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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2019-11-19 11:47:35 +1100
committerStephen Rothwell <sfr@canb.auug.org.au>2019-11-25 17:09:57 +1100
commit9a83348f946c8fe4b205a9b7463efa34e2cd90ec (patch)
tree9b08336928b13c0b7d581fa57ae781ce1936839e
parent328d46f5e6df9a171d5eeeec605db9483f3eef38 (diff)
download96b-common-9a83348f946c8fe4b205a9b7463efa34e2cd90ec.tar.gz
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> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
-rw-r--r--include/linux/kernel.h19
1 files changed, 14 insertions, 5 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index d83d403dac2e..351d731954fe 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -355,8 +355,7 @@ 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)
{
@@ -384,8 +383,7 @@ 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)
{
@@ -461,7 +459,18 @@ 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: 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);