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| author | Vladimir Kondratyev <wulf@FreeBSD.org> | 2020-04-21 22:38:14 +0000 |
|---|---|---|
| committer | Vladimir Kondratyev <wulf@FreeBSD.org> | 2021-01-07 23:18:42 +0000 |
| commit | 3b8c8b35de3a1a8a24169d144189b6a4db82ce10 (patch) | |
| tree | 0c4ab1221f08828654358da47415420372c48de7 | |
| parent | d276eae674d22214d6a58d1f4871053ceb0cb9f5 (diff) | |
| download | src-3b8c8b35de3a1a8a24169d144189b6a4db82ce10.tar.gz src-3b8c8b35de3a1a8a24169d144189b6a4db82ce10.zip | |
evdev: Allow open() handler to be interrupted by a signal
It is possible that the client list lock is taken by other process for too
long due to e.g. IO timeouts. Allow user to terminate open() in this case.
Reviewed by: markj (as part of D27865)
| -rw-r--r-- | sys/dev/evdev/cdev.c | 11 | ||||
| -rw-r--r-- | sys/dev/evdev/evdev_private.h | 9 |
2 files changed, 15 insertions, 5 deletions
diff --git a/sys/dev/evdev/cdev.c b/sys/dev/evdev/cdev.c index c4550362ebce..ec60a12dbf2d 100644 --- a/sys/dev/evdev/cdev.c +++ b/sys/dev/evdev/cdev.c @@ -126,19 +126,20 @@ evdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) mtx_init(&client->ec_buffer_mtx, "evclient", "evdev", MTX_DEF); knlist_init_mtx(&client->ec_selp.si_note, &client->ec_buffer_mtx); + ret = EVDEV_LIST_LOCK_SIG(evdev); + if (ret != 0) + goto out; /* Avoid race with evdev_unregister */ - EVDEV_LIST_LOCK(evdev); if (dev->si_drv1 == NULL) ret = ENODEV; else ret = evdev_register_client(evdev, client); - - if (ret != 0) - evdev_revoke_client(client); EVDEV_LIST_UNLOCK(evdev); - +out: if (ret == 0) ret = devfs_set_cdevpriv(client, evdev_dtor); + else + client->ec_revoked = true; if (ret != 0) { debugf(client, "cannot register evdev client"); diff --git a/sys/dev/evdev/evdev_private.h b/sys/dev/evdev/evdev_private.h index 66a059c763bc..19636823b804 100644 --- a/sys/dev/evdev/evdev_private.h +++ b/sys/dev/evdev/evdev_private.h @@ -206,6 +206,15 @@ struct evdev_dev else \ sx_assert(&(evdev)->ev_list_lock, MA_OWNED); \ } while (0) +static inline int +EVDEV_LIST_LOCK_SIG(struct evdev_dev *evdev) +{ + if (evdev->ev_lock_type == EV_LOCK_MTX) { + EVDEV_LOCK(evdev); + return (0); + } + return (sx_xlock_sig(&evdev->ev_list_lock)); +} struct evdev_client { |