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[Xen-changelog] [xen master] x86/shim: don't use 32-bit compare on boolean variable



commit 98dc9606868a807206ad0f4c3a45046d4e0e1260
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Feb 1 11:32:45 2018 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Feb 1 11:32:45 2018 +0100

    x86/shim: don't use 32-bit compare on boolean variable
    
    Current upstream gas silently assumes 32-bit operand size for most
    operations where the size can't be inferred from an involved register
    (my own one doesn't anymore, which is how I've noticed this). It is pure
    luck that the 3 bytes following pvh_boot are currently padding ones.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper@xxxxxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
 xen/arch/x86/boot/head.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/boot/head.S b/xen/arch/x86/boot/head.S
index 3cb66fc..63bc1b3 100644
--- a/xen/arch/x86/boot/head.S
+++ b/xen/arch/x86/boot/head.S
@@ -585,7 +585,7 @@ trampoline_setup:
         push    %eax                /* Magic number. */
         call    reloc
 #ifdef CONFIG_PVH_GUEST
-        cmp     $0, sym_fs(pvh_boot)
+        cmpb    $0, sym_fs(pvh_boot)
         je      1f
         mov     %eax, sym_fs(pvh_start_info_pa)
         jmp     2f
--
generated by git-patchbot for /home/xen/git/xen.git#master

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