diff options
author | Jiri Slaby <jslaby@suse.cz> | 2020-06-15 09:48:45 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-06-24 17:08:32 +0200 |
commit | ede98d12b6c2bdb34efcd64369ca3ab2af304e16 (patch) | |
tree | 810bef35e8f6fea36a42a447b06bf1a84e49873b /drivers/tty/vt | |
parent | vt: separate unicode handling into vc_translate_unicode (diff) | |
download | linux-ede98d12b6c2bdb34efcd64369ca3ab2af304e16.tar.xz linux-ede98d12b6c2bdb34efcd64369ca3ab2af304e16.zip |
vt: rearrange vc_translate_unicode
The code was too overcomplicated. Extract vc_sanitize_unicode to a
separate function and flatten the code. I believe the code is
straightforward now.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/vt')
-rw-r--r-- | drivers/tty/vt/vt.c | 121 |
1 files changed, 64 insertions, 57 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index caaad820413a..5004242d601b 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2572,6 +2572,19 @@ static inline int vc_translate_ascii(const struct vc_data *vc, int c) return c; } + +/** + * vc_sanitize_unicode -- Replace invalid Unicode code points with U+FFFD + * @c: the received character, or U+FFFD for invalid sequences. + */ +static inline int vc_sanitize_unicode(const int c) +{ + if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff) + return 0xfffd; + + return c; +} + /** * vc_translate_unicode -- Combine UTF-8 into Unicode in @vc_utf_char * @@ -2586,69 +2599,63 @@ static int vc_translate_unicode(struct vc_data *vc, int c, bool *rescan) 0x001fffff, 0x03ffffff, 0x7fffffff }; + /* Continuation byte received */ if ((c & 0xc0) == 0x80) { - /* Continuation byte received */ - if (vc->vc_utf_count) { - vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f); - vc->vc_npar++; - if (--vc->vc_utf_count) { - /* Still need some bytes */ - return -1; - } - /* Got a whole character */ - c = vc->vc_utf_char; - /* Reject overlong sequences */ - if (c <= utf8_length_changes[vc->vc_npar - 1] || - c > utf8_length_changes[vc->vc_npar]) - return 0xfffd; - } else { - /* Unexpected continuation byte */ - vc->vc_utf_count = 0; + /* Unexpected continuation byte? */ + if (!vc->vc_utf_count) return 0xfffd; - } - } else { - /* Single ASCII byte or first byte of a sequence received */ - if (vc->vc_utf_count) { - /* Continuation byte expected */ - *rescan = true; - vc->vc_utf_count = 0; + + vc->vc_utf_char = (vc->vc_utf_char << 6) | (c & 0x3f); + vc->vc_npar++; + if (--vc->vc_utf_count) + goto need_more_bytes; + + /* Got a whole character */ + c = vc->vc_utf_char; + /* Reject overlong sequences */ + if (c <= utf8_length_changes[vc->vc_npar - 1] || + c > utf8_length_changes[vc->vc_npar]) return 0xfffd; - } else if (c > 0x7f) { - /* First byte of a multibyte sequence received */ - vc->vc_npar = 0; - if ((c & 0xe0) == 0xc0) { - vc->vc_utf_count = 1; - vc->vc_utf_char = (c & 0x1f); - } else if ((c & 0xf0) == 0xe0) { - vc->vc_utf_count = 2; - vc->vc_utf_char = (c & 0x0f); - } else if ((c & 0xf8) == 0xf0) { - vc->vc_utf_count = 3; - vc->vc_utf_char = (c & 0x07); - } else if ((c & 0xfc) == 0xf8) { - vc->vc_utf_count = 4; - vc->vc_utf_char = (c & 0x03); - } else if ((c & 0xfe) == 0xfc) { - vc->vc_utf_count = 5; - vc->vc_utf_char = (c & 0x01); - } else { - /* 254 and 255 are invalid */ - return 0xfffd; - } - if (vc->vc_utf_count) { - /* Still need some bytes */ - return -1; - } - } - /* Nothing to do if an ASCII byte was received */ + + return vc_sanitize_unicode(c); } - /* End of UTF-8 decoding. */ - /* c is the received character, or U+FFFD for invalid sequences. */ - /* Replace invalid Unicode code points with U+FFFD too */ - if ((c >= 0xd800 && c <= 0xdfff) || c == 0xfffe || c == 0xffff) + + /* Single ASCII byte or first byte of a sequence received */ + if (vc->vc_utf_count) { + /* Continuation byte expected */ + *rescan = true; + vc->vc_utf_count = 0; return 0xfffd; + } - return c; + /* Nothing to do if an ASCII byte was received */ + if (c <= 0x7f) + return c; + + /* First byte of a multibyte sequence received */ + vc->vc_npar = 0; + if ((c & 0xe0) == 0xc0) { + vc->vc_utf_count = 1; + vc->vc_utf_char = (c & 0x1f); + } else if ((c & 0xf0) == 0xe0) { + vc->vc_utf_count = 2; + vc->vc_utf_char = (c & 0x0f); + } else if ((c & 0xf8) == 0xf0) { + vc->vc_utf_count = 3; + vc->vc_utf_char = (c & 0x07); + } else if ((c & 0xfc) == 0xf8) { + vc->vc_utf_count = 4; + vc->vc_utf_char = (c & 0x03); + } else if ((c & 0xfe) == 0xfc) { + vc->vc_utf_count = 5; + vc->vc_utf_char = (c & 0x01); + } else { + /* 254 and 255 are invalid */ + return 0xfffd; + } + +need_more_bytes: + return -1; } /* acquires console_lock */ |