Unverified Commit f0b93323 authored by Cezary Rojewski's avatar Cezary Rojewski Committed by Mark Brown
Browse files

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: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: default avatarAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: default avatarCezary Rojewski <cezary.rojewski@intel.com>
Link: https://lore.kernel.org/r/20220904102840.862395-2-cezary.rojewski@intel.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 376be51c

include/linux/string_helpers.h

+2 −0
Original line number Diff line number Diff line
@@ -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)

lib/string_helpers.c

+44 −0
Original line number Diff line number Diff line
@@ -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;