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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-05 11:59:05 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-05 11:59:05 -0700
commit9f0346dcbea363787186c94ef94dd01aaa215afa (patch)
treeb81c168f4d0dbe4c7f4750f4598d48a6deb72094 /lib/ucs2_string.c
downloadlinux-stable-9f0346dcbea363787186c94ef94dd01aaa215afa.tar.gz
linux-stable-9f0346dcbea363787186c94ef94dd01aaa215afa.zip
Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-coregrafted
Pull driver core fixes from Danilo Krummrich: - Fix kernfs listxattr() not returning security xattr names (e.g. SELinux labels) when the kernfs node has no allocated kernfs_iattrs - Fix silent truncation of IRQ vector indices in the Rust PCI abstractions - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is disabled instead of silently enabling extra kernel functionality - Russ Weight is retiring from kernel development; update the Firmware Loader sysfs contact to the driver-core mailing list, add a CREDITS entry for Firmware Upload, and update MAINTAINERS accordingly * tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Remove Russ Weight from Firmware Loader CREDITS: Add CREDITS entry for Firmware Upload firmware_loader: Change contact for sysfs nodes rust: pci: reject IRQ vector indices that do not fit in u32 kernfs: preserve security xattrs without allocating iattrs drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF
Diffstat (limited to 'lib/ucs2_string.c')
-rw-r--r--lib/ucs2_string.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c
new file mode 100644
index 000000000..1f7dd4eb6
--- /dev/null
+++ b/lib/ucs2_string.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ucs2_string.h>
+#include <linux/module.h>
+
+/* Return the number of unicode characters in data */
+unsigned long
+ucs2_strnlen(const ucs2_char_t *s, size_t maxlength)
+{
+ unsigned long length = 0;
+
+ while (length < maxlength && *s++ != 0)
+ length++;
+ return length;
+}
+EXPORT_SYMBOL(ucs2_strnlen);
+
+unsigned long
+ucs2_strlen(const ucs2_char_t *s)
+{
+ return ucs2_strnlen(s, ~0UL);
+}
+EXPORT_SYMBOL(ucs2_strlen);
+
+/*
+ * Return the number of bytes is the length of this string
+ * Note: this is NOT the same as the number of unicode characters
+ */
+unsigned long
+ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength)
+{
+ return ucs2_strnlen(data, maxlength/sizeof(ucs2_char_t)) * sizeof(ucs2_char_t);
+}
+EXPORT_SYMBOL(ucs2_strsize);
+
+/**
+ * ucs2_strscpy() - Copy a UCS2 string into a sized buffer.
+ *
+ * @dst: Pointer to the destination buffer where to copy the string to.
+ * @src: Pointer to the source buffer where to copy the string from.
+ * @count: Size of the destination buffer, in UCS2 (16-bit) characters.
+ *
+ * Like strscpy(), only for UCS2 strings.
+ *
+ * Copy the source string @src, or as much of it as fits, into the destination
+ * buffer @dst. The behavior is undefined if the string buffers overlap. The
+ * destination buffer @dst is always NUL-terminated, unless it's zero-sized.
+ *
+ * Return: The number of characters copied into @dst (excluding the trailing
+ * %NUL terminator) or -E2BIG if @count is 0 or @src was truncated due to the
+ * destination buffer being too small.
+ */
+ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count)
+{
+ long res;
+
+ /*
+ * Ensure that we have a valid amount of space. We need to store at
+ * least one NUL-character.
+ */
+ if (count == 0 || WARN_ON_ONCE(count > INT_MAX / sizeof(*dst)))
+ return -E2BIG;
+
+ /*
+ * Copy at most 'count' characters, return early if we find a
+ * NUL-terminator.
+ */
+ for (res = 0; res < count; res++) {
+ ucs2_char_t c;
+
+ c = src[res];
+ dst[res] = c;
+
+ if (!c)
+ return res;
+ }
+
+ /*
+ * The loop above terminated without finding a NUL-terminator,
+ * exceeding the 'count': Enforce proper NUL-termination and return
+ * error.
+ */
+ dst[count - 1] = 0;
+ return -E2BIG;
+}
+EXPORT_SYMBOL(ucs2_strscpy);
+
+int
+ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len)
+{
+ while (1) {
+ if (len == 0)
+ return 0;
+ if (*a < *b)
+ return -1;
+ if (*a > *b)
+ return 1;
+ if (*a == 0) /* implies *b == 0 */
+ return 0;
+ a++;
+ b++;
+ len--;
+ }
+}
+EXPORT_SYMBOL(ucs2_strncmp);
+
+unsigned long
+ucs2_utf8size(const ucs2_char_t *src)
+{
+ unsigned long i;
+ unsigned long j = 0;
+
+ for (i = 0; src[i]; i++) {
+ u16 c = src[i];
+
+ if (c >= 0x800)
+ j += 3;
+ else if (c >= 0x80)
+ j += 2;
+ else
+ j += 1;
+ }
+
+ return j;
+}
+EXPORT_SYMBOL(ucs2_utf8size);
+
+/*
+ * copy at most maxlength bytes of whole utf8 characters to dest from the
+ * ucs2 string src.
+ *
+ * The return value is the number of characters copied, not including the
+ * final NUL character.
+ */
+unsigned long
+ucs2_as_utf8(u8 *dest, const ucs2_char_t *src, unsigned long maxlength)
+{
+ unsigned int i;
+ unsigned long j = 0;
+ unsigned long limit = ucs2_strnlen(src, maxlength);
+
+ for (i = 0; maxlength && i < limit; i++) {
+ u16 c = src[i];
+
+ if (c >= 0x800) {
+ if (maxlength < 3)
+ break;
+ maxlength -= 3;
+ dest[j++] = 0xe0 | (c & 0xf000) >> 12;
+ dest[j++] = 0x80 | (c & 0x0fc0) >> 6;
+ dest[j++] = 0x80 | (c & 0x003f);
+ } else if (c >= 0x80) {
+ if (maxlength < 2)
+ break;
+ maxlength -= 2;
+ dest[j++] = 0xc0 | (c & 0x7c0) >> 6;
+ dest[j++] = 0x80 | (c & 0x03f);
+ } else {
+ maxlength -= 1;
+ dest[j++] = c & 0x7f;
+ }
+ }
+ if (maxlength)
+ dest[j] = '\0';
+ return j;
+}
+EXPORT_SYMBOL(ucs2_as_utf8);
+
+MODULE_DESCRIPTION("UCS2 string handling");
+MODULE_LICENSE("GPL v2");