Messages in this thread Patch in this message | | | From | Maximilian Luz <> | Subject | [PATCH v5 1/3] lib/ucs2_string: Add UCS-2 strscpy function | Date | Sun, 30 Jul 2023 18:19:02 +0200 |
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Add a ucs2_strscpy() function for UCS-2 strings. The behavior is equivalent to the standard strscpy() function, just for 16-bit character UCS-2 strings.
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com> ---
Changes in v5: - Add ucs2_strscpy() instead of ucs2_strlcpy()
Patch introduced in v4.
--- include/linux/ucs2_string.h | 1 + lib/ucs2_string.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/include/linux/ucs2_string.h b/include/linux/ucs2_string.h index cf3ada3e820e..c499ae809c7d 100644 --- a/include/linux/ucs2_string.h +++ b/include/linux/ucs2_string.h @@ -10,6 +10,7 @@ typedef u16 ucs2_char_t; unsigned long ucs2_strnlen(const ucs2_char_t *s, size_t maxlength); unsigned long ucs2_strlen(const ucs2_char_t *s); unsigned long ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength); +ssize_t ucs2_strscpy(ucs2_char_t *dst, const ucs2_char_t *src, size_t count); int ucs2_strncmp(const ucs2_char_t *a, const ucs2_char_t *b, size_t len); unsigned long ucs2_utf8size(const ucs2_char_t *src); diff --git a/lib/ucs2_string.c b/lib/ucs2_string.c index 0a559a42359b..b608129fcbdc 100644 --- a/lib/ucs2_string.c +++ b/lib/ucs2_string.c @@ -32,6 +32,41 @@ ucs2_strsize(const ucs2_char_t *data, unsigned long maxlength) } EXPORT_SYMBOL(ucs2_strsize); +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)) + return -E2BIG; + + /* + * Copy at most 'count' bytes, 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) { -- 2.41.0
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