[Xen-changelog] [xen master] x86/HVM: fix setting mem access to default

[patchbot@xxxxxxx]

commit ca0f21841ddc4b2e2f4e4a74e2e39b70bd6b0aff
Author:     Jan Beulich <JBeulich@xxxxxxxx>
AuthorDate: Wed Apr 2 09:09:33 2014 +0100
Commit:     Tim Deegan <tim@xxxxxxx>
CommitDate: Thu Apr 3 10:48:48 2014 +0100

    x86/HVM: fix setting mem access to default
    
    commit 3b0bcb89 ("x86/mm/p2m: Move p2m code in HVMOP_[gs]et_mem_access
    into p2m.c") introduced an off-by-one mistake forcing an input of
    HVMMEM_access_default to always fail. Since related, also eliminate the
    inefficient setup of an on-stack array for each function invocation.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Tim Deegan <tim@xxxxxxx>
---
 xen/arch/x86/mm/p2m.c |   39 +++++++++++++++++++++++----------------
 1 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index fcc3ed6..c38f334 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1358,25 +1358,32 @@ long p2m_set_mem_access(struct domain *d, unsigned long 
pfn, uint32_t nr,
     mfn_t mfn;
     long rc = 0;
 
-    /* N.B. _not_ static: initializer depends on p2m->default_access */
-    p2m_access_t memaccess[] = {
-        p2m_access_n,
-        p2m_access_r,
-        p2m_access_w,
-        p2m_access_rw,
-        p2m_access_x,
-        p2m_access_rx,
-        p2m_access_wx,
-        p2m_access_rwx,
-        p2m_access_rx2rw,
-        p2m_access_n2rwx,
-        p2m->default_access,
+    static const p2m_access_t memaccess[] = {
+#define ACCESS(ac) [HVMMEM_access_##ac] = p2m_access_##ac
+        ACCESS(n),
+        ACCESS(r),
+        ACCESS(w),
+        ACCESS(rw),
+        ACCESS(x),
+        ACCESS(rx),
+        ACCESS(wx),
+        ACCESS(rwx),
+        ACCESS(rx2rw),
+        ACCESS(n2rwx),
+#undef ACCESS
     };
 
-    if ( (unsigned) access >= HVMMEM_access_default )
+    switch ( access )
+    {
+    case 0 ... ARRAY_SIZE(memaccess) - 1:
+        a = memaccess[access];
+        break;
+    case HVMMEM_access_default:
+        a = p2m->default_access;
+        break;
+    default:
         return -EINVAL;
-
-    a = memaccess[access];
+    }
 
     /* If request to set default access */
     if ( pfn == ~0ul )
--
generated by git-patchbot for /home/xen/git/xen.git#master

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