diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 11:53:09 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 11:53:09 -0800 |
commit | 7acfd4274e26e05a4f12ad31bf331fef11ebc6a3 (patch) | |
tree | e9e2cb25a659e92e41d856aceba4f6a62c317286 /drivers | |
parent | 571b12dd1ad41f371448b693c0bd2e64968c7af4 (diff) | |
parent | 1c728719a4da6e654afb9cc047164755072ed7c9 (diff) |
Merge tag 'for-linus-5.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen updates from Juergen Gross:
"Fixes for security issues just having been disclosed:
- a five patch series for fixing of XSA-349 (DoS via resource
depletion in Xen dom0)
- a patch fixing XSA-350 (access of stale pointer in a Xen dom0)"
* tag 'for-linus-5.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen-blkback: set ring->xenblkd to NULL after kthread_stop()
xenbus/xenbus_backend: Disallow pending watch messages
xen/xenbus: Count pending messages for each watch
xen/xenbus/xen_bus_type: Support will_handle watch callback
xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()
xen/xenbus: Allow watches discard events before queueing
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/block/xen-blkback/xenbus.c | 4 | ||||
-rw-r--r-- | drivers/net/xen-netback/xenbus.c | 6 | ||||
-rw-r--r-- | drivers/xen/xen-pciback/xenbus.c | 2 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus.h | 2 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 8 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.c | 1 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe_backend.c | 7 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 34 |
8 files changed, 48 insertions, 16 deletions
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c index 76912c584a76..9860d4842f36 100644 --- a/drivers/block/xen-blkback/xenbus.c +++ b/drivers/block/xen-blkback/xenbus.c @@ -274,6 +274,7 @@ static int xen_blkif_disconnect(struct xen_blkif *blkif) if (ring->xenblkd) { kthread_stop(ring->xenblkd); + ring->xenblkd = NULL; wake_up(&ring->shutdown_wq); } @@ -675,7 +676,8 @@ static int xen_blkbk_probe(struct xenbus_device *dev, /* setup back pointer */ be->blkif->be = be; - err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, + err = xenbus_watch_pathfmt(dev, &be->backend_watch, NULL, + backend_changed, "%s/%s", dev->nodename, "physical-device"); if (err) goto fail; diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index f1c1624cec8f..6f10e0998f1c 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -557,12 +557,14 @@ static int xen_register_credit_watch(struct xenbus_device *dev, return -ENOMEM; snprintf(node, maxlen, "%s/rate", dev->nodename); vif->credit_watch.node = node; + vif->credit_watch.will_handle = NULL; vif->credit_watch.callback = xen_net_rate_changed; err = register_xenbus_watch(&vif->credit_watch); if (err) { pr_err("Failed to set watcher %s\n", vif->credit_watch.node); kfree(node); vif->credit_watch.node = NULL; + vif->credit_watch.will_handle = NULL; vif->credit_watch.callback = NULL; } return err; @@ -609,6 +611,7 @@ static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, snprintf(node, maxlen, "%s/request-multicast-control", dev->otherend); vif->mcast_ctrl_watch.node = node; + vif->mcast_ctrl_watch.will_handle = NULL; vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed; err = register_xenbus_watch(&vif->mcast_ctrl_watch); if (err) { @@ -616,6 +619,7 @@ static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev, vif->mcast_ctrl_watch.node); kfree(node); vif->mcast_ctrl_watch.node = NULL; + vif->mcast_ctrl_watch.will_handle = NULL; vif->mcast_ctrl_watch.callback = NULL; } return err; @@ -820,7 +824,7 @@ static void connect(struct backend_info *be) xenvif_carrier_on(be->vif); unregister_hotplug_status_watch(be); - err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, + err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL, hotplug_status_changed, "%s/%s", dev->nodename, "hotplug-status"); if (!err) diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c index 4b99ec3dec58..e7c692cfb2cf 100644 --- a/drivers/xen/xen-pciback/xenbus.c +++ b/drivers/xen/xen-pciback/xenbus.c @@ -689,7 +689,7 @@ static int xen_pcibk_xenbus_probe(struct xenbus_device *dev, /* watch the backend node for backend configuration information */ err = xenbus_watch_path(dev, dev->nodename, &pdev->be_watch, - xen_pcibk_be_watch); + NULL, xen_pcibk_be_watch); if (err) goto out; diff --git a/drivers/xen/xenbus/xenbus.h b/drivers/xen/xenbus/xenbus.h index 5f5b8a7d5b80..2a93b7c9c159 100644 --- a/drivers/xen/xenbus/xenbus.h +++ b/drivers/xen/xenbus/xenbus.h @@ -44,6 +44,8 @@ struct xen_bus_type { int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename); int (*probe)(struct xen_bus_type *bus, const char *type, const char *dir); + bool (*otherend_will_handle)(struct xenbus_watch *watch, + const char *path, const char *token); void (*otherend_changed)(struct xenbus_watch *watch, const char *path, const char *token); struct bus_type bus; diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index fd80e318b99c..0cd728961fce 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -127,18 +127,22 @@ EXPORT_SYMBOL_GPL(xenbus_strstate); */ int xenbus_watch_path(struct xenbus_device *dev, const char *path, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *)) { int err; watch->node = path; + watch->will_handle = will_handle; watch->callback = callback; err = register_xenbus_watch(watch); if (err) { watch->node = NULL; + watch->will_handle = NULL; watch->callback = NULL; xenbus_dev_fatal(dev, err, "adding watch on %s", path); } @@ -165,6 +169,8 @@ EXPORT_SYMBOL_GPL(xenbus_watch_path); */ int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, + bool (*will_handle)(struct xenbus_watch *, + const char *, const char *), void (*callback)(struct xenbus_watch *, const char *, const char *), const char *pathfmt, ...) @@ -181,7 +187,7 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch"); return -ENOMEM; } - err = xenbus_watch_path(dev, path, watch, callback); + err = xenbus_watch_path(dev, path, watch, will_handle, callback); if (err) kfree(path); diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 38725d97d909..44634d970a5c 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -136,6 +136,7 @@ static int watch_otherend(struct xenbus_device *dev) container_of(dev->dev.bus, struct xen_bus_type, bus); return xenbus_watch_pathfmt(dev, &dev->otherend_watch, + bus->otherend_will_handle, bus->otherend_changed, "%s/%s", dev->otherend, "state"); } diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c index 2ba699897e6d..5abded97e1a7 100644 --- a/drivers/xen/xenbus/xenbus_probe_backend.c +++ b/drivers/xen/xenbus/xenbus_probe_backend.c @@ -180,6 +180,12 @@ static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type, return err; } +static bool frontend_will_handle(struct xenbus_watch *watch, + const char *path, const char *token) +{ + return watch->nr_pending == 0; +} + static void frontend_changed(struct xenbus_watch *watch, const char *path, const char *token) { @@ -191,6 +197,7 @@ static struct xen_bus_type xenbus_backend = { .levels = 3, /* backend/type/<frontend>/<id> */ .get_bus_id = backend_bus_id, .probe = xenbus_probe_backend, + .otherend_will_handle = frontend_will_handle, .otherend_changed = frontend_changed, .bus = { .name = "xen-backend", diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 3a06eb699f33..12e02eb01f59 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -705,9 +705,13 @@ int xs_watch_msg(struct xs_watch_event *event) spin_lock(&watches_lock); event->handle = find_watch(event->token); - if (event->handle != NULL) { + if (event->handle != NULL && + (!event->handle->will_handle || + event->handle->will_handle(event->handle, + event->path, event->token))) { spin_lock(&watch_events_lock); list_add_tail(&event->list, &watch_events); + event->handle->nr_pending++; wake_up(&watch_events_waitq); spin_unlock(&watch_events_lock); } else @@ -765,6 +769,8 @@ int register_xenbus_watch(struct xenbus_watch *watch) sprintf(token, "%lX", (long)watch); + watch->nr_pending = 0; + down_read(&xs_watch_rwsem); spin_lock(&watches_lock); @@ -814,11 +820,14 @@ void unregister_xenbus_watch(struct xenbus_watch *watch) /* Cancel pending watch events. */ spin_lock(&watch_events_lock); - list_for_each_entry_safe(event, tmp, &watch_events, list) { - if (event->handle != watch) - continue; - list_del(&event->list); - kfree(event); + if (watch->nr_pending) { + list_for_each_entry_safe(event, tmp, &watch_events, list) { + if (event->handle != watch) + continue; + list_del(&event->list); + kfree(event); + } + watch->nr_pending = 0; } spin_unlock(&watch_events_lock); @@ -865,7 +874,6 @@ void xs_suspend_cancel(void) static int xenwatch_thread(void *unused) { - struct list_head *ent; struct xs_watch_event *event; xenwatch_pid = current->pid; @@ -880,13 +888,15 @@ static int xenwatch_thread(void *unused) mutex_lock(&xenwatch_mutex); spin_lock(&watch_events_lock); - ent = watch_events.next; - if (ent != &watch_events) - list_del(ent); + event = list_first_entry_or_null(&watch_events, + struct xs_watch_event, list); + if (event) { + list_del(&event->list); + event->handle->nr_pending--; + } spin_unlock(&watch_events_lock); - if (ent != &watch_events) { - event = list_entry(ent, struct xs_watch_event, list); + if (event) { event->handle->callback(event->handle, event->path, event->token); kfree(event); |