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[84.3.50.134]) by smtp.gmail.com with ESMTPSA id a11sm6912156wmh.40.2019.11.20.05.16.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Nov 2019 05:16:29 -0800 (PST) Date: Wed, 20 Nov 2019 14:16:27 +0100 From: Ingo Molnar To: Jann Horn Cc: Borislav Petkov , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , the arch/x86 maintainers , Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev , kernel list , Andrey Konovalov , Andy Lutomirski , Sean Christopherson , Andi Kleen Subject: Re: [PATCH v3 2/4] x86/traps: Print non-canonical address on #GP Message-ID: <20191120131627.GA54414@gmail.com> References: <20191120103613.63563-1-jannh@google.com> <20191120103613.63563-2-jannh@google.com> <20191120111859.GA115930@gmail.com> <20191120112408.GC2634@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jann Horn wrote: > On Wed, Nov 20, 2019 at 12:24 PM Borislav Petkov wrote: > > On Wed, Nov 20, 2019 at 12:18:59PM +0100, Ingo Molnar wrote: > > > How was this maximum string length of '90' derived? In what way will > > > that have to change if someone changes the message? > > > > That was me counting the string length in a dirty patch in a previous > > thread. We probably should say why we decided for a certain length and > > maybe have a define for it. > > Do you think something like this would be better? > > char desc[sizeof(GPFSTR) + 50 + 2*sizeof(unsigned long) + 1] = GPFSTR; I'd much prefer this for, because it's a big honking warning for people to not just assume things but double check the limits. I.e. this mild obfuscation of the array size *helps* code quality in the long run :-) Thanks, Ingo