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[209.85.167.45]) by smtp.gmail.com with ESMTPSA id s7sm204757ljc.10.2020.10.23.09.02.12 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 23 Oct 2020 09:02:12 -0700 (PDT) Received: by mail-lf1-f45.google.com with SMTP id b1so2682835lfp.11 for ; Fri, 23 Oct 2020 09:02:12 -0700 (PDT) X-Received: by 2002:a2e:8815:: with SMTP id x21mr1227378ljh.312.1603468500894; Fri, 23 Oct 2020 08:55:00 -0700 (PDT) MIME-Version: 1.0 References: <20201023050214.GG23681@linux.intel.com> <356811ab-cb08-7685-ca01-fe58b5654953@rasmusvillemoes.dk> In-Reply-To: <356811ab-cb08-7685-ca01-fe58b5654953@rasmusvillemoes.dk> From: Linus Torvalds Date: Fri, 23 Oct 2020 08:54:44 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [LTP] mmstress[1309]: segfault at 7f3d71a36ee8 ip 00007f3d77132bdf sp 00007f3d71a36ee8 error 4 in libc-2.27.so[7f3d77058000+1aa000] To: Rasmus Villemoes Cc: Sean Christopherson , =?UTF-8?B?RGFuaWVsIETDrWF6?= , Naresh Kamboju , Stephen Rothwell , "Matthew Wilcox (Oracle)" , zenglg.jy@cn.fujitsu.com, "Peter Zijlstra (Intel)" , Viresh Kumar , X86 ML , open list , lkft-triage@lists.linaro.org, "Eric W. Biederman" , linux-mm , linux-m68k , Linux-Next Mailing List , Thomas Gleixner , kasan-dev , Dmitry Vyukov , Geert Uytterhoeven , Christian Brauner , Ingo Molnar , LTP List , Al Viro Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 23, 2020 at 12:14 AM Rasmus Villemoes wrote: > > That's certainly garbage. Now, I don't know if it's a sufficient fix (or > could break something else), but the obvious first step of rearranging > so that the ptr argument is evaluated before the assignment to __val_pu Ack. We could do that. I'm more inclined to just bite the bullet and go back to the ugly conditional on the size that I had hoped to avoid, but if that turns out too ugly, mind signing off on your patch and I'll have that as a fallback? Linus