From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD0F3C43334 for ; Sun, 17 Jul 2022 20:38:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231459AbiGQUi4 (ORCPT ); Sun, 17 Jul 2022 16:38:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229544AbiGQUiy (ORCPT ); Sun, 17 Jul 2022 16:38:54 -0400 Received: from mail-yb1-xb36.google.com (mail-yb1-xb36.google.com [IPv6:2607:f8b0:4864:20::b36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D667D5F77; Sun, 17 Jul 2022 13:38:53 -0700 (PDT) Received: by mail-yb1-xb36.google.com with SMTP id 64so17756075ybt.12; Sun, 17 Jul 2022 13:38:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=iiYSup99uwU5NOviKuuMKo7BhkLIiiIQ+0H1fe5hX1k=; b=Y2tgy3kJv7l7mn79jdIYcMmXZNJpLRhygh+ca6MPCH1qymdCA8+NrjuArg6Of6/hxP F6kb8+EEhQLJj9qBBUo2oJSBuufPnzt20uMKJylBWGxePp7pl7I4MA5OUi3PAqksXJPP xmFhRsTKCnwWfZJ2j17dGlfiSkQTyuW5lf0xUNky0IkcurbqP/bt1CEUTKGOli+3X+KG l0yOn079Sh9TFVlrULEmkHpz8UEXg7692CGY6tytlgaN6PAmdFf+YX3LKON2bUuciUMZ JD3Y2H72PE74P0Rc/3mLAsv+ySjCDhkaq1kl9TTgWBmAwZOZS3gW9sgSp61bH6aEu+H1 tXHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=iiYSup99uwU5NOviKuuMKo7BhkLIiiIQ+0H1fe5hX1k=; b=7XAOFzdXuBjP7PHP2M/gR2sorjJ2kY41d6jVYaHqZ1YoFPl4QPKpKPxPRbzFup0xMl gf8bUO7aWY3H7WcNM46Rc9hRaZxYVSILezsM8YB6H8Vu2dJSxRgPhU+y8835OVmLdJsT k8krvl6NJiO5go1DICf1WpnxqiZpya1m6sqTt6m9yNiObAbG9iM4HZp2YareFm5kCgQr qvdbFVVVoY/jnJ8Pb5ZT7/CCH6MvaJp2kEDGZVrFzoV2ScoRxtKfkKbmLkaGEYW8GX0e cGhABzXCo3Uw1QXGFjtsisPr8Yj17heNB6AEM8CbrRaSpIqNyDikUL2JAGiBxg4fH4PF tEwQ== X-Gm-Message-State: AJIora/8gD64C/eX/nCBeNUaJldCTDeVdKpjuwxK3YOF4Ut8mUochQXq 6r5Rq6rMijFcU1DfJEYy3Fy0BdvvLQuWB8OQ0c4= X-Google-Smtp-Source: AGRyM1soBR/gucIFEFNRakwNssNATZ5/O9lI3lT9DpslecEmedxGh+4cL15CKNkF/Mk658qlDEcYXio+htFRg7jSobY= X-Received: by 2002:a25:6b0f:0:b0:66e:cba3:8f2d with SMTP id g15-20020a256b0f000000b0066ecba38f2dmr23046365ybc.183.1658090333076; Sun, 17 Jul 2022 13:38:53 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Sudip Mukherjee Date: Sun, 17 Jul 2022 21:38:17 +0100 Message-ID: Subject: Re: mainline build failure of powerpc allmodconfig for prom_init_check To: Linus Torvalds Cc: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Kees Cook , linuxppc-dev , linux-kernel , linux-hardening@vger.kernel.org, Segher Boessenkool Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Jul 17, 2022 at 9:29 PM Linus Torvalds wrote: > > On Sun, Jul 17, 2022 at 1:25 PM Sudip Mukherjee > wrote: > > > > And the generated assembly still has the memset for "struct prom_args". > > Strange. That smells like a compiler bug to me. Both gcc-12 and clang gives this error. > > But I can't read powerpc assembly code - it's been too many years, and > even back when I did read it I hated how the register "names" worked. > > Maybe it was never the args array, and it was about the other fields. > Not that that makes any sense either, but it makes more sense than the > compiler turning a series of volatile accesses into a memset. I have also tried adding volatile to all the members of that struct. :( -- Regards Sudip