diff options
Diffstat (limited to 'sys/kern/subr_kdb.c')
| -rw-r--r-- | sys/kern/subr_kdb.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/sys/kern/subr_kdb.c b/sys/kern/subr_kdb.c index 1d67864..c2f6e99 100644 --- a/sys/kern/subr_kdb.c +++ b/sys/kern/subr_kdb.c @@ -244,29 +244,44 @@ kdb_reboot(void) #define KEY_CRTLP 16 /* ^P */ #define KEY_CRTLR 18 /* ^R */ +/* States of th KDB "alternate break sequence" detecting state machine. */ +enum { + KDB_ALT_BREAK_SEEN_NONE, + KDB_ALT_BREAK_SEEN_CR, + KDB_ALT_BREAK_SEEN_CR_TILDE, +}; + int kdb_alt_break(int key, int *state) { int brk; + /* All states transition to KDB_ALT_BREAK_SEEN_CR on a CR. */ + if (key == KEY_CR) { + *state = KDB_ALT_BREAK_SEEN_CR; + return (0); + } + brk = 0; switch (*state) { - case 0: - if (key == KEY_CR) - *state = 1; - break; - case 1: + case KDB_ALT_BREAK_SEEN_CR: + *state = KDB_ALT_BREAK_SEEN_NONE; if (key == KEY_TILDE) - *state = 2; + *state = KDB_ALT_BREAK_SEEN_CR_TILDE; break; - case 2: + case KDB_ALT_BREAK_SEEN_CR_TILDE: + *state = KDB_ALT_BREAK_SEEN_NONE; if (key == KEY_CRTLB) brk = KDB_REQ_DEBUGGER; else if (key == KEY_CRTLP) brk = KDB_REQ_PANIC; else if (key == KEY_CRTLR) brk = KDB_REQ_REBOOT; - *state = 0; + break; + case KDB_ALT_BREAK_SEEN_NONE: + default: + *state = KDB_ALT_BREAK_SEEN_NONE; + break; } return (brk); } |
