diff options
| author | Ian Moffett <ian@osmora.org> | 2025-05-26 21:38:18 -0400 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-05-26 21:38:18 -0400 |
| commit | 978dfa5e02acfcc35b9f31b9c88255c79ebcfb54 (patch) | |
| tree | b781519f8a8ee26fec5cb45e125959944707aa57 | |
| parent | 5fb5b80ca4aed97ef01858bfc19a9e752dd25e83 (diff) | |
kernel: cons: Fix newline caused by excessive '\b'
Before this commit, if you were to write out too many backspace
characters, it would result in an integer underflow for the
scr->curs_col and scr->ch_col state resulting in the console logic
assuming the cursor has gone too far off the screen which would cause
behavior similar to as if you wrote out a line-feed character.
Signed-off-by: Ian Moffett <ian@osmora.org>
| -rw-r--r-- | sys/dev/cons/cons.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/sys/dev/cons/cons.c b/sys/dev/cons/cons.c index bcd19bf..61254a7 100644 --- a/sys/dev/cons/cons.c +++ b/sys/dev/cons/cons.c @@ -165,8 +165,10 @@ cons_handle_special(struct cons_screen *scr, char c) } HIDE_CURSOR(scr); - --scr->ch_col; - --scr->curs_col; + if (scr->ch_col > 0 && scr->curs_col > 0) { + --scr->ch_col; + --scr->curs_col; + } SHOW_CURSOR(scr); return 0; case ASCII_LF: |