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-rw-r--r--system/xen/xsa/xsa343-1.patch199
1 files changed, 0 insertions, 199 deletions
diff --git a/system/xen/xsa/xsa343-1.patch b/system/xen/xsa/xsa343-1.patch
deleted file mode 100644
index 0abbc03e8d..0000000000
--- a/system/xen/xsa/xsa343-1.patch
+++ /dev/null
@@ -1,199 +0,0 @@
-From: Jan Beulich <jbeulich@suse.com>
-Subject: evtchn: evtchn_reset() shouldn't succeed with still-open ports
-
-While the function closes all ports, it does so without holding any
-lock, and hence racing requests may be issued causing new ports to get
-opened. This would have been problematic in particular if such a newly
-opened port had a port number above the new implementation limit (i.e.
-when switching from FIFO to 2-level) after the reset, as prior to
-"evtchn: relax port_is_valid()" this could have led to e.g.
-evtchn_close()'s "BUG_ON(!port_is_valid(d2, port2))" to trigger.
-
-Introduce a counter of active ports and check that it's (still) no
-larger then the number of Xen internally used ones after obtaining the
-necessary lock in evtchn_reset().
-
-As to the access model of the new {active,xen}_evtchns fields - while
-all writes get done using write_atomic(), reads ought to use
-read_atomic() only when outside of a suitably locked region.
-
-Note that as of now evtchn_bind_virq() and evtchn_bind_ipi() don't have
-a need to call check_free_port().
-
-This is part of XSA-343.
-
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
-Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
-Reviewed-by: Julien Grall <jgrall@amazon.com>
----
-v7: Drop optimization from evtchn_reset().
-v6: Fix loop exit condition in evtchn_reset(). Use {read,write}_atomic()
- also for xen_evtchns.
-v5: Move increment in alloc_unbound_xen_event_channel() out of the inner
- locked region.
-v4: Account for Xen internal ports.
-v3: Document intended access next to new struct field.
-v2: Add comment to check_free_port(). Drop commented out calls.
-
---- a/xen/common/event_channel.c
-+++ b/xen/common/event_channel.c
-@@ -188,6 +188,8 @@ int evtchn_allocate_port(struct domain *
- write_atomic(&d->valid_evtchns, d->valid_evtchns + EVTCHNS_PER_BUCKET);
- }
-
-+ write_atomic(&d->active_evtchns, d->active_evtchns + 1);
-+
- return 0;
- }
-
-@@ -211,11 +213,26 @@ static int get_free_port(struct domain *
- return -ENOSPC;
- }
-
-+/*
-+ * Check whether a port is still marked free, and if so update the domain
-+ * counter accordingly. To be used on function exit paths.
-+ */
-+static void check_free_port(struct domain *d, evtchn_port_t port)
-+{
-+ if ( port_is_valid(d, port) &&
-+ evtchn_from_port(d, port)->state == ECS_FREE )
-+ write_atomic(&d->active_evtchns, d->active_evtchns - 1);
-+}
-+
- void evtchn_free(struct domain *d, struct evtchn *chn)
- {
- /* Clear pending event to avoid unexpected behavior on re-bind. */
- evtchn_port_clear_pending(d, chn);
-
-+ if ( consumer_is_xen(chn) )
-+ write_atomic(&d->xen_evtchns, d->xen_evtchns - 1);
-+ write_atomic(&d->active_evtchns, d->active_evtchns - 1);
-+
- /* Reset binding to vcpu0 when the channel is freed. */
- chn->state = ECS_FREE;
- chn->notify_vcpu_id = 0;
-@@ -258,6 +275,7 @@ static long evtchn_alloc_unbound(evtchn_
- alloc->port = port;
-
- out:
-+ check_free_port(d, port);
- spin_unlock(&d->event_lock);
- rcu_unlock_domain(d);
-
-@@ -351,6 +369,7 @@ static long evtchn_bind_interdomain(evtc
- bind->local_port = lport;
-
- out:
-+ check_free_port(ld, lport);
- spin_unlock(&ld->event_lock);
- if ( ld != rd )
- spin_unlock(&rd->event_lock);
-@@ -488,7 +507,7 @@ static long evtchn_bind_pirq(evtchn_bind
- struct domain *d = current->domain;
- struct vcpu *v = d->vcpu[0];
- struct pirq *info;
-- int port, pirq = bind->pirq;
-+ int port = 0, pirq = bind->pirq;
- long rc;
-
- if ( (pirq < 0) || (pirq >= d->nr_pirqs) )
-@@ -536,6 +555,7 @@ static long evtchn_bind_pirq(evtchn_bind
- arch_evtchn_bind_pirq(d, pirq);
-
- out:
-+ check_free_port(d, port);
- spin_unlock(&d->event_lock);
-
- return rc;
-@@ -1011,10 +1031,10 @@ int evtchn_unmask(unsigned int port)
- return 0;
- }
-
--
- int evtchn_reset(struct domain *d)
- {
- unsigned int i;
-+ int rc = 0;
-
- if ( d != current->domain && !d->controller_pause_count )
- return -EINVAL;
-@@ -1024,7 +1044,9 @@ int evtchn_reset(struct domain *d)
-
- spin_lock(&d->event_lock);
-
-- if ( d->evtchn_fifo )
-+ if ( d->active_evtchns > d->xen_evtchns )
-+ rc = -EAGAIN;
-+ else if ( d->evtchn_fifo )
- {
- /* Switching back to 2-level ABI. */
- evtchn_fifo_destroy(d);
-@@ -1033,7 +1055,7 @@ int evtchn_reset(struct domain *d)
-
- spin_unlock(&d->event_lock);
-
-- return 0;
-+ return rc;
- }
-
- static long evtchn_set_priority(const struct evtchn_set_priority *set_priority)
-@@ -1219,10 +1241,9 @@ int alloc_unbound_xen_event_channel(
-
- spin_lock(&ld->event_lock);
-
-- rc = get_free_port(ld);
-+ port = rc = get_free_port(ld);
- if ( rc < 0 )
- goto out;
-- port = rc;
- chn = evtchn_from_port(ld, port);
-
- rc = xsm_evtchn_unbound(XSM_TARGET, ld, chn, remote_domid);
-@@ -1238,7 +1259,10 @@ int alloc_unbound_xen_event_channel(
-
- spin_unlock(&chn->lock);
-
-+ write_atomic(&ld->xen_evtchns, ld->xen_evtchns + 1);
-+
- out:
-+ check_free_port(ld, port);
- spin_unlock(&ld->event_lock);
-
- return rc < 0 ? rc : port;
-@@ -1314,6 +1338,7 @@ int evtchn_init(struct domain *d, unsign
- return -EINVAL;
- }
- evtchn_from_port(d, 0)->state = ECS_RESERVED;
-+ write_atomic(&d->active_evtchns, 0);
-
- #if MAX_VIRT_CPUS > BITS_PER_LONG
- d->poll_mask = xzalloc_array(unsigned long, BITS_TO_LONGS(d->max_vcpus));
-@@ -1340,6 +1365,8 @@ void evtchn_destroy(struct domain *d)
- for ( i = 0; port_is_valid(d, i); i++ )
- evtchn_close(d, i, 0);
-
-+ ASSERT(!d->active_evtchns);
-+
- clear_global_virq_handlers(d);
-
- evtchn_fifo_destroy(d);
---- a/xen/include/xen/sched.h
-+++ b/xen/include/xen/sched.h
-@@ -361,6 +361,16 @@ struct domain
- struct evtchn **evtchn_group[NR_EVTCHN_GROUPS]; /* all other buckets */
- unsigned int max_evtchn_port; /* max permitted port number */
- unsigned int valid_evtchns; /* number of allocated event channels */
-+ /*
-+ * Number of in-use event channels. Writers should use write_atomic().
-+ * Readers need to use read_atomic() only when not holding event_lock.
-+ */
-+ unsigned int active_evtchns;
-+ /*
-+ * Number of event channels used internally by Xen (not subject to
-+ * EVTCHNOP_reset). Read/write access like for active_evtchns.
-+ */
-+ unsigned int xen_evtchns;
- spinlock_t event_lock;
- const struct evtchn_port_ops *evtchn_port_ops;
- struct evtchn_fifo_domain *evtchn_fifo;
generated by cgit v1.2.3 (git 2.32.0) at 2024-05-14 03:41:19 +0200