[Xen-changelog] [xen stable-4.4] domctl: fix IRQ permission granting/revocation

[patchbot@xxxxxxx]

commit b72cea07db320ff04378c7126301e4b174ee8388
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Feb 3 12:27:12 2015 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Feb 3 12:27:12 2015 +0100

    domctl: fix IRQ permission granting/revocation
    
    Commit 545607eb3c ("x86: fix various issues with handling guest IRQs")
    wasn't really consistent in one respect: The granting of access to an
    IRQ shouldn't assume the pIRQ->IRQ translation to be the same in both
    domains. In fact it is wrong to assume that a translation is already/
    still in place at the time access is being granted/revoked.
    
    What is wanted is to translate the incoming pIRQ to an IRQ for
    the invoking domain (as the pIRQ is the only notion the invoking
    domain has of the IRQ), and grant the subject domain access to
    the resulting IRQ.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reported-by: Sander Eikelenboom <linux@xxxxxxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
    Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
    master commit: 6fb3a07bc0ad656b5f76eb9fc961bcd1d3cace58
    master date: 2015-01-05 10:20:24 -0500
---
 xen/common/domctl.c     |   14 +++++++++-----
 xen/include/xen/iocap.h |   17 +++--------------
 2 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 3a55883..49e2c23 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -778,17 +778,21 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
 
     case XEN_DOMCTL_irq_permission:
     {
-        unsigned int pirq = op->u.irq_permission.pirq;
+        unsigned int pirq = op->u.irq_permission.pirq, irq;
         int allow = op->u.irq_permission.allow_access;
 
-        if ( pirq >= d->nr_pirqs )
+        if ( pirq >= current->domain->nr_pirqs )
+        {
             ret = -EINVAL;
-        else if ( xsm_irq_permission(XSM_HOOK, d, pirq, allow) )
+            break;
+        }
+        irq = pirq_access_permitted(current->domain, pirq);
+        if ( !irq || xsm_irq_permission(XSM_HOOK, d, irq, allow) )
             ret = -EPERM;
         else if ( allow )
-            ret = pirq_permit_access(d, pirq);
+            ret = irq_permit_access(d, irq);
         else
-            ret = pirq_deny_access(d, pirq);
+            ret = irq_deny_access(d, irq);
     }
     break;
 
diff --git a/xen/include/xen/iocap.h b/xen/include/xen/iocap.h
index b755ecb..1ca3858 100644
--- a/xen/include/xen/iocap.h
+++ b/xen/include/xen/iocap.h
@@ -28,22 +28,11 @@
 #define irq_access_permitted(d, i)                      \
     rangeset_contains_singleton((d)->irq_caps, i)
 
-#define pirq_permit_access(d, i) ({                     \
-    struct domain *d__ = (d);                           \
-    int i__ = domain_pirq_to_irq(d__, i);               \
-    i__ > 0 ? rangeset_add_singleton(d__->irq_caps, i__)\
-            : -EINVAL;                                  \
-})
-#define pirq_deny_access(d, i) ({                       \
-    struct domain *d__ = (d);                           \
-    int i__ = domain_pirq_to_irq(d__, i);               \
-    i__ > 0 ? rangeset_remove_singleton(d__->irq_caps, i__)\
-            : -EINVAL;                                  \
-})
 #define pirq_access_permitted(d, i) ({                  \
     struct domain *d__ = (d);                           \
-    rangeset_contains_singleton(d__->irq_caps,          \
-                                domain_pirq_to_irq(d__, i));\
+    int irq__ = domain_pirq_to_irq(d__, i);             \
+    irq__ > 0 && irq_access_permitted(d__, irq__)       \
+    ? irq__ : 0;                                        \
 })
 
 #endif /* __XEN_IOCAP_H__ */
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.4

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