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![Andy Shevchenko](/assets/img/avatar_default.png)
It's more useful to return the pointer to the string itself with strreplace(), so it may be used like attr->name = strreplace(name, '/', '_'); While at it, amend the kernel documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20230605170553.7835-3-andriy.shevchenko@linux.intel.com
1034 lines
24 KiB
C
1034 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Helpers for formatting and printing strings
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*
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* Copyright 31 August 2008 James Bottomley
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* Copyright (C) 2013, Intel Corporation
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*/
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#include <linux/bug.h>
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#include <linux/kernel.h>
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#include <linux/math64.h>
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#include <linux/export.h>
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#include <linux/ctype.h>
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/limits.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/string_helpers.h>
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/**
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* string_get_size - get the size in the specified units
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* @size: The size to be converted in blocks
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* @blk_size: Size of the block (use 1 for size in bytes)
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* @units: units to use (powers of 1000 or 1024)
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* @buf: buffer to format to
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* @len: length of buffer
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*
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* This function returns a string formatted to 3 significant figures
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* giving the size in the required units. @buf should have room for
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* at least 9 bytes and will always be zero terminated.
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*
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*/
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void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
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char *buf, int len)
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{
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static const char *const units_10[] = {
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"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
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};
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static const char *const units_2[] = {
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"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
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};
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static const char *const *const units_str[] = {
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[STRING_UNITS_10] = units_10,
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[STRING_UNITS_2] = units_2,
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};
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static const unsigned int divisor[] = {
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[STRING_UNITS_10] = 1000,
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[STRING_UNITS_2] = 1024,
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};
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static const unsigned int rounding[] = { 500, 50, 5 };
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int i = 0, j;
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u32 remainder = 0, sf_cap;
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char tmp[8];
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const char *unit;
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tmp[0] = '\0';
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if (blk_size == 0)
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size = 0;
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if (size == 0)
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goto out;
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/* This is Napier's algorithm. Reduce the original block size to
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*
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* coefficient * divisor[units]^i
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*
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* we do the reduction so both coefficients are just under 32 bits so
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* that multiplying them together won't overflow 64 bits and we keep
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* as much precision as possible in the numbers.
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*
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* Note: it's safe to throw away the remainders here because all the
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* precision is in the coefficients.
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*/
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while (blk_size >> 32) {
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do_div(blk_size, divisor[units]);
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i++;
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}
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while (size >> 32) {
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do_div(size, divisor[units]);
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i++;
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}
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/* now perform the actual multiplication keeping i as the sum of the
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* two logarithms */
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size *= blk_size;
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/* and logarithmically reduce it until it's just under the divisor */
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while (size >= divisor[units]) {
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remainder = do_div(size, divisor[units]);
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i++;
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}
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/* work out in j how many digits of precision we need from the
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* remainder */
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sf_cap = size;
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for (j = 0; sf_cap*10 < 1000; j++)
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sf_cap *= 10;
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if (units == STRING_UNITS_2) {
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/* express the remainder as a decimal. It's currently the
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* numerator of a fraction whose denominator is
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* divisor[units], which is 1 << 10 for STRING_UNITS_2 */
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remainder *= 1000;
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remainder >>= 10;
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}
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/* add a 5 to the digit below what will be printed to ensure
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* an arithmetical round up and carry it through to size */
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remainder += rounding[j];
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if (remainder >= 1000) {
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remainder -= 1000;
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size += 1;
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}
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if (j) {
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snprintf(tmp, sizeof(tmp), ".%03u", remainder);
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tmp[j+1] = '\0';
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}
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out:
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if (i >= ARRAY_SIZE(units_2))
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unit = "UNK";
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else
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unit = units_str[units][i];
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snprintf(buf, len, "%u%s %s", (u32)size,
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tmp, unit);
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}
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EXPORT_SYMBOL(string_get_size);
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/**
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* parse_int_array_user - Split string into a sequence of integers
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* @from: The user space buffer to read from
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* @count: The maximum number of bytes to read
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* @array: Returned pointer to sequence of integers
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*
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* On success @array is allocated and initialized with a sequence of
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* integers extracted from the @from plus an additional element that
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* begins the sequence and specifies the integers count.
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*
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* Caller takes responsibility for freeing @array when it is no longer
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* needed.
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*/
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int parse_int_array_user(const char __user *from, size_t count, int **array)
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{
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int *ints, nints;
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char *buf;
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int ret = 0;
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buf = memdup_user_nul(from, count);
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if (IS_ERR(buf))
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return PTR_ERR(buf);
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get_options(buf, 0, &nints);
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if (!nints) {
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ret = -ENOENT;
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goto free_buf;
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}
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ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL);
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if (!ints) {
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ret = -ENOMEM;
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goto free_buf;
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}
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get_options(buf, nints + 1, ints);
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*array = ints;
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free_buf:
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kfree(buf);
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return ret;
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}
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EXPORT_SYMBOL(parse_int_array_user);
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static bool unescape_space(char **src, char **dst)
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{
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char *p = *dst, *q = *src;
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switch (*q) {
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case 'n':
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*p = '\n';
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break;
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case 'r':
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*p = '\r';
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break;
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case 't':
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*p = '\t';
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break;
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case 'v':
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*p = '\v';
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break;
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case 'f':
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*p = '\f';
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break;
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default:
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return false;
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}
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*dst += 1;
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*src += 1;
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return true;
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}
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static bool unescape_octal(char **src, char **dst)
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{
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char *p = *dst, *q = *src;
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u8 num;
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if (isodigit(*q) == 0)
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return false;
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num = (*q++) & 7;
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while (num < 32 && isodigit(*q) && (q - *src < 3)) {
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num <<= 3;
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num += (*q++) & 7;
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}
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*p = num;
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*dst += 1;
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*src = q;
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return true;
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}
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static bool unescape_hex(char **src, char **dst)
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{
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char *p = *dst, *q = *src;
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int digit;
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u8 num;
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if (*q++ != 'x')
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return false;
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num = digit = hex_to_bin(*q++);
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if (digit < 0)
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return false;
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digit = hex_to_bin(*q);
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if (digit >= 0) {
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q++;
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num = (num << 4) | digit;
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}
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*p = num;
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*dst += 1;
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*src = q;
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return true;
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}
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static bool unescape_special(char **src, char **dst)
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{
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char *p = *dst, *q = *src;
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switch (*q) {
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case '\"':
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*p = '\"';
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break;
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case '\\':
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*p = '\\';
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break;
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case 'a':
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*p = '\a';
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break;
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case 'e':
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*p = '\e';
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break;
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default:
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return false;
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}
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*dst += 1;
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*src += 1;
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return true;
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}
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/**
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* string_unescape - unquote characters in the given string
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* @src: source buffer (escaped)
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* @dst: destination buffer (unescaped)
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* @size: size of the destination buffer (0 to unlimit)
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* @flags: combination of the flags.
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*
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* Description:
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* The function unquotes characters in the given string.
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*
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* Because the size of the output will be the same as or less than the size of
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* the input, the transformation may be performed in place.
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*
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* Caller must provide valid source and destination pointers. Be aware that
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* destination buffer will always be NULL-terminated. Source string must be
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* NULL-terminated as well. The supported flags are::
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*
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* UNESCAPE_SPACE:
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* '\f' - form feed
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* '\n' - new line
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* '\r' - carriage return
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* '\t' - horizontal tab
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* '\v' - vertical tab
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* UNESCAPE_OCTAL:
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* '\NNN' - byte with octal value NNN (1 to 3 digits)
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* UNESCAPE_HEX:
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* '\xHH' - byte with hexadecimal value HH (1 to 2 digits)
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* UNESCAPE_SPECIAL:
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* '\"' - double quote
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* '\\' - backslash
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* '\a' - alert (BEL)
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* '\e' - escape
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* UNESCAPE_ANY:
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* all previous together
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*
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* Return:
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* The amount of the characters processed to the destination buffer excluding
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* trailing '\0' is returned.
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*/
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int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
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{
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char *out = dst;
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while (*src && --size) {
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if (src[0] == '\\' && src[1] != '\0' && size > 1) {
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src++;
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size--;
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if (flags & UNESCAPE_SPACE &&
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unescape_space(&src, &out))
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continue;
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if (flags & UNESCAPE_OCTAL &&
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unescape_octal(&src, &out))
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continue;
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if (flags & UNESCAPE_HEX &&
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unescape_hex(&src, &out))
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continue;
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if (flags & UNESCAPE_SPECIAL &&
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unescape_special(&src, &out))
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continue;
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*out++ = '\\';
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}
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*out++ = *src++;
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}
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*out = '\0';
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return out - dst;
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}
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EXPORT_SYMBOL(string_unescape);
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static bool escape_passthrough(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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if (out < end)
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*out = c;
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*dst = out + 1;
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return true;
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}
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static bool escape_space(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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unsigned char to;
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switch (c) {
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case '\n':
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to = 'n';
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break;
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case '\r':
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to = 'r';
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break;
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case '\t':
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to = 't';
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break;
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case '\v':
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to = 'v';
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break;
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case '\f':
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to = 'f';
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break;
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default:
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return false;
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}
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if (out < end)
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*out = '\\';
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++out;
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if (out < end)
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*out = to;
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++out;
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*dst = out;
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return true;
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}
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static bool escape_special(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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unsigned char to;
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switch (c) {
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case '\\':
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to = '\\';
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break;
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case '\a':
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to = 'a';
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break;
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case '\e':
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to = 'e';
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break;
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case '"':
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to = '"';
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break;
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default:
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return false;
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}
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if (out < end)
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*out = '\\';
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++out;
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if (out < end)
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*out = to;
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++out;
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*dst = out;
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return true;
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}
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static bool escape_null(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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if (c)
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return false;
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if (out < end)
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*out = '\\';
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++out;
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if (out < end)
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*out = '0';
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++out;
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*dst = out;
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return true;
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}
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static bool escape_octal(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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if (out < end)
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*out = '\\';
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++out;
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if (out < end)
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*out = ((c >> 6) & 0x07) + '0';
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++out;
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if (out < end)
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*out = ((c >> 3) & 0x07) + '0';
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++out;
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if (out < end)
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*out = ((c >> 0) & 0x07) + '0';
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++out;
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*dst = out;
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return true;
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}
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static bool escape_hex(unsigned char c, char **dst, char *end)
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{
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char *out = *dst;
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if (out < end)
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*out = '\\';
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++out;
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if (out < end)
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*out = 'x';
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++out;
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if (out < end)
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*out = hex_asc_hi(c);
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++out;
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if (out < end)
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*out = hex_asc_lo(c);
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++out;
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*dst = out;
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return true;
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}
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|
|
/**
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* string_escape_mem - quote characters in the given memory buffer
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* @src: source buffer (unescaped)
|
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* @isz: source buffer size
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* @dst: destination buffer (escaped)
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* @osz: destination buffer size
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|
* @flags: combination of the flags
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* @only: NULL-terminated string containing characters used to limit
|
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* the selected escape class. If characters are included in @only
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* that would not normally be escaped by the classes selected
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* in @flags, they will be copied to @dst unescaped.
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|
*
|
|
* Description:
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* The process of escaping byte buffer includes several parts. They are applied
|
|
* in the following sequence.
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*
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* 1. The character is not matched to the one from @only string and thus
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* must go as-is to the output.
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* 2. The character is matched to the printable and ASCII classes, if asked,
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* and in case of match it passes through to the output.
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* 3. The character is matched to the printable or ASCII class, if asked,
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|
* and in case of match it passes through to the output.
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* 4. The character is checked if it falls into the class given by @flags.
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* %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any
|
|
* character. Note that they actually can't go together, otherwise
|
|
* %ESCAPE_HEX will be ignored.
|
|
*
|
|
* Caller must provide valid source and destination pointers. Be aware that
|
|
* destination buffer will not be NULL-terminated, thus caller have to append
|
|
* it if needs. The supported flags are::
|
|
*
|
|
* %ESCAPE_SPACE: (special white space, not space itself)
|
|
* '\f' - form feed
|
|
* '\n' - new line
|
|
* '\r' - carriage return
|
|
* '\t' - horizontal tab
|
|
* '\v' - vertical tab
|
|
* %ESCAPE_SPECIAL:
|
|
* '\"' - double quote
|
|
* '\\' - backslash
|
|
* '\a' - alert (BEL)
|
|
* '\e' - escape
|
|
* %ESCAPE_NULL:
|
|
* '\0' - null
|
|
* %ESCAPE_OCTAL:
|
|
* '\NNN' - byte with octal value NNN (3 digits)
|
|
* %ESCAPE_ANY:
|
|
* all previous together
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|
* %ESCAPE_NP:
|
|
* escape only non-printable characters, checked by isprint()
|
|
* %ESCAPE_ANY_NP:
|
|
* all previous together
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|
* %ESCAPE_HEX:
|
|
* '\xHH' - byte with hexadecimal value HH (2 digits)
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|
* %ESCAPE_NA:
|
|
* escape only non-ascii characters, checked by isascii()
|
|
* %ESCAPE_NAP:
|
|
* escape only non-printable or non-ascii characters
|
|
* %ESCAPE_APPEND:
|
|
* append characters from @only to be escaped by the given classes
|
|
*
|
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* %ESCAPE_APPEND would help to pass additional characters to the escaped, when
|
|
* one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided.
|
|
*
|
|
* One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the
|
|
* higher priority than the rest of the flags (%ESCAPE_NAP is the highest).
|
|
* It doesn't make much sense to use either of them without %ESCAPE_OCTAL
|
|
* or %ESCAPE_HEX, because they cover most of the other character classes.
|
|
* %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to
|
|
* the above.
|
|
*
|
|
* Return:
|
|
* The total size of the escaped output that would be generated for
|
|
* the given input and flags. To check whether the output was
|
|
* truncated, compare the return value to osz. There is room left in
|
|
* dst for a '\0' terminator if and only if ret < osz.
|
|
*/
|
|
int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
|
|
unsigned int flags, const char *only)
|
|
{
|
|
char *p = dst;
|
|
char *end = p + osz;
|
|
bool is_dict = only && *only;
|
|
bool is_append = flags & ESCAPE_APPEND;
|
|
|
|
while (isz--) {
|
|
unsigned char c = *src++;
|
|
bool in_dict = is_dict && strchr(only, c);
|
|
|
|
/*
|
|
* Apply rules in the following sequence:
|
|
* - the @only string is supplied and does not contain a
|
|
* character under question
|
|
* - the character is printable and ASCII, when @flags has
|
|
* %ESCAPE_NAP bit set
|
|
* - the character is printable, when @flags has
|
|
* %ESCAPE_NP bit set
|
|
* - the character is ASCII, when @flags has
|
|
* %ESCAPE_NA bit set
|
|
* - the character doesn't fall into a class of symbols
|
|
* defined by given @flags
|
|
* In these cases we just pass through a character to the
|
|
* output buffer.
|
|
*
|
|
* When %ESCAPE_APPEND is passed, the characters from @only
|
|
* have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and
|
|
* %ESCAPE_NA cases.
|
|
*/
|
|
if (!(is_append || in_dict) && is_dict &&
|
|
escape_passthrough(c, &p, end))
|
|
continue;
|
|
|
|
if (!(is_append && in_dict) && isascii(c) && isprint(c) &&
|
|
flags & ESCAPE_NAP && escape_passthrough(c, &p, end))
|
|
continue;
|
|
|
|
if (!(is_append && in_dict) && isprint(c) &&
|
|
flags & ESCAPE_NP && escape_passthrough(c, &p, end))
|
|
continue;
|
|
|
|
if (!(is_append && in_dict) && isascii(c) &&
|
|
flags & ESCAPE_NA && escape_passthrough(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_NULL && escape_null(c, &p, end))
|
|
continue;
|
|
|
|
/* ESCAPE_OCTAL and ESCAPE_HEX always go last */
|
|
if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
|
|
continue;
|
|
|
|
if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
|
|
continue;
|
|
|
|
escape_passthrough(c, &p, end);
|
|
}
|
|
|
|
return p - dst;
|
|
}
|
|
EXPORT_SYMBOL(string_escape_mem);
|
|
|
|
/*
|
|
* Return an allocated string that has been escaped of special characters
|
|
* and double quotes, making it safe to log in quotes.
|
|
*/
|
|
char *kstrdup_quotable(const char *src, gfp_t gfp)
|
|
{
|
|
size_t slen, dlen;
|
|
char *dst;
|
|
const int flags = ESCAPE_HEX;
|
|
const char esc[] = "\f\n\r\t\v\a\e\\\"";
|
|
|
|
if (!src)
|
|
return NULL;
|
|
slen = strlen(src);
|
|
|
|
dlen = string_escape_mem(src, slen, NULL, 0, flags, esc);
|
|
dst = kmalloc(dlen + 1, gfp);
|
|
if (!dst)
|
|
return NULL;
|
|
|
|
WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen);
|
|
dst[dlen] = '\0';
|
|
|
|
return dst;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kstrdup_quotable);
|
|
|
|
/*
|
|
* Returns allocated NULL-terminated string containing process
|
|
* command line, with inter-argument NULLs replaced with spaces,
|
|
* and other special characters escaped.
|
|
*/
|
|
char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp)
|
|
{
|
|
char *buffer, *quoted;
|
|
int i, res;
|
|
|
|
buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
|
|
if (!buffer)
|
|
return NULL;
|
|
|
|
res = get_cmdline(task, buffer, PAGE_SIZE - 1);
|
|
buffer[res] = '\0';
|
|
|
|
/* Collapse trailing NULLs, leave res pointing to last non-NULL. */
|
|
while (--res >= 0 && buffer[res] == '\0')
|
|
;
|
|
|
|
/* Replace inter-argument NULLs. */
|
|
for (i = 0; i <= res; i++)
|
|
if (buffer[i] == '\0')
|
|
buffer[i] = ' ';
|
|
|
|
/* Make sure result is printable. */
|
|
quoted = kstrdup_quotable(buffer, gfp);
|
|
kfree(buffer);
|
|
return quoted;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline);
|
|
|
|
/*
|
|
* Returns allocated NULL-terminated string containing pathname,
|
|
* with special characters escaped, able to be safely logged. If
|
|
* there is an error, the leading character will be "<".
|
|
*/
|
|
char *kstrdup_quotable_file(struct file *file, gfp_t gfp)
|
|
{
|
|
char *temp, *pathname;
|
|
|
|
if (!file)
|
|
return kstrdup("<unknown>", gfp);
|
|
|
|
/* We add 11 spaces for ' (deleted)' to be appended */
|
|
temp = kmalloc(PATH_MAX + 11, GFP_KERNEL);
|
|
if (!temp)
|
|
return kstrdup("<no_memory>", gfp);
|
|
|
|
pathname = file_path(file, temp, PATH_MAX + 11);
|
|
if (IS_ERR(pathname))
|
|
pathname = kstrdup("<too_long>", gfp);
|
|
else
|
|
pathname = kstrdup_quotable(pathname, gfp);
|
|
|
|
kfree(temp);
|
|
return pathname;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kstrdup_quotable_file);
|
|
|
|
/**
|
|
* kasprintf_strarray - allocate and fill array of sequential strings
|
|
* @gfp: flags for the slab allocator
|
|
* @prefix: prefix to be used
|
|
* @n: amount of lines to be allocated and filled
|
|
*
|
|
* Allocates and fills @n strings using pattern "%s-%zu", where prefix
|
|
* is provided by caller. The caller is responsible to free them with
|
|
* kfree_strarray() after use.
|
|
*
|
|
* Returns array of strings or NULL when memory can't be allocated.
|
|
*/
|
|
char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n)
|
|
{
|
|
char **names;
|
|
size_t i;
|
|
|
|
names = kcalloc(n + 1, sizeof(char *), gfp);
|
|
if (!names)
|
|
return NULL;
|
|
|
|
for (i = 0; i < n; i++) {
|
|
names[i] = kasprintf(gfp, "%s-%zu", prefix, i);
|
|
if (!names[i]) {
|
|
kfree_strarray(names, i);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
return names;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kasprintf_strarray);
|
|
|
|
/**
|
|
* kfree_strarray - free a number of dynamically allocated strings contained
|
|
* in an array and the array itself
|
|
*
|
|
* @array: Dynamically allocated array of strings to free.
|
|
* @n: Number of strings (starting from the beginning of the array) to free.
|
|
*
|
|
* Passing a non-NULL @array and @n == 0 as well as NULL @array are valid
|
|
* use-cases. If @array is NULL, the function does nothing.
|
|
*/
|
|
void kfree_strarray(char **array, size_t n)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (!array)
|
|
return;
|
|
|
|
for (i = 0; i < n; i++)
|
|
kfree(array[i]);
|
|
kfree(array);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kfree_strarray);
|
|
|
|
struct strarray {
|
|
char **array;
|
|
size_t n;
|
|
};
|
|
|
|
static void devm_kfree_strarray(struct device *dev, void *res)
|
|
{
|
|
struct strarray *array = res;
|
|
|
|
kfree_strarray(array->array, array->n);
|
|
}
|
|
|
|
char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n)
|
|
{
|
|
struct strarray *ptr;
|
|
|
|
ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL);
|
|
if (!ptr)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n);
|
|
if (!ptr->array) {
|
|
devres_free(ptr);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
ptr->n = n;
|
|
devres_add(dev, ptr);
|
|
|
|
return ptr->array;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_kasprintf_strarray);
|
|
|
|
/**
|
|
* strscpy_pad() - Copy a C-string into a sized buffer
|
|
* @dest: Where to copy the string to
|
|
* @src: Where to copy the string from
|
|
* @count: Size of destination buffer
|
|
*
|
|
* Copy the string, or as much of it as fits, into the dest buffer. The
|
|
* behavior is undefined if the string buffers overlap. The destination
|
|
* buffer is always %NUL terminated, unless it's zero-sized.
|
|
*
|
|
* If the source string is shorter than the destination buffer, zeros
|
|
* the tail of the destination buffer.
|
|
*
|
|
* For full explanation of why you may want to consider using the
|
|
* 'strscpy' functions please see the function docstring for strscpy().
|
|
*
|
|
* Returns:
|
|
* * The number of characters copied (not including the trailing %NUL)
|
|
* * -E2BIG if count is 0 or @src was truncated.
|
|
*/
|
|
ssize_t strscpy_pad(char *dest, const char *src, size_t count)
|
|
{
|
|
ssize_t written;
|
|
|
|
written = strscpy(dest, src, count);
|
|
if (written < 0 || written == count - 1)
|
|
return written;
|
|
|
|
memset(dest + written + 1, 0, count - written - 1);
|
|
|
|
return written;
|
|
}
|
|
EXPORT_SYMBOL(strscpy_pad);
|
|
|
|
/**
|
|
* skip_spaces - Removes leading whitespace from @str.
|
|
* @str: The string to be stripped.
|
|
*
|
|
* Returns a pointer to the first non-whitespace character in @str.
|
|
*/
|
|
char *skip_spaces(const char *str)
|
|
{
|
|
while (isspace(*str))
|
|
++str;
|
|
return (char *)str;
|
|
}
|
|
EXPORT_SYMBOL(skip_spaces);
|
|
|
|
/**
|
|
* strim - Removes leading and trailing whitespace from @s.
|
|
* @s: The string to be stripped.
|
|
*
|
|
* Note that the first trailing whitespace is replaced with a %NUL-terminator
|
|
* in the given string @s. Returns a pointer to the first non-whitespace
|
|
* character in @s.
|
|
*/
|
|
char *strim(char *s)
|
|
{
|
|
size_t size;
|
|
char *end;
|
|
|
|
size = strlen(s);
|
|
if (!size)
|
|
return s;
|
|
|
|
end = s + size - 1;
|
|
while (end >= s && isspace(*end))
|
|
end--;
|
|
*(end + 1) = '\0';
|
|
|
|
return skip_spaces(s);
|
|
}
|
|
EXPORT_SYMBOL(strim);
|
|
|
|
/**
|
|
* sysfs_streq - return true if strings are equal, modulo trailing newline
|
|
* @s1: one string
|
|
* @s2: another string
|
|
*
|
|
* This routine returns true iff two strings are equal, treating both
|
|
* NUL and newline-then-NUL as equivalent string terminations. It's
|
|
* geared for use with sysfs input strings, which generally terminate
|
|
* with newlines but are compared against values without newlines.
|
|
*/
|
|
bool sysfs_streq(const char *s1, const char *s2)
|
|
{
|
|
while (*s1 && *s1 == *s2) {
|
|
s1++;
|
|
s2++;
|
|
}
|
|
|
|
if (*s1 == *s2)
|
|
return true;
|
|
if (!*s1 && *s2 == '\n' && !s2[1])
|
|
return true;
|
|
if (*s1 == '\n' && !s1[1] && !*s2)
|
|
return true;
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL(sysfs_streq);
|
|
|
|
/**
|
|
* match_string - matches given string in an array
|
|
* @array: array of strings
|
|
* @n: number of strings in the array or -1 for NULL terminated arrays
|
|
* @string: string to match with
|
|
*
|
|
* This routine will look for a string in an array of strings up to the
|
|
* n-th element in the array or until the first NULL element.
|
|
*
|
|
* Historically the value of -1 for @n, was used to search in arrays that
|
|
* are NULL terminated. However, the function does not make a distinction
|
|
* when finishing the search: either @n elements have been compared OR
|
|
* the first NULL element was found.
|
|
*
|
|
* Return:
|
|
* index of a @string in the @array if matches, or %-EINVAL otherwise.
|
|
*/
|
|
int match_string(const char * const *array, size_t n, const char *string)
|
|
{
|
|
int index;
|
|
const char *item;
|
|
|
|
for (index = 0; index < n; index++) {
|
|
item = array[index];
|
|
if (!item)
|
|
break;
|
|
if (!strcmp(item, string))
|
|
return index;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL(match_string);
|
|
|
|
/**
|
|
* __sysfs_match_string - matches given string in an array
|
|
* @array: array of strings
|
|
* @n: number of strings in the array or -1 for NULL terminated arrays
|
|
* @str: string to match with
|
|
*
|
|
* Returns index of @str in the @array or -EINVAL, just like match_string().
|
|
* Uses sysfs_streq instead of strcmp for matching.
|
|
*
|
|
* This routine will look for a string in an array of strings up to the
|
|
* n-th element in the array or until the first NULL element.
|
|
*
|
|
* Historically the value of -1 for @n, was used to search in arrays that
|
|
* are NULL terminated. However, the function does not make a distinction
|
|
* when finishing the search: either @n elements have been compared OR
|
|
* the first NULL element was found.
|
|
*/
|
|
int __sysfs_match_string(const char * const *array, size_t n, const char *str)
|
|
{
|
|
const char *item;
|
|
int index;
|
|
|
|
for (index = 0; index < n; index++) {
|
|
item = array[index];
|
|
if (!item)
|
|
break;
|
|
if (sysfs_streq(item, str))
|
|
return index;
|
|
}
|
|
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL(__sysfs_match_string);
|
|
|
|
/**
|
|
* strreplace - Replace all occurrences of character in string.
|
|
* @str: The string to operate on.
|
|
* @old: The character being replaced.
|
|
* @new: The character @old is replaced with.
|
|
*
|
|
* Replaces the each @old character with a @new one in the given string @str.
|
|
*
|
|
* Return: pointer to the string @str itself.
|
|
*/
|
|
char *strreplace(char *str, char old, char new)
|
|
{
|
|
char *s = str;
|
|
|
|
for (; *s; ++s)
|
|
if (*s == old)
|
|
*s = new;
|
|
return str;
|
|
}
|
|
EXPORT_SYMBOL(strreplace);
|
|
|
|
/**
|
|
* memcpy_and_pad - Copy one buffer to another with padding
|
|
* @dest: Where to copy to
|
|
* @dest_len: The destination buffer size
|
|
* @src: Where to copy from
|
|
* @count: The number of bytes to copy
|
|
* @pad: Character to use for padding if space is left in destination.
|
|
*/
|
|
void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
|
|
int pad)
|
|
{
|
|
if (dest_len > count) {
|
|
memcpy(dest, src, count);
|
|
memset(dest + count, pad, dest_len - count);
|
|
} else {
|
|
memcpy(dest, src, dest_len);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(memcpy_and_pad);
|
|
|
|
#ifdef CONFIG_FORTIFY_SOURCE
|
|
/* These are placeholders for fortify compile-time warnings. */
|
|
void __read_overflow2_field(size_t avail, size_t wanted) { }
|
|
EXPORT_SYMBOL(__read_overflow2_field);
|
|
void __write_overflow_field(size_t avail, size_t wanted) { }
|
|
EXPORT_SYMBOL(__write_overflow_field);
|
|
|
|
void fortify_panic(const char *name)
|
|
{
|
|
pr_emerg("detected buffer overflow in %s\n", name);
|
|
BUG();
|
|
}
|
|
EXPORT_SYMBOL(fortify_panic);
|
|
#endif /* CONFIG_FORTIFY_SOURCE */
|