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Diffstat (limited to 'lib/vsprintf.c')
| -rw-r--r-- | lib/vsprintf.c | 3727 |
1 files changed, 3727 insertions, 0 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c new file mode 100644 index 0000000000..2aa408441c --- /dev/null +++ b/lib/vsprintf.c @@ -0,0 +1,3727 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/lib/vsprintf.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + */ + +/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */ +/* + * Wirzenius wrote this portably, Torvalds fucked it up :-) + */ + +/* + * Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com> + * - changed to provide snprintf and vsnprintf functions + * So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de> + * - scnprintf and vscnprintf + */ + +#include <linux/stdarg.h> +#include <linux/build_bug.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/errname.h> +#include <linux/module.h> /* for KSYM_SYMBOL_LEN */ +#include <linux/types.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/kernel.h> +#include <linux/kallsyms.h> +#include <linux/math64.h> +#include <linux/uaccess.h> +#include <linux/ioport.h> +#include <linux/dcache.h> +#include <linux/cred.h> +#include <linux/rtc.h> +#include <linux/sprintf.h> +#include <linux/time.h> +#include <linux/uuid.h> +#include <linux/of.h> +#include <net/addrconf.h> +#include <linux/siphash.h> +#include <linux/compiler.h> +#include <linux/property.h> +#include <linux/notifier.h> +#ifdef CONFIG_BLOCK +#include <linux/blkdev.h> +#endif + +#include "../mm/internal.h" /* For the trace_print_flags arrays */ + +#include <asm/page.h> /* for PAGE_SIZE */ +#include <asm/byteorder.h> /* cpu_to_le16 */ +#include <asm/unaligned.h> + +#include <linux/string_helpers.h> +#include "kstrtox.h" + +/* Disable pointer hashing if requested */ +bool no_hash_pointers __ro_after_init; +EXPORT_SYMBOL_GPL(no_hash_pointers); + +static noinline unsigned long long simple_strntoull(const char *startp, size_t max_chars, char **endp, unsigned int base) +{ + const char *cp; + unsigned long long result = 0ULL; + size_t prefix_chars; + unsigned int rv; + + cp = _parse_integer_fixup_radix(startp, &base); + prefix_chars = cp - startp; + if (prefix_chars < max_chars) { + rv = _parse_integer_limit(cp, base, &result, max_chars - prefix_chars); + /* FIXME */ + cp += (rv & ~KSTRTOX_OVERFLOW); + } else { + /* Field too short for prefix + digit, skip over without converting */ + cp = startp + max_chars; + } + + if (endp) + *endp = (char *)cp; + + return result; +} + +/** + * simple_strtoull - convert a string to an unsigned long long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + * + * This function has caveats. Please use kstrtoull instead. + */ +noinline +unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) +{ + return simple_strntoull(cp, INT_MAX, endp, base); +} +EXPORT_SYMBOL(simple_strtoull); + +/** + * simple_strtoul - convert a string to an unsigned long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + * + * This function has caveats. Please use kstrtoul instead. + */ +unsigned long simple_strtoul(const char *cp, char **endp, unsigned int base) +{ + return simple_strtoull(cp, endp, base); +} +EXPORT_SYMBOL(simple_strtoul); + +/** + * simple_strtol - convert a string to a signed long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + * + * This function has caveats. Please use kstrtol instead. + */ +long simple_strtol(const char *cp, char **endp, unsigned int base) +{ + if (*cp == '-') + return -simple_strtoul(cp + 1, endp, base); + + return simple_strtoul(cp, endp, base); +} +EXPORT_SYMBOL(simple_strtol); + +static long long simple_strntoll(const char *cp, size_t max_chars, char **endp, + unsigned int base) +{ + /* + * simple_strntoull() safely handles receiving max_chars==0 in the + * case cp[0] == '-' && max_chars == 1. + * If max_chars == 0 we can drop through and pass it to simple_strntoull() + * and the content of *cp is irrelevant. + */ + if (*cp == '-' && max_chars > 0) + return -simple_strntoull(cp + 1, max_chars - 1, endp, base); + + return simple_strntoull(cp, max_chars, endp, base); +} + +/** + * simple_strtoll - convert a string to a signed long long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + * + * This function has caveats. Please use kstrtoll instead. + */ +long long simple_strtoll(const char *cp, char **endp, unsigned int base) +{ + return simple_strntoll(cp, INT_MAX, endp, base); +} +EXPORT_SYMBOL(simple_strtoll); + +static noinline_for_stack +int skip_atoi(const char **s) +{ + int i = 0; + + do { + i = i*10 + *((*s)++) - '0'; + } while (isdigit(**s)); + + return i; +} + +/* + * Decimal conversion is by far the most typical, and is used for + * /proc and /sys data. This directly impacts e.g. top performance + * with many processes running. We optimize it for speed by emitting + * two characters at a time, using a 200 byte lookup table. This + * roughly halves the number of multiplications compared to computing + * the digits one at a time. Implementation strongly inspired by the + * previous version, which in turn used ideas described at + * <http://www.cs.uiowa.edu/~jones/bcd/divide.html> (with permission + * from the author, Douglas W. Jones). + * + * It turns out there is precisely one 26 bit fixed-point + * approximation a of 64/100 for which x/100 == (x * (u64)a) >> 32 + * holds for all x in [0, 10^8-1], namely a = 0x28f5c29. The actual + * range happens to be somewhat larger (x <= 1073741898), but that's + * irrelevant for our purpose. + * + * For dividing a number in the range [10^4, 10^6-1] by 100, we still + * need a 32x32->64 bit multiply, so we simply use the same constant. + * + * For dividing a number in the range [100, 10^4-1] by 100, there are + * several options. The simplest is (x * 0x147b) >> 19, which is valid + * for all x <= 43698. + */ + +static const u16 decpair[100] = { +#define _(x) (__force u16) cpu_to_le16(((x % 10) | ((x / 10) << 8)) + 0x3030) + _( 0), _( 1), _( 2), _( 3), _( 4), _( 5), _( 6), _( 7), _( 8), _( 9), + _(10), _(11), _(12), _(13), _(14), _(15), _(16), _(17), _(18), _(19), + _(20), _(21), _(22), _(23), _(24), _(25), _(26), _(27), _(28), _(29), + _(30), _(31), _(32), _(33), _(34), _(35), _(36), _(37), _(38), _(39), + _(40), _(41), _(42), _(43), _(44), _(45), _(46), _(47), _(48), _(49), + _(50), _(51), _(52), _(53), _(54), _(55), _(56), _(57), _(58), _(59), + _(60), _(61), _(62), _(63), _(64), _(65), _(66), _(67), _(68), _(69), + _(70), _(71), _(72), _(73), _(74), _(75), _(76), _(77), _(78), _(79), + _(80), _(81), _(82), _(83), _(84), _(85), _(86), _(87), _(88), _(89), + _(90), _(91), _(92), _(93), _(94), _(95), _(96), _(97), _(98), _(99), +#undef _ +}; + +/* + * This will print a single '0' even if r == 0, since we would + * immediately jump to out_r where two 0s would be written but only + * one of them accounted for in buf. This is needed by ip4_string + * below. All other callers pass a non-zero value of r. +*/ +static noinline_for_stack +char *put_dec_trunc8(char *buf, unsigned r) +{ + unsigned q; + + /* 1 <= r < 10^8 */ + if (r < 100) + goto out_r; + + /* 100 <= r < 10^8 */ + q = (r * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + + /* 1 <= q < 10^6 */ + if (q < 100) + goto out_q; + + /* 100 <= q < 10^6 */ + r = (q * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[q - 100*r]; + buf += 2; + + /* 1 <= r < 10^4 */ + if (r < 100) + goto out_r; + + /* 100 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; +out_q: + /* 1 <= q < 100 */ + r = q; +out_r: + /* 1 <= r < 100 */ + *((u16 *)buf) = decpair[r]; + buf += r < 10 ? 1 : 2; + return buf; +} + +#if BITS_PER_LONG == 64 && BITS_PER_LONG_LONG == 64 +static noinline_for_stack +char *put_dec_full8(char *buf, unsigned r) +{ + unsigned q; + + /* 0 <= r < 10^8 */ + q = (r * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + + /* 0 <= q < 10^6 */ + r = (q * (u64)0x28f5c29) >> 32; + *((u16 *)buf) = decpair[q - 100*r]; + buf += 2; + + /* 0 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + + /* 0 <= q < 100 */ + *((u16 *)buf) = decpair[q]; + buf += 2; + return buf; +} + +static noinline_for_stack +char *put_dec(char *buf, unsigned long long n) +{ + if (n >= 100*1000*1000) + buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); + /* 1 <= n <= 1.6e11 */ + if (n >= 100*1000*1000) + buf = put_dec_full8(buf, do_div(n, 100*1000*1000)); + /* 1 <= n < 1e8 */ + return put_dec_trunc8(buf, n); +} + +#elif BITS_PER_LONG == 32 && BITS_PER_LONG_LONG == 64 + +static void +put_dec_full4(char *buf, unsigned r) +{ + unsigned q; + + /* 0 <= r < 10^4 */ + q = (r * 0x147b) >> 19; + *((u16 *)buf) = decpair[r - 100*q]; + buf += 2; + /* 0 <= q < 100 */ + *((u16 *)buf) = decpair[q]; +} + +/* + * Call put_dec_full4 on x % 10000, return x / 10000. + * The approximation x/10000 == (x * 0x346DC5D7) >> 43 + * holds for all x < 1,128,869,999. The largest value this + * helper will ever be asked to convert is 1,125,520,955. + * (second call in the put_dec code, assuming n is all-ones). + */ +static noinline_for_stack +unsigned put_dec_helper4(char *buf, unsigned x) +{ + uint32_t q = (x * (uint64_t)0x346DC5D7) >> 43; + + put_dec_full4(buf, x - q * 10000); + return q; +} + +/* Based on code by Douglas W. Jones found at + * <http://www.cs.uiowa.edu/~jones/bcd/decimal.html#sixtyfour> + * (with permission from the author). + * Performs no 64-bit division and hence should be fast on 32-bit machines. + */ +static +char *put_dec(char *buf, unsigned long long n) +{ + uint32_t d3, d2, d1, q, h; + + if (n < 100*1000*1000) + return put_dec_trunc8(buf, n); + + d1 = ((uint32_t)n >> 16); /* implicit "& 0xffff" */ + h = (n >> 32); + d2 = (h ) & 0xffff; + d3 = (h >> 16); /* implicit "& 0xffff" */ + + /* n = 2^48 d3 + 2^32 d2 + 2^16 d1 + d0 + = 281_4749_7671_0656 d3 + 42_9496_7296 d2 + 6_5536 d1 + d0 */ + q = 656 * d3 + 7296 * d2 + 5536 * d1 + ((uint32_t)n & 0xffff); + q = put_dec_helper4(buf, q); + + q += 7671 * d3 + 9496 * d2 + 6 * d1; + q = put_dec_helper4(buf+4, q); + + q += 4749 * d3 + 42 * d2; + q = put_dec_helper4(buf+8, q); + + q += 281 * d3; + buf += 12; + if (q) + buf = put_dec_trunc8(buf, q); + else while (buf[-1] == '0') + --buf; + + return buf; +} + +#endif + +/* + * Convert passed number to decimal string. + * Returns the length of string. On buffer overflow, returns 0. + * + * If speed is not important, use snprintf(). It's easy to read the code. + */ +int num_to_str(char *buf, int size, unsigned long long num, unsigned int width) +{ + /* put_dec requires 2-byte alignment of the buffer. */ + char tmp[sizeof(num) * 3] __aligned(2); + int idx, len; + + /* put_dec() may work incorrectly for num = 0 (generate "", not "0") */ + if (num <= 9) { + tmp[0] = '0' + num; + len = 1; + } else { + len = put_dec(tmp, num) - tmp; + } + + if (len > size || width > size) + return 0; + + if (width > len) { + width = width - len; + for (idx = 0; idx < width; idx++) + buf[idx] = ' '; + } else { + width = 0; + } + + for (idx = 0; idx < len; ++idx) + buf[idx + width] = tmp[len - idx - 1]; + + return len + width; +} + +#define SIGN 1 /* unsigned/signed, must be 1 */ +#define LEFT 2 /* left justified */ +#define PLUS 4 /* show plus */ +#define SPACE 8 /* space if plus */ +#define ZEROPAD 16 /* pad with zero, must be 16 == '0' - ' ' */ +#define SMALL 32 /* use lowercase in hex (must be 32 == 0x20) */ +#define SPECIAL 64 /* prefix hex with "0x", octal with "0" */ + +static_assert(SIGN == 1); +static_assert(ZEROPAD == ('0' - ' ')); +static_assert(SMALL == ('a' ^ 'A')); + +enum format_type { + FORMAT_TYPE_NONE, /* Just a string part */ + FORMAT_TYPE_WIDTH, + FORMAT_TYPE_PRECISION, + FORMAT_TYPE_CHAR, + FORMAT_TYPE_STR, + FORMAT_TYPE_PTR, + FORMAT_TYPE_PERCENT_CHAR, + FORMAT_TYPE_INVALID, + FORMAT_TYPE_LONG_LONG, + FORMAT_TYPE_ULONG, + FORMAT_TYPE_LONG, + FORMAT_TYPE_UBYTE, + FORMAT_TYPE_BYTE, + FORMAT_TYPE_USHORT, + FORMAT_TYPE_SHORT, + FORMAT_TYPE_UINT, + FORMAT_TYPE_INT, + FORMAT_TYPE_SIZE_T, + FORMAT_TYPE_PTRDIFF +}; + +struct printf_spec { + unsigned int type:8; /* format_type enum */ + signed int field_width:24; /* width of output field */ + unsigned int flags:8; /* flags to number() */ + unsigned int base:8; /* number base, 8, 10 or 16 only */ + signed int precision:16; /* # of digits/chars */ +} __packed; +static_assert(sizeof(struct printf_spec) == 8); + +#define FIELD_WIDTH_MAX ((1 << 23) - 1) +#define PRECISION_MAX ((1 << 15) - 1) + +static noinline_for_stack +char *number(char *buf, char *end, unsigned long long num, + struct printf_spec spec) +{ + /* put_dec requires 2-byte alignment of the buffer. */ + char tmp[3 * sizeof(num)] __aligned(2); + char sign; + char locase; + int need_pfx = ((spec.flags & SPECIAL) && spec.base != 10); + int i; + bool is_zero = num == 0LL; + int field_width = spec.field_width; + int precision = spec.precision; + + /* locase = 0 or 0x20. ORing digits or letters with 'locase' + * produces same digits or (maybe lowercased) letters */ + locase = (spec.flags & SMALL); + if (spec.flags & LEFT) + spec.flags &= ~ZEROPAD; + sign = 0; + if (spec.flags & SIGN) { + if ((signed long long)num < 0) { + sign = '-'; + num = -(signed long long)num; + field_width--; + } else if (spec.flags & PLUS) { + sign = '+'; + field_width--; + } else if (spec.flags & SPACE) { + sign = ' '; + field_width--; + } + } + if (need_pfx) { + if (spec.base == 16) + field_width -= 2; + else if (!is_zero) + field_width--; + } + + /* generate full string in tmp[], in reverse order */ + i = 0; + if (num < spec.base) + tmp[i++] = hex_asc_upper[num] | locase; + else if (spec.base != 10) { /* 8 or 16 */ + int mask = spec.base - 1; + int shift = 3; + + if (spec.base == 16) + shift = 4; + do { + tmp[i++] = (hex_asc_upper[((unsigned char)num) & mask] | locase); + num >>= shift; + } while (num); + } else { /* base 10 */ + i = put_dec(tmp, num) - tmp; + } + + /* printing 100 using %2d gives "100", not "00" */ + if (i > precision) + precision = i; + /* leading space padding */ + field_width -= precision; + if (!(spec.flags & (ZEROPAD | LEFT))) { + while (--field_width >= 0) { + if (buf < end) + *buf = ' '; + ++buf; + } + } + /* sign */ + if (sign) { + if (buf < end) + *buf = sign; + ++buf; + } + /* "0x" / "0" prefix */ + if (need_pfx) { + if (spec.base == 16 || !is_zero) { + if (buf < end) + *buf = '0'; + ++buf; + } + if (spec.base == 16) { + if (buf < end) + *buf = ('X' | locase); + ++buf; + } + } + /* zero or space padding */ + if (!(spec.flags & LEFT)) { + char c = ' ' + (spec.flags & ZEROPAD); + + while (--field_width >= 0) { + if (buf < end) + *buf = c; + ++buf; + } + } + /* hmm even more zero padding? */ + while (i <= --precision) { + if (buf < end) + *buf = '0'; + ++buf; + } + /* actual digits of result */ + while (--i >= 0) { + if (buf < end) + *buf = tmp[i]; + ++buf; + } + /* trailing space padding */ + while (--field_width >= 0) { + if (buf < end) + *buf = ' '; + ++buf; + } + + return buf; +} + +static noinline_for_stack +char *special_hex_number(char *buf, char *end, unsigned long long num, int size) +{ + struct printf_spec spec; + + spec.type = FORMAT_TYPE_PTR; + spec.field_width = 2 + 2 * size; /* 0x + hex */ + spec.flags = SPECIAL | SMALL | ZEROPAD; + spec.base = 16; + spec.precision = -1; + + return number(buf, end, num, spec); +} + +static void move_right(char *buf, char *end, unsigned len, unsigned spaces) +{ + size_t size; + if (buf >= end) /* nowhere to put anything */ + return; + size = end - buf; + if (size <= spaces) { + memset(buf, ' ', size); + return; + } + if (len) { + if (len > size - spaces) + len = size - spaces; + memmove(buf + spaces, buf, len); + } + memset(buf, ' ', spaces); +} + +/* + * Handle field width padding for a string. + * @buf: current buffer position + * @n: length of string + * @end: end of output buffer + * @spec: for field width and flags + * Returns: new buffer position after padding. + */ +static noinline_for_stack +char *widen_string(char *buf, int n, char *end, struct printf_spec spec) +{ + unsigned spaces; + + if (likely(n >= spec.field_width)) + return buf; + /* we want to pad the sucker */ + spaces = spec.field_width - n; + if (!(spec.flags & LEFT)) { + move_right(buf - n, end, n, spaces); + return buf + spaces; + } + while (spaces--) { + if (buf < end) + *buf = ' '; + ++buf; + } + return buf; +} + +/* Handle string from a well known address. */ +static char *string_nocheck(char *buf, char *end, const char *s, + struct printf_spec spec) +{ + int len = 0; + int lim = spec.precision; + + while (lim--) { + char c = *s++; + if (!c) + break; + if (buf < end) + *buf = c; + ++buf; + ++len; + } + return widen_string(buf, len, end, spec); +} + +static char *err_ptr(char *buf, char *end, void *ptr, + struct printf_spec spec) +{ + int err = PTR_ERR(ptr); + const char *sym = errname(err); + + if (sym) + return string_nocheck(buf, end, sym, spec); + + /* + * Somebody passed ERR_PTR(-1234) or some other non-existing + * Efoo - or perhaps CONFIG_SYMBOLIC_ERRNAME=n. Fall back to + * printing it as its decimal representation. + */ + spec.flags |= SIGN; + spec.base = 10; + return number(buf, end, err, spec); +} + +/* Be careful: error messages must fit into the given buffer. */ +static char *error_string(char *buf, char *end, const char *s, + struct printf_spec spec) +{ + /* + * Hard limit to avoid a completely insane messages. It actually + * works pretty well because most error messages are in + * the many pointer format modifiers. + */ + if (spec.precision == -1) + spec.precision = 2 * sizeof(void *); + + return string_nocheck(buf, end, s, spec); +} + +/* + * Do not call any complex external code here. Nested printk()/vsprintf() + * might cause infinite loops. Failures might break printk() and would + * be hard to debug. + */ +static const char *check_pointer_msg(const void *ptr) +{ + if (!ptr) + return "(null)"; + + if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr)) + return "(efault)"; + + return NULL; +} + +static int check_pointer(char **buf, char *end, const void *ptr, + struct printf_spec spec) +{ + const char *err_msg; + + err_msg = check_pointer_msg(ptr); + if (err_msg) { + *buf = error_string(*buf, end, err_msg, spec); + return -EFAULT; + } + + return 0; +} + +static noinline_for_stack +char *string(char *buf, char *end, const char *s, + struct printf_spec spec) +{ + if (check_pointer(&buf, end, s, spec)) + return buf; + + return string_nocheck(buf, end, s, spec); +} + +static char *pointer_string(char *buf, char *end, + const void *ptr, + struct printf_spec spec) +{ + spec.base = 16; + spec.flags |= SMALL; + if (spec.field_width == -1) { + spec.field_width = 2 * sizeof(ptr); + spec.flags |= ZEROPAD; + } + + return number(buf, end, (unsigned long int)ptr, spec); +} + +/* Make pointers available for printing early in the boot sequence. */ +static int debug_boot_weak_hash __ro_after_init; + +static int __init debug_boot_weak_hash_enable(char *str) +{ + debug_boot_weak_hash = 1; + pr_info("debug_boot_weak_hash enabled\n"); + return 0; +} +early_param("debug_boot_weak_hash", debug_boot_weak_hash_enable); + +static bool filled_random_ptr_key __read_mostly; +static siphash_key_t ptr_key __read_mostly; + +static int fill_ptr_key(struct notifier_block *nb, unsigned long action, void *data) +{ + get_random_bytes(&ptr_key, sizeof(ptr_key)); + + /* Pairs with smp_rmb() before reading ptr_key. */ + smp_wmb(); + WRITE_ONCE(filled_random_ptr_key, true); + return NOTIFY_DONE; +} + +static int __init vsprintf_init_hashval(void) +{ + static struct notifier_block fill_ptr_key_nb = { .notifier_call = fill_ptr_key }; + execute_with_initialized_rng(&fill_ptr_key_nb); + return 0; +} +subsys_initcall(vsprintf_init_hashval) + +/* Maps a pointer to a 32 bit unique identifier. */ +static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out) +{ + unsigned long hashval; + + if (!READ_ONCE(filled_random_ptr_key)) + return -EBUSY; + + /* Pairs with smp_wmb() after writing ptr_key. */ + smp_rmb(); + +#ifdef CONFIG_64BIT + hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key); + /* + * Mask off the first 32 bits, this makes explicit that we have + * modified the address (and 32 bits is plenty for a unique ID). + */ + hashval = hashval & 0xffffffff; +#else + hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key); +#endif + *hashval_out = hashval; + return 0; +} + +int ptr_to_hashval(const void *ptr, unsigned long *hashval_out) +{ + return __ptr_to_hashval(ptr, hashval_out); +} + +static char *ptr_to_id(char *buf, char *end, const void *ptr, + struct printf_spec spec) +{ + const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)"; + unsigned long hashval; + int ret; + + /* + * Print the real pointer value for NULL and error pointers, + * as they are not actual addresses. + */ + if (IS_ERR_OR_NULL(ptr)) + return pointer_string(buf, end, ptr, spec); + + /* When debugging early boot use non-cryptographically secure hash. */ + if (unlikely(debug_boot_weak_hash)) { + hashval = hash_long((unsigned long)ptr, 32); + return pointer_string(buf, end, (const void *)hashval, spec); + } + + ret = __ptr_to_hashval(ptr, &hashval); + if (ret) { + spec.field_width = 2 * sizeof(ptr); + /* string length must be less than default_width */ + return error_string(buf, end, str, spec); + } + + return pointer_string(buf, end, (const void *)hashval, spec); +} + +static char *default_pointer(char *buf, char *end, const void *ptr, + struct printf_spec spec) +{ + /* + * default is to _not_ leak addresses, so hash before printing, + * unless no_hash_pointers is specified on the command line. + */ + if (unlikely(no_hash_pointers)) + return pointer_string(buf, end, ptr, spec); + + return ptr_to_id(buf, end, ptr, spec); +} + +int kptr_restrict __read_mostly; + +static noinline_for_stack +char *restricted_pointer(char *buf, char *end, const void *ptr, + struct printf_spec spec) +{ + switch (kptr_restrict) { + case 0: + /* Handle as %p, hash and do _not_ leak addresses. */ + return default_pointer(buf, end, ptr, spec); + case 1: { + const struct cred *cred; + + /* + * kptr_restrict==1 cannot be used in IRQ context + * because its test for CAP_SYSLOG would be meaningless. + */ + if (in_hardirq() || in_serving_softirq() || in_nmi()) { + if (spec.field_width == -1) + spec.field_width = 2 * sizeof(ptr); + return error_string(buf, end, "pK-error", spec); + } + + /* + * Only print the real pointer value if the current + * process has CAP_SYSLOG and is running with the + * same credentials it started with. This is because + * access to files is checked at open() time, but %pK + * checks permission at read() time. We don't want to + * leak pointer values if a binary opens a file using + * %pK and then elevates privileges before reading it. + */ + cred = current_cred(); + if (!has_capability_noaudit(current, CAP_SYSLOG) || + !uid_eq(cred->euid, cred->uid) || + !gid_eq(cred->egid, cred->gid)) + ptr = NULL; + break; + } + case 2: + default: + /* Always print 0's for %pK */ + ptr = NULL; + break; + } + + return pointer_string(buf, end, ptr, spec); +} + +static noinline_for_stack +char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec, + const char *fmt) +{ + const char *array[4], *s; + const struct dentry *p; + int depth; + int i, n; + + switch (fmt[1]) { + case '2': case '3': case '4': + depth = fmt[1] - '0'; + break; + default: + depth = 1; + } + + rcu_read_lock(); + for (i = 0; i < depth; i++, d = p) { + if (check_pointer(&buf, end, d, spec)) { + rcu_read_unlock(); + return buf; + } + + p = READ_ONCE(d->d_parent); + array[i] = READ_ONCE(d->d_name.name); + if (p == d) { + if (i) + array[i] = ""; + i++; + break; + } + } + s = array[--i]; + for (n = 0; n != spec.precision; n++, buf++) { + char c = *s++; + if (!c) { + if (!i) + break; + c = '/'; + s = array[--i]; + } + if (buf < end) + *buf = c; + } + rcu_read_unlock(); + return widen_string(buf, n, end, spec); +} + +static noinline_for_stack +char *file_dentry_name(char *buf, char *end, const struct file *f, + struct printf_spec spec, const char *fmt) +{ + if (check_pointer(&buf, end, f, spec)) + return buf; + + return dentry_name(buf, end, f->f_path.dentry, spec, fmt); +} +#ifdef CONFIG_BLOCK +static noinline_for_stack +char *bdev_name(char *buf, char *end, struct block_device *bdev, + struct printf_spec spec, const char *fmt) +{ + struct gendisk *hd; + + if (check_pointer(&buf, end, bdev, spec)) + return buf; + + hd = bdev->bd_disk; + buf = string(buf, end, hd->disk_name, spec); + if (bdev->bd_partno) { + if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) { + if (buf < end) + *buf = 'p'; + buf++; + } + buf = number(buf, end, bdev->bd_partno, spec); + } + return buf; +} +#endif + +static noinline_for_stack +char *symbol_string(char *buf, char *end, void *ptr, + struct printf_spec spec, const char *fmt) +{ + unsigned long value; +#ifdef CONFIG_KALLSYMS + char sym[KSYM_SYMBOL_LEN]; +#endif + + if (fmt[1] == 'R') + ptr = __builtin_extract_return_addr(ptr); + value = (unsigned long)ptr; + +#ifdef CONFIG_KALLSYMS + if (*fmt == 'B' && fmt[1] == 'b') + sprint_backtrace_build_id(sym, value); + else if (*fmt == 'B') + sprint_backtrace(sym, value); + else if (*fmt == 'S' && (fmt[1] == 'b' || (fmt[1] == 'R' && fmt[2] == 'b'))) + sprint_symbol_build_id(sym, value); + else if (*fmt != 's') + sprint_symbol(sym, value); + else + sprint_symbol_no_offset(sym, value); + + return string_nocheck(buf, end, sym, spec); +#else + return special_hex_number(buf, end, value, sizeof(void *)); +#endif +} + +static const struct printf_spec default_str_spec = { + .field_width = -1, + .precision = -1, +}; + +static const struct printf_spec default_flag_spec = { + .base = 16, + .precision = -1, + .flags = SPECIAL | SMALL, +}; + +static const struct printf_spec default_dec_spec = { + .base = 10, + .precision = -1, +}; + +static const struct printf_spec default_dec02_spec = { + .base = 10, + .field_width = 2, + .precision = -1, + .flags = ZEROPAD, +}; + +static const struct printf_spec default_dec04_spec = { + .base = 10, + .field_width = 4, + .precision = -1, + .flags = ZEROPAD, +}; + +static noinline_for_stack +char *resource_string(char *buf, char *end, struct resource *res, + struct printf_spec spec, const char *fmt) +{ +#ifndef IO_RSRC_PRINTK_SIZE +#define IO_RSRC_PRINTK_SIZE 6 +#endif + +#ifndef MEM_RSRC_PRINTK_SIZE +#define MEM_RSRC_PRINTK_SIZE 10 +#endif + static const struct printf_spec io_spec = { + .base = 16, + .field_width = IO_RSRC_PRINTK_SIZE, + .precision = -1, + .flags = SPECIAL | SMALL | ZEROPAD, + }; + static const struct printf_spec mem_spec = { + .base = 16, + .field_width = MEM_RSRC_PRINTK_SIZE, + .precision = -1, + .flags = SPECIAL | SMALL | ZEROPAD, + }; + static const struct printf_spec bus_spec = { + .base = 16, + .field_width = 2, + .precision = -1, + .flags = SMALL | ZEROPAD, + }; + static const struct printf_spec str_spec = { + .field_width = -1, + .precision = 10, + .flags = LEFT, + }; + + /* 32-bit res (sizeof==4): 10 chars in dec, 10 in hex ("0x" + 8) + * 64-bit res (sizeof==8): 20 chars in dec, 18 in hex ("0x" + 16) */ +#define RSRC_BUF_SIZE ((2 * sizeof(resource_size_t)) + 4) +#define FLAG_BUF_SIZE (2 * sizeof(res->flags)) +#define DECODED_BUF_SIZE sizeof("[mem - 64bit pref window disabled]") +#define RAW_BUF_SIZE sizeof("[mem - flags 0x]") + char sym[max(2*RSRC_BUF_SIZE + DECODED_BUF_SIZE, + 2*RSRC_BUF_SIZE + FLAG_BUF_SIZE + RAW_BUF_SIZE)]; + + char *p = sym, *pend = sym + sizeof(sym); + int decode = (fmt[0] == 'R') ? 1 : 0; + const struct printf_spec *specp; + + if (check_pointer(&buf, end, res, spec)) + return buf; + + *p++ = '['; + if (res->flags & IORESOURCE_IO) { + p = string_nocheck(p, pend, "io ", str_spec); + specp = &io_spec; + } else if (res->flags & IORESOURCE_MEM) { + p = string_nocheck(p, pend, "mem ", str_spec); + specp = &mem_spec; + } else if (res->flags & IORESOURCE_IRQ) { + p = string_nocheck(p, pend, "irq ", str_spec); + specp = &default_dec_spec; + } else if (res->flags & IORESOURCE_DMA) { + p = string_nocheck(p, pend, "dma ", str_spec); + specp = &default_dec_spec; + } else if (res->flags & IORESOURCE_BUS) { + p = string_nocheck(p, pend, "bus ", str_spec); + specp = &bus_spec; + } else { + p = string_nocheck(p, pend, "??? ", str_spec); + specp = &mem_spec; + decode = 0; + } + if (decode && res->flags & IORESOURCE_UNSET) { + p = string_nocheck(p, pend, "size ", str_spec); + p = number(p, pend, resource_size(res), *specp); + } else { + p = number(p, pend, res->start, *specp); + if (res->start != res->end) { + *p++ = '-'; + p = number(p, pend, res->end, *specp); + } + } + if (decode) { + if (res->flags & IORESOURCE_MEM_64) + p = string_nocheck(p, pend, " 64bit", str_spec); + if (res->flags & IORESOURCE_PREFETCH) + p = string_nocheck(p, pend, " pref", str_spec); + if (res->flags & IORESOURCE_WINDOW) + p = string_nocheck(p, pend, " window", str_spec); + if (res->flags & IORESOURCE_DISABLED) + p = string_nocheck(p, pend, " disabled", str_spec); + } else { + p = string_nocheck(p, pend, " flags ", str_spec); + p = number(p, pend, res->flags, default_flag_spec); + } + *p++ = ']'; + *p = '\0'; + + return string_nocheck(buf, end, sym, spec); +} + +static noinline_for_stack +char *hex_string(char *buf, char *end, u8 *addr, struct printf_spec spec, + const char *fmt) +{ + int i, len = 1; /* if we pass '%ph[CDN]', field width remains + negative value, fallback to the default */ + char separator; + + if (spec.field_width == 0) + /* nothing to print */ + return buf; + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + switch (fmt[1]) { + case 'C': + separator = ':'; + break; + case 'D': + separator = '-'; + break; + case 'N': + separator = 0; + break; + default: + separator = ' '; + break; + } + + if (spec.field_width > 0) + len = min_t(int, spec.field_width, 64); + + for (i = 0; i < len; ++i) { + if (buf < end) + *buf = hex_asc_hi(addr[i]); + ++buf; + if (buf < end) + *buf = hex_asc_lo(addr[i]); + ++buf; + + if (separator && i != len - 1) { + if (buf < end) + *buf = separator; + ++buf; + } + } + + return buf; +} + +static noinline_for_stack +char *bitmap_string(char *buf, char *end, const unsigned long *bitmap, + struct printf_spec spec, const char *fmt) +{ + const int CHUNKSZ = 32; + int nr_bits = max_t(int, spec.field_width, 0); + int i, chunksz; + bool first = true; + + if (check_pointer(&buf, end, bitmap, spec)) + return buf; + + /* reused to print numbers */ + spec = (struct printf_spec){ .flags = SMALL | ZEROPAD, .base = 16 }; + + chunksz = nr_bits & (CHUNKSZ - 1); + if (chunksz == 0) + chunksz = CHUNKSZ; + + i = ALIGN(nr_bits, CHUNKSZ) - CHUNKSZ; + for (; i >= 0; i -= CHUNKSZ) { + u32 chunkmask, val; + int word, bit; + + chunkmask = ((1ULL << chunksz) - 1); + word = i / BITS_PER_LONG; + bit = i % BITS_PER_LONG; + val = (bitmap[word] >> bit) & chunkmask; + + if (!first) { + if (buf < end) + *buf = ','; + buf++; + } + first = false; + + spec.field_width = DIV_ROUND_UP(chunksz, 4); + buf = number(buf, end, val, spec); + + chunksz = CHUNKSZ; + } + return buf; +} + +static noinline_for_stack +char *bitmap_list_string(char *buf, char *end, const unsigned long *bitmap, + struct printf_spec spec, const char *fmt) +{ + int nr_bits = max_t(int, spec.field_width, 0); + bool first = true; + int rbot, rtop; + + if (check_pointer(&buf, end, bitmap, spec)) + return buf; + + for_each_set_bitrange(rbot, rtop, bitmap, nr_bits) { + if (!first) { + if (buf < end) + *buf = ','; + buf++; + } + first = false; + + buf = number(buf, end, rbot, default_dec_spec); + if (rtop == rbot + 1) + continue; + + if (buf < end) + *buf = '-'; + buf = number(++buf, end, rtop - 1, default_dec_spec); + } + return buf; +} + +static noinline_for_stack +char *mac_address_string(char *buf, char *end, u8 *addr, + struct printf_spec spec, const char *fmt) +{ + char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")]; + char *p = mac_addr; + int i; + char separator; + bool reversed = false; + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + switch (fmt[1]) { + case 'F': + separator = '-'; + break; + + case 'R': + reversed = true; + fallthrough; + + default: + separator = ':'; + break; + } + + for (i = 0; i < 6; i++) { + if (reversed) + p = hex_byte_pack(p, addr[5 - i]); + else + p = hex_byte_pack(p, addr[i]); + + if (fmt[0] == 'M' && i != 5) + *p++ = separator; + } + *p = '\0'; + + return string_nocheck(buf, end, mac_addr, spec); +} + +static noinline_for_stack +char *ip4_string(char *p, const u8 *addr, const char *fmt) +{ + int i; + bool leading_zeros = (fmt[0] == 'i'); + int index; + int step; + + switch (fmt[2]) { + case 'h': +#ifdef __BIG_ENDIAN + index = 0; + step = 1; +#else + index = 3; + step = -1; +#endif + break; + case 'l': + index = 3; + step = -1; + break; + case 'n': + case 'b': + default: + index = 0; + step = 1; + break; + } + for (i = 0; i < 4; i++) { + char temp[4] __aligned(2); /* hold each IP quad in reverse order */ + int digits = put_dec_trunc8(temp, addr[index]) - temp; + if (leading_zeros) { + if (digits < 3) + *p++ = '0'; + if (digits < 2) + *p++ = '0'; + } + /* reverse the digits in the quad */ + while (digits--) + *p++ = temp[digits]; + if (i < 3) + *p++ = '.'; + index += step; + } + *p = '\0'; + + return p; +} + +static noinline_for_stack +char *ip6_compressed_string(char *p, const char *addr) +{ + int i, j, range; + unsigned char zerolength[8]; + int longest = 1; + int colonpos = -1; + u16 word; + u8 hi, lo; + bool needcolon = false; + bool useIPv4; + struct in6_addr in6; + + memcpy(&in6, addr, sizeof(struct in6_addr)); + + useIPv4 = ipv6_addr_v4mapped(&in6) || ipv6_addr_is_isatap(&in6); + + memset(zerolength, 0, sizeof(zerolength)); + + if (useIPv4) + range = 6; + else + range = 8; + + /* find position of longest 0 run */ + for (i = 0; i < range; i++) { + for (j = i; j < range; j++) { + if (in6.s6_addr16[j] != 0) + break; + zerolength[i]++; + } + } + for (i = 0; i < range; i++) { + if (zerolength[i] > longest) { + longest = zerolength[i]; + colonpos = i; + } + } + if (longest == 1) /* don't compress a single 0 */ + colonpos = -1; + + /* emit address */ + for (i = 0; i < range; i++) { + if (i == colonpos) { + if (needcolon || i == 0) + *p++ = ':'; + *p++ = ':'; + needcolon = false; + i += longest - 1; + continue; + } + if (needcolon) { + *p++ = ':'; + needcolon = false; + } + /* hex u16 without leading 0s */ + word = ntohs(in6.s6_addr16[i]); + hi = word >> 8; + lo = word & 0xff; + if (hi) { + if (hi > 0x0f) + p = hex_byte_pack(p, hi); + else + *p++ = hex_asc_lo(hi); + p = hex_byte_pack(p, lo); + } + else if (lo > 0x0f) + p = hex_byte_pack(p, lo); + else + *p++ = hex_asc_lo(lo); + needcolon = true; + } + + if (useIPv4) { + if (needcolon) + *p++ = ':'; + p = ip4_string(p, &in6.s6_addr[12], "I4"); + } + *p = '\0'; + + return p; +} + +static noinline_for_stack +char *ip6_string(char *p, const char *addr, const char *fmt) +{ + int i; + + for (i = 0; i < 8; i++) { + p = hex_byte_pack(p, *addr++); + p = hex_byte_pack(p, *addr++); + if (fmt[0] == 'I' && i != 7) + *p++ = ':'; + } + *p = '\0'; + + return p; +} + +static noinline_for_stack +char *ip6_addr_string(char *buf, char *end, const u8 *addr, + struct printf_spec spec, const char *fmt) +{ + char ip6_addr[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255")]; + + if (fmt[0] == 'I' && fmt[2] == 'c') + ip6_compressed_string(ip6_addr, addr); + else + ip6_string(ip6_addr, addr, fmt); + + return string_nocheck(buf, end, ip6_addr, spec); +} + +static noinline_for_stack +char *ip4_addr_string(char *buf, char *end, const u8 *addr, + struct printf_spec spec, const char *fmt) +{ + char ip4_addr[sizeof("255.255.255.255")]; + + ip4_string(ip4_addr, addr, fmt); + + return string_nocheck(buf, end, ip4_addr, spec); +} + +static noinline_for_stack +char *ip6_addr_string_sa(char *buf, char *end, const struct sockaddr_in6 *sa, + struct printf_spec spec, const char *fmt) +{ + bool have_p = false, have_s = false, have_f = false, have_c = false; + char ip6_addr[sizeof("[xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255]") + + sizeof(":12345") + sizeof("/123456789") + + sizeof("%1234567890")]; + char *p = ip6_addr, *pend = ip6_addr + sizeof(ip6_addr); + const u8 *addr = (const u8 *) &sa->sin6_addr; + char fmt6[2] = { fmt[0], '6' }; + u8 off = 0; + + fmt++; + while (isalpha(*++fmt)) { + switch (*fmt) { + case 'p': + have_p = true; + break; + case 'f': + have_f = true; + break; + case 's': + have_s = true; + break; + case 'c': + have_c = true; + break; + } + } + + if (have_p || have_s || have_f) { + *p = '['; + off = 1; + } + + if (fmt6[0] == 'I' && have_c) + p = ip6_compressed_string(ip6_addr + off, addr); + else + p = ip6_string(ip6_addr + off, addr, fmt6); + + if (have_p || have_s || have_f) + *p++ = ']'; + + if (have_p) { + *p++ = ':'; + p = number(p, pend, ntohs(sa->sin6_port), spec); + } + if (have_f) { + *p++ = '/'; + p = number(p, pend, ntohl(sa->sin6_flowinfo & + IPV6_FLOWINFO_MASK), spec); + } + if (have_s) { + *p++ = '%'; + p = number(p, pend, sa->sin6_scope_id, spec); + } + *p = '\0'; + + return string_nocheck(buf, end, ip6_addr, spec); +} + +static noinline_for_stack +char *ip4_addr_string_sa(char *buf, char *end, const struct sockaddr_in *sa, + struct printf_spec spec, const char *fmt) +{ + bool have_p = false; + char *p, ip4_addr[sizeof("255.255.255.255") + sizeof(":12345")]; + char *pend = ip4_addr + sizeof(ip4_addr); + const u8 *addr = (const u8 *) &sa->sin_addr.s_addr; + char fmt4[3] = { fmt[0], '4', 0 }; + + fmt++; + while (isalpha(*++fmt)) { + switch (*fmt) { + case 'p': + have_p = true; + break; + case 'h': + case 'l': + case 'n': + case 'b': + fmt4[2] = *fmt; + break; + } + } + + p = ip4_string(ip4_addr, addr, fmt4); + if (have_p) { + *p++ = ':'; + p = number(p, pend, ntohs(sa->sin_port), spec); + } + *p = '\0'; + + return string_nocheck(buf, end, ip4_addr, spec); +} + +static noinline_for_stack +char *ip_addr_string(char *buf, char *end, const void *ptr, + struct printf_spec spec, const char *fmt) +{ + char *err_fmt_msg; + + if (check_pointer(&buf, end, ptr, spec)) + return buf; + + switch (fmt[1]) { + case '6': + return ip6_addr_string(buf, end, ptr, spec, fmt); + case '4': + return ip4_addr_string(buf, end, ptr, spec, fmt); + case 'S': { + const union { + struct sockaddr raw; + struct sockaddr_in v4; + struct sockaddr_in6 v6; + } *sa = ptr; + + switch (sa->raw.sa_family) { + case AF_INET: + return ip4_addr_string_sa(buf, end, &sa->v4, spec, fmt); + case AF_INET6: + return ip6_addr_string_sa(buf, end, &sa->v6, spec, fmt); + default: + return error_string(buf, end, "(einval)", spec); + }} + } + + err_fmt_msg = fmt[0] == 'i' ? "(%pi?)" : "(%pI?)"; + return error_string(buf, end, err_fmt_msg, spec); +} + +static noinline_for_stack +char *escaped_string(char *buf, char *end, u8 *addr, struct printf_spec spec, + const char *fmt) +{ + bool found = true; + int count = 1; + unsigned int flags = 0; + int len; + + if (spec.field_width == 0) + return buf; /* nothing to print */ + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + do { + switch (fmt[count++]) { + case 'a': + flags |= ESCAPE_ANY; + break; + case 'c': + flags |= ESCAPE_SPECIAL; + break; + case 'h': + flags |= ESCAPE_HEX; + break; + case 'n': + flags |= ESCAPE_NULL; + break; + case 'o': + flags |= ESCAPE_OCTAL; + break; + case 'p': + flags |= ESCAPE_NP; + break; + case 's': + flags |= ESCAPE_SPACE; + break; + default: + found = false; + break; + } + } while (found); + + if (!flags) + flags = ESCAPE_ANY_NP; + + len = spec.field_width < 0 ? 1 : spec.field_width; + + /* + * string_escape_mem() writes as many characters as it can to + * the given buffer, and returns the total size of the output + * had the buffer been big enough. + */ + buf += string_escape_mem(addr, len, buf, buf < end ? end - buf : 0, flags, NULL); + + return buf; +} + +static char *va_format(char *buf, char *end, struct va_format *va_fmt, + struct printf_spec spec, const char *fmt) +{ + va_list va; + + if (check_pointer(&buf, end, va_fmt, spec)) + return buf; + + va_copy(va, *va_fmt->va); + buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va); + va_end(va); + + return buf; +} + +static noinline_for_stack +char *uuid_string(char *buf, char *end, const u8 *addr, + struct printf_spec spec, const char *fmt) +{ + char uuid[UUID_STRING_LEN + 1]; + char *p = uuid; + int i; + const u8 *index = uuid_index; + bool uc = false; + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + switch (*(++fmt)) { + case 'L': + uc = true; + fallthrough; + case 'l': + index = guid_index; + break; + case 'B': + uc = true; + break; + } + + for (i = 0; i < 16; i++) { + if (uc) + p = hex_byte_pack_upper(p, addr[index[i]]); + else + p = hex_byte_pack(p, addr[index[i]]); + switch (i) { + case 3: + case 5: + case 7: + case 9: + *p++ = '-'; + break; + } + } + + *p = 0; + + return string_nocheck(buf, end, uuid, spec); +} + +static noinline_for_stack +char *netdev_bits(char *buf, char *end, const void *addr, + struct printf_spec spec, const char *fmt) +{ + unsigned long long num; + int size; + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + switch (fmt[1]) { + case 'F': + num = *(const netdev_features_t *)addr; + size = sizeof(netdev_features_t); + break; + default: + return error_string(buf, end, "(%pN?)", spec); + } + + return special_hex_number(buf, end, num, size); +} + +static noinline_for_stack +char *fourcc_string(char *buf, char *end, const u32 *fourcc, + struct printf_spec spec, const char *fmt) +{ + char output[sizeof("0123 little-endian (0x01234567)")]; + char *p = output; + unsigned int i; + u32 orig, val; + + if (fmt[1] != 'c' || fmt[2] != 'c') + return error_string(buf, end, "(%p4?)", spec); + + if (check_pointer(&buf, end, fourcc, spec)) + return buf; + + orig = get_unaligned(fourcc); + val = orig & ~BIT(31); + + for (i = 0; i < sizeof(u32); i++) { + unsigned char c = val >> (i * 8); + + /* Print non-control ASCII characters as-is, dot otherwise */ + *p++ = isascii(c) && isprint(c) ? c : '.'; + } + + *p++ = ' '; + strcpy(p, orig & BIT(31) ? "big-endian" : "little-endian"); + p += strlen(p); + + *p++ = ' '; + *p++ = '('; + p = special_hex_number(p, output + sizeof(output) - 2, orig, sizeof(u32)); + *p++ = ')'; + *p = '\0'; + + return string(buf, end, output, spec); +} + +static noinline_for_stack +char *address_val(char *buf, char *end, const void *addr, + struct printf_spec spec, const char *fmt) +{ + unsigned long long num; + int size; + + if (check_pointer(&buf, end, addr, spec)) + return buf; + + switch (fmt[1]) { + case 'd': + num = *(const dma_addr_t *)addr; + size = sizeof(dma_addr_t); + break; + case 'p': + default: + num = *(const phys_addr_t *)addr; + size = sizeof(phys_addr_t); + break; + } + + return special_hex_number(buf, end, num, size); +} + +static noinline_for_stack +char *date_str(char *buf, char *end, const struct rtc_time *tm, bool r) +{ + int year = tm->tm_year + (r ? 0 : 1900); + int mon = tm->tm_mon + (r ? 0 : 1); + + buf = number(buf, end, year, default_dec04_spec); + if (buf < end) + *buf = '-'; + buf++; + + buf = number(buf, end, mon, default_dec02_spec); + if (buf < end) + *buf = '-'; + buf++; + + return number(buf, end, tm->tm_mday, default_dec02_spec); +} + +static noinline_for_stack +char *time_str(char *buf, char *end, const struct rtc_time *tm, bool r) +{ + buf = number(buf, end, tm->tm_hour, default_dec02_spec); + if (buf < end) + *buf = ':'; + buf++; + + buf = number(buf, end, tm->tm_min, default_dec02_spec); + if (buf < end) + *buf = ':'; + buf++; + + return number(buf, end, tm->tm_sec, default_dec02_spec); +} + +static noinline_for_stack +char *rtc_str(char *buf, char *end, const struct rtc_time *tm, + struct printf_spec spec, const char *fmt) +{ + bool have_t = true, have_d = true; + bool raw = false, iso8601_separator = true; + bool found = true; + int count = 2; + + if (check_pointer(&buf, end, tm, spec)) + return buf; + + switch (fmt[count]) { + case 'd': + have_t = false; + count++; + break; + case 't': + have_d = false; + count++; + break; + } + + do { + switch (fmt[count++]) { + case 'r': + raw = true; + break; + case 's': + iso8601_separator = false; + break; + default: + found = false; + break; + } + } while (found); + + if (have_d) + buf = date_str(buf, end, tm, raw); + if (have_d && have_t) { + if (buf < end) + *buf = iso8601_separator ? 'T' : ' '; + buf++; + } + if (have_t) + buf = time_str(buf, end, tm, raw); + + return buf; +} + +static noinline_for_stack +char *time64_str(char *buf, char *end, const time64_t time, + struct printf_spec spec, const char *fmt) +{ + struct rtc_time rtc_time; + struct tm tm; + + time64_to_tm(time, 0, &tm); + + rtc_time.tm_sec = tm.tm_sec; + rtc_time.tm_min = tm.tm_min; + rtc_time.tm_hour = tm.tm_hour; + rtc_time.tm_mday = tm.tm_mday; + rtc_time.tm_mon = tm.tm_mon; + rtc_time.tm_year = tm.tm_year; + rtc_time.tm_wday = tm.tm_wday; + rtc_time.tm_yday = tm.tm_yday; + + rtc_time.tm_isdst = 0; + + return rtc_str(buf, end, &rtc_time, spec, fmt); +} + +static noinline_for_stack +char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec, + const char *fmt) +{ + switch (fmt[1]) { + case 'R': + return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt); + case 'T': + return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt); + default: + return error_string(buf, end, "(%pt?)", spec); + } +} + +static noinline_for_stack +char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec, + const char *fmt) +{ + if (!IS_ENABLED(CONFIG_HAVE_CLK)) + return error_string(buf, end, "(%pC?)", spec); + + if (check_pointer(&buf, end, clk, spec)) + return buf; + + switch (fmt[1]) { + case 'n': + default: +#ifdef CONFIG_COMMON_CLK + return string(buf, end, __clk_get_name(clk), spec); +#else + return ptr_to_id(buf, end, clk, spec); +#endif + } +} + +static +char *format_flags(char *buf, char *end, unsigned long flags, + const struct trace_print_flags *names) +{ + unsigned long mask; + + for ( ; flags && names->name; names++) { + mask = names->mask; + if ((flags & mask) != mask) + continue; + + buf = string(buf, end, names->name, default_str_spec); + + flags &= ~mask; + if (flags) { + if (buf < end) + *buf = '|'; + buf++; + } + } + + if (flags) + buf = number(buf, end, flags, default_flag_spec); + + return buf; +} + +struct page_flags_fields { + int width; + int shift; + int mask; + const struct printf_spec *spec; + const char *name; +}; + +static const struct page_flags_fields pff[] = { + {SECTIONS_WIDTH, SECTIONS_PGSHIFT, SECTIONS_MASK, + &default_dec_spec, "section"}, + {NODES_WIDTH, NODES_PGSHIFT, NODES_MASK, + &default_dec_spec, "node"}, + {ZONES_WIDTH, ZONES_PGSHIFT, ZONES_MASK, + &default_dec_spec, "zone"}, + {LAST_CPUPID_WIDTH, LAST_CPUPID_PGSHIFT, LAST_CPUPID_MASK, + &default_flag_spec, "lastcpupid"}, + {KASAN_TAG_WIDTH, KASAN_TAG_PGSHIFT, KASAN_TAG_MASK, + &default_flag_spec, "kasantag"}, +}; + +static +char *format_page_flags(char *buf, char *end, unsigned long flags) +{ + unsigned long main_flags = flags & PAGEFLAGS_MASK; + bool append = false; + int i; + + buf = number(buf, end, flags, default_flag_spec); + if (buf < end) + *buf = '('; + buf++; + + /* Page flags from the main area. */ + if (main_flags) { + buf = format_flags(buf, end, main_flags, pageflag_names); + append = true; + } + + /* Page flags from the fields area */ + for (i = 0; i < ARRAY_SIZE(pff); i++) { + /* Skip undefined fields. */ + if (!pff[i].width) + continue; + + /* Format: Flag Name + '=' (equals sign) + Number + '|' (separator) */ + if (append) { + if (buf < end) + *buf = '|'; + buf++; + } + + buf = string(buf, end, pff[i].name, default_str_spec); + if (buf < end) + *buf = '='; + buf++; + buf = number(buf, end, (flags >> pff[i].shift) & pff[i].mask, + *pff[i].spec); + + append = true; + } + if (buf < end) + *buf = ')'; + buf++; + + return buf; +} + +static +char *format_page_type(char *buf, char *end, unsigned int page_type) +{ + buf = number(buf, end, page_type, default_flag_spec); + + if (buf < end) + *buf = '('; + buf++; + + if (page_type_has_type(page_type)) + buf = format_flags(buf, end, ~page_type, pagetype_names); + + if (buf < end) + *buf = ')'; + buf++; + + return buf; +} + +static noinline_for_stack +char *flags_string(char *buf, char *end, void *flags_ptr, + struct printf_spec spec, const char *fmt) +{ + unsigned long flags; + const struct trace_print_flags *names; + + if (check_pointer(&buf, end, flags_ptr, spec)) + return buf; + + switch (fmt[1]) { + case 'p': + return format_page_flags(buf, end, *(unsigned long *)flags_ptr); + case 't': + return format_page_type(buf, end, *(unsigned int *)flags_ptr); + case 'v': + flags = *(unsigned long *)flags_ptr; + names = vmaflag_names; + break; + case 'g': + flags = (__force unsigned long)(*(gfp_t *)flags_ptr); + names = gfpflag_names; + break; + default: + return error_string(buf, end, "(%pG?)", spec); + } + + return format_flags(buf, end, flags, names); +} + +static noinline_for_stack +char *fwnode_full_name_string(struct fwnode_handle *fwnode, char *buf, + char *end) +{ + int depth; + + /* Loop starting from the root node to the current node. */ + for (depth = fwnode_count_parents(fwnode); depth >= 0; depth--) { + /* + * Only get a reference for other nodes (i.e. parent nodes). + * fwnode refcount may be 0 here. + */ + struct fwnode_handle *__fwnode = depth ? + fwnode_get_nth_parent(fwnode, depth) : fwnode; + + buf = string(buf, end, fwnode_get_name_prefix(__fwnode), + default_str_spec); + buf = string(buf, end, fwnode_get_name(__fwnode), + default_str_spec); + + if (depth) + fwnode_handle_put(__fwnode); + } + + return buf; +} + +static noinline_for_stack +char *device_node_string(char *buf, char *end, struct device_node *dn, + struct printf_spec spec, const char *fmt) +{ + char tbuf[sizeof("xxxx") + 1]; + const char *p; + int ret; + char *buf_start = buf; + struct property *prop; + bool has_mult, pass; + + struct printf_spec str_spec = spec; + str_spec.field_width = -1; + + if (fmt[0] != 'F') + return error_string(buf, end, "(%pO?)", spec); + + if (!IS_ENABLED(CONFIG_OF)) + return error_string(buf, end, "(%pOF?)", spec); + + if (check_pointer(&buf, end, dn, spec)) + return buf; + + /* simple case without anything any more format specifiers */ + fmt++; + if (fmt[0] == '\0' || strcspn(fmt,"fnpPFcC") > 0) + fmt = "f"; + + for (pass = false; strspn(fmt,"fnpPFcC"); fmt++, pass = true) { + int precision; + if (pass) { + if (buf < end) + *buf = ':'; + buf++; + } + + switch (*fmt) { + case 'f': /* full_name */ + buf = fwnode_full_name_string(of_fwnode_handle(dn), buf, + end); + break; + case 'n': /* name */ + p = fwnode_get_name(of_fwnode_handle(dn)); + precision = str_spec.precision; + str_spec.precision = strchrnul(p, '@') - p; + buf = string(buf, end, p, str_spec); + str_spec.precision = precision; + break; + case 'p': /* phandle */ + buf = number(buf, end, (unsigned int)dn->phandle, default_dec_spec); + break; + case 'P': /* path-spec */ + p = fwnode_get_name(of_fwnode_handle(dn)); + if (!p[1]) + p = "/"; + buf = string(buf, end, p, str_spec); + break; + case 'F': /* flags */ + tbuf[0] = of_node_check_flag(dn, OF_DYNAMIC) ? 'D' : '-'; + tbuf[1] = of_node_check_flag(dn, OF_DETACHED) ? 'd' : '-'; + tbuf[2] = of_node_check_flag(dn, OF_POPULATED) ? 'P' : '-'; + tbuf[3] = of_node_check_flag(dn, OF_POPULATED_BUS) ? 'B' : '-'; + tbuf[4] = 0; + buf = string_nocheck(buf, end, tbuf, str_spec); + break; + case 'c': /* major compatible string */ + ret = of_property_read_string(dn, "compatible", &p); + if (!ret) + buf = string(buf, end, p, str_spec); + break; + case 'C': /* full compatible string */ + has_mult = false; + of_property_for_each_string(dn, "compatible", prop, p) { + if (has_mult) + buf = string_nocheck(buf, end, ",", str_spec); + buf = string_nocheck(buf, end, "\"", str_spec); + buf = string(buf, end, p, str_spec); + buf = string_nocheck(buf, end, "\"", str_spec); + + has_mult = true; + } + break; + default: + break; + } + } + + return widen_string(buf, buf - buf_start, end, spec); +} + +static noinline_for_stack +char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode, + struct printf_spec spec, const char *fmt) +{ + struct printf_spec str_spec = spec; + char *buf_start = buf; + + str_spec.field_width = -1; + + if (*fmt != 'w') + return error_string(buf, end, "(%pf?)", spec); + + if (check_pointer(&buf, end, fwnode, spec)) + return buf; + + fmt++; + + switch (*fmt) { + case 'P': /* name */ + buf = string(buf, end, fwnode_get_name(fwnode), str_spec); + break; + case 'f': /* full_name */ + default: + buf = fwnode_full_name_string(fwnode, buf, end); + break; + } + + return widen_string(buf, buf - buf_start, end, spec); +} + +int __init no_hash_pointers_enable(char *str) +{ + if (no_hash_pointers) + return 0; + + no_hash_pointers = true; + + pr_warn("**********************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** This system shows unhashed kernel memory addresses **\n"); + pr_warn("** via the console, logs, and other interfaces. This **\n"); + pr_warn("** might reduce the security of your system. **\n"); + pr_warn("** **\n"); + pr_warn("** If you see this message and you are not debugging **\n"); + pr_warn("** the kernel, report this immediately to your system **\n"); + pr_warn("** administrator! **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("**********************************************************\n"); + + return 0; +} +early_param("no_hash_pointers", no_hash_pointers_enable); + +/* Used for Rust formatting ('%pA'). */ +char *rust_fmt_argument(char *buf, char *end, void *ptr); + +/* + * Show a '%p' thing. A kernel extension is that the '%p' is followed + * by an extra set of alphanumeric characters that are extended format + * specifiers. + * + * Please update scripts/checkpatch.pl when adding/removing conversion + * characters. (Search for "check for vsprintf extension"). + * + * Right now we handle: + * + * - 'S' For symbolic direct pointers (or function descriptors) with offset + * - 's' For symbolic direct pointers (or function descriptors) without offset + * - '[Ss]R' as above with __builtin_extract_return_addr() translation + * - 'S[R]b' as above with module build ID (for use in backtraces) + * - '[Ff]' %pf and %pF were obsoleted and later removed in favor of + * %ps and %pS. Be careful when re-using these specifiers. + * - 'B' For backtraced symbolic direct pointers with offset + * - 'Bb' as above with module build ID (for use in backtraces) + * - 'R' For decoded struct resource, e.g., [mem 0x0-0x1f 64bit pref] + * - 'r' For raw struct resource, e.g., [mem 0x0-0x1f flags 0x201] + * - 'b[l]' For a bitmap, the number of bits is determined by the field + * width which must be explicitly specified either as part of the + * format string '%32b[l]' or through '%*b[l]', [l] selects + * range-list format instead of hex format + * - 'M' For a 6-byte MAC address, it prints the address in the + * usual colon-separated hex notation + * - 'm' For a 6-byte MAC address, it prints the hex address without colons + * - 'MF' For a 6-byte MAC FDDI address, it prints the address + * with a dash-separated hex notation + * - '[mM]R' For a 6-byte MAC address, Reverse order (Bluetooth) + * - 'I' [46] for IPv4/IPv6 addresses printed in the usual way + * IPv4 uses dot-separated decimal without leading 0's (1.2.3.4) + * IPv6 uses colon separated network-order 16 bit hex with leading 0's + * [S][pfs] + * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to + * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] + * - 'i' [46] for 'raw' IPv4/IPv6 addresses + * IPv6 omits the colons (01020304...0f) + * IPv4 uses dot-separated decimal with leading 0's (010.123.045.006) + * [S][pfs] + * Generic IPv4/IPv6 address (struct sockaddr *) that falls back to + * [4] or [6] and is able to print port [p], flowinfo [f], scope [s] + * - '[Ii][4S][hnbl]' IPv4 addresses in host, network, big or little endian order + * - 'I[6S]c' for IPv6 addresses printed as specified by + * https://tools.ietf.org/html/rfc5952 + * - 'E[achnops]' For an escaped buffer, where rules are defined by combination + * of the following flags (see string_escape_mem() for the + * details): + * a - ESCAPE_ANY + * c - ESCAPE_SPECIAL + * h - ESCAPE_HEX + * n - ESCAPE_NULL + * o - ESCAPE_OCTAL + * p - ESCAPE_NP + * s - ESCAPE_SPACE + * By default ESCAPE_ANY_NP is used. + * - 'U' For a 16 byte UUID/GUID, it prints the UUID/GUID in the form + * "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" + * Options for %pU are: + * b big endian lower case hex (default) + * B big endian UPPER case hex + * l little endian lower case hex + * L little endian UPPER case hex + * big endian output byte order is: + * [0][1][2][3]-[4][5]-[6][7]-[8][9]-[10][11][12][13][14][15] + * little endian output byte order is: + * [3][2][1][0]-[5][4]-[7][6]-[8][9]-[10][11][12][13][14][15] + * - 'V' For a struct va_format which contains a format string * and va_list *, + * call vsnprintf(->format, *->va_list). + * Implements a "recursive vsnprintf". + * Do not use this feature without some mechanism to verify the + * correctness of the format string and va_list arguments. + * - 'K' For a kernel pointer that should be hidden from unprivileged users. + * Use only for procfs, sysfs and similar files, not printk(); please + * read the documentation (path below) first. + * - 'NF' For a netdev_features_t + * - '4cc' V4L2 or DRM FourCC code, with endianness and raw numerical value. + * - 'h[CDN]' For a variable-length buffer, it prints it as a hex string with + * a certain separator (' ' by default): + * C colon + * D dash + * N no separator + * The maximum supported length is 64 bytes of the input. Consider + * to use print_hex_dump() for the larger input. + * - 'a[pd]' For address types [p] phys_addr_t, [d] dma_addr_t and derivatives + * (default assumed to be phys_addr_t, passed by reference) + * - 'd[234]' For a dentry name (optionally 2-4 last components) + * - 'D[234]' Same as 'd' but for a struct file + * - 'g' For block_device name (gendisk + partition number) + * - 't[RT][dt][r][s]' For time and date as represented by: + * R struct rtc_time + * T time64_t + * - 'C' For a clock, it prints the name (Common Clock Framework) or address + * (legacy clock framework) of the clock + * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address + * (legacy clock framework) of the clock + * - 'G' For flags to be printed as a collection of symbolic strings that would + * construct the specific value. Supported flags given by option: + * p page flags (see struct page) given as pointer to unsigned long + * g gfp flags (GFP_* and __GFP_*) given as pointer to gfp_t + * v vma flags (VM_*) given as pointer to unsigned long + * - 'OF[fnpPcCF]' For a device tree object + * Without any optional arguments prints the full_name + * f device node full_name + * n device node name + * p device node phandle + * P device node path spec (name + @unit) + * F device node flags + * c major compatible string + * C full compatible string + * - 'fw[fP]' For a firmware node (struct fwnode_handle) pointer + * Without an option prints the full name of the node + * f full name + * P node name, including a possible unit address + * - 'x' For printing the address unmodified. Equivalent to "%lx". + * Please read the documentation (path below) before using! + * - '[ku]s' For a BPF/tracing related format specifier, e.g. used out of + * bpf_trace_printk() where [ku] prefix specifies either kernel (k) + * or user (u) memory to probe, and: + * s a string, equivalent to "%s" on direct vsnprintf() use + * + * ** When making changes please also update: + * Documentation/core-api/printk-formats.rst + * + * Note: The default behaviour (unadorned %p) is to hash the address, + * rendering it useful as a unique identifier. + * + * There is also a '%pA' format specifier, but it is only intended to be used + * from Rust code to format core::fmt::Arguments. Do *not* use it from C. + * See rust/kernel/print.rs for details. + */ +static noinline_for_stack +char *pointer(const char *fmt, char *buf, char *end, void *ptr, + struct printf_spec spec) +{ + switch (*fmt) { + case 'S': + case 's': + ptr = dereference_symbol_descriptor(ptr); + fallthrough; + case 'B': + return symbol_string(buf, end, ptr, spec, fmt); + case 'R': + case 'r': + return resource_string(buf, end, ptr, spec, fmt); + case 'h': + return hex_string(buf, end, ptr, spec, fmt); + case 'b': + switch (fmt[1]) { + case 'l': + return bitmap_list_string(buf, end, ptr, spec, fmt); + default: + return bitmap_string(buf, end, ptr, spec, fmt); + } + case 'M': /* Colon separated: 00:01:02:03:04:05 */ + case 'm': /* Contiguous: 000102030405 */ + /* [mM]F (FDDI) */ + /* [mM]R (Reverse order; Bluetooth) */ + return mac_address_string(buf, end, ptr, spec, fmt); + case 'I': /* Formatted IP supported + * 4: 1.2.3.4 + * 6: 0001:0203:...:0708 + * 6c: 1::708 or 1::1.2.3.4 + */ + case 'i': /* Contiguous: + * 4: 001.002.003.004 + * 6: 000102...0f + */ + return ip_addr_string(buf, end, ptr, spec, fmt); + case 'E': + return escaped_string(buf, end, ptr, spec, fmt); + case 'U': + return uuid_string(buf, end, ptr, spec, fmt); + case 'V': + return va_format(buf, end, ptr, spec, fmt); + case 'K': + return restricted_pointer(buf, end, ptr, spec); + case 'N': + return netdev_bits(buf, end, ptr, spec, fmt); + case '4': + return fourcc_string(buf, end, ptr, spec, fmt); + case 'a': + return address_val(buf, end, ptr, spec, fmt); + case 'd': + return dentry_name(buf, end, ptr, spec, fmt); + case 't': + return time_and_date(buf, end, ptr, spec, fmt); + case 'C': + return clock(buf, end, ptr, spec, fmt); + case 'D': + return file_dentry_name(buf, end, ptr, spec, fmt); +#ifdef CONFIG_BLOCK + case 'g': + return bdev_name(buf, end, ptr, spec, fmt); +#endif + + case 'G': + return flags_string(buf, end, ptr, spec, fmt); + case 'O': + return device_node_string(buf, end, ptr, spec, fmt + 1); + case 'f': + return fwnode_string(buf, end, ptr, spec, fmt + 1); + case 'A': + if (!IS_ENABLED(CONFIG_RUST)) { + WARN_ONCE(1, "Please remove %%pA from non-Rust code\n"); + return error_string(buf, end, "(%pA?)", spec); + } + return rust_fmt_argument(buf, end, ptr); + case 'x': + return pointer_string(buf, end, ptr, spec); + case 'e': + /* %pe with a non-ERR_PTR gets treated as plain %p */ + if (!IS_ERR(ptr)) + return default_pointer(buf, end, ptr, spec); + return err_ptr(buf, end, ptr, spec); + case 'u': + case 'k': + switch (fmt[1]) { + case 's': + return string(buf, end, ptr, spec); + default: + return error_string(buf, end, "(einval)", spec); + } + default: + return default_pointer(buf, end, ptr, spec); + } +} + +/* + * Helper function to decode printf style format. + * Each call decode a token from the format and return the + * number of characters read (or likely the delta where it wants + * to go on the next call). + * The decoded token is returned through the parameters + * + * 'h', 'l', or 'L' for integer fields + * 'z' support added 23/7/1999 S.H. + * 'z' changed to 'Z' --davidm 1/25/99 + * 'Z' changed to 'z' --adobriyan 2017-01-25 + * 't' added for ptrdiff_t + * + * @fmt: the format string + * @type of the token returned + * @flags: various flags such as +, -, # tokens.. + * @field_width: overwritten width + * @base: base of the number (octal, hex, ...) + * @precision: precision of a number + * @qualifier: qualifier of a number (long, size_t, ...) + */ +static noinline_for_stack +int format_decode(const char *fmt, struct printf_spec *spec) +{ + const char *start = fmt; + char qualifier; + + /* we finished early by reading the field width */ + if (spec->type == FORMAT_TYPE_WIDTH) { + if (spec->field_width < 0) { + spec->field_width = -spec->field_width; + spec->flags |= LEFT; + } + spec->type = FORMAT_TYPE_NONE; + goto precision; + } + + /* we finished early by reading the precision */ + if (spec->type == FORMAT_TYPE_PRECISION) { + if (spec->precision < 0) + spec->precision = 0; + + spec->type = FORMAT_TYPE_NONE; + goto qualifier; + } + + /* By default */ + spec->type = FORMAT_TYPE_NONE; + + for (; *fmt ; ++fmt) { + if (*fmt == '%') + break; + } + + /* Return the current non-format string */ + if (fmt != start || !*fmt) + return fmt - start; + + /* Process flags */ + spec->flags = 0; + + while (1) { /* this also skips first '%' */ + bool found = true; + + ++fmt; + + switch (*fmt) { + case '-': spec->flags |= LEFT; break; + case '+': spec->flags |= PLUS; break; + case ' ': spec->flags |= SPACE; break; + case '#': spec->flags |= SPECIAL; break; + case '0': spec->flags |= ZEROPAD; break; + default: found = false; + } + + if (!found) + break; + } + + /* get field width */ + spec->field_width = -1; + + if (isdigit(*fmt)) + spec->field_width = skip_atoi(&fmt); + else if (*fmt == '*') { + /* it's the next argument */ + spec->type = FORMAT_TYPE_WIDTH; + return ++fmt - start; + } + +precision: + /* get the precision */ + spec->precision = -1; + if (*fmt == '.') { + ++fmt; + if (isdigit(*fmt)) { + spec->precision = skip_atoi(&fmt); + if (spec->precision < 0) + spec->precision = 0; + } else if (*fmt == '*') { + /* it's the next argument */ + spec->type = FORMAT_TYPE_PRECISION; + return ++fmt - start; + } + } + +qualifier: + /* get the conversion qualifier */ + qualifier = 0; + if (*fmt == 'h' || _tolower(*fmt) == 'l' || + *fmt == 'z' || *fmt == 't') { + qualifier = *fmt++; + if (unlikely(qualifier == *fmt)) { + if (qualifier == 'l') { + qualifier = 'L'; + ++fmt; + } else if (qualifier == 'h') { + qualifier = 'H'; + ++fmt; + } + } + } + + /* default base */ + spec->base = 10; + switch (*fmt) { + case 'c': + spec->type = FORMAT_TYPE_CHAR; + return ++fmt - start; + + case 's': + spec->type = FORMAT_TYPE_STR; + return ++fmt - start; + + case 'p': + spec->type = FORMAT_TYPE_PTR; + return ++fmt - start; + + case '%': + spec->type = FORMAT_TYPE_PERCENT_CHAR; + return ++fmt - start; + + /* integer number formats - set up the flags and "break" */ + case 'o': + spec->base = 8; + break; + + case 'x': + spec->flags |= SMALL; + fallthrough; + + case 'X': + spec->base = 16; + break; + + case 'd': + case 'i': + spec->flags |= SIGN; + break; + case 'u': + break; + + case 'n': + /* + * Since %n poses a greater security risk than + * utility, treat it as any other invalid or + * unsupported format specifier. + */ + fallthrough; + + default: + WARN_ONCE(1, "Please remove unsupported %%%c in format string\n", *fmt); + spec->type = FORMAT_TYPE_INVALID; + return fmt - start; + } + + if (qualifier == 'L') + spec->type = FORMAT_TYPE_LONG_LONG; + else if (qualifier == 'l') { + BUILD_BUG_ON(FORMAT_TYPE_ULONG + SIGN != FORMAT_TYPE_LONG); + spec->type = FORMAT_TYPE_ULONG + (spec->flags & SIGN); + } else if (qualifier == 'z') { + spec->type = FORMAT_TYPE_SIZE_T; + } else if (qualifier == 't') { + spec->type = FORMAT_TYPE_PTRDIFF; + } else if (qualifier == 'H') { + BUILD_BUG_ON(FORMAT_TYPE_UBYTE + SIGN != FORMAT_TYPE_BYTE); + spec->type = FORMAT_TYPE_UBYTE + (spec->flags & SIGN); + } else if (qualifier == 'h') { + BUILD_BUG_ON(FORMAT_TYPE_USHORT + SIGN != FORMAT_TYPE_SHORT); + spec->type = FORMAT_TYPE_USHORT + (spec->flags & SIGN); + } else { + BUILD_BUG_ON(FORMAT_TYPE_UINT + SIGN != FORMAT_TYPE_INT); + spec->type = FORMAT_TYPE_UINT + (spec->flags & SIGN); + } + + return ++fmt - start; +} + +static void +set_field_width(struct printf_spec *spec, int width) +{ + spec->field_width = width; + if (WARN_ONCE(spec->field_width != width, "field width %d too large", width)) { + spec->field_width = clamp(width, -FIELD_WIDTH_MAX, FIELD_WIDTH_MAX); + } +} + +static void +set_precision(struct printf_spec *spec, int prec) +{ + spec->precision = prec; + if (WARN_ONCE(spec->precision != prec, "precision %d too large", prec)) { + spec->precision = clamp(prec, 0, PRECISION_MAX); + } +} + +/** + * vsnprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @args: Arguments for the format string + * + * This function generally follows C99 vsnprintf, but has some + * extensions and a few limitations: + * + * - ``%n`` is unsupported + * - ``%p*`` is handled by pointer() + * + * See pointer() or Documentation/core-api/printk-formats.rst for more + * extensive description. + * + * **Please update the documentation in both places when making changes** + * + * The return value is the number of characters which would + * be generated for the given input, excluding the trailing + * '\0', as per ISO C99. If you want to have the exact + * number of characters written into @buf as return value + * (not including the trailing '\0'), use vscnprintf(). If the + * return is greater than or equal to @size, the resulting + * string is truncated. + * + * If you're not already dealing with a va_list consider using snprintf(). + */ +int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) +{ + unsigned long long num; + char *str, *end; + struct printf_spec spec = {0}; + + /* Reject out-of-range values early. Large positive sizes are + used for unknown buffer sizes. */ + if (WARN_ON_ONCE(size > INT_MAX)) + return 0; + + str = buf; + end = buf + size; + + /* Make sure end is always >= buf */ + if (end < buf) { + end = ((void *)-1); + size = end - buf; + } + + while (*fmt) { + const char *old_fmt = fmt; + int read = format_decode(fmt, &spec); + + fmt += read; + + switch (spec.type) { + case FORMAT_TYPE_NONE: { + int copy = read; + if (str < end) { + if (copy > end - str) + copy = end - str; + memcpy(str, old_fmt, copy); + } + str += read; + break; + } + + case FORMAT_TYPE_WIDTH: + set_field_width(&spec, va_arg(args, int)); + break; + + case FORMAT_TYPE_PRECISION: + set_precision(&spec, va_arg(args, int)); + break; + + case FORMAT_TYPE_CHAR: { + char c; + + if (!(spec.flags & LEFT)) { + while (--spec.field_width > 0) { + if (str < end) + *str = ' '; + ++str; + + } + } + c = (unsigned char) va_arg(args, int); + if (str < end) + *str = c; + ++str; + while (--spec.field_width > 0) { + if (str < end) + *str = ' '; + ++str; + } + break; + } + + case FORMAT_TYPE_STR: + str = string(str, end, va_arg(args, char *), spec); + break; + + case FORMAT_TYPE_PTR: + str = pointer(fmt, str, end, va_arg(args, void *), + spec); + while (isalnum(*fmt)) + fmt++; + break; + + case FORMAT_TYPE_PERCENT_CHAR: + if (str < end) + *str = '%'; + ++str; + break; + + case FORMAT_TYPE_INVALID: + /* + * Presumably the arguments passed gcc's type + * checking, but there is no safe or sane way + * for us to continue parsing the format and + * fetching from the va_list; the remaining + * specifiers and arguments would be out of + * sync. + */ + goto out; + + default: + switch (spec.type) { + case FORMAT_TYPE_LONG_LONG: + num = va_arg(args, long long); + break; + case FORMAT_TYPE_ULONG: + num = va_arg(args, unsigned long); + break; + case FORMAT_TYPE_LONG: + num = va_arg(args, long); + break; + case FORMAT_TYPE_SIZE_T: + if (spec.flags & SIGN) + num = va_arg(args, ssize_t); + else + num = va_arg(args, size_t); + break; + case FORMAT_TYPE_PTRDIFF: + num = va_arg(args, ptrdiff_t); + break; + case FORMAT_TYPE_UBYTE: + num = (unsigned char) va_arg(args, int); + break; + case FORMAT_TYPE_BYTE: + num = (signed char) va_arg(args, int); + break; + case FORMAT_TYPE_USHORT: + num = (unsigned short) va_arg(args, int); + break; + case FORMAT_TYPE_SHORT: + num = (short) va_arg(args, int); + break; + case FORMAT_TYPE_INT: + num = (int) va_arg(args, int); + break; + default: + num = va_arg(args, unsigned int); + } + + str = number(str, end, num, spec); + } + } + +out: + if (size > 0) { + if (str < end) + *str = '\0'; + else + end[-1] = '\0'; + } + + /* the trailing null byte doesn't count towards the total */ + return str-buf; + +} +EXPORT_SYMBOL(vsnprintf); + +/** + * vscnprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @args: Arguments for the format string + * + * The return value is the number of characters which have been written into + * the @buf not including the trailing '\0'. If @size is == 0 the function + * returns 0. + * + * If you're not already dealing with a va_list consider using scnprintf(). + * + * See the vsnprintf() documentation for format string extensions over C99. + */ +int vscnprintf(char *buf, size_t size, const char *fmt, va_list args) +{ + int i; + + if (unlikely(!size)) + return 0; + + i = vsnprintf(buf, size, fmt, args); + + if (likely(i < size)) + return i; + + return size - 1; +} +EXPORT_SYMBOL(vscnprintf); + +/** + * snprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @...: Arguments for the format string + * + * The return value is the number of characters which would be + * generated for the given input, excluding the trailing null, + * as per ISO C99. If the return is greater than or equal to + * @size, the resulting string is truncated. + * + * See the vsnprintf() documentation for format string extensions over C99. + */ +int snprintf(char *buf, size_t size, const char *fmt, ...) +{ + va_list args; + int i; + + va_start(args, fmt); + i = vsnprintf(buf, size, fmt, args); + va_end(args); + + return i; +} +EXPORT_SYMBOL(snprintf); + +/** + * scnprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @...: Arguments for the format string + * + * The return value is the number of characters written into @buf not including + * the trailing '\0'. If @size is == 0 the function returns 0. + */ + +int scnprintf(char *buf, size_t size, const char *fmt, ...) +{ + va_list args; + int i; + + va_start(args, fmt); + i = vscnprintf(buf, size, fmt, args); + va_end(args); + + return i; +} +EXPORT_SYMBOL(scnprintf); + +/** + * vsprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @fmt: The format string to use + * @args: Arguments for the format string + * + * The function returns the number of characters written + * into @buf. Use vsnprintf() or vscnprintf() in order to avoid + * buffer overflows. + * + * If you're not already dealing with a va_list consider using sprintf(). + * + * See the vsnprintf() documentation for format string extensions over C99. + */ +int vsprintf(char *buf, const char *fmt, va_list args) +{ + return vsnprintf(buf, INT_MAX, fmt, args); +} +EXPORT_SYMBOL(vsprintf); + +/** + * sprintf - Format a string and place it in a buffer + * @buf: The buffer to place the result into + * @fmt: The format string to use + * @...: Arguments for the format string + * + * The function returns the number of characters written + * into @buf. Use snprintf() or scnprintf() in order to avoid + * buffer overflows. + * + * See the vsnprintf() documentation for format string extensions over C99. + */ +int sprintf(char *buf, const char *fmt, ...) +{ + va_list args; + int i; + + va_start(args, fmt); + i = vsnprintf(buf, INT_MAX, fmt, args); + va_end(args); + + return i; +} +EXPORT_SYMBOL(sprintf); + +#ifdef CONFIG_BINARY_PRINTF +/* + * bprintf service: + * vbin_printf() - VA arguments to binary data + * bstr_printf() - Binary data to text string + */ + +/** + * vbin_printf - Parse a format string and place args' binary value in a buffer + * @bin_buf: The buffer to place args' binary value + * @size: The size of the buffer(by words(32bits), not characters) + * @fmt: The format string to use + * @args: Arguments for the format string + * + * The format follows C99 vsnprintf, except %n is ignored, and its argument + * is skipped. + * + * The return value is the number of words(32bits) which would be generated for + * the given input. + * + * NOTE: + * If the return value is greater than @size, the resulting bin_buf is NOT + * valid for bstr_printf(). + */ +int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args) +{ + struct printf_spec spec = {0}; + char *str, *end; + int width; + + str = (char *)bin_buf; + end = (char *)(bin_buf + size); + +#define save_arg(type) \ +({ \ + unsigned long long value; \ + if (sizeof(type) == 8) { \ + unsigned long long val8; \ + str = PTR_ALIGN(str, sizeof(u32)); \ + val8 = va_arg(args, unsigned long long); \ + if (str + sizeof(type) <= end) { \ + *(u32 *)str = *(u32 *)&val8; \ + *(u32 *)(str + 4) = *((u32 *)&val8 + 1); \ + } \ + value = val8; \ + } else { \ + unsigned int val4; \ + str = PTR_ALIGN(str, sizeof(type)); \ + val4 = va_arg(args, int); \ + if (str + sizeof(type) <= end) \ + *(typeof(type) *)str = (type)(long)val4; \ + value = (unsigned long long)val4; \ + } \ + str += sizeof(type); \ + value; \ +}) + + while (*fmt) { + int read = format_decode(fmt, &spec); + + fmt += read; + + switch (spec.type) { + case FORMAT_TYPE_NONE: + case FORMAT_TYPE_PERCENT_CHAR: + break; + case FORMAT_TYPE_INVALID: + goto out; + + case FORMAT_TYPE_WIDTH: + case FORMAT_TYPE_PRECISION: + width = (int)save_arg(int); + /* Pointers may require the width */ + if (*fmt == 'p') + set_field_width(&spec, width); + break; + + case FORMAT_TYPE_CHAR: + save_arg(char); + break; + + case FORMAT_TYPE_STR: { + const char *save_str = va_arg(args, char *); + const char *err_msg; + size_t len; + + err_msg = check_pointer_msg(save_str); + if (err_msg) + save_str = err_msg; + + len = strlen(save_str) + 1; + if (str + len < end) + memcpy(str, save_str, len); + str += len; + break; + } + + case FORMAT_TYPE_PTR: + /* Dereferenced pointers must be done now */ + switch (*fmt) { + /* Dereference of functions is still OK */ + case 'S': + case 's': + case 'x': + case 'K': + case 'e': + save_arg(void *); + break; + default: + if (!isalnum(*fmt)) { + save_arg(void *); + break; + } + str = pointer(fmt, str, end, va_arg(args, void *), + spec); + if (str + 1 < end) + *str++ = '\0'; + else + end[-1] = '\0'; /* Must be nul terminated */ + } + /* skip all alphanumeric pointer suffixes */ + while (isalnum(*fmt)) + fmt++; + break; + + default: + switch (spec.type) { + + case FORMAT_TYPE_LONG_LONG: + save_arg(long long); + break; + case FORMAT_TYPE_ULONG: + case FORMAT_TYPE_LONG: + save_arg(unsigned long); + break; + case FORMAT_TYPE_SIZE_T: + save_arg(size_t); + break; + case FORMAT_TYPE_PTRDIFF: + save_arg(ptrdiff_t); + break; + case FORMAT_TYPE_UBYTE: + case FORMAT_TYPE_BYTE: + save_arg(char); + break; + case FORMAT_TYPE_USHORT: + case FORMAT_TYPE_SHORT: + save_arg(short); + break; + default: + save_arg(int); + } + } + } + +out: + return (u32 *)(PTR_ALIGN(str, sizeof(u32))) - bin_buf; +#undef save_arg +} +EXPORT_SYMBOL_GPL(vbin_printf); + +/** + * bstr_printf - Format a string from binary arguments and place it in a buffer + * @buf: The buffer to place the result into + * @size: The size of the buffer, including the trailing null space + * @fmt: The format string to use + * @bin_buf: Binary arguments for the format string + * + * This function like C99 vsnprintf, but the difference is that vsnprintf gets + * arguments from stack, and bstr_printf gets arguments from @bin_buf which is + * a binary buffer that generated by vbin_printf. + * + * The format follows C99 vsnprintf, but has some extensions: + * see vsnprintf comment for details. + * + * The return value is the number of characters which would + * be generated for the given input, excluding the trailing + * '\0', as per ISO C99. If you want to have the exact + * number of characters written into @buf as return value + * (not including the trailing '\0'), use vscnprintf(). If the + * return is greater than or equal to @size, the resulting + * string is truncated. + */ +int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) +{ + struct printf_spec spec = {0}; + char *str, *end; + const char *args = (const char *)bin_buf; + + if (WARN_ON_ONCE(size > INT_MAX)) + return 0; + + str = buf; + end = buf + size; + +#define get_arg(type) \ +({ \ + typeof(type) value; \ + if (sizeof(type) == 8) { \ + args = PTR_ALIGN(args, sizeof(u32)); \ + *(u32 *)&value = *(u32 *)args; \ + *((u32 *)&value + 1) = *(u32 *)(args + 4); \ + } else { \ + args = PTR_ALIGN(args, sizeof(type)); \ + value = *(typeof(type) *)args; \ + } \ + args += sizeof(type); \ + value; \ +}) + + /* Make sure end is always >= buf */ + if (end < buf) { + end = ((void *)-1); + size = end - buf; + } + + while (*fmt) { + const char *old_fmt = fmt; + int read = format_decode(fmt, &spec); + + fmt += read; + + switch (spec.type) { + case FORMAT_TYPE_NONE: { + int copy = read; + if (str < end) { + if (copy > end - str) + copy = end - str; + memcpy(str, old_fmt, copy); + } + str += read; + break; + } + + case FORMAT_TYPE_WIDTH: + set_field_width(&spec, get_arg(int)); + break; + + case FORMAT_TYPE_PRECISION: + set_precision(&spec, get_arg(int)); + break; + + case FORMAT_TYPE_CHAR: { + char c; + + if (!(spec.flags & LEFT)) { + while (--spec.field_width > 0) { + if (str < end) + *str = ' '; + ++str; + } + } + c = (unsigned char) get_arg(char); + if (str < end) + *str = c; + ++str; + while (--spec.field_width > 0) { + if (str < end) + *str = ' '; + ++str; + } + break; + } + + case FORMAT_TYPE_STR: { + const char *str_arg = args; + args += strlen(str_arg) + 1; + str = string(str, end, (char *)str_arg, spec); + break; + } + + case FORMAT_TYPE_PTR: { + bool process = false; + int copy, len; + /* Non function dereferences were already done */ + switch (*fmt) { + case 'S': + case 's': + case 'x': + case 'K': + case 'e': + process = true; + break; + default: + if (!isalnum(*fmt)) { + process = true; + break; + } + /* Pointer dereference was already processed */ + if (str < end) { + len = copy = strlen(args); + if (copy > end - str) + copy = end - str; + memcpy(str, args, copy); + str += len; + args += len + 1; + } + } + if (process) + str = pointer(fmt, str, end, get_arg(void *), spec); + + while (isalnum(*fmt)) + fmt++; + break; + } + + case FORMAT_TYPE_PERCENT_CHAR: + if (str < end) + *str = '%'; + ++str; + break; + + case FORMAT_TYPE_INVALID: + goto out; + + default: { + unsigned long long num; + + switch (spec.type) { + + case FORMAT_TYPE_LONG_LONG: + num = get_arg(long long); + break; + case FORMAT_TYPE_ULONG: + case FORMAT_TYPE_LONG: + num = get_arg(unsigned long); + break; + case FORMAT_TYPE_SIZE_T: + num = get_arg(size_t); + break; + case FORMAT_TYPE_PTRDIFF: + num = get_arg(ptrdiff_t); + break; + case FORMAT_TYPE_UBYTE: + num = get_arg(unsigned char); + break; + case FORMAT_TYPE_BYTE: + num = get_arg(signed char); + break; + case FORMAT_TYPE_USHORT: + num = get_arg(unsigned short); + break; + case FORMAT_TYPE_SHORT: + num = get_arg(short); + break; + case FORMAT_TYPE_UINT: + num = get_arg(unsigned int); + break; + default: + num = get_arg(int); + } + + str = number(str, end, num, spec); + } /* default: */ + } /* switch(spec.type) */ + } /* while(*fmt) */ + +out: + if (size > 0) { + if (str < end) + *str = '\0'; + else + end[-1] = '\0'; + } + +#undef get_arg + + /* the trailing null byte doesn't count towards the total */ + return str - buf; +} +EXPORT_SYMBOL_GPL(bstr_printf); + +/** + * bprintf - Parse a format string and place args' binary value in a buffer + * @bin_buf: The buffer to place args' binary value + * @size: The size of the buffer(by words(32bits), not characters) + * @fmt: The format string to use + * @...: Arguments for the format string + * + * The function returns the number of words(u32) written + * into @bin_buf. + */ +int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) +{ + va_list args; + int ret; + + va_start(args, fmt); + ret = vbin_printf(bin_buf, size, fmt, args); + va_end(args); + + return ret; +} +EXPORT_SYMBOL_GPL(bprintf); + +#endif /* CONFIG_BINARY_PRINTF */ + +/** + * vsscanf - Unformat a buffer into a list of arguments + * @buf: input buffer + * @fmt: format of buffer + * @args: arguments + */ +int vsscanf(const char *buf, const char *fmt, va_list args) +{ + const char *str = buf; + char *next; + char digit; + int num = 0; + u8 qualifier; + unsigned int base; + union { + long long s; + unsigned long long u; + } val; + s16 field_width; + bool is_sign; + + while (*fmt) { + /* skip any white space in format */ + /* white space in format matches any amount of + * white space, including none, in the input. + */ + if (isspace(*fmt)) { + fmt = skip_spaces(++fmt); + str = skip_spaces(str); + } + + /* anything that is not a conversion must match exactly */ + if (*fmt != '%' && *fmt) { + if (*fmt++ != *str++) + break; + continue; + } + + if (!*fmt) + break; + ++fmt; + + /* skip this conversion. + * advance both strings to next white space + */ + if (*fmt == '*') { + if (!*str) + break; + while (!isspace(*fmt) && *fmt != '%' && *fmt) { + /* '%*[' not yet supported, invalid format */ + if (*fmt == '[') + return num; + fmt++; + } + while (!isspace(*str) && *str) + str++; + continue; + } + + /* get field width */ + field_width = -1; + if (isdigit(*fmt)) { + field_width = skip_atoi(&fmt); + if (field_width <= 0) + break; + } + + /* get conversion qualifier */ + qualifier = -1; + if (*fmt == 'h' || _tolower(*fmt) == 'l' || + *fmt == 'z') { + qualifier = *fmt++; + if (unlikely(qualifier == *fmt)) { + if (qualifier == 'h') { + qualifier = 'H'; + fmt++; + } else if (qualifier == 'l') { + qualifier = 'L'; + fmt++; + } + } + } + + if (!*fmt) + break; + + if (*fmt == 'n') { + /* return number of characters read so far */ + *va_arg(args, int *) = str - buf; + ++fmt; + continue; + } + + if (!*str) + break; + + base = 10; + is_sign = false; + + switch (*fmt++) { + case 'c': + { + char *s = (char *)va_arg(args, char*); + if (field_width == -1) + field_width = 1; + do { + *s++ = *str++; + } while (--field_width > 0 && *str); + num++; + } + continue; + case 's': + { + char *s = (char *)va_arg(args, char *); + if (field_width == -1) + field_width = SHRT_MAX; + /* first, skip leading white space in buffer */ + str = skip_spaces(str); + + /* now copy until next white space */ + while (*str && !isspace(*str) && field_width--) + *s++ = *str++; + *s = '\0'; + num++; + } + continue; + /* + * Warning: This implementation of the '[' conversion specifier + * deviates from its glibc counterpart in the following ways: + * (1) It does NOT support ranges i.e. '-' is NOT a special + * character + * (2) It cannot match the closing bracket ']' itself + * (3) A field width is required + * (4) '%*[' (discard matching input) is currently not supported + * + * Example usage: + * ret = sscanf("00:0a:95","%2[^:]:%2[^:]:%2[^:]", + * buf1, buf2, buf3); + * if (ret < 3) + * // etc.. + */ + case '[': + { + char *s = (char *)va_arg(args, char *); + DECLARE_BITMAP(set, 256) = {0}; + unsigned int len = 0; + bool negate = (*fmt == '^'); + + /* field width is required */ + if (field_width == -1) + return num; + + if (negate) + ++fmt; + + for ( ; *fmt && *fmt != ']'; ++fmt, ++len) + __set_bit((u8)*fmt, set); + + /* no ']' or no character set found */ + if (!*fmt || !len) + return num; + ++fmt; + + if (negate) { + bitmap_complement(set, set, 256); + /* exclude null '\0' byte */ + __clear_bit(0, set); + } + + /* match must be non-empty */ + if (!test_bit((u8)*str, set)) + return num; + + while (test_bit((u8)*str, set) && field_width--) + *s++ = *str++; + *s = '\0'; + ++num; + } + continue; + case 'o': + base = 8; + break; + case 'x': + case 'X': + base = 16; + break; + case 'i': + base = 0; + fallthrough; + case 'd': + is_sign = true; + fallthrough; + case 'u': + break; + case '%': + /* looking for '%' in str */ + if (*str++ != '%') + return num; + continue; + default: + /* invalid format; stop here */ + return num; + } + + /* have some sort of integer conversion. + * first, skip white space in buffer. + */ + str = skip_spaces(str); + + digit = *str; + if (is_sign && digit == '-') { + if (field_width == 1) + break; + + digit = *(str + 1); + } + + if (!digit + || (base == 16 && !isxdigit(digit)) + || (base == 10 && !isdigit(digit)) + || (base == 8 && !isodigit(digit)) + || (base == 0 && !isdigit(digit))) + break; + + if (is_sign) + val.s = simple_strntoll(str, + field_width >= 0 ? field_width : INT_MAX, + &next, base); + else + val.u = simple_strntoull(str, + field_width >= 0 ? field_width : INT_MAX, + &next, base); + + switch (qualifier) { + case 'H': /* that's 'hh' in format */ + if (is_sign) + *va_arg(args, signed char *) = val.s; + else + *va_arg(args, unsigned char *) = val.u; + break; + case 'h': + if (is_sign) + *va_arg(args, short *) = val.s; + else + *va_arg(args, unsigned short *) = val.u; + break; + case 'l': + if (is_sign) + *va_arg(args, long *) = val.s; + else + *va_arg(args, unsigned long *) = val.u; + break; + case 'L': + if (is_sign) + *va_arg(args, long long *) = val.s; + else + *va_arg(args, unsigned long long *) = val.u; + break; + case 'z': + *va_arg(args, size_t *) = val.u; + break; + default: + if (is_sign) + *va_arg(args, int *) = val.s; + else + *va_arg(args, unsigned int *) = val.u; + break; + } + num++; + + if (!next) + break; + str = next; + } + + return num; +} +EXPORT_SYMBOL(vsscanf); + +/** + * sscanf - Unformat a buffer into a list of arguments + * @buf: input buffer + * @fmt: formatting of buffer + * @...: resulting arguments + */ +int sscanf(const char *buf, const char *fmt, ...) +{ + va_list args; + int i; + + va_start(args, fmt); + i = vsscanf(buf, fmt, args); + va_end(args); + + return i; +} +EXPORT_SYMBOL(sscanf); |