`log_mtx' mutex(9) already used for message buffer protection, so use it
to protect `logread_filtops' too.
ok?
Index: sys/kern/subr_log.c
===================================================================
RCS file: /cvs/src/sys/kern/subr_log.c,v
retrieving revision 1.77
diff -u -p -r1.77 subr_log.c
--- sys/kern/subr_log.c 14 Jul 2023 07:07:08 -0000 1.77
+++ sys/kern/subr_log.c 14 Sep 2023 10:04:41 -0000
@@ -50,6 +50,7 @@
#include <sys/filedesc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
+#include <sys/event.h>
#include <sys/fcntl.h>
#include <sys/mutex.h>
#include <sys/timeout.h>
@@ -75,7 +76,7 @@
*/
struct logsoftc {
int sc_state; /* [L] see above for possibilities */
- struct selinfo sc_selp; /* process waiting on select call */
+ struct klist sc_klist; /* process waiting on kevent call */
struct sigio_ref sc_sigio; /* async I/O registration */
int sc_need_wakeup; /* if set, wake up waiters */
struct timeout sc_tick; /* wakeup poll timeout */
@@ -99,12 +100,16 @@ struct mutex log_mtx =
void filt_logrdetach(struct knote *kn);
int filt_logread(struct knote *kn, long hint);
+int filt_logmodify(struct kevent *, struct knote *);
+int filt_logprocess(struct knote *, struct kevent *);
const struct filterops logread_filtops = {
- .f_flags = FILTEROP_ISFD,
+ .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
.f_attach = NULL,
.f_detach = filt_logrdetach,
.f_event = filt_logread,
+ .f_modify = filt_logmodify,
+ .f_process = filt_logprocess,
};
int dosendsyslog(struct proc *, const char *, size_t, int, enum uio_seg);
@@ -191,11 +196,9 @@ msgbuf_getlen(struct msgbuf *mbp)
{
long len;
- mtx_enter(&log_mtx);
len = mbp->msg_bufx - mbp->msg_bufr;
if (len < 0)
len += mbp->msg_bufs;
- mtx_leave(&log_mtx);
return (len);
}
@@ -205,6 +208,7 @@ logopen(dev_t dev, int flags, int mode,
if (log_open)
return (EBUSY);
log_open = 1;
+ klist_init_mutex(&logsoftc.sc_klist, &log_mtx);
sigio_init(&logsoftc.sc_sigio);
timeout_set(&logsoftc.sc_tick, logtick, NULL);
timeout_add_msec(&logsoftc.sc_tick, LOG_TICK);
@@ -225,6 +229,10 @@ logclose(dev_t dev, int flag, int mode,
FRELE(fp, p);
log_open = 0;
timeout_del(&logsoftc.sc_tick);
+
+ klist_invalidate(&logsoftc.sc_klist);
+ klist_free(&logsoftc.sc_klist);
+
logsoftc.sc_state = 0;
sigio_free(&logsoftc.sc_sigio);
return (0);
@@ -301,11 +309,10 @@ int
logkqfilter(dev_t dev, struct knote *kn)
{
struct klist *klist;
- int s;
switch (kn->kn_filter) {
case EVFILT_READ:
- klist = &logsoftc.sc_selp.si_note;
+ klist = &logsoftc.sc_klist;
kn->kn_fop = &logread_filtops;
break;
default:
@@ -313,10 +320,7 @@ logkqfilter(dev_t dev, struct knote *kn)
}
kn->kn_hook = (void *)msgbufp;
-
- s = splhigh();
- klist_insert_locked(klist, kn);
- splx(s);
+ klist_insert(klist, kn);
return (0);
}
@@ -324,11 +328,7 @@ logkqfilter(dev_t dev, struct knote *kn)
void
filt_logrdetach(struct knote *kn)
{
- int s;
-
- s = splhigh();
- klist_remove_locked(&logsoftc.sc_selp.si_note, kn);
- splx(s);
+ klist_remove(&logsoftc.sc_klist, kn);
}
int
@@ -340,6 +340,30 @@ filt_logread(struct knote *kn, long hint
return (kn->kn_data != 0);
}
+int
+filt_logmodify(struct kevent *kev, struct knote *kn)
+{
+ int active;
+
+ mtx_enter(&log_mtx);
+ active = knote_modify(kev, kn);
+ mtx_leave(&log_mtx);
+
+ return (active);
+}
+
+int
+filt_logprocess(struct knote *kn, struct kevent *kev)
+{
+ int active;
+
+ mtx_enter(&log_mtx);
+ active = knote_process(kn, kev);
+ mtx_leave(&log_mtx);
+
+ return (active);
+}
+
void
logwakeup(void)
{
@@ -380,9 +404,9 @@ logtick(void *arg)
state = logsoftc.sc_state;
if (logsoftc.sc_state & LOG_RDWAIT)
logsoftc.sc_state &= ~LOG_RDWAIT;
+ knote_locked(&logsoftc.sc_klist, 0);
mtx_leave(&log_mtx);
- selwakeup(&logsoftc.sc_selp);
if (state & LOG_ASYNC)
pgsigio(&logsoftc.sc_sigio, SIGIO, 0);
if (state & LOG_RDWAIT)
@@ -401,7 +425,9 @@ logioctl(dev_t dev, u_long com, caddr_t
/* return number of characters immediately available */
case FIONREAD:
+ mtx_enter(&log_mtx);
*(int *)data = (int)msgbuf_getlen(msgbufp);
+ mtx_leave(&log_mtx);
break;
case FIONBIO:
