diff options
| -rw-r--r-- | sys/dev/random/randomdev.c | 68 | ||||
| -rw-r--r-- | sys/kern/kern_intr.c | 4 | ||||
| -rw-r--r-- | sys/kern/subr_witness.c | 2 |
3 files changed, 58 insertions, 16 deletions
diff --git a/sys/dev/random/randomdev.c b/sys/dev/random/randomdev.c index 68793e545524..8086841efce8 100644 --- a/sys/dev/random/randomdev.c +++ b/sys/dev/random/randomdev.c @@ -78,12 +78,19 @@ static void random_write_internal(void *, int); MALLOC_DEFINE(M_ENTROPY, "entropy", "Entropy harvesting buffers"); -/* FIFO queues holding harvested entropy */ -static struct harvestfifo { +/* Lockable FIFO queue holding entropy buffers */ +struct entropyfifo { struct mtx lock; int count; STAILQ_HEAD(harvestlist, harvest) head; -} harvestfifo[ENTROPYSOURCE]; +}; + +/* Empty entropy buffers */ +static struct entropyfifo emptyfifo; +#define EMPTYBUFFERS 1024 + +/* Harvested entropy */ +static struct entropyfifo harvestfifo[ENTROPYSOURCE]; static struct random_systat { u_int seeded; /* 0 causes blocking 1 allows normal output */ @@ -239,10 +246,20 @@ random_modevent(module_t mod __unused, int type, void *data __unused) random_systat.seeded = 1; /* Initialise the harvest fifos */ + STAILQ_INIT(&emptyfifo.head); + emptyfifo.count = 0; + mtx_init(&emptyfifo.lock, "entropy harvest buffers", NULL, + MTX_SPIN); + for (i = 0; i < EMPTYBUFFERS; i++) { + np = malloc(sizeof(struct harvest), M_ENTROPY, + M_WAITOK); + STAILQ_INSERT_TAIL(&emptyfifo.head, np, next); + } for (i = 0; i < ENTROPYSOURCE; i++) { STAILQ_INIT(&harvestfifo[i].head); harvestfifo[i].count = 0; - mtx_init(&harvestfifo[i].lock, "entropy harvest", NULL, MTX_DEF); + mtx_init(&harvestfifo[i].lock, "entropy harvest", NULL, + MTX_SPIN); } if (bootverbose) @@ -274,6 +291,12 @@ random_modevent(module_t mod __unused, int type, void *data __unused) tsleep((void *)&random_kthread_control, PUSER, "term", 0); /* Destroy the harvest fifos */ + while (!STAILQ_EMPTY(&emptyfifo.head)) { + np = STAILQ_FIRST(&emptyfifo.head); + STAILQ_REMOVE_HEAD(&emptyfifo.head, next); + free(np, M_ENTROPY); + } + mtx_destroy(&emptyfifo.lock); for (i = 0; i < ENTROPYSOURCE; i++) { while (!STAILQ_EMPTY(&harvestfifo[i].head)) { np = STAILQ_FIRST(&harvestfifo[i].head); @@ -318,7 +341,7 @@ random_kthread(void *arg __unused) found = 0; /* Lock up queue draining */ - mtx_lock(&harvestfifo[source].lock); + mtx_lock_spin(&harvestfifo[source].lock); if (!STAILQ_EMPTY(&harvestfifo[source].head)) { @@ -327,17 +350,26 @@ random_kthread(void *arg __unused) event = STAILQ_FIRST(&harvestfifo[source].head); STAILQ_REMOVE_HEAD(&harvestfifo[source].head, next); + active = found = 1; } /* Unlock the queue */ - mtx_unlock(&harvestfifo[source].lock); + mtx_unlock_spin(&harvestfifo[source].lock); /* Deal with the event and dispose of it */ if (found) { + random_process_event(event); - free(event, M_ENTROPY); + + /* Lock the empty event buffer fifo */ + mtx_lock_spin(&emptyfifo.lock); + + STAILQ_INSERT_TAIL(&emptyfifo.head, event, next); + + mtx_unlock_spin(&emptyfifo.lock); + } } @@ -362,14 +394,26 @@ random_harvest_internal(u_int64_t somecounter, void *entropy, u_int count, struct harvest *event; /* Lock the particular fifo */ - mtx_lock(&harvestfifo[origin].lock); + mtx_lock_spin(&harvestfifo[origin].lock); - /* Don't make the harvest queues too big - memory is precious */ + /* Don't make the harvest queues too big - help to prevent + * low-grade entropy swamping + */ if (harvestfifo[origin].count < RANDOM_FIFO_MAX) { - event = malloc(sizeof(struct harvest), M_ENTROPY, M_NOWAIT); + /* Lock the empty event buffer fifo */ + mtx_lock_spin(&emptyfifo.lock); + + if (!STAILQ_EMPTY(&emptyfifo.head)) { + event = STAILQ_FIRST(&emptyfifo.head); + STAILQ_REMOVE_HEAD(&emptyfifo.head, next); + } + else + event = NULL; + + mtx_unlock_spin(&emptyfifo.lock); - /* If we can't malloc() a buffer, tough */ + /* If we didn't obtain a buffer, tough */ if (event) { /* Add the harvested data to the fifo */ @@ -389,7 +433,7 @@ random_harvest_internal(u_int64_t somecounter, void *entropy, u_int count, } - mtx_unlock(&harvestfifo[origin].lock); + mtx_unlock_spin(&harvestfifo[origin].lock); } diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c index 87b3c9b9c3a4..e42cd10385cc 100644 --- a/sys/kern/kern_intr.c +++ b/sys/kern/kern_intr.c @@ -356,9 +356,7 @@ ok: int ithread_schedule(struct ithd *ithread, int do_switch) { -#if 0 struct int_entropy entropy; -#endif struct thread *td; struct thread *ctd; struct proc *p; @@ -370,7 +368,6 @@ ithread_schedule(struct ithd *ithread, int do_switch) return (EINVAL); ctd = curthread; -#if 0 /* * If any of the handlers for this ithread claim to be good * sources of entropy, then gather some. @@ -381,7 +378,6 @@ ithread_schedule(struct ithd *ithread, int do_switch) random_harvest(&entropy, sizeof(entropy), 2, 0, RANDOM_INTERRUPT); } -#endif td = ithread->it_td; p = td->td_proc; diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c index 28d56059a36a..02ba3a1481a2 100644 --- a/sys/kern/subr_witness.c +++ b/sys/kern/subr_witness.c @@ -288,6 +288,8 @@ static struct witness_order_list_entry order_lists[] = { { "turnstile chain", &lock_class_mtx_spin }, { "td_contested", &lock_class_mtx_spin }, { "callout", &lock_class_mtx_spin }, + { "entropy harvest", &lock_class_mtx_spin }, + { "entropy harvest buffers", &lock_class_mtx_spin }, /* * leaf locks */ |