[PATCH CORRECT 03/10] parse_integer: convert sscanf()

[Alexey Dobriyan <adobriyan@gmail.com>]

Rewrite kstrto*() functions through parse_integer().

_kstrtoul() and _kstrtol() are removed because parse_integer()
can dispatch based on BITS_PER_LONG saving function call.

Also move function definitions and comment one instance.
Remove redundant boilerplate comments from elsewhere.

High bit base hack suggested by Andrew M.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

	I copied patch twice, lol.

 include/linux/kernel.h        |  124 -----------------------
 include/linux/parse-integer.h |  109 ++++++++++++++++++++
 lib/kstrtox.c                 |  222 ------------------------------------------
 lib/parse-integer.c           |   38 ++++++-
 4 files changed, 143 insertions(+), 350 deletions(-)

--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -264,130 +264,6 @@ void do_exit(long error_code)
 void complete_and_exit(struct completion *, long)
 	__noreturn;
 
-/* Internal, do not use. */
-int __must_check _kstrtoul(const char *s, unsigned int base, unsigned long *res);
-int __must_check _kstrtol(const char *s, unsigned int base, long *res);
-
-int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res);
-int __must_check kstrtoll(const char *s, unsigned int base, long long *res);
-
-/**
- * kstrtoul - convert a string to an unsigned long
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign, but not a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
-*/
-static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
-{
-	/*
-	 * We want to shortcut function call, but
-	 * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0.
-	 */
-	if (sizeof(unsigned long) == sizeof(unsigned long long) &&
-	    __alignof__(unsigned long) == __alignof__(unsigned long long))
-		return kstrtoull(s, base, (unsigned long long *)res);
-	else
-		return _kstrtoul(s, base, res);
-}
-
-/**
- * kstrtol - convert a string to a long
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign or a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
- */
-static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
-{
-	/*
-	 * We want to shortcut function call, but
-	 * __builtin_types_compatible_p(long, long long) = 0.
-	 */
-	if (sizeof(long) == sizeof(long long) &&
-	    __alignof__(long) == __alignof__(long long))
-		return kstrtoll(s, base, (long long *)res);
-	else
-		return _kstrtol(s, base, res);
-}
-
-int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res);
-int __must_check kstrtoint(const char *s, unsigned int base, int *res);
-
-static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
-{
-	return kstrtoull(s, base, res);
-}
-
-static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
-{
-	return kstrtoll(s, base, res);
-}
-
-static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
-{
-	return kstrtouint(s, base, res);
-}
-
-static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
-{
-	return kstrtoint(s, base, res);
-}
-
-int __must_check kstrtou16(const char *s, unsigned int base, u16 *res);
-int __must_check kstrtos16(const char *s, unsigned int base, s16 *res);
-int __must_check kstrtou8(const char *s, unsigned int base, u8 *res);
-int __must_check kstrtos8(const char *s, unsigned int base, s8 *res);
-
-int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
-int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
-int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
-int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
-int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
-int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
-int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
-int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
-int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
-int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
-
-static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
-{
-	return kstrtoull_from_user(s, count, base, res);
-}
-
-static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
-{
-	return kstrtoll_from_user(s, count, base, res);
-}
-
-static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
-{
-	return kstrtouint_from_user(s, count, base, res);
-}
-
-static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
-{
-	return kstrtoint_from_user(s, count, base, res);
-}
-
 /*
  * Obsolete, do not use.
  * Use parse_integer(), kstrto*(), kstrto*_from_user(), sscanf().
--- a/include/linux/parse-integer.h
+++ b/include/linux/parse-integer.h
@@ -76,4 +76,113 @@ int _parse_integer_ll(const char *s, unsigned int base, long long *val);
 int _parse_integer_ull(const char *s, unsigned int base, unsigned long long *val);
 void _parse_integer_link_time_error(void);
 const char *_parse_integer_fixup_radix(const char *s, unsigned int *base);
+#define PARSE_INTEGER_NEWLINE 0x80000000u
+
+/*
+ * Convert integer string representation terminated by \n\0 or \0 to an integer.
+ *
+ * Return 0 on success or -E.
+ *
+ * See parse_integer().
+ */
+static inline int __must_check kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtoll(const char *s, unsigned int base, long long *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtoul(const char *s, unsigned int base, unsigned long *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtol(const char *s, unsigned int base, long *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtouint(const char *s, unsigned int base, unsigned int *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtoint(const char *s, unsigned int base, int *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtou64(const char *s, unsigned int base, u64 *res)
+{
+	return kstrtoull(s, base, res);
+}
+
+static inline int __must_check kstrtos64(const char *s, unsigned int base, s64 *res)
+{
+	return kstrtoll(s, base, res);
+}
+
+static inline int __must_check kstrtou32(const char *s, unsigned int base, u32 *res)
+{
+	return kstrtouint(s, base, res);
+}
+
+static inline int __must_check kstrtos32(const char *s, unsigned int base, s32 *res)
+{
+	return kstrtoint(s, base, res);
+}
+
+static inline int __must_check kstrtou16(const char *s, unsigned int base, u16 *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtos16(const char *s, unsigned int base, s16 *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtou8(const char *s, unsigned int base, u8 *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+static inline int __must_check kstrtos8(const char *s, unsigned int base, s8 *res)
+{
+	return parse_integer(s, base | PARSE_INTEGER_NEWLINE, res);
+}
+
+int __must_check kstrtoull_from_user(const char __user *s, size_t count, unsigned int base, unsigned long long *res);
+int __must_check kstrtoll_from_user(const char __user *s, size_t count, unsigned int base, long long *res);
+int __must_check kstrtoul_from_user(const char __user *s, size_t count, unsigned int base, unsigned long *res);
+int __must_check kstrtol_from_user(const char __user *s, size_t count, unsigned int base, long *res);
+int __must_check kstrtouint_from_user(const char __user *s, size_t count, unsigned int base, unsigned int *res);
+int __must_check kstrtoint_from_user(const char __user *s, size_t count, unsigned int base, int *res);
+int __must_check kstrtou16_from_user(const char __user *s, size_t count, unsigned int base, u16 *res);
+int __must_check kstrtos16_from_user(const char __user *s, size_t count, unsigned int base, s16 *res);
+int __must_check kstrtou8_from_user(const char __user *s, size_t count, unsigned int base, u8 *res);
+int __must_check kstrtos8_from_user(const char __user *s, size_t count, unsigned int base, s8 *res);
+
+static inline int __must_check kstrtou64_from_user(const char __user *s, size_t count, unsigned int base, u64 *res)
+{
+	return kstrtoull_from_user(s, count, base, res);
+}
+
+static inline int __must_check kstrtos64_from_user(const char __user *s, size_t count, unsigned int base, s64 *res)
+{
+	return kstrtoll_from_user(s, count, base, res);
+}
+
+static inline int __must_check kstrtou32_from_user(const char __user *s, size_t count, unsigned int base, u32 *res)
+{
+	return kstrtouint_from_user(s, count, base, res);
+}
+
+static inline int __must_check kstrtos32_from_user(const char __user *s, size_t count, unsigned int base, s32 *res)
+{
+	return kstrtoint_from_user(s, count, base, res);
+}
 #endif
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -67,228 +67,6 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
 	return rv;
 }
 
-/**
- * kstrtoull - convert a string to an unsigned long long
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign, but not a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
- */
-int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
-{
-	unsigned long long _res;
-	int rv;
-
-	rv = parse_integer(s, base, &_res);
-	if (rv < 0)
-		return rv;
-	s += rv;
-	if (*s == '\n')
-		s++;
-	if (*s)
-		return -EINVAL;
-	*res = _res;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtoull);
-
-/**
- * kstrtoll - convert a string to a long long
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign or a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
- */
-int kstrtoll(const char *s, unsigned int base, long long *res)
-{
-	long long _res;
-	int rv;
-
-	rv = parse_integer(s, base, &_res);
-	if (rv < 0)
-		return rv;
-	s += rv;
-	if (*s == '\n')
-		s++;
-	if (*s)
-		return -EINVAL;
-	*res = _res;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtoll);
-
-/* Internal, do not use. */
-int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
-{
-	unsigned long long tmp;
-	int rv;
-
-	rv = kstrtoull(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (unsigned long long)(unsigned long)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(_kstrtoul);
-
-/* Internal, do not use. */
-int _kstrtol(const char *s, unsigned int base, long *res)
-{
-	long long tmp;
-	int rv;
-
-	rv = kstrtoll(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (long long)(long)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(_kstrtol);
-
-/**
- * kstrtouint - convert a string to an unsigned int
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign, but not a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
- */
-int kstrtouint(const char *s, unsigned int base, unsigned int *res)
-{
-	unsigned long long tmp;
-	int rv;
-
-	rv = kstrtoull(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (unsigned long long)(unsigned int)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtouint);
-
-/**
- * kstrtoint - convert a string to an int
- * @s: The start of the string. The string must be null-terminated, and may also
- *  include a single newline before its terminating null. The first character
- *  may also be a plus sign or a minus sign.
- * @base: The number base to use. The maximum supported base is 16. If base is
- *  given as 0, then the base of the string is automatically detected with the
- *  conventional semantics - If it begins with 0x the number will be parsed as a
- *  hexadecimal (case insensitive), if it otherwise begins with 0, it will be
- *  parsed as an octal number. Otherwise it will be parsed as a decimal.
- * @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.
- */
-int kstrtoint(const char *s, unsigned int base, int *res)
-{
-	long long tmp;
-	int rv;
-
-	rv = kstrtoll(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (long long)(int)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtoint);
-
-int kstrtou16(const char *s, unsigned int base, u16 *res)
-{
-	unsigned long long tmp;
-	int rv;
-
-	rv = kstrtoull(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (unsigned long long)(u16)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtou16);
-
-int kstrtos16(const char *s, unsigned int base, s16 *res)
-{
-	long long tmp;
-	int rv;
-
-	rv = kstrtoll(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (long long)(s16)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtos16);
-
-int kstrtou8(const char *s, unsigned int base, u8 *res)
-{
-	unsigned long long tmp;
-	int rv;
-
-	rv = kstrtoull(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (unsigned long long)(u8)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtou8);
-
-int kstrtos8(const char *s, unsigned int base, s8 *res)
-{
-	long long tmp;
-	int rv;
-
-	rv = kstrtoll(s, base, &tmp);
-	if (rv < 0)
-		return rv;
-	if (tmp != (long long)(s8)tmp)
-		return -ERANGE;
-	*res = tmp;
-	return 0;
-}
-EXPORT_SYMBOL(kstrtos8);
-
 #define kstrto_from_user(f, g, type)					\
 int f(const char __user *s, size_t count, unsigned int base, type *res)	\
 {									\
--- a/lib/parse-integer.c
+++ b/lib/parse-integer.c
@@ -31,7 +31,7 @@ const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
 	return s;
 }
 
-static int __parse_integer(const char *s, unsigned int base, unsigned long long *val)
+static int ___parse_integer(const char *s, unsigned int base, unsigned long long *val)
 {
 	const char *s0 = s, *sd;
 	unsigned long long acc;
@@ -63,6 +63,27 @@ static int __parse_integer(const char *s, unsigned int base, unsigned long long
 	return s - s0;
 }
 
+static int __parse_integer(const char *s, unsigned int base, unsigned long long *val)
+{
+	if (base & PARSE_INTEGER_NEWLINE) {
+		unsigned long long _val;
+		int rv;
+
+		/* Accept "integer\0" or "integer\n\0" */
+		rv = ___parse_integer(s, base & ~PARSE_INTEGER_NEWLINE, &_val);
+		if (rv < 0)
+			return rv;
+		s += rv;
+		if (*s == '\n')
+			s++;
+		if (*s)
+			return -EINVAL;
+		*val = _val;
+		return 0;
+	} else
+		return ___parse_integer(s, base, val);
+}
+
 int _parse_integer_ull(const char *s, unsigned int base, unsigned long long *val)
 {
 	int rv;
@@ -73,7 +94,10 @@ int _parse_integer_ull(const char *s, unsigned int base, unsigned long long *val
 		rv = __parse_integer(s + 1, base, val);
 		if (rv < 0)
 			return rv;
-		return rv + 1;
+		if (base & PARSE_INTEGER_NEWLINE)
+			return 0;
+		else
+			return rv + 1;
 	} else
 		return __parse_integer(s, base, val);
 }
@@ -91,7 +115,10 @@ int _parse_integer_ll(const char *s, unsigned int base, long long *val)
 		if ((long long)-tmp >= 0)
 			return -ERANGE;
 		*val = -tmp;
-		return rv + 1;
+		if (base & PARSE_INTEGER_NEWLINE)
+			return 0;
+		else
+			return rv + 1;
 	} else if (*s == '+') {
 		rv = __parse_integer(s + 1, base, &tmp);
 		if (rv < 0)
@@ -99,7 +126,10 @@ int _parse_integer_ll(const char *s, unsigned int base, long long *val)
 		if ((long long)tmp < 0)
 			return -ERANGE;
 		*val = tmp;
-		return rv + 1;
+		if (base & PARSE_INTEGER_NEWLINE)
+			return 0;
+		else
+			return rv + 1;
 	} else {
 		rv = __parse_integer(s, base, &tmp);
 		if (rv < 0)