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SubjectRe: [PATCH v4 1/2] lib/string_helpers: Introduce parse_int_array_user()
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On 9/2/2022 2:29 PM, Cezary Rojewski wrote:
> 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 <andy.shevchenko@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
> ---
> include/linux/string_helpers.h | 2 ++
> lib/string_helpers.c | 45 ++++++++++++++++++++++++++++++++++
> 2 files changed, 47 insertions(+)
>
> diff --git a/include/linux/string_helpers.h b/include/linux/string_helpers.h
> index 4d72258d42fd..dc2e726fd820 100644
> --- a/include/linux/string_helpers.h
> +++ b/include/linux/string_helpers.h
> @@ -21,6 +21,8 @@ enum string_size_units {
> void string_get_size(u64 size, u64 blk_size, enum string_size_units units,
> char *buf, int len);
>
> +int parse_int_array_user(const char __user *from, size_t count, int **array);
> +
> #define UNESCAPE_SPACE BIT(0)
> #define UNESCAPE_OCTAL BIT(1)
> #define UNESCAPE_HEX BIT(2)
> diff --git a/lib/string_helpers.c b/lib/string_helpers.c
> index 5ed3beb066e6..d0c8f6ecf84c 100644
> --- a/lib/string_helpers.c
> +++ b/lib/string_helpers.c
> @@ -131,6 +131,51 @@ 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
> + * @ppos: The current position in the buffer

There is no such parameter?

> + * @count: The maximum number of bytes to read
> + * @tkns: Returned pointer to sequence of integers

s/tkns/array/ ?

> + *
> + * On success @tkns is allocated and initialized with a sequence of

ditto

> + * integers extracted from the @from plus an additional element that
> + * begins the sequence and specifies the integers count.
> + *
> + * Caller takes responsibility for freeing @tkns when it is no longer

ditto

> + * 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;

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