v4.19.13 snapshot.
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
new file mode 100644
index 0000000..661a1e8
--- /dev/null
+++ b/lib/kstrtox.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/export.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include "kstrtox.h"
+
+const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
+{
+ 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;
+ return s;
+}
+
+/*
+ * 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 *p)
+{
+ unsigned long long res;
+ unsigned int rv;
+
+ res = 0;
+ rv = 0;
+ while (1) {
+ unsigned int c = *s;
+ unsigned int lc = c | 0x20; /* don't tolower() this line */
+ unsigned int val;
+
+ if ('0' <= c && c <= '9')
+ val = c - '0';
+ else if ('a' <= lc && lc <= 'f')
+ val = lc - 'a' + 10;
+ else
+ break;
+
+ if (val >= base)
+ break;
+ /*
+ * Check for overflow only if we are within range of
+ * it in the max base we support (16)
+ */
+ if (unlikely(res & (~0ull << 60))) {
+ if (res > div_u64(ULLONG_MAX - val, base))
+ rv |= KSTRTOX_OVERFLOW;
+ }
+ res = res * base + val;
+ rv++;
+ s++;
+ }
+ *p = res;
+ 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;
+ if (rv == 0)
+ return -EINVAL;
+ s += rv;
+ if (*s == '\n')
+ s++;
+ if (*s)
+ return -EINVAL;
+ *res = _res;
+ return 0;
+}
+
+/**
+ * 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)
+{
+ if (s[0] == '+')
+ s++;
+ return _kstrtoull(s, base, res);
+}
+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)
+{
+ 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);
+
+/**
+ * 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);
+
+/**
+ * kstrtobool - convert common user inputs into boolean values
+ * @s: input string
+ * @res: result
+ *
+ * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
+ * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
+ * pointed to by res is updated upon finding a match.
+ */
+int kstrtobool(const char *s, bool *res)
+{
+ if (!s)
+ return -EINVAL;
+
+ switch (s[0]) {
+ case 'y':
+ case 'Y':
+ case '1':
+ *res = true;
+ return 0;
+ case 'n':
+ case 'N':
+ case '0':
+ *res = false;
+ return 0;
+ case 'o':
+ case 'O':
+ switch (s[1]) {
+ case 'n':
+ case 'N':
+ *res = true;
+ return 0;
+ case 'f':
+ case 'F':
+ *res = false;
+ return 0;
+ default:
+ break;
+ }
+ default:
+ break;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(kstrtobool);
+
+/*
+ * Since "base" would be a nonsense argument, this open-codes the
+ * _from_user helper instead of using the helper macro below.
+ */
+int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
+{
+ /* Longest string needed to differentiate, newline, terminator */
+ char buf[4];
+
+ count = min(count, sizeof(buf) - 1);
+ if (copy_from_user(buf, s, count))
+ return -EFAULT;
+ buf[count] = '\0';
+ return kstrtobool(buf, res);
+}
+EXPORT_SYMBOL(kstrtobool_from_user);
+
+#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);