[PATCH v3 1/2] kernel.h: Update comment about simple_strto() functions

Andy Shevchenko
2019-07-04T11:55:39Z

There were discussions in the past about use cases for
simple_strto<foo>() functions and, in some rare cases,
they have a benefit over kstrto<foo>() ones.

Update a comment to reduce confusion about special use cases.

Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
- update comment based on Geert's input
include/linux/kernel.h | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 0c9bc231107f..63663c44933d 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -332,8 +332,7 @@ int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
* @res: Where to write the result of the conversion on success.
*
* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
- * Used as a replacement for the obsolete simple_strtoull. Return code must
- * be checked.
+ * Used as a replacement for the simple_strtoull. Return code must be checked.
*/
static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
{
@@ -361,8 +360,7 @@ static inline int __must_check kstrtoul(const char *s, unsigned int base, unsign
* @res: Where to write the result of the conversion on success.
*
* Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
- * Used as a replacement for the obsolete simple_strtoull. Return code must
- * be checked.
+ * Used as a replacement for the simple_strtoull. Return code must be checked.
*/
static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
{
@@ -438,7 +436,16 @@ static inline int __must_check kstrtos32_from_user(const char __user *s, size_t
return kstrtoint_from_user(s, count, base, res);
}

-/* Obsolete, do not use. Use kstrto<foo> instead */
+/*
+ * Use kstrto<foo> instead.
+ *
+ * NOTE: The simple_strto<foo> does not check for overflow and,
+ * depending on the input, may give interesting results.
+ *
+ * Use these functions if and only if you cannot use kstrto<foo>, because
+ * the number is not immediately followed by a NUL-character in the buffer.
+ * Keep in mind above caveat.
+ */

extern unsigned long simple_strtoul(const char *,char **,unsigned int);
extern long simple_strtol(const char *,char **,unsigned int);
--
2.20.1