diff mbox series

[17/86] kernel.h: update comment about simple_strto<foo>() functions

Message ID 20191205005032.dmBtlfFNf%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [01/86] mm/kasan/common.c: fix compile error | expand

Commit Message

Andrew Morton Dec. 5, 2019, 12:50 a.m. UTC 
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: kernel.h: update comment about simple_strto<foo>() functions

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.

Link: http://lkml.kernel.org/r/20190801192904.41087-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Mans Rullgard <mans@mansr.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/kernel.h |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)
diff mbox series

Patch

--- a/include/linux/kernel.h~kernelh-update-comment-about-simple_strtofoo-functions
+++ a/include/linux/kernel.h
@@ -348,8 +348,7 @@  int __must_check kstrtoll(const char *s,
  * @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)
 {
@@ -377,8 +376,7 @@  static inline int __must_check kstrtoul(
  * @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)
 {
@@ -454,7 +452,18 @@  static inline int __must_check kstrtos32
 	return kstrtoint_from_user(s, count, base, res);
 }
 
-/* Obsolete, do not use.  Use kstrto<foo> instead */
+/*
+ * Use kstrto<foo> instead.
+ *
+ * NOTE: simple_strto<foo> does not check for the range overflow and,
+ *	 depending on the input, may give interesting results.
+ *
+ * Use these functions if and only if you cannot use kstrto<foo>, because
+ * the conversion ends on the first non-digit character, which may be far
+ * beyond the supported range. It might be useful to parse the strings like
+ * 10x50 or 12:21 without altering original string or temporary buffer in use.
+ * Keep in mind above caveat.
+ */
 
 extern unsigned long simple_strtoul(const char *,char **,unsigned int);
 extern long simple_strtol(const char *,char **,unsigned int);