From: H. Peter Anvin Date: Wed, 21 Nov 2012 22:41:21 +0000 (-0800) Subject: x86, kvm: Remove incorrect redundant assembly constraint X-Git-Tag: firefly_0821_release~3680^2~1567^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cb7cb2864e758a1b040040bc55e404c677c911cb;p=firefly-linux-kernel-4.4.55.git x86, kvm: Remove incorrect redundant assembly constraint In __emulate_1op_rax_rdx, we use "+a" and "+d" which are input/output constraints, and *then* use "a" and "d" as input constraints. This is incorrect, but happens to work on some versions of gcc. However, it breaks gcc with -O0 and icc, and may break on future versions of gcc. Reported-and-tested-by: Melanie Blower Signed-off-by: H. Peter Anvin Link: http://lkml.kernel.org/r/B3584E72CFEBED439A3ECA9BCE67A4EF1B17AF90@FMSMSX107.amr.corp.intel.com Reviewed-by: Paolo Bonzini Acked-by: Marcelo Tosatti --- diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 39171cb307ea..bba39bfa1c4b 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -426,8 +426,7 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt) _ASM_EXTABLE(1b, 3b) \ : "=m" ((ctxt)->eflags), "=&r" (_tmp), \ "+a" (*rax), "+d" (*rdx), "+qm"(_ex) \ - : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val), \ - "a" (*rax), "d" (*rdx)); \ + : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val)); \ } while (0) /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */