[Xen-changelog] [xen master] x86: serialize page table population in map_domain_page_global()

[patchbot@xxxxxxx]

commit 69b0fbfe6036516303a7058b0a182c925c3c56c8
Author:     Tim Deegan <tim@xxxxxxx>
AuthorDate: Tue Apr 9 10:30:33 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Apr 9 10:30:33 2013 +0200

    x86: serialize page table population in map_domain_page_global()
    
    Looking at map_domain_page_global, there doesn't seem to be any locking
    preventing two CPUs from populating a page of global-map l1es at the
    same time.
    
    Signed-off-by: Tim Deegan <tim@xxxxxxx>
---
 xen/arch/x86/domain_page.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index 7421e03..efda6af 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -354,9 +354,10 @@ void *map_domain_page_global(unsigned long mfn)
     set_bit(idx, inuse);
     inuse_cursor = idx + 1;
 
+    pl1e = virt_to_xen_l1e(va);
+
     spin_unlock(&globalmap_lock);
 
-    pl1e = virt_to_xen_l1e(va);
     if ( !pl1e )
         return NULL;
     l1e_write(pl1e, l1e_from_pfn(mfn, __PAGE_HYPERVISOR));
--
generated by git-patchbot for /home/xen/git/xen.git#master

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