[PATCH v2 1/2] kernel.h: Update comment about simple_strto<foo>() functions

From: Andy Shevchenko
Date: Wed Jun 26 2019 - 05:39:52 EST


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

Update a comment to reduce confusing about special use cases.

Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
- Cc to Andrew
include/linux/kernel.h | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 74b1ee9027f5..e156b8b41d05 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -331,8 +331,7 @@ 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)
{
@@ -360,8 +359,7 @@ 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)
{
@@ -437,7 +435,15 @@ 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 the code will need in place
+ * conversion and otherwise looks very ugly. 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