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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /lib/kstrtox.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'lib/kstrtox.c')
-rw-r--r--lib/kstrtox.c442
1 files changed, 442 insertions, 0 deletions
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
new file mode 100644
index 000000000..edc4eb7c1
--- /dev/null
+++ b/lib/kstrtox.c
@@ -0,0 +1,442 @@
+// 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/export.h>
+#include <linux/kstrtox.h>
+#include <linux/math64.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "kstrtox.h"
+
+noinline
+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;
+}
+
+/**
+ * _parse_integer_limit - Convert integer string representation to an integer
+ * @s: Integer string representation
+ * @base: Radix
+ * @p: Where to store result
+ * @max_chars: Maximum amount of characters to convert
+ *
+ * Convert non-negative integer string representation in explicitly given
+ * radix to an integer. If overflow occurs, value at @p is set to ULLONG_MAX.
+ *
+ * This function is the workhorse of other string conversion functions and it
+ * is discouraged to use it explicitly. Consider kstrto*() family instead.
+ *
+ * Return: Number of characters consumed, maybe ORed with overflow bit
+ */
+noinline
+unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p,
+ size_t max_chars)
+{
+ unsigned int rv, overflow = 0;
+ unsigned long long res;
+
+ res = 0;
+ for (rv = 0; rv < max_chars; rv++, s++) {
+ unsigned int c = *s;
+ unsigned int lc = _tolower(c);
+ 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 (check_mul_overflow(res, base, &res) ||
+ check_add_overflow(res, val, &res)) {
+ res = ULLONG_MAX;
+ overflow = KSTRTOX_OVERFLOW;
+ }
+ } else {
+ res = res * base + val;
+ }
+ }
+ *p = res;
+ return rv | overflow;
+}
+
+noinline
+unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
+{
+ return _parse_integer_limit(s, base, p, INT_MAX);
+}
+
+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.
+ * Preferred over simple_strtoull(). Return code must be checked.
+ */
+noinline
+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.
+ * Preferred over simple_strtoll(). Return code must be checked.
+ */
+noinline
+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)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)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.
+ * Preferred over simple_strtoul(). Return code must be checked.
+ */
+noinline
+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 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.
+ * Preferred over simple_strtol(). Return code must be checked.
+ */
+noinline
+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 != (int)tmp)
+ return -ERANGE;
+ *res = tmp;
+ return 0;
+}
+EXPORT_SYMBOL(kstrtoint);
+
+noinline
+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 != (u16)tmp)
+ return -ERANGE;
+ *res = tmp;
+ return 0;
+}
+EXPORT_SYMBOL(kstrtou16);
+
+noinline
+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 != (s16)tmp)
+ return -ERANGE;
+ *res = tmp;
+ return 0;
+}
+EXPORT_SYMBOL(kstrtos16);
+
+noinline
+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 != (u8)tmp)
+ return -ERANGE;
+ *res = tmp;
+ return 0;
+}
+EXPORT_SYMBOL(kstrtou8);
+
+noinline
+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 != (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 'EeYyTt1DdNnFf0',
+ * or [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
+ * pointed to by res is updated upon finding a match.
+ */
+noinline
+int kstrtobool(const char *s, bool *res)
+{
+ if (!s)
+ return -EINVAL;
+
+ switch (s[0]) {
+ case 'e':
+ case 'E':
+ case 'y':
+ case 'Y':
+ case 't':
+ case 'T':
+ case '1':
+ *res = true;
+ return 0;
+ case 'd':
+ case 'D':
+ case 'n':
+ case 'N':
+ case 'f':
+ case 'F':
+ 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;
+ }
+ 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);