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-rw-r--r--lib/kstrtox.c250
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);