Re: [PATCH 1/1] XEN: enlighten, use uninitialized_var(cx)
From: Ingo Molnar <hidden>
Date: 2009-08-26 06:09:38
Also in:
lkml, xen-devel
* Jiri Slaby [off-list ref] wrote:
quoted hunk ↗ jump to hunk
To avoid a wrong compiler warning, use unitialized_var(cx) in xen_init_cpuid_mask. cx needn't be initialized for cpuid when ax is 1. Signed-off-by: Jiri Slaby <redacted> Cc: Jeremy Fitzhardinge <redacted> Cc: Chris Wright <redacted> --- arch/x86/xen/enlighten.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index e90540a..5ab75e2 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c@@ -202,7 +202,7 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx, static __init void xen_init_cpuid_mask(void) { - unsigned int ax, bx, cx, dx; + unsigned int ax, bx, uninitialized_var(cx), dx;
Please dont use uninitialized_var(), it's an unreliable facility: if this variable ever grows a real used-without-initialization bug in the future, the compiler warning is turned off permanently. It's rare but might happen. We are better off with initializing it to zero. Ingo