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4277eedd79
Optimize integer-to-string conversion in vsprintf.c for base 10. This is by far the most used conversion, and in some use cases it impacts performance. For example, top reads /proc/$PID/stat for every process, and with 4000 processes decimal conversion alone takes noticeable time. Using code from http://www.cs.uiowa.edu/~jones/bcd/decimal.html (with permission from the author, Douglas W. Jones) binary-to-decimal-string conversion is done in groups of five digits at once, using only additions/subtractions/shifts (with -O2; -Os throws in some multiply instructions). On i386 arch gcc 4.1.2 -O2 generates ~500 bytes of code. This patch is run tested. Userspace benchmark/test is also attached. I tested it on PIII and AMD64 and new code is generally ~2.5 times faster. On AMD64: # ./vsprintf_verify-O2 Original decimal conv: .......... 151 ns per iteration Patched decimal conv: .......... 62 ns per iteration Testing correctness 12895992590592 ok... [Ctrl-C] # ./vsprintf_verify-O2 Original decimal conv: .......... 151 ns per iteration Patched decimal conv: .......... 62 ns per iteration Testing correctness 26025406464 ok... [Ctrl-C] More realistic test: top from busybox project was modified to report how many us it took to scan /proc (this does not account any processing done after that, like sorting process list), and then I test it with 4000 processes: #!/bin/sh i=4000 while test $i != 0; do sleep 30 & let i-- done busybox top -b -n3 >/dev/null on unpatched kernel: top: 4120 processes took 102864 microseconds to scan top: 4120 processes took 91757 microseconds to scan top: 4120 processes took 92517 microseconds to scan top: 4120 processes took 92581 microseconds to scan on patched kernel: top: 4120 processes took 75460 microseconds to scan top: 4120 processes took 66451 microseconds to scan top: 4120 processes took 67267 microseconds to scan top: 4120 processes took 67618 microseconds to scan The speedup comes from much faster generation of /proc/PID/stat by sprintf() calls inside the kernel. Signed-off-by: Douglas W Jones <jones@cs.uiowa.edu> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1016 lines
22 KiB
C
1016 lines
22 KiB
C
/*
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* linux/lib/vsprintf.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*/
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/* vsprintf.c -- Lars Wirzenius & Linus Torvalds. */
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/*
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* Wirzenius wrote this portably, Torvalds fucked it up :-)
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*/
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/*
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* Fri Jul 13 2001 Crutcher Dunnavant <crutcher+kernel@datastacks.com>
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* - changed to provide snprintf and vsnprintf functions
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* So Feb 1 16:51:32 CET 2004 Juergen Quade <quade@hsnr.de>
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* - scnprintf and vscnprintf
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*/
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#include <stdarg.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/kernel.h>
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#include <asm/page.h> /* for PAGE_SIZE */
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#include <asm/div64.h>
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/**
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* simple_strtoul - convert a string to an unsigned long
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* @cp: The start of the string
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* @endp: A pointer to the end of the parsed string will be placed here
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* @base: The number base to use
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*/
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unsigned long simple_strtoul(const char *cp,char **endp,unsigned int base)
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{
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unsigned long result = 0,value;
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if (!base) {
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base = 10;
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if (*cp == '0') {
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base = 8;
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cp++;
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if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
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cp++;
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base = 16;
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}
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}
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} else if (base == 16) {
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if (cp[0] == '0' && toupper(cp[1]) == 'X')
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cp += 2;
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}
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while (isxdigit(*cp) &&
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(value = isdigit(*cp) ? *cp-'0' : toupper(*cp)-'A'+10) < base) {
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result = result*base + value;
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cp++;
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}
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if (endp)
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*endp = (char *)cp;
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return result;
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}
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EXPORT_SYMBOL(simple_strtoul);
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/**
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* simple_strtol - convert a string to a signed long
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* @cp: The start of the string
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* @endp: A pointer to the end of the parsed string will be placed here
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* @base: The number base to use
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*/
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long simple_strtol(const char *cp,char **endp,unsigned int base)
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{
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if(*cp=='-')
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return -simple_strtoul(cp+1,endp,base);
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return simple_strtoul(cp,endp,base);
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}
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EXPORT_SYMBOL(simple_strtol);
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/**
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* simple_strtoull - convert a string to an unsigned long long
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* @cp: The start of the string
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* @endp: A pointer to the end of the parsed string will be placed here
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* @base: The number base to use
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*/
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unsigned long long simple_strtoull(const char *cp,char **endp,unsigned int base)
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{
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unsigned long long result = 0,value;
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if (!base) {
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base = 10;
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if (*cp == '0') {
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base = 8;
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cp++;
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if ((toupper(*cp) == 'X') && isxdigit(cp[1])) {
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cp++;
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base = 16;
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}
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}
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} else if (base == 16) {
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if (cp[0] == '0' && toupper(cp[1]) == 'X')
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cp += 2;
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}
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while (isxdigit(*cp) && (value = isdigit(*cp) ? *cp-'0' : (islower(*cp)
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? toupper(*cp) : *cp)-'A'+10) < base) {
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result = result*base + value;
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cp++;
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}
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if (endp)
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*endp = (char *)cp;
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return result;
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}
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EXPORT_SYMBOL(simple_strtoull);
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/**
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* simple_strtoll - convert a string to a signed long long
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* @cp: The start of the string
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* @endp: A pointer to the end of the parsed string will be placed here
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* @base: The number base to use
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*/
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long long simple_strtoll(const char *cp,char **endp,unsigned int base)
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{
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if(*cp=='-')
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return -simple_strtoull(cp+1,endp,base);
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return simple_strtoull(cp,endp,base);
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}
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static int skip_atoi(const char **s)
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{
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int i=0;
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while (isdigit(**s))
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i = i*10 + *((*s)++) - '0';
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return i;
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}
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/* Decimal conversion is by far the most typical, and is used
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* for /proc and /sys data. This directly impacts e.g. top performance
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* with many processes running. We optimize it for speed
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* using code from
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* http://www.cs.uiowa.edu/~jones/bcd/decimal.html
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* (with permission from the author, Douglas W. Jones). */
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/* Formats correctly any integer in [0,99999].
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* Outputs from one to five digits depending on input.
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* On i386 gcc 4.1.2 -O2: ~250 bytes of code. */
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static char* put_dec_trunc(char *buf, unsigned q)
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{
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unsigned d3, d2, d1, d0;
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d1 = (q>>4) & 0xf;
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d2 = (q>>8) & 0xf;
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d3 = (q>>12);
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d0 = 6*(d3 + d2 + d1) + (q & 0xf);
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q = (d0 * 0xcd) >> 11;
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d0 = d0 - 10*q;
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*buf++ = d0 + '0'; /* least significant digit */
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d1 = q + 9*d3 + 5*d2 + d1;
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if (d1 != 0) {
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q = (d1 * 0xcd) >> 11;
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d1 = d1 - 10*q;
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*buf++ = d1 + '0'; /* next digit */
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d2 = q + 2*d2;
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if ((d2 != 0) || (d3 != 0)) {
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q = (d2 * 0xd) >> 7;
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d2 = d2 - 10*q;
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*buf++ = d2 + '0'; /* next digit */
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d3 = q + 4*d3;
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if (d3 != 0) {
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q = (d3 * 0xcd) >> 11;
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d3 = d3 - 10*q;
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*buf++ = d3 + '0'; /* next digit */
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if (q != 0)
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*buf++ = q + '0'; /* most sign. digit */
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}
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}
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}
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return buf;
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}
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/* Same with if's removed. Always emits five digits */
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static char* put_dec_full(char *buf, unsigned q)
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{
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/* BTW, if q is in [0,9999], 8-bit ints will be enough, */
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/* but anyway, gcc produces better code with full-sized ints */
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unsigned d3, d2, d1, d0;
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d1 = (q>>4) & 0xf;
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d2 = (q>>8) & 0xf;
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d3 = (q>>12);
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/* Possible ways to approx. divide by 10 */
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/* gcc -O2 replaces multiply with shifts and adds */
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// (x * 0xcd) >> 11: 11001101 - shorter code than * 0x67 (on i386)
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// (x * 0x67) >> 10: 1100111
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// (x * 0x34) >> 9: 110100 - same
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// (x * 0x1a) >> 8: 11010 - same
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// (x * 0x0d) >> 7: 1101 - same, shortest code (on i386)
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d0 = 6*(d3 + d2 + d1) + (q & 0xf);
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q = (d0 * 0xcd) >> 11;
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d0 = d0 - 10*q;
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*buf++ = d0 + '0';
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d1 = q + 9*d3 + 5*d2 + d1;
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q = (d1 * 0xcd) >> 11;
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d1 = d1 - 10*q;
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*buf++ = d1 + '0';
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d2 = q + 2*d2;
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q = (d2 * 0xd) >> 7;
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d2 = d2 - 10*q;
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*buf++ = d2 + '0';
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d3 = q + 4*d3;
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q = (d3 * 0xcd) >> 11; /* - shorter code */
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/* q = (d3 * 0x67) >> 10; - would also work */
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d3 = d3 - 10*q;
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*buf++ = d3 + '0';
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*buf++ = q + '0';
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return buf;
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}
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/* No inlining helps gcc to use registers better */
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static noinline char* put_dec(char *buf, unsigned long long num)
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{
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while (1) {
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unsigned rem;
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if (num < 100000)
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return put_dec_trunc(buf, num);
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rem = do_div(num, 100000);
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buf = put_dec_full(buf, rem);
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}
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}
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#define ZEROPAD 1 /* pad with zero */
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#define SIGN 2 /* unsigned/signed long */
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#define PLUS 4 /* show plus */
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#define SPACE 8 /* space if plus */
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#define LEFT 16 /* left justified */
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#define SPECIAL 32 /* 0x */
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#define LARGE 64 /* use 'ABCDEF' instead of 'abcdef' */
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static char *number(char *buf, char *end, unsigned long long num, int base, int size, int precision, int type)
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{
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char sign,tmp[66];
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const char *digits;
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/* we are called with base 8, 10 or 16, only, thus don't need "g..." */
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static const char small_digits[] = "0123456789abcdefx"; /* "ghijklmnopqrstuvwxyz"; */
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static const char large_digits[] = "0123456789ABCDEFX"; /* "GHIJKLMNOPQRSTUVWXYZ"; */
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int need_pfx = ((type & SPECIAL) && base != 10);
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int i;
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digits = (type & LARGE) ? large_digits : small_digits;
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if (type & LEFT)
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type &= ~ZEROPAD;
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if (base < 2 || base > 36)
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return NULL;
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sign = 0;
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if (type & SIGN) {
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if ((signed long long) num < 0) {
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sign = '-';
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num = - (signed long long) num;
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size--;
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} else if (type & PLUS) {
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sign = '+';
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size--;
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} else if (type & SPACE) {
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sign = ' ';
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size--;
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}
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}
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if (need_pfx) {
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size--;
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if (base == 16)
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size--;
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}
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/* generate full string in tmp[], in reverse order */
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i = 0;
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if (num == 0)
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tmp[i++] = '0';
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/* Generic code, for any base:
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else do {
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tmp[i++] = digits[do_div(num,base)];
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} while (num != 0);
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*/
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else if (base != 10) { /* 8 or 16 */
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int mask = base - 1;
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int shift = 3;
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if (base == 16) shift = 4;
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do {
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tmp[i++] = digits[((unsigned char)num) & mask];
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num >>= shift;
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} while (num);
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} else { /* base 10 */
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i = put_dec(tmp, num) - tmp;
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}
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/* printing 100 using %2d gives "100", not "00" */
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if (i > precision)
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precision = i;
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/* leading space padding */
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size -= precision;
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if (!(type & (ZEROPAD+LEFT))) {
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while(--size >= 0) {
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if (buf < end)
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*buf = ' ';
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++buf;
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}
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}
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/* sign */
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if (sign) {
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if (buf < end)
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*buf = sign;
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++buf;
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}
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/* "0x" / "0" prefix */
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if (need_pfx) {
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if (buf < end)
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*buf = '0';
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++buf;
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if (base == 16) {
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if (buf < end)
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*buf = digits[16]; /* for arbitrary base: digits[33]; */
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++buf;
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}
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}
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/* zero or space padding */
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if (!(type & LEFT)) {
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char c = (type & ZEROPAD) ? '0' : ' ';
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while (--size >= 0) {
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if (buf < end)
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*buf = c;
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++buf;
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}
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}
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/* hmm even more zero padding? */
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while (i <= --precision) {
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if (buf < end)
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*buf = '0';
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++buf;
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}
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/* actual digits of result */
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while (--i >= 0) {
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if (buf < end)
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*buf = tmp[i];
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++buf;
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}
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/* trailing space padding */
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while (--size >= 0) {
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if (buf < end)
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*buf = ' ';
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++buf;
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}
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return buf;
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}
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/**
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* vsnprintf - Format a string and place it in a buffer
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* @buf: The buffer to place the result into
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* @size: The size of the buffer, including the trailing null space
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* @fmt: The format string to use
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* @args: Arguments for the format string
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*
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* The return value is the number of characters which would
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* be generated for the given input, excluding the trailing
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* '\0', as per ISO C99. If you want to have the exact
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* number of characters written into @buf as return value
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* (not including the trailing '\0'), use vscnprintf(). If the
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* return is greater than or equal to @size, the resulting
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* string is truncated.
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*
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* Call this function if you are already dealing with a va_list.
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* You probably want snprintf() instead.
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*/
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int vsnprintf(char *buf, size_t size, const char *fmt, va_list args)
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{
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int len;
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unsigned long long num;
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int i, base;
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char *str, *end, c;
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const char *s;
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int flags; /* flags to number() */
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int field_width; /* width of output field */
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int precision; /* min. # of digits for integers; max
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number of chars for from string */
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int qualifier; /* 'h', 'l', or 'L' for integer fields */
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/* 'z' support added 23/7/1999 S.H. */
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/* 'z' changed to 'Z' --davidm 1/25/99 */
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/* 't' added for ptrdiff_t */
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/* Reject out-of-range values early. Large positive sizes are
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used for unknown buffer sizes. */
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if (unlikely((int) size < 0)) {
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/* There can be only one.. */
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static char warn = 1;
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WARN_ON(warn);
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warn = 0;
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return 0;
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}
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str = buf;
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end = buf + size;
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/* Make sure end is always >= buf */
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if (end < buf) {
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end = ((void *)-1);
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size = end - buf;
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}
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for (; *fmt ; ++fmt) {
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if (*fmt != '%') {
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if (str < end)
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*str = *fmt;
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++str;
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continue;
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}
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/* process flags */
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flags = 0;
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repeat:
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++fmt; /* this also skips first '%' */
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switch (*fmt) {
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case '-': flags |= LEFT; goto repeat;
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case '+': flags |= PLUS; goto repeat;
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case ' ': flags |= SPACE; goto repeat;
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case '#': flags |= SPECIAL; goto repeat;
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case '0': flags |= ZEROPAD; goto repeat;
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}
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/* get field width */
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field_width = -1;
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if (isdigit(*fmt))
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field_width = skip_atoi(&fmt);
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else if (*fmt == '*') {
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++fmt;
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/* it's the next argument */
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field_width = va_arg(args, int);
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if (field_width < 0) {
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field_width = -field_width;
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flags |= LEFT;
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}
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}
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/* get the precision */
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precision = -1;
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if (*fmt == '.') {
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++fmt;
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if (isdigit(*fmt))
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precision = skip_atoi(&fmt);
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else if (*fmt == '*') {
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++fmt;
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/* it's the next argument */
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precision = va_arg(args, int);
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}
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if (precision < 0)
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precision = 0;
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}
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/* get the conversion qualifier */
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qualifier = -1;
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if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
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*fmt =='Z' || *fmt == 'z' || *fmt == 't') {
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qualifier = *fmt;
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++fmt;
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if (qualifier == 'l' && *fmt == 'l') {
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qualifier = 'L';
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++fmt;
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}
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}
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/* default base */
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base = 10;
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switch (*fmt) {
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case 'c':
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if (!(flags & LEFT)) {
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while (--field_width > 0) {
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if (str < end)
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*str = ' ';
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++str;
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}
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}
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c = (unsigned char) va_arg(args, int);
|
|
if (str < end)
|
|
*str = c;
|
|
++str;
|
|
while (--field_width > 0) {
|
|
if (str < end)
|
|
*str = ' ';
|
|
++str;
|
|
}
|
|
continue;
|
|
|
|
case 's':
|
|
s = va_arg(args, char *);
|
|
if ((unsigned long)s < PAGE_SIZE)
|
|
s = "<NULL>";
|
|
|
|
len = strnlen(s, precision);
|
|
|
|
if (!(flags & LEFT)) {
|
|
while (len < field_width--) {
|
|
if (str < end)
|
|
*str = ' ';
|
|
++str;
|
|
}
|
|
}
|
|
for (i = 0; i < len; ++i) {
|
|
if (str < end)
|
|
*str = *s;
|
|
++str; ++s;
|
|
}
|
|
while (len < field_width--) {
|
|
if (str < end)
|
|
*str = ' ';
|
|
++str;
|
|
}
|
|
continue;
|
|
|
|
case 'p':
|
|
if (field_width == -1) {
|
|
field_width = 2*sizeof(void *);
|
|
flags |= ZEROPAD;
|
|
}
|
|
str = number(str, end,
|
|
(unsigned long) va_arg(args, void *),
|
|
16, field_width, precision, flags);
|
|
continue;
|
|
|
|
|
|
case 'n':
|
|
/* FIXME:
|
|
* What does C99 say about the overflow case here? */
|
|
if (qualifier == 'l') {
|
|
long * ip = va_arg(args, long *);
|
|
*ip = (str - buf);
|
|
} else if (qualifier == 'Z' || qualifier == 'z') {
|
|
size_t * ip = va_arg(args, size_t *);
|
|
*ip = (str - buf);
|
|
} else {
|
|
int * ip = va_arg(args, int *);
|
|
*ip = (str - buf);
|
|
}
|
|
continue;
|
|
|
|
case '%':
|
|
if (str < end)
|
|
*str = '%';
|
|
++str;
|
|
continue;
|
|
|
|
/* integer number formats - set up the flags and "break" */
|
|
case 'o':
|
|
base = 8;
|
|
break;
|
|
|
|
case 'X':
|
|
flags |= LARGE;
|
|
case 'x':
|
|
base = 16;
|
|
break;
|
|
|
|
case 'd':
|
|
case 'i':
|
|
flags |= SIGN;
|
|
case 'u':
|
|
break;
|
|
|
|
default:
|
|
if (str < end)
|
|
*str = '%';
|
|
++str;
|
|
if (*fmt) {
|
|
if (str < end)
|
|
*str = *fmt;
|
|
++str;
|
|
} else {
|
|
--fmt;
|
|
}
|
|
continue;
|
|
}
|
|
if (qualifier == 'L')
|
|
num = va_arg(args, long long);
|
|
else if (qualifier == 'l') {
|
|
num = va_arg(args, unsigned long);
|
|
if (flags & SIGN)
|
|
num = (signed long) num;
|
|
} else if (qualifier == 'Z' || qualifier == 'z') {
|
|
num = va_arg(args, size_t);
|
|
} else if (qualifier == 't') {
|
|
num = va_arg(args, ptrdiff_t);
|
|
} else if (qualifier == 'h') {
|
|
num = (unsigned short) va_arg(args, int);
|
|
if (flags & SIGN)
|
|
num = (signed short) num;
|
|
} else {
|
|
num = va_arg(args, unsigned int);
|
|
if (flags & SIGN)
|
|
num = (signed int) num;
|
|
}
|
|
str = number(str, end, num, base,
|
|
field_width, precision, flags);
|
|
}
|
|
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.
|
|
*
|
|
* Call this function if you are already dealing with a va_list.
|
|
* You probably want scnprintf() instead.
|
|
*/
|
|
int vscnprintf(char *buf, size_t size, const char *fmt, va_list args)
|
|
{
|
|
int i;
|
|
|
|
i=vsnprintf(buf,size,fmt,args);
|
|
return (i >= size) ? (size - 1) : i;
|
|
}
|
|
|
|
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.
|
|
*/
|
|
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 = vsnprintf(buf, size, fmt, args);
|
|
va_end(args);
|
|
return (i >= size) ? (size - 1) : 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.
|
|
*
|
|
* Call this function if you are already dealing with a va_list.
|
|
* You probably want sprintf() instead.
|
|
*/
|
|
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.
|
|
*/
|
|
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);
|
|
|
|
/**
|
|
* 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;
|
|
int qualifier;
|
|
int base;
|
|
int field_width;
|
|
int is_sign = 0;
|
|
|
|
while(*fmt && *str) {
|
|
/* skip any white space in format */
|
|
/* white space in format matchs any amount of
|
|
* white space, including none, in the input.
|
|
*/
|
|
if (isspace(*fmt)) {
|
|
while (isspace(*fmt))
|
|
++fmt;
|
|
while (isspace(*str))
|
|
++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 == '*') {
|
|
while (!isspace(*fmt) && *fmt)
|
|
fmt++;
|
|
while (!isspace(*str) && *str)
|
|
str++;
|
|
continue;
|
|
}
|
|
|
|
/* get field width */
|
|
field_width = -1;
|
|
if (isdigit(*fmt))
|
|
field_width = skip_atoi(&fmt);
|
|
|
|
/* get conversion qualifier */
|
|
qualifier = -1;
|
|
if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L' ||
|
|
*fmt == 'Z' || *fmt == 'z') {
|
|
qualifier = *fmt++;
|
|
if (unlikely(qualifier == *fmt)) {
|
|
if (qualifier == 'h') {
|
|
qualifier = 'H';
|
|
fmt++;
|
|
} else if (qualifier == 'l') {
|
|
qualifier = 'L';
|
|
fmt++;
|
|
}
|
|
}
|
|
}
|
|
base = 10;
|
|
is_sign = 0;
|
|
|
|
if (!*fmt || !*str)
|
|
break;
|
|
|
|
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 = INT_MAX;
|
|
/* first, skip leading white space in buffer */
|
|
while (isspace(*str))
|
|
str++;
|
|
|
|
/* now copy until next white space */
|
|
while (*str && !isspace(*str) && field_width--) {
|
|
*s++ = *str++;
|
|
}
|
|
*s = '\0';
|
|
num++;
|
|
}
|
|
continue;
|
|
case 'n':
|
|
/* return number of characters read so far */
|
|
{
|
|
int *i = (int *)va_arg(args,int*);
|
|
*i = str - buf;
|
|
}
|
|
continue;
|
|
case 'o':
|
|
base = 8;
|
|
break;
|
|
case 'x':
|
|
case 'X':
|
|
base = 16;
|
|
break;
|
|
case 'i':
|
|
base = 0;
|
|
case 'd':
|
|
is_sign = 1;
|
|
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.
|
|
*/
|
|
while (isspace(*str))
|
|
str++;
|
|
|
|
digit = *str;
|
|
if (is_sign && digit == '-')
|
|
digit = *(str + 1);
|
|
|
|
if (!digit
|
|
|| (base == 16 && !isxdigit(digit))
|
|
|| (base == 10 && !isdigit(digit))
|
|
|| (base == 8 && (!isdigit(digit) || digit > '7'))
|
|
|| (base == 0 && !isdigit(digit)))
|
|
break;
|
|
|
|
switch(qualifier) {
|
|
case 'H': /* that's 'hh' in format */
|
|
if (is_sign) {
|
|
signed char *s = (signed char *) va_arg(args,signed char *);
|
|
*s = (signed char) simple_strtol(str,&next,base);
|
|
} else {
|
|
unsigned char *s = (unsigned char *) va_arg(args, unsigned char *);
|
|
*s = (unsigned char) simple_strtoul(str, &next, base);
|
|
}
|
|
break;
|
|
case 'h':
|
|
if (is_sign) {
|
|
short *s = (short *) va_arg(args,short *);
|
|
*s = (short) simple_strtol(str,&next,base);
|
|
} else {
|
|
unsigned short *s = (unsigned short *) va_arg(args, unsigned short *);
|
|
*s = (unsigned short) simple_strtoul(str, &next, base);
|
|
}
|
|
break;
|
|
case 'l':
|
|
if (is_sign) {
|
|
long *l = (long *) va_arg(args,long *);
|
|
*l = simple_strtol(str,&next,base);
|
|
} else {
|
|
unsigned long *l = (unsigned long*) va_arg(args,unsigned long*);
|
|
*l = simple_strtoul(str,&next,base);
|
|
}
|
|
break;
|
|
case 'L':
|
|
if (is_sign) {
|
|
long long *l = (long long*) va_arg(args,long long *);
|
|
*l = simple_strtoll(str,&next,base);
|
|
} else {
|
|
unsigned long long *l = (unsigned long long*) va_arg(args,unsigned long long*);
|
|
*l = simple_strtoull(str,&next,base);
|
|
}
|
|
break;
|
|
case 'Z':
|
|
case 'z':
|
|
{
|
|
size_t *s = (size_t*) va_arg(args,size_t*);
|
|
*s = (size_t) simple_strtoul(str,&next,base);
|
|
}
|
|
break;
|
|
default:
|
|
if (is_sign) {
|
|
int *i = (int *) va_arg(args, int*);
|
|
*i = (int) simple_strtol(str,&next,base);
|
|
} else {
|
|
unsigned int *i = (unsigned int*) va_arg(args, unsigned int*);
|
|
*i = (unsigned int) simple_strtoul(str,&next,base);
|
|
}
|
|
break;
|
|
}
|
|
num++;
|
|
|
|
if (!next)
|
|
break;
|
|
str = next;
|
|
}
|
|
|
|
/*
|
|
* Now we've come all the way through so either the input string or the
|
|
* format ended. In the former case, there can be a %n at the current
|
|
* position in the format that needs to be filled.
|
|
*/
|
|
if (*fmt == '%' && *(fmt + 1) == 'n') {
|
|
int *p = (int *)va_arg(args, int *);
|
|
*p = str - buf;
|
|
}
|
|
|
|
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);
|
|
|
|
|
|
/* Simplified asprintf. */
|
|
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
|
|
{
|
|
unsigned int len;
|
|
char *p;
|
|
va_list aq;
|
|
|
|
va_copy(aq, ap);
|
|
len = vsnprintf(NULL, 0, fmt, aq);
|
|
va_end(aq);
|
|
|
|
p = kmalloc(len+1, gfp);
|
|
if (!p)
|
|
return NULL;
|
|
|
|
vsnprintf(p, len+1, fmt, ap);
|
|
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(kvasprintf);
|
|
|
|
char *kasprintf(gfp_t gfp, const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
char *p;
|
|
|
|
va_start(ap, fmt);
|
|
p = kvasprintf(gfp, fmt, ap);
|
|
va_end(ap);
|
|
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(kasprintf);
|