Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 4 Oct 2021 12:10:55 +0200 (CEST)
From:   torvic9@mailbox.org
To:     Paolo Bonzini <pbonzini@redhat.com>,
        "seanjc@google.com" <seanjc@google.com>,
        "vkuznets@redhat.com" <vkuznets@redhat.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "ndesaulniers@google.com" <ndesaulniers@google.com>,
        "nathan@kernel.org" <nathan@kernel.org>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "bp@alien8.de" <bp@alien8.de>
Message-ID: <1723492337.161319.1633342255263@office.mailbox.org>
In-Reply-To: <c4773ecc-053f-9bc6-03af-5039397a4531@redhat.com>
References: <1446878298.170497.1633338512925@office.mailbox.org>
 <b6abc5a3-39ea-b463-9df5-f50bdcb16d08@redhat.com>
 <936688112.157288.1633339838738@office.mailbox.org>
 <c4773ecc-053f-9bc6-03af-5039397a4531@redhat.com>
Subject: Re: [BUG] [5.15] Compilation error in arch/x86/kvm/mmu/spte.h with
 clang-14
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Importance: Normal
Precedence: bulk


> Paolo Bonzini <pbonzini@redhat.com> hat am 04.10.2021 11:49 geschrieben:
> 
>  
> On 04/10/21 11:30, torvic9@mailbox.org wrote:
> > 
> >> Paolo Bonzini <pbonzini@redhat.com> hat am 04.10.2021 11:26 geschrieben:
> >>
> >>   
> >> On 04/10/21 11:08, torvic9@mailbox.org wrote:
> >>> I encounter the following issue when compiling 5.15-rc4 with clang-14:
> >>>
> >>> In file included from arch/x86/kvm/mmu/mmu.c:27:
> >>> arch/x86/kvm/mmu/spte.h:318:9: error: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
> >>>           return __is_bad_mt_xwr(rsvd_check, spte) |
> >>>                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >>>                                                    ||
> >>> arch/x86/kvm/mmu/spte.h:318:9: note: cast one or both operands to int to silence this warning
> >>
> >> The warning is wrong, as mentioned in the line right above:
> > 
> > So it's an issue with clang-14 then?
> > (I add Nick and Nathan)
> 
> My clang here doesn't have the option, so I'm going to ask---are you 
> using W=1?  I can see why clang is warning for KVM's code, but in my 
> opinion such a check should only be in -Wextra.

I don't use any options (not that I'm aware of).
Clang version 14.0.0 5f7a5353301b776ffb0e5fb048992898507bf7ee

> 
> Paolo
> 
> >>
> >>           /*
> >>            * Use a bitwise-OR instead of a logical-OR to aggregate the reserved
> >>            * bits and EPT's invalid memtype/XWR checks to avoid an extra Jcc
> >>            * (this is extremely unlikely to be short-circuited as true).
> >>            */
> >>
> >> Paolo
> >