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Subject[PATCH 22/22] tty: vt: decrypt magic constants in vc_is_control()
Date
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>
---
drivers/tty/vt/vt.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index e35f7a31a7bd..463be4e48dc8 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -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
--
2.43.0

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