initial_commit

1 files changed, 250 insertions, 0 deletions

diff --git a/lib/kstrtox.c b/lib/kstrtox.c
new file mode 100644
index 00000000..2dbae880
--- /dev/null
+++ b/lib/kstrtox.c
@@ -0,0 +1,250 @@
+/*
+ * Convert integer string representation to an integer.
+ * If an integer doesn't fit into specified type, -E is returned.
+ *
+ * Integer starts with optional sign.
+ * kstrtou*() functions do not accept sign "-".
+ *
+ * Radix 0 means autodetection: leading "0x" implies radix 16,
+ * leading "0" implies radix 8, otherwise radix is 10.
+ * Autodetection hints work after optional sign, but not before.
+ *
+ * If -E is returned, result is not touched.
+ */
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <asm/uaccess.h>
+
+static inline char _tolower(const char c)
+{
+	return c | 0x20;
+}
+
+static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	unsigned long long acc;
+	int ok;
+
+	if (base == 0) {
+		if (s[0] == '0') {
+			if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
+				base = 16;
+			else
+				base = 8;
+		} else
+			base = 10;
+	}
+	if (base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
+		s += 2;
+
+	acc = 0;
+	ok = 0;
+	while (*s) {
+		unsigned int val;
+
+		if ('0' <= *s && *s <= '9')
+			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;
+
+		if (val >= base)
+			return -EINVAL;
+		if (acc > div_u64(ULLONG_MAX - val, base))
+			return -ERANGE;
+		acc = acc * base + val;
+		ok = 1;
+
+		s++;
+	}
+	if (!ok)
+		return -EINVAL;
+	*res = acc;
+	return 0;
+}
+
+int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
+{
+	if (s[0] == '+')
+		s++;
+	return _kstrtoull(s, base, res);
+}
+EXPORT_SYMBOL(kstrtoull);
+
+int kstrtoll(const char *s, unsigned int base, long long *res)
+{
+	unsigned long long tmp;
+	int rv;
+
+	if (s[0] == '-') {
+		rv = _kstrtoull(s + 1, base, &tmp);
+		if (rv < 0)
+			return rv;
+		if ((long long)(-tmp) >= 0)
+			return -ERANGE;
+		*res = -tmp;
+	} else {
+		rv = kstrtoull(s, base, &tmp);
+		if (rv < 0)
+			return rv;
+		if ((long long)tmp < 0)
+			return -ERANGE;
+		*res = tmp;
+	}
+	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);
+
+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);
+
+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)	\
+{									\
+	/* sign, base 2 representation, newline, terminator */		\
+	char buf[1 + sizeof(type) * 8 + 1 + 1];				\
+									\
+	count = min(count, sizeof(buf) - 1);				\
+	if (copy_from_user(buf, s, count))				\
+		return -EFAULT;						\
+	buf[count] = '\0';						\
+	return g(buf, base, res);					\
+}									\
+EXPORT_SYMBOL(f)
+
+kstrto_from_user(kstrtoull_from_user,	kstrtoull,	unsigned long long);
+kstrto_from_user(kstrtoll_from_user,	kstrtoll,	long long);
+kstrto_from_user(kstrtoul_from_user,	kstrtoul,	unsigned long);
+kstrto_from_user(kstrtol_from_user,	kstrtol,	long);
+kstrto_from_user(kstrtouint_from_user,	kstrtouint,	unsigned int);
+kstrto_from_user(kstrtoint_from_user,	kstrtoint,	int);
+kstrto_from_user(kstrtou16_from_user,	kstrtou16,	u16);
+kstrto_from_user(kstrtos16_from_user,	kstrtos16,	s16);
+kstrto_from_user(kstrtou8_from_user,	kstrtou8,	u8);
+kstrto_from_user(kstrtos8_from_user,	kstrtos8,	s8);