On Mon, Apr 17, 2023 at 05:53:28PM +0200, Alexander Bluhm wrote:
> On Mon, Apr 17, 2023 at 04:32:13PM +0200, Alexander Bluhm wrote:
> > On Mon, Apr 17, 2023 at 02:36:57AM +0300, Vitaliy Makkoveev wrote:
> > > It seems rt_setsource() needs some attention, but sysctl_source() could
> > > be called with shared netlock just now.
> >
> > I think rtable_setsource() is not MP safe. It is documented as [K]
> > kernel lock. But that is not true and makes no sense. It should
> > be exclusive netlock. in_pcbselsrc() calls rtable_getsource() with
> > netlock. We should rename source to ar_source so we can grep for
> > its users.
>
> Perhaps something like this. I will run it through regress.
Rebased after your rename commit. Regress test did not trigger
lock assertions. ar_source is a pointer to an ifa_addr, so net
lock should be safe.
ok?
bluhm
Index: net/art.h
===================================================================
RCS file: /cvs/src/sys/net/art.h,v
retrieving revision 1.22
diff -u -p -r1.22 art.h
--- net/art.h 18 Apr 2023 10:19:16 -0000 1.22
+++ net/art.h 18 Apr 2023 13:32:46 -0000
@@ -41,7 +41,7 @@ struct art_root {
uint8_t ar_nlvl; /* [I] Number of levels */
uint8_t ar_alen; /* [I] Address length in bits */
uint8_t ar_off; /* [I] Offset of key in bytes */
- struct sockaddr *ar_source; /* [K] optional src addr to use
*/
+ struct sockaddr *ar_source; /* [N] use optional src addr */
};
#define ISLEAF(e) (((unsigned long)(e) & 1) == 0)
Index: net/rtable.c
===================================================================
RCS file: /cvs/src/sys/net/rtable.c,v
retrieving revision 1.81
diff -u -p -r1.81 rtable.c
--- net/rtable.c 18 Apr 2023 10:19:16 -0000 1.81
+++ net/rtable.c 18 Apr 2023 13:32:46 -0000
@@ -376,6 +376,8 @@ rtable_setsource(unsigned int rtableid,
{
struct art_root *ar;
+ NET_ASSERT_LOCKED_EXCLUSIVE();
+
if ((ar = rtable_get(rtableid, af)) == NULL)
return (EAFNOSUPPORT);
@@ -388,6 +390,8 @@ struct sockaddr *
rtable_getsource(unsigned int rtableid, int af)
{
struct art_root *ar;
+
+ NET_ASSERT_LOCKED();
ar = rtable_get(rtableid, af);
if (ar == NULL)
Index: net/rtsock.c
===================================================================
RCS file: /cvs/src/sys/net/rtsock.c,v
retrieving revision 1.362
diff -u -p -r1.362 rtsock.c
--- net/rtsock.c 18 Apr 2023 09:56:54 -0000 1.362
+++ net/rtsock.c 18 Apr 2023 13:32:46 -0000
@@ -853,8 +853,10 @@ route_output(struct mbuf *m, struct sock
error = EINVAL;
goto fail;
}
- if ((error =
- rt_setsource(tableid, info.rti_info[RTAX_IFA])) != 0)
+ NET_LOCK();
+ error = rt_setsource(tableid, info.rti_info[RTAX_IFA]);
+ NET_UNLOCK();
+ if (error)
goto fail;
} else {
error = rtm_output(rtm, &rt, &info, prio, tableid);
@@ -862,7 +864,9 @@ route_output(struct mbuf *m, struct sock
type = rtm->rtm_type;
seq = rtm->rtm_seq;
free(rtm, M_RTABLE, len);
+ NET_LOCK_SHARED();
rtm = rtm_report(rt, type, seq, tableid);
+ NET_UNLOCK_SHARED();
len = rtm->rtm_msglen;
}
}
