xfnw/plan9fox
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity

sdvirtio: be more carefull at wakeup

Browse source 
wakeup cannot access r->sleep once we set r->done because the
sleeper might just return at this point making r invalid. make
a copy of the sleep rendez pointer before setting r->done.
This commit is contained in:
cinap_lenrek 2012-08-24 12:52:34 +02:00
parent 8e5dd37eba
commit 80a5bfc1d8
1 changed files with 5 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
sys/src/9/pc/sdvirtio.c
View file

@ -218,6 +218,7 @@ viointerrupt(Ureg *, void *arg)
{
int id, free, m;
struct Rock *r;
Rendez *z;
Vqueue *q;
Vdev *vd;
@ -231,8 +232,10 @@ viointerrupt(Ureg *, void *arg)
id = q->usedent[q->lastused++ & m].id;
if(r = q->rock[id]){
q->rock[id] = nil;
r->done = 1;
wakeup(r->sleep);
z = r->sleep;
r->done = 1; /* hands off */
if(z != nil)
wakeup(z);
}
do {
free = id;