From f0b933236ec97de5ee49c60aae57a9c5c4dadc87 Mon Sep 17 00:00:00 2001 From: Cezary Rojewski Date: Sun, 4 Sep 2022 12:28:39 +0200 Subject: lib/string_helpers: Introduce parse_int_array_user() Add new helper function to allow for splitting specified user string into a sequence of integers. Internally it makes use of get_options() so the returned sequence contains the integers extracted plus an additional element that begins the sequence and specifies the integers count. Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Signed-off-by: Cezary Rojewski Link: https://lore.kernel.org/r/20220904102840.862395-2-cezary.rojewski@intel.com Signed-off-by: Mark Brown --- lib/string_helpers.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'lib') diff --git a/lib/string_helpers.c b/lib/string_helpers.c index 5ed3beb066e6..230020a2e076 100644 --- a/lib/string_helpers.c +++ b/lib/string_helpers.c @@ -131,6 +131,50 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, } EXPORT_SYMBOL(string_get_size); +/** + * parse_int_array_user - Split string into a sequence of integers + * @from: The user space buffer to read from + * @count: The maximum number of bytes to read + * @array: Returned pointer to sequence of integers + * + * On success @array is allocated and initialized with a sequence of + * integers extracted from the @from plus an additional element that + * begins the sequence and specifies the integers count. + * + * Caller takes responsibility for freeing @array when it is no longer + * needed. + */ +int parse_int_array_user(const char __user *from, size_t count, int **array) +{ + int *ints, nints; + char *buf; + int ret = 0; + + buf = memdup_user_nul(from, count); + if (IS_ERR(buf)) + return PTR_ERR(buf); + + get_options(buf, 0, &nints); + if (!nints) { + ret = -ENOENT; + goto free_buf; + } + + ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL); + if (!ints) { + ret = -ENOMEM; + goto free_buf; + } + + get_options(buf, nints + 1, ints); + *array = ints; + +free_buf: + kfree(buf); + return ret; +} +EXPORT_SYMBOL(parse_int_array_user); + static bool unescape_space(char **src, char **dst) { char *p = *dst, *q = *src; -- cgit v1.2.3