system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-10-05 02:44:13 +00:00
Code Issues Packages Projects Releases Wiki Activity

tty: vt: decrypt magic constants in vc_is_control()

Browse source 
0x0d00ff81 and 0x0800f501 are bitmasks of ASCII characters. Spell them
explicitly using BIT() + ASCII constants. GENMASK() is used for the
9-bit range in CTRL_ACTION.

This also modifies the 'if' checking if the masks should be applied.
>From a "random" ' ' to the actual size of the bitmasks' type.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-23-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby (SUSE) 2024-02-02 07:56:08 +01:00 committed by Greg Kroah-Hartman
parent 3701400a39
commit 6cc3028f79
1 changed files with 7 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
drivers/tty/vt/vt.c
View file

@ -2893,9 +2893,13 @@ static bool vc_is_control(struct vc_data *vc, int tc, int c)
* as cursor movement) and should not be displayed as a glyph unless
* the disp_ctrl mode is explicitly enabled.
*/
static const u32 CTRL_ACTION = 0x0d00ff81;
static const u32 CTRL_ACTION = BIT(ASCII_NULL) |
GENMASK(ASCII_SHIFTIN, ASCII_BELL) | BIT(ASCII_CANCEL) |
BIT(ASCII_SUBSTITUTE) | BIT(ASCII_ESCAPE);
/* Cannot be overridden by disp_ctrl */
static const u32 CTRL_ALWAYS = 0x0800f501;
static const u32 CTRL_ALWAYS = BIT(ASCII_NULL) | BIT(ASCII_BACKSPACE) |
BIT(ASCII_LINEFEED) | BIT(ASCII_SHIFTIN) | BIT(ASCII_SHIFTOUT) |
BIT(ASCII_CAR_RET) | BIT(ASCII_FORMFEED) | BIT(ASCII_ESCAPE);
if (vc->vc_state != ESnormal)
return true;
@ -2912,7 +2916,7 @@ static bool vc_is_control(struct vc_data *vc, int tc, int c)
* useless without them; to display an arbitrary font position use the
* direct-to-font zone in UTF-8 mode.
*/
if (c < ' ') {
if (c < BITS_PER_TYPE(CTRL_ALWAYS)) {
if (vc->vc_disp_ctrl)
return CTRL_ALWAYS & BIT(c);
else