diff options
Diffstat (limited to 'sys/dev/dt')
| -rw-r--r-- | sys/dev/dt/dt_dev.c | 43 |
1 files changed, 9 insertions, 34 deletions
diff --git a/sys/dev/dt/dt_dev.c b/sys/dev/dt/dt_dev.c index a7533e55b1a..a2da0b51cce 100644 --- a/sys/dev/dt/dt_dev.c +++ b/sys/dev/dt/dt_dev.c @@ -1,4 +1,4 @@ -/* $OpenBSD: dt_dev.c,v 1.2 2020/01/24 14:00:31 mpi Exp $ */ +/* $OpenBSD: dt_dev.c,v 1.3 2020/01/27 17:13:33 visa Exp $ */ /* * Copyright (c) 2019 Martin Pieuchot <mpi@openbsd.org> @@ -91,7 +91,7 @@ unsigned int dt_nprobes; /* [I] # of probes available */ SIMPLEQ_HEAD(, dt_probe) dt_probe_list; /* [I] list of probes */ struct rwlock dt_lock = RWLOCK_INITIALIZER("dtlk"); -volatile uint32_t dt_tracing = 0; /* [d] # of processes tracing */ +volatile uint32_t dt_tracing = 0; /* [k] # of processes tracing */ void dtattach(struct device *, struct device *, void *); int dtopen(dev_t, int, int, struct proc *); @@ -108,9 +108,6 @@ void dt_ioctl_record_stop(struct dt_softc *); int dt_ioctl_probe_enable(struct dt_softc *, struct dtioc_req *); void dt_ioctl_probe_disable(struct dt_softc *, struct dtioc_req *); -int dt_enter(void); -void dt_leave(uint32_t); - int dt_pcb_ring_copy(struct dt_pcb *, struct dt_evt *, size_t, uint64_t *); void @@ -379,7 +376,6 @@ int dt_ioctl_record_start(struct dt_softc *sc) { struct dt_pcb *dp; - int count; if (sc->ds_recording) return EBUSY; @@ -388,16 +384,15 @@ dt_ioctl_record_start(struct dt_softc *sc) if (TAILQ_EMPTY(&sc->ds_pcbs)) return ENOENT; - count = dt_enter(); + rw_enter_write(&dt_lock); TAILQ_FOREACH(dp, &sc->ds_pcbs, dp_snext) { struct dt_probe *dtp = dp->dp_dtp; - rw_assert_wrlock(&dt_lock); SMR_SLIST_INSERT_HEAD_LOCKED(&dtp->dtp_pcbs, dp, dp_pnext); dtp->dtp_recording++; dtp->dtp_prov->dtpv_recording++; } - dt_leave(count); + rw_exit_write(&dt_lock); sc->ds_recording = 1; dt_tracing++; @@ -409,7 +404,6 @@ void dt_ioctl_record_stop(struct dt_softc *sc) { struct dt_pcb *dp; - int count; KASSERT(suser(curproc) == 0); @@ -421,16 +415,18 @@ dt_ioctl_record_stop(struct dt_softc *sc) dt_tracing--; sc->ds_recording = 0; - count = dt_enter(); + rw_enter_write(&dt_lock); TAILQ_FOREACH(dp, &sc->ds_pcbs, dp_snext) { struct dt_probe *dtp = dp->dp_dtp; - rw_assert_wrlock(&dt_lock); dtp->dtp_recording--; dtp->dtp_prov->dtpv_recording--; SMR_SLIST_REMOVE_LOCKED(&dtp->dtp_pcbs, dp, dt_pcb, dp_pnext); } - dt_leave(count); + rw_exit_write(&dt_lock); + + /* Wait until readers cannot access the PCBs. */ + smr_barrier(); } int @@ -470,27 +466,6 @@ dt_ioctl_probe_enable(struct dt_softc *sc, struct dtioc_req *dtrq) return 0; } -int -dt_enter(void) -{ - uint32_t count; - - rw_enter_write(&dt_lock); - count = dt_tracing; - dt_tracing = 0; - - smr_barrier(); - - return count; -} - -void -dt_leave(uint32_t count) -{ - dt_tracing = count; - rw_exit_write(&dt_lock); -} - struct dt_probe * dt_dev_alloc_probe(const char *func, const char *name, struct dt_provider *dtpv) { |