[Xen-changelog] [xen stable-4.11] x86/mem-sharing: Don't leave the altp2m lock held when nominating a page

[patchbot@xxxxxxx]

commit 7d1bd985ebd4c1473c4dfd50b6d3a33c8e1b1a93
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Fri Feb 1 11:28:45 2019 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Feb 1 11:28:45 2019 +0100

    x86/mem-sharing: Don't leave the altp2m lock held when nominating a page
    
    get_gfn_type_access() internally takes the p2m lock, and nothing ever 
unlocks
    it.  Switch to using the unlocked accessor instead.
    
    This wasn't included in XSA-277 because neither mem-sharing nor altp2m are
    supported.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: d6e02850d3b45c9658457214a749cc48097bdef4
    master date: 2018-11-22 17:58:46 +0000
---
 xen/arch/x86/mm/mem_sharing.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm/mem_sharing.c b/xen/arch/x86/mm/mem_sharing.c
index fad8a9df13..536262d9b7 100644
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -819,7 +819,8 @@ static int nominate_page(struct domain *d, gfn_t gfn,
             if ( !ap2m )
                 continue;
 
-            amfn = get_gfn_type_access(ap2m, gfn_x(gfn), &ap2mt, &ap2ma, 0, 
NULL);
+            amfn = __get_gfn_type_access(ap2m, gfn_x(gfn), &ap2mt, &ap2ma,
+                                         0, NULL, false);
             if ( mfn_valid(amfn) && (!mfn_eq(amfn, mfn) || ap2ma != p2ma) )
             {
                 altp2m_list_unlock(d);
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.11

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