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psm(4): Fix panic occuring soon after PS/2 packet has been rejected by

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synaptics or elantech sanity checker.

After packet has been rejected contents of packet buffer is not cleared
with setting of inputbytes counter to 0. So when this packet buffer is
filled again being an element of circular queue, new data appends to old
data rather than overwrites it. This leads to packet buffer overflow
after 10 rounds.

Fix it with setting of packet's inputbytes counter to 0 after rejection.

While here add extra logging of rejected packets.

PR:		222667 (for reference)
Reported by:	Neel Chauhan <neel@neelc.org>
Tested by:	Neel Chauhan <neel@neelc.org>
MFC after:	1 week
This commit is contained in:
Vladimir Kondratyev 2018-02-04 23:01:48 +00:00
parent 68a574863d
commit 74a53bd131
1 changed files with 9 additions and 3 deletions
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12
sys/dev/atkbdc/psm.c
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@ -4935,13 +4935,19 @@ psmsoftintr(void *arg)
break;
case MOUSE_MODEL_SYNAPTICS:
if (proc_synaptics(sc, pb, &ms, &x, &y, &z) != 0)
if (proc_synaptics(sc, pb, &ms, &x, &y, &z) != 0) {
VLOG(3, (LOG_DEBUG, "synaptics: "
"packet rejected\n"));
goto next;
}
break;
case MOUSE_MODEL_ELANTECH:
if (proc_elantech(sc, pb, &ms, &x, &y, &z) != 0)
if (proc_elantech(sc, pb, &ms, &x, &y, &z) != 0) {
VLOG(3, (LOG_DEBUG, "elantech: "
"packet rejected\n"));
goto next;
}
break;
case MOUSE_MODEL_TRACKPOINT:
@ -5037,9 +5043,9 @@ psmsoftintr(void *arg)
sizeof(sc->queue.buf);
sc->queue.count += pb->inputbytes;
}
pb->inputbytes = 0;
next:
pb->inputbytes = 0;
if (++sc->pqueue_start >= PSM_PACKETQUEUE)
sc->pqueue_start = 0;
} while (sc->pqueue_start != sc->pqueue_end);