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 <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20220904102840.862395-2-cezary.rojewski@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Cezary Rojewski 2022-09-04 12:28:39 +02:00 committed by Mark Brown
parent 376be51caf
commit f0b933236e
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2 changed files with 46 additions and 0 deletions

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@ -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)

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@ -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;