[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v6 3/3] xen/evtchn: revert 52e1fc47abc3a0123
With the event channel lock no longer disabling interrupts commit 52e1fc47abc3a0123 ("evtchn/Flask: pre-allocate node on send path") can be reverted again. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- xen/common/event_channel.c | 6 --- xen/include/xsm/xsm.h | 1 - xen/xsm/flask/avc.c | 78 ++++--------------------------------- xen/xsm/flask/hooks.c | 10 ----- xen/xsm/flask/include/avc.h | 2 - 5 files changed, 7 insertions(+), 90 deletions(-) diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c index 43e3520df6..eacd96b92f 100644 --- a/xen/common/event_channel.c +++ b/xen/common/event_channel.c @@ -740,12 +740,6 @@ int evtchn_send(struct domain *ld, unsigned int lport) if ( !port_is_valid(ld, lport) ) return -EINVAL; - /* - * As the call further down needs to avoid allocations (due to running - * with IRQs off), give XSM a chance to pre-allocate if needed. - */ - xsm_evtchn_send(XSM_HOOK, ld, NULL); - lchn = evtchn_from_port(ld, lport); evtchn_read_lock(lchn); diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h index 358ec13ba8..7bd03d8817 100644 --- a/xen/include/xsm/xsm.h +++ b/xen/include/xsm/xsm.h @@ -59,7 +59,6 @@ struct xsm_operations { int (*evtchn_interdomain) (struct domain *d1, struct evtchn *chn1, struct domain *d2, struct evtchn *chn2); void (*evtchn_close_post) (struct evtchn *chn); - /* Note: Next hook may be called with 'chn' set to NULL. See call site. */ int (*evtchn_send) (struct domain *d, struct evtchn *chn); int (*evtchn_status) (struct domain *d, struct evtchn *chn); int (*evtchn_reset) (struct domain *d1, struct domain *d2); diff --git a/xen/xsm/flask/avc.c b/xen/xsm/flask/avc.c index 2dfa1f4295..87ea38b7a0 100644 --- a/xen/xsm/flask/avc.c +++ b/xen/xsm/flask/avc.c @@ -24,9 +24,7 @@ #include <xen/prefetch.h> #include <xen/kernel.h> #include <xen/sched.h> -#include <xen/cpu.h> #include <xen/init.h> -#include <xen/percpu.h> #include <xen/rcupdate.h> #include <asm/atomic.h> #include <asm/current.h> @@ -343,79 +341,17 @@ static inline int avc_reclaim_node(void) return ecx; } -static struct avc_node *new_node(void) -{ - struct avc_node *node = xzalloc(struct avc_node); - - if ( node ) - { - INIT_RCU_HEAD(&node->rhead); - INIT_HLIST_NODE(&node->list); - avc_cache_stats_incr(allocations); - } - - return node; -} - -/* - * avc_has_perm_noaudit() may consume up to two nodes, which we may not be - * able to obtain from the allocator at that point. Since the is merely - * about caching earlier decisions, allow for (just) one pre-allocated node. - */ -static DEFINE_PER_CPU(struct avc_node *, prealloc_node); - -void avc_prealloc(void) -{ - struct avc_node **prealloc = &this_cpu(prealloc_node); - - if ( !*prealloc ) - *prealloc = new_node(); -} - -static int cpu_callback(struct notifier_block *nfb, unsigned long action, - void *hcpu) -{ - unsigned int cpu = (unsigned long)hcpu; - struct avc_node **prealloc = &per_cpu(prealloc_node, cpu); - - if ( action == CPU_DEAD && *prealloc ) - { - xfree(*prealloc); - *prealloc = NULL; - avc_cache_stats_incr(frees); - } - - return NOTIFY_DONE; -} - -static struct notifier_block cpu_nfb = { - .notifier_call = cpu_callback, - .priority = 99 -}; - -static int __init cpu_nfb_init(void) -{ - register_cpu_notifier(&cpu_nfb); - return 0; -} -__initcall(cpu_nfb_init); - static struct avc_node *avc_alloc_node(void) { - struct avc_node *node, **prealloc = &this_cpu(prealloc_node); + struct avc_node *node; - node = *prealloc; - *prealloc = NULL; + node = xzalloc(struct avc_node); + if (!node) + goto out; - if ( !node ) - { - /* Must not call xmalloc() & Co with IRQs off. */ - if ( !local_irq_is_enabled() ) - goto out; - node = new_node(); - if ( !node ) - goto out; - } + INIT_RCU_HEAD(&node->rhead); + INIT_HLIST_NODE(&node->list); + avc_cache_stats_incr(allocations); atomic_inc(&avc_cache.active_nodes); if ( atomic_read(&avc_cache.active_nodes) > avc_cache_threshold ) diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c index de050cc9fe..19b0d9e3eb 100644 --- a/xen/xsm/flask/hooks.c +++ b/xen/xsm/flask/hooks.c @@ -281,16 +281,6 @@ static int flask_evtchn_send(struct domain *d, struct evtchn *chn) { int rc; - /* - * When called with non-NULL chn, memory allocation may not be permitted. - * Allow AVC to preallocate nodes as necessary upon early notification. - */ - if ( !chn ) - { - avc_prealloc(); - return 0; - } - switch ( chn->state ) { case ECS_INTERDOMAIN: diff --git a/xen/xsm/flask/include/avc.h b/xen/xsm/flask/include/avc.h index 722919b762..c14bd07a2b 100644 --- a/xen/xsm/flask/include/avc.h +++ b/xen/xsm/flask/include/avc.h @@ -91,8 +91,6 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid, u16 tclass, u32 requested, int avc_has_perm(u32 ssid, u32 tsid, u16 tclass, u32 requested, struct avc_audit_data *auditdata); -void avc_prealloc(void); - /* Exported to selinuxfs */ struct xen_flask_hash_stats; int avc_get_hash_stats(struct xen_flask_hash_stats *arg); -- 2.26.2
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