lib/kstrtox: common code between kstrto*() and simple_strto*() functions
Currently termination logic (\0 or \n\0) is hardcoded in _kstrtoull(),
avoid that for code reuse between kstrto*() and simple_strtoull().
Essentially, make them different only in termination logic.
simple_strtoull() (and scanf(), BTW) ignores integer overflow, that's a
bug we currently don't have guts to fix, making KSTRTOX_OVERFLOW hack
necessary.
Almost forgot: patch shrinks code size by about ~80 bytes on x86_64.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index 5e06675..7a94c8f 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -18,26 +18,40 @@
#include <linux/module.h>
#include <linux/types.h>
#include <asm/uaccess.h>
+#include "kstrtox.h"
-static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
{
- unsigned long long acc;
- int ok;
-
- if (base == 0) {
+ if (*base == 0) {
if (s[0] == '0') {
if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
- base = 16;
+ *base = 16;
else
- base = 8;
+ *base = 8;
} else
- base = 10;
+ *base = 10;
}
- if (base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
+ if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
s += 2;
+ return s;
+}
- acc = 0;
- ok = 0;
+/*
+ * Convert non-negative integer string representation in explicitly given radix
+ * to an integer.
+ * Return number of characters consumed maybe or-ed with overflow bit.
+ * If overflow occurs, result integer (incorrect) is still returned.
+ *
+ * Don't you dare use this function.
+ */
+unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *res)
+{
+ unsigned int rv;
+ int overflow;
+
+ *res = 0;
+ rv = 0;
+ overflow = 0;
while (*s) {
unsigned int val;
@@ -45,23 +59,40 @@
val = *s - '0';
else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
val = _tolower(*s) - 'a' + 10;
- else if (*s == '\n' && *(s + 1) == '\0')
- break;
else
- return -EINVAL;
+ break;
if (val >= base)
- return -EINVAL;
- if (acc > div_u64(ULLONG_MAX - val, base))
- return -ERANGE;
- acc = acc * base + val;
- ok = 1;
-
+ break;
+ if (*res > div_u64(ULLONG_MAX - val, base))
+ overflow = 1;
+ *res = *res * base + val;
+ rv++;
s++;
}
- if (!ok)
+ if (overflow)
+ rv |= KSTRTOX_OVERFLOW;
+ return rv;
+}
+
+static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+ unsigned long long _res;
+ unsigned int rv;
+
+ s = _parse_integer_fixup_radix(s, &base);
+ rv = _parse_integer(s, base, &_res);
+ if (rv & KSTRTOX_OVERFLOW)
+ return -ERANGE;
+ rv &= ~KSTRTOX_OVERFLOW;
+ if (rv == 0)
return -EINVAL;
- *res = acc;
+ s += rv;
+ if (*s == '\n')
+ s++;
+ if (*s)
+ return -EINVAL;
+ *res = _res;
return 0;
}