From: Jan Beulich <jbeulich@suse.com>
Date: Tue, 7 Jul 2020 12:36:24 +0000 (+0200)
Subject: x86/shadow: correct an inverted conditional in dirty VRAM tracking
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~23
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=23a216f99d40fbfbc2318ade89d8213eea6ba1f8;p=xen.git

x86/shadow: correct an inverted conditional in dirty VRAM tracking

This originally was "mfn_x(mfn) == INVALID_MFN". Make it like this
again, taking the opportunity to also drop the unnecessary nearby
braces.

This is XSA-319.

Fixes: 246a5a3377c2 ("xen: Use a typesafe to define INVALID_MFN")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 5fcb04ce8b..773777321f 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -3253,10 +3253,8 @@ int shadow_track_dirty_vram(struct domain *d,
             int dirty = 0;
             paddr_t sl1ma = dirty_vram->sl1ma[i];
 
-            if ( !mfn_eq(mfn, INVALID_MFN) )
-            {
+            if ( mfn_eq(mfn, INVALID_MFN) )
                 dirty = 1;
-            }
             else
             {
                 page = mfn_to_page(mfn);