diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/subr_kdb.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/sys/kern/subr_kdb.c b/sys/kern/subr_kdb.c index e2ea277..4e53c89 100644 --- a/sys/kern/subr_kdb.c +++ b/sys/kern/subr_kdb.c @@ -66,6 +66,18 @@ SYSCTL_PROC(_debug_kdb, OID_AUTO, current, CTLTYPE_STRING | CTLFLAG_RW, 0, 0, SYSCTL_PROC(_debug_kdb, OID_AUTO, enter, CTLTYPE_INT | CTLFLAG_RW, 0, 0, kdb_sysctl_enter, "I", "set to enter the debugger"); +/* + * Flag indicating whether or not to IPI the other CPUs to stop them on + * entering the debugger. Sometimes, this will result in a deadlock as + * stop_cpus() waits for the other cpus to stop, so we allow it to be + * disabled. + */ +#ifdef SMP +static int kdb_stop_cpus = 1; +SYSCTL_INT(_debug_kdb, OID_AUTO, stop_cpus, CTLTYPE_INT | CTLFLAG_RW, + &kdb_stop_cpus, 0, ""); +#endif + static int kdb_sysctl_available(SYSCTL_HANDLER_ARGS) { @@ -374,6 +386,9 @@ kdb_thr_select(struct thread *thr) int kdb_trap(int type, int code, struct trapframe *tf) { +#ifdef SMP + int did_stop_cpus; +#endif int handled; if (kdb_dbbe == NULL || kdb_dbbe->dbbe_trap == NULL) @@ -392,7 +407,8 @@ kdb_trap(int type, int code, struct trapframe *tf) kdb_thr_select(curthread); #ifdef SMP - stop_cpus(PCPU_GET(other_cpus)); + if ((did_stop_cpus = kdb_stop_cpus) != 0) + stop_cpus(PCPU_GET(other_cpus)); #endif /* Let MD code do its thing first... */ @@ -401,7 +417,8 @@ kdb_trap(int type, int code, struct trapframe *tf) handled = kdb_dbbe->dbbe_trap(type, code); #ifdef SMP - restart_cpus(stopped_cpus); + if (did_stop_cpus) + restart_cpus(stopped_cpus); #endif kdb_active--; |
