Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754660AbaFCNO5 (ORCPT ); Tue, 3 Jun 2014 09:14:57 -0400 Received: from isrv.corpit.ru ([86.62.121.231]:33354 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751201AbaFCNOy (ORCPT ); Tue, 3 Jun 2014 09:14:54 -0400 X-Greylist: delayed 520 seconds by postgrey-1.27 at vger.kernel.org; Tue, 03 Jun 2014 09:14:54 EDT Message-ID: <538DC844.2040808@msgid.tls.msk.ru> Date: Tue, 03 Jun 2014 17:06:12 +0400 From: Michael Tokarev Organization: Telecom Service, JSC User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.5.0 MIME-Version: 1.0 To: Paolo Bonzini , Rickard Strandqvist , Gleb Natapov CC: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arch: x86: kvm: x86.c: Cleaning up uninitialized variables References: <1401577506-4112-1-git-send-email-rickard_strandqvist@spectrumdigital.se> <538DB9B4.2070607@redhat.com> In-Reply-To: <538DB9B4.2070607@redhat.com> X-Enigmail-Version: 1.6 OpenPGP: id=804465C5 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 03.06.2014 16:04, Paolo Bonzini wrote: > Il 01/06/2014 01:05, Rickard Strandqvist ha scritto: >> There is a risk that the variable will be used without being initialized. >> >> This was largely found by using a static code analysis program called cppcheck. >> >> Signed-off-by: Rickard Strandqvist > > No, there isn't. The full context looks like this: > > longmode = is_long_mode(vcpu) && cs_l == 1; > if (!longmode) { > param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) | > (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff); > ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) | > (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff); > outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) | > (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff); > } > #ifdef CONFIG_X86_64 > else { > param = kvm_register_read(vcpu, VCPU_REGS_RCX); > ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX); > outgpa = kvm_register_read(vcpu, VCPU_REGS_R8); > } > #endif > > and longmode must be zero if !CONFIG_X86_64: This is not the first time this code is attempted to be changed. Maybe adding an additional #ifdef..endif around the longmode assignment and the "if" above will solve this for good? Or maybe something like this: #ifdef CONFIG_X86_64 if (!(is_long_mode(vcpu) && cs_l == 1)) { #else if (1) { #endif param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) | (kvm_register_read(vcpu, VCPU_REGS_RAX) & 0xffffffff); ingpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RBX) << 32) | (kvm_register_read(vcpu, VCPU_REGS_RCX) & 0xffffffff); outgpa = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDI) << 32) | (kvm_register_read(vcpu, VCPU_REGS_RSI) & 0xffffffff); } else { param = kvm_register_read(vcpu, VCPU_REGS_RCX); ingpa = kvm_register_read(vcpu, VCPU_REGS_RDX); outgpa = kvm_register_read(vcpu, VCPU_REGS_R8); } , to make it all explicit and obvious? Thanks, /mjt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/