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-rw-r--r--util/async.c13
-rw-r--r--util/qemu-coroutine-sleep.c12
-rw-r--r--util/qemu-coroutine.c14
3 files changed, 39 insertions, 0 deletions
diff --git a/util/async.c b/util/async.c
index 0e1bd8780a..4dd9d95a9e 100644
--- a/util/async.c
+++ b/util/async.c
@@ -388,6 +388,9 @@ static void co_schedule_bh_cb(void *opaque)
QSLIST_REMOVE_HEAD(&straight, co_scheduled_next);
trace_aio_co_schedule_bh_cb(ctx, co);
aio_context_acquire(ctx);
+
+ /* Protected by write barrier in qemu_aio_coroutine_enter */
+ atomic_set(&co->scheduled, NULL);
qemu_coroutine_enter(co);
aio_context_release(ctx);
}
@@ -438,6 +441,16 @@ fail:
void aio_co_schedule(AioContext *ctx, Coroutine *co)
{
trace_aio_co_schedule(ctx, co);
+ const char *scheduled = atomic_cmpxchg(&co->scheduled, NULL,
+ __func__);
+
+ if (scheduled) {
+ fprintf(stderr,
+ "%s: Co-routine was already scheduled in '%s'\n",
+ __func__, scheduled);
+ abort();
+ }
+
QSLIST_INSERT_HEAD_ATOMIC(&ctx->scheduled_coroutines,
co, co_scheduled_next);
qemu_bh_schedule(ctx->co_schedule_bh);
diff --git a/util/qemu-coroutine-sleep.c b/util/qemu-coroutine-sleep.c
index 9c5655041b..254349cdbb 100644
--- a/util/qemu-coroutine-sleep.c
+++ b/util/qemu-coroutine-sleep.c
@@ -13,6 +13,7 @@
#include "qemu/osdep.h"
#include "qemu/coroutine.h"
+#include "qemu/coroutine_int.h"
#include "qemu/timer.h"
#include "block/aio.h"
@@ -25,6 +26,8 @@ static void co_sleep_cb(void *opaque)
{
CoSleepCB *sleep_cb = opaque;
+ /* Write of schedule protected by barrier write in aio_co_schedule */
+ atomic_set(&sleep_cb->co->scheduled, NULL);
aio_co_wake(sleep_cb->co);
}
@@ -34,6 +37,15 @@ void coroutine_fn co_aio_sleep_ns(AioContext *ctx, QEMUClockType type,
CoSleepCB sleep_cb = {
.co = qemu_coroutine_self(),
};
+
+ const char *scheduled = atomic_cmpxchg(&sleep_cb.co->scheduled, NULL,
+ __func__);
+ if (scheduled) {
+ fprintf(stderr,
+ "%s: Co-routine was already scheduled in '%s'\n",
+ __func__, scheduled);
+ abort();
+ }
sleep_cb.ts = aio_timer_new(ctx, type, SCALE_NS, co_sleep_cb, &sleep_cb);
timer_mod(sleep_cb.ts, qemu_clock_get_ns(type) + ns);
qemu_coroutine_yield();
diff --git a/util/qemu-coroutine.c b/util/qemu-coroutine.c
index d6095c1d5a..9eff7fd450 100644
--- a/util/qemu-coroutine.c
+++ b/util/qemu-coroutine.c
@@ -107,8 +107,22 @@ void qemu_aio_coroutine_enter(AioContext *ctx, Coroutine *co)
Coroutine *self = qemu_coroutine_self();
CoroutineAction ret;
+ /* Cannot rely on the read barrier for co in aio_co_wake(), as there are
+ * callers outside of aio_co_wake() */
+ const char *scheduled = atomic_mb_read(&co->scheduled);
+
trace_qemu_aio_coroutine_enter(ctx, self, co, co->entry_arg);
+ /* if the Coroutine has already been scheduled, entering it again will
+ * cause us to enter it twice, potentially even after the coroutine has
+ * been deleted */
+ if (scheduled) {
+ fprintf(stderr,
+ "%s: Co-routine was already scheduled in '%s'\n",
+ __func__, scheduled);
+ abort();
+ }
+
if (co->caller) {
fprintf(stderr, "Co-routine re-entered recursively\n");
abort();