[Xen-devel] [PATCH] xen: xen_init_cpuid_mask: Zero cx before calling xen_cpuid

[Josh Triplett <josh@xxxxxxxxxxxxxxxx>]

CPUID function 1 doesn't use cx, but xen_cpuid doesn't know that,
resulting in this warning:

arch/x86/xen/enlighten.c: In function âxen_start_kernelâ:
arch/x86/xen/enlighten.c:192: warning: âcxâ may be used uninitialized in this 
function
arch/x86/xen/enlighten.c:205: note: âcxâ was declared here

Set cx = 0 to avoid this warning.  This seems preferable to implementing
a xen_cpuid_nocount without the input constraint for cx, and either of
those seem preferable to just ignoring the warning.

Signed-off-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---

Build-tested only.

 arch/x86/xen/enlighten.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 0a1700a..6ee2ef8 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -215,6 +215,7 @@ static __init void xen_init_cpuid_mask(void)
                          (1 << X86_FEATURE_ACPI));  /* disable ACPI */
 
        ax = 1;
+       cx = 0;
        xen_cpuid(&ax, &bx, &cx, &dx);
 
        /* cpuid claims we support xsave; try enabling it to see what happens */
-- 
1.5.6.5


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