578 return ++fmt
- start
;
2582 /* get the precision */
2583 spec
->precision
= -1;
2586 if (isdigit(*fmt
)) {
2587 spec
->precision
= skip_atoi(&fmt
);
2588 if (spec
->precision
< 0)
2589 spec
->precision
= 0;
2590 } else if (*fmt
== '*') {
2591 /* it's the next argument */
2592 spec
->type
= FORMAT_TYPE_PRECISION
;
2593 return ++fmt
- start
;
2598 /* get the conversion qualifier */
2600 if (*fmt
== 'h' || _tolower(*fmt
) == 'l' ||
2601 *fmt
== 'z' || *fmt
== 't') {
2603 if (unlikely(qualifier
== *fmt
)) {
2604 if (qualifier
== 'l') {
2607 } else if (qualifier
== 'h') {
2618 spec
->type
= FORMAT_TYPE_CHAR
;
2619 return ++fmt
- start
;
2622 spec
->type
= FORMAT_TYPE_STR
;
2623 return ++fmt
- start
;
2626 spec
->type
= FORMAT_TYPE_PTR
;
2627 return ++fmt
- start
;
2630 spec
->type
= FORMAT_TYPE_PERCENT_CHAR
;
2631 return ++fmt
- start
;
2633 /* integer number formats - set up the flags and "break" */
2639 spec
->flags
|= SMALL
;
2648 spec
->flags
|= SIGN
;
2655 * Since %n poses a greater security risk than
2656 * utility, treat it as any other invalid or
2657 * unsupported format specifier.
2662 WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt
);
2663 spec
->type
= FORMAT_TYPE_INVALID
;
2667 if (qualifier
== 'L')
2668 spec
->type
= FORMAT_TYPE_LONG_LONG
;
2669 else if (qualifier
== 'l') {
2670 BUILD_BUG_ON(FORMAT_TYPE_ULONG
+ SIGN
!= FORMAT_TYPE_LONG
);
2671 spec
->type
= FORMAT_TYPE_ULONG
+ (spec
->flags
& SIGN
);
2672 } else if (qualifier
== 'z') {
2673 spec
->type
= FORMAT_TYPE_SIZE_T
;
2674 } else if (qualifier
== 't') {
2675 spec
->type
= FORMAT_TYPE_PTRDIFF
;
2676 } else if (qualifier
== 'H') {
2677 BUILD_BUG_ON(FORMAT_TYPE_UBYTE
+ SIGN
!= FORMAT_TYPE_BYTE
);
2678 spec
->type
= FORMAT_TYPE_UBYTE
+ (spec
->flags
& SIGN
);
2679 } else if (qualifier
== 'h') {
2680 BUILD_BUG_ON(FORMAT_TYPE_USHORT
+ SIGN
!= FORMAT_TYPE_SHORT
);
2681 spec
->type
= FORMAT_TYPE_USHORT
+ (spec
->flags
& SIGN
);
2683 BUILD_BUG_ON(FORMAT_TYPE_UINT
+ SIGN
!= FORMAT_TYPE_INT
);
2684 spec
->type
= FORMAT_TYPE_UINT
+ (spec
->flags
& SIGN
);
2687 return ++fmt
- start
;
2691 set_field_width(struct printf_spec
*spec
, int width
)
2693 spec
->field_width
= width
;
2694 if (WARN_ONCE(spec
->field_width
!= width
, "field width %d too large", width
)) {
2695 spec
->field_width
= clamp(width
, -FIELD_WIDTH_MAX
, FIELD_WIDTH_MAX
);
2700 set_precision(struct printf_spec
*spec
, int prec
)
2702 spec
->precision
= prec
;
2703 if (WARN_ONCE(spec
->precision
!= prec
, "precision %d too large", prec
)) {
2704 spec
->precision
= clamp(prec
, 0, PRECISION_MAX
);
2709 * vsnprintf - Format a string and place it in a buffer
2710 * @buf: The buffer to place the result into
2711 * @size: The size of the buffer, including the trailing null space
2712 * @fmt: The format string to use
2713 * @args: Arguments for the format string
2715 * This function generally follows C99 vsnprintf, but has some
2716 * extensions and a few limitations:
2718 * - ``%n`` is unsupported
2719 * - ``%p*`` is handled by pointer()
2721 * See pointer() or Documentation/core-api/printk-formats.rst for more
2722 * extensive description.
2724 * **Please update the documentation in both places when making changes**
2726 * The return value is the number of characters which would
2727 * be generated for the given input, excluding the trailing
2728 * '\0', as per ISO C99. If you want to have the exact
2729 * number of characters written into @buf as return value
2730 * (not including the trailing '\0'), use vscnprintf(). If the
2731 * return is greater than or equal to @size, the resulting
2732 * string is truncated.
2734 * If you're not already dealing with a va_list consider using snprintf().
2736 int vsnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
)
2738 unsigned long long num
;
2740 struct printf_spec spec
= {0};
2742 /* Reject out-of-range values early. Large positive sizes are
2743 used for unknown buffer sizes. */
2744 if (WARN_ON_ONCE(size
> INT_MAX
))
2750 /* Make sure end is always >= buf */
2757 const char *old_fmt
= fmt
;
2758 int read
= format_decode(fmt
, &spec
);
2762 switch (spec
.type
) {
2763 case FORMAT_TYPE_NONE
: {
2766 if (copy
> end
- str
)
2768 memcpy(str
, old_fmt
, copy
);
2774 case FORMAT_TYPE_WIDTH
:
2775 set_field_width(&spec
, va_arg(args
, int));
2778 case FORMAT_TYPE_PRECISION
:
2779 set_precision(&spec
, va_arg(args
, int));
2782 case FORMAT_TYPE_CHAR
: {
2785 if (!(spec
.flags
& LEFT
)) {
2786 while (--spec
.field_width
> 0) {
2793 c
= (unsigned char) va_arg(args
, int);
2797 while (--spec
.field_width
> 0) {
2805 case FORMAT_TYPE_STR
:
2806 str
= string(str
, end
, va_arg(args
, char *), spec
);
2809 case FORMAT_TYPE_PTR
:
2810 str
= pointer(fmt
, str
, end
, va_arg(args
, void *),
2812 while (isalnum(*fmt
))
2816 case FORMAT_TYPE_PERCENT_CHAR
:
2822 case FORMAT_TYPE_INVALID
:
2824 * Presumably the arguments passed gcc's type
2825 * checking, but there is no safe or sane way
2826 * for us to continue parsing the format and
2827 * fetching from the va_list; the remaining
2828 * specifiers and arguments would be out of
2834 switch (spec
.type
) {
2835 case FORMAT_TYPE_LONG_LONG
:
2836 num
= va_arg(args
, long long);
2838 case FORMAT_TYPE_ULONG
:
2839 num
= va_arg(args
, unsigned long);
2841 case FORMAT_TYPE_LONG
:
2842 num
= va_arg(args
, long);
2844 case FORMAT_TYPE_SIZE_T
:
2845 if (spec
.flags
& SIGN
)
2846 num
= va_arg(args
, ssize_t
);
2848 num
= va_arg(args
, size_t);
2850 case FORMAT_TYPE_PTRDIFF
:
2851 num
= va_arg(args
, ptrdiff_t);
2853 case FORMAT_TYPE_UBYTE
:
2854 num
= (unsigned char) va_arg(args
, int);
2856 case FORMAT_TYPE_BYTE
:
2857 num
= (signed char) va_arg(args
, int);
2859 case FORMAT_TYPE_USHORT
:
2860 num
= (unsigned short) va_arg(args
, int);
2862 case FORMAT_TYPE_SHORT
:
2863 num
= (short) va_arg(args
, int);
2865 case FORMAT_TYPE_INT
:
2866 num
= (int) va_arg(args
, int);
2869 num
= va_arg(args
, unsigned int);
2872 str
= number(str
, end
, num
, spec
);
2884 /* the trailing null byte doesn't count towards the total */
2888 EXPORT_SYMBOL(vsnprintf
);
2891 * vscnprintf - Format a string and place it in a buffer
2892 * @buf: The buffer to place the result into
2893 * @size: The size of the buffer, including the trailing null space
2894 * @fmt: The format string to use
2895 * @args: Arguments for the format string
2897 * The return value is the number of characters which have been written into
2898 * the @buf not including the trailing '\0'. If @size is == 0 the function
2901 * If you're not already dealing with a va_list consider using scnprintf().
2903 * See the vsnprintf() documentation for format string extensions over C99.
2905 int vscnprintf(char *buf
, size_t size
, const char *fmt
, va_list args
)
2909 i
= vsnprintf(buf
, size
, fmt
, args
);
2911 if (likely(i
< size
))
2917 EXPORT_SYMBOL(vscnprintf
);
2920 * snprintf - Format a string and place it in a buffer
2921 * @buf: The buffer to place the result into
2922 * @size: The size of the buffer, including the trailing null space
2923 * @fmt: The format string to use
2924 * @...: Arguments for the format string
2926 * The return value is the number of characters which would be
2927 * generated for the given input, excluding the trailing null,
2928 * as per ISO C99. If the return is greater than or equal to
2929 * @size, the resulting string is truncated.
2931 * See the vsnprintf() documentation for format string extensions over C99.
2933 int snprintf(char *buf
, size_t size
, const char *fmt
, ...)
2938 va_start(args
, fmt
);
2939 i
= vsnprintf(buf
, size
, fmt
, args
);
2944 EXPORT_SYMBOL(snprintf
);
2947 * scnprintf - Format a string and place it in a buffer
2948 * @buf: The buffer to place the result into
2949 * @size: The size of the buffer, including the trailing null space
2950 * @fmt: The format string to use
2951 * @...: Arguments for the format string
2953 * The return value is the number of characters written into @buf not including
2954 * the trailing '\0'. If @size is == 0 the function returns 0.
2957 int scnprintf(char *buf
, size_t size
, const char *fmt
, ...)
2962 va_start(args
, fmt
);
2963 i
= vscnprintf(buf
, size
, fmt
, args
);
2968 EXPORT_SYMBOL(scnprintf
);
2971 * vsprintf - Format a string and place it in a buffer
2972 * @buf: The buffer to place the result into
2973 * @fmt: The format string to use
2974 * @args: Arguments for the format string
2976 * The function returns the number of characters written
2977 * into @buf. Use vsnprintf() or vscnprintf() in order to avoid
2980 * If you're not already dealing with a va_list consider using sprintf().
2982 * See the vsnprintf() documentation for format string extensions over C99.
2984 int vsprintf(char *buf
, const char *fmt
, va_list args
)
2986 return vsnprintf(buf
, INT_MAX
, fmt
, args
);
2988 EXPORT_SYMBOL(vsprintf
);
2991 * sprintf - Format a string and place it in a buffer
2992 * @buf: The buffer to place the result into
2993 * @fmt: The format string to use
2994 * @...: Arguments for the format string
2996 * The function returns the number of characters written
2997 * into @buf. Use snprintf() or scnprintf() in order to avoid
3000 * See the vsnprintf() documentation for format string extensions over C99.
3002 int sprintf(char *buf
, const char *fmt
, ...)
3007 va_start(args
, fmt
);
3008 i
= vsnprintf(buf
, INT_MAX
, fmt
, args
);
3013 EXPORT_SYMBOL(sprintf
);
3015 #ifdef CONFIG_BINARY_PRINTF
3018 * vbin_printf() - VA arguments to binary data
3019 * bstr_printf() - Binary data to text string
3023 * vbin_printf - Parse a format string and place args' binary value in a buffer
3024 * @bin_buf: The buffer to place args' binary value
3025 * @size: The size of the buffer(by words(32bits), not characters)
3026 * @fmt: The format string to use
3027 * @args: Arguments for the format string
3029 * The format follows C99 vsnprintf, except %n is ignored, and its argument
3032 * The return value is the number of words(32bits) which would be generated for
3036 * If the return value is greater than @size, the resulting bin_buf is NOT
3037 * valid for bstr_printf().
3039 int vbin_printf(u32
*bin_buf
, size_t size
, const char *fmt
, va_list args
)
3041 struct printf_spec spec
= {0};
3045 str
= (char *)bin_buf
;
3046 end
= (char *)(bin_buf
+ size
);
3048 #define save_arg(type) \
3050 unsigned long long value; \
3051 if (sizeof(type) == 8) { \
3052 unsigned long long val8; \
3053 str = PTR_ALIGN(str, sizeof(u32)); \
3054 val8 = va_arg(args, unsigned long long); \
3055 if (str + sizeof(type) <= end) { \
3056 *(u32 *)str = *(u32 *)&val8; \
3057 *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \
3061 unsigned int val4; \
3062 str = PTR_ALIGN(str, sizeof(type)); \
3063 val4 = va_arg(args, int); \
3064 if (str + sizeof(type) <= end) \
3065 *(typeof(type) *)str = (type)(long)val4; \
3066 value = (unsigned long long)val4; \
3068 str += sizeof(type); \
3073 int read
= format_decode(fmt
, &spec
);
3077 switch (spec
.type
) {
3078 case FORMAT_TYPE_NONE
:
3079 case FORMAT_TYPE_PERCENT_CHAR
:
3081 case FORMAT_TYPE_INVALID
:
3084 case FORMAT_TYPE_WIDTH
:
3085 case FORMAT_TYPE_PRECISION
:
3086 width
= (int)save_arg(int);
3087 /* Pointers may require the width */
3089 set_field_width(&spec
, width
);
3092 case FORMAT_TYPE_CHAR
:
3096 case FORMAT_TYPE_STR
: {
3097 const char *save_str
= va_arg(args
, char *);
3098 const char *err_msg
;
3101 err_msg
= check_pointer_msg(save_str
);
3105 len
= strlen(save_str
) + 1;
3106 if (str
+ len
< end
)
3107 memcpy(str
, save_str
, len
);
3112 case FORMAT_TYPE_PTR
:
3113 /* Dereferenced pointers must be done now */
3115 /* Dereference of functions is still OK */
3124 if (!isalnum(*fmt
)) {
3128 str
= pointer(fmt
, str
, end
, va_arg(args
, void *),
3133 end
[-1] = '\0'; /* Must be nul terminated */
3135 /* skip all alphanumeric pointer suffixes */
3136 while (isalnum(*fmt
))
3141 switch (spec
.type
) {
3143 case FORMAT_TYPE_LONG_LONG
:
3144 save_arg(long long);
3146 case FORMAT_TYPE_ULONG
:
3147 case FORMAT_TYPE_LONG
:
3148 save_arg(unsigned long);
3150 case FORMAT_TYPE_SIZE_T
:
3153 case FORMAT_TYPE_PTRDIFF
:
3154 save_arg(ptrdiff_t);
3156 case FORMAT_TYPE_UBYTE
:
3157 case FORMAT_TYPE_BYTE
:
3160 case FORMAT_TYPE_USHORT
:
3161 case FORMAT_TYPE_SHORT
:
3171 return (u32
*)(PTR_ALIGN(str
, sizeof(u32
))) - bin_buf
;
3174 EXPORT_SYMBOL_GPL(vbin_printf
);
3177 * bstr_printf - Format a string from binary arguments and place it in a buffer
3178 * @buf: The buffer to place the result into
3179 * @size: The size of the buffer, including the trailing null space
3180 * @fmt: The format string to use
3181 * @bin_buf: Binary arguments for the format string
3183 * This function like C99 vsnprintf, but the difference is that vsnprintf gets
3184 * arguments from stack, and bstr_printf gets arguments from @bin_buf which is
3185 * a binary buffer that generated by vbin_printf.
3187 * The format follows C99 vsnprintf, but has some extensions:
3188 * see vsnprintf comment for details.
3190 * The return value is the number of characters which would
3191 * be generated for the given input, excluding the trailing
3192 * '\0', as per ISO C99. If you want to have the exact
3193 * number of characters written into @buf as return value
3194 * (not including the trailing '\0'), use vscnprintf(). If the
3195 * return is greater than or equal to @size, the resulting
3196 * string is truncated.
3198 int bstr_printf(char *buf
, size_t size
, const char *fmt
, const u32
*bin_buf
)
3200 struct printf_spec spec
= {0};
3202 const char *args
= (const char *)bin_buf
;
3204 if (WARN_ON_ONCE(size
> INT_MAX
))
3210 #define get_arg(type) \
3212 typeof(type) value; \
3213 if (sizeof(type) == 8) { \
3214 args = PTR_ALIGN(args, sizeof(u32)); \
3215 *(u32 *)&value = *(u32 *)args; \
3216 *((u32 *)&value + 1) = *(u32 *)(args + 4); \
3218 args = PTR_ALIGN(args, sizeof(type)); \
3219 value = *(typeof(type) *)args; \
3221 args += sizeof(type); \
3225 /* Make sure end is always >= buf */
3232 const char *old_fmt
= fmt
;
3233 int read
= format_decode(fmt
, &spec
);
3237 switch (spec
.type
) {
3238 case FORMAT_TYPE_NONE
: {
3241 if (copy
> end
- str
)
3243 memcpy(str
, old_fmt
, copy
);
3249 case FORMAT_TYPE_WIDTH
:
3250 set_field_width(&spec
, get_arg(int));
3253 case FORMAT_TYPE_PRECISION
:
3254 set_precision(&spec
, get_arg(int));
3257 case FORMAT_TYPE_CHAR
: {
3260 if (!(spec
.flags
& LEFT
)) {
3261 while (--spec
.field_width
> 0) {
3267 c
= (unsigned char) get_arg(char);
3271 while (--spec
.field_width
> 0) {
3279 case FORMAT_TYPE_STR
: {
3280 const char *str_arg
= args
;
3281 args
+= strlen(str_arg
) + 1;
3282 str
= string(str
, end
, (char *)str_arg
, spec
);
3286 case FORMAT_TYPE_PTR
: {
3287 bool process
= false;
3289 /* Non function dereferences were already done */
3299 if (!isalnum(*fmt
)) {
3303 /* Pointer dereference was already processed */
3305 len
= copy
= strlen(args
);
3306 if (copy
> end
- str
)
3308 memcpy(str
, args
, copy
);
3314 str
= pointer(fmt
, str
, end
, get_arg(void *), spec
);
3316 while (isalnum(*fmt
))
3321 case FORMAT_TYPE_PERCENT_CHAR
:
3327 case FORMAT_TYPE_INVALID
:
3331 unsigned long long num
;
3333 switch (spec
.type
) {
3335 case FORMAT_TYPE_LONG_LONG
:
3336 num
= get_arg(long long);
3338 case FORMAT_TYPE_ULONG
:
3339 case FORMAT_TYPE_LONG
:
3340 num
= get_arg(unsigned long);
3342 case FORMAT_TYPE_SIZE_T
:
3343 num
= get_arg(size_t);
3345 case FORMAT_TYPE_PTRDIFF
:
3346 num
= get_arg(ptrdiff_t);
3348 case FORMAT_TYPE_UBYTE
:
3349 num
= get_arg(unsigned char);
3351 case FORMAT_TYPE_BYTE
:
3352 num
= get_arg(signed char);
3354 case FORMAT_TYPE_USHORT
:
3355 num
= get_arg(unsigned short);
3357 case FORMAT_TYPE_SHORT
:
3358 num
= get_arg(short);
3360 case FORMAT_TYPE_UINT
:
3361 num
= get_arg(unsigned int);
3367 str
= number(str
, end
, num
, spec
);
3369 } /* switch(spec.type) */
3382 /* the trailing null byte doesn't count towards the total */
3385 EXPORT_SYMBOL_GPL(bstr_printf
);
3388 * bprintf - Parse a format string and place args' binary value in a buffer
3389 * @bin_buf: The buffer to place args' binary value
3390 * @size: The size of the buffer(by words(32bits), not characters)
3391 * @fmt: The format string to use
3392 * @...: Arguments for the format string
3394 * The function returns the number of words(u32) written
3397 int bprintf(u32
*bin_buf
, size_t size
, const char *fmt
, ...)
3402 va_start(args
, fmt
);
3403 ret
= vbin_printf(bin_buf
, size
, fmt
, args
);
3408 EXPORT_SYMBOL_GPL(bprintf
);
3410 #endif /* CONFIG_BINARY_PRINTF */
3413 * vsscanf - Unformat a buffer into a list of arguments
3414 * @buf: input buffer
3415 * @fmt: format of buffer
3418 int vsscanf(const char *buf
, const char *fmt
, va_list args
)
3420 const char *str
= buf
;
3428 unsigned long long u
;
3434 /* skip any white space in format */
3435 /* white space in format matches any amount of
3436 * white space, including none, in the input.
3438 if (isspace(*fmt
)) {
3439 fmt
= skip_spaces(++fmt
);
3440 str
= skip_spaces(str
);
3443 /* anything that is not a conversion must match exactly */
3444 if (*fmt
!= '%' && *fmt
) {
3445 if (*fmt
++ != *str
++)
3454 /* skip this conversion.
3455 * advance both strings to next white space
3460 while (!isspace(*fmt
) && *fmt
!= '%' && *fmt
) {
3461 /* '%*[' not yet supported, invalid format */
3466 while (!isspace(*str
) && *str
)
3471 /* get field width */
3473 if (isdigit(*fmt
)) {
3474 field_width
= skip_atoi(&fmt
);
3475 if (field_width
<= 0)
3479 /* get conversion qualifier */
3481 if (*fmt
== 'h' || _tolower(*fmt
) == 'l' ||
3484 if (unlikely(qualifier
== *fmt
)) {
3485 if (qualifier
== 'h') {
3488 } else if (qualifier
== 'l') {
3499 /* return number of characters read so far */
3500 *va_arg(args
, int *) = str
- buf
;
3514 char *s
= (char *)va_arg(args
, char*);
3515 if (field_width
== -1)
3519 } while (--field_width
> 0 && *str
);
3525 char *s
= (char *)va_arg(args
, char *);
3526 if (field_width
== -1)
3527 field_width
= SHRT_MAX
;
3528 /* first, skip leading white space in buffer */
3529 str
= skip_spaces(str
);
3531 /* now copy until next white space */
3532 while (*str
&& !isspace(*str
) && field_width
--)
3539 * Warning: This implementation of the '[' conversion specifier
3540 * deviates from its glibc counterpart in the following ways:
3541 * (1) It does NOT support ranges i.e. '-' is NOT a special
3543 * (2) It cannot match the closing bracket ']' itself
3544 * (3) A field width is required
3545 * (4) '%*[' (discard matching input) is currently not supported
3548 * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]",
3549 * buf1, buf2, buf3);
3555 char *s
= (char *)va_arg(args
, char *);
3556 DECLARE_BITMAP(set
, 256) = {0};
3557 unsigned int len
= 0;
3558 bool negate
= (*fmt
== '^');
3560 /* field width is required */
3561 if (field_width
== -1)
3567 for ( ; *fmt
&& *fmt
!= ']'; ++fmt
, ++len
)
3568 set_bit((u8
)*fmt
, set
);
3570 /* no ']' or no character set found */
3576 bitmap_complement(set
, set
, 256);
3577 /* exclude null '\0' byte */
3581 /* match must be non-empty */
3582 if (!test_bit((u8
)*str
, set
))
3585 while (test_bit((u8
)*str
, set
) && field_width
--)
3607 /* looking for '%' in str */
3612 /* invalid format; stop here */
3616 /* have some sort of integer conversion.
3617 * first, skip white space in buffer.
3619 str
= skip_spaces(str
);
3622 if (is_sign
&& digit
== '-') {
3623 if (field_width
== 1)
3630 || (base
== 16 && !isxdigit(digit
))
3631 || (base
== 10 && !isdigit(digit
))
3632 || (base
== 8 && (!isdigit(digit
) || digit
> '7'))
3633 || (base
== 0 && !isdigit(digit
)))
3637 val
.s
= simple_strntoll(str
,
3638 field_width
>= 0 ? field_width
: INT_MAX
,
3641 val
.u
= simple_strntoull(str
,
3642 field_width
>= 0 ? field_width
: INT_MAX
,
3645 switch (qualifier
) {
3646 case 'H': /* that's 'hh' in format */
3648 *va_arg(args
, signed char *) = val
.s
;
3650 *va_arg(args
, unsigned char *) = val
.u
;
3654 *va_arg(args
, short *) = val
.s
;
3656 *va_arg(args
, unsigned short *) = val
.u
;
3660 *va_arg(args
, long *) = val
.s
;
3662 *va_arg(args
, unsigned long *) = val
.u
;
3666 *va_arg(args
, long long *) = val
.s
;
3668 *va_arg(args
, unsigned long long *) = val
.u
;
3671 *va_arg(args
, size_t *) = val
.u
;
3675 *va_arg(args
, int *) = val
.s
;
3677 *va_arg(args
, unsigned int *) = val
.u
;
3689 EXPORT_SYMBOL(vsscanf
);
3692 * sscanf - Unformat a buffer into a list of arguments
3693 * @buf: input buffer
3694 * @fmt: formatting of buffer
3695 * @...: resulting arguments
3697 int sscanf(const char *buf
, const char *fmt
, ...)
3702 va_start(args
, fmt
);
3703 i
= vsscanf(buf
, fmt
, args
);
3708 EXPORT_SYMBOL(sscanf
);