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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B03CDC433EF for ; Sun, 17 Jul 2022 20:39:33 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4LmH5H6zHPz3c93 for ; Mon, 18 Jul 2022 06:39:31 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Y2tgy3kJ; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::b2d; helo=mail-yb1-xb2d.google.com; envelope-from=sudipm.mukherjee@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=Y2tgy3kJ; dkim-atps=neutral Received: from mail-yb1-xb2d.google.com (mail-yb1-xb2d.google.com [IPv6:2607:f8b0:4864:20::b2d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4LmH4c2THMz305d for ; Mon, 18 Jul 2022 06:38:55 +1000 (AEST) Received: by mail-yb1-xb2d.google.com with SMTP id l11so17748199ybu.13 for ; Sun, 17 Jul 2022 13:38:55 -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=jRxhZtpGWX45c3sUo0GKmyVq3rfxOaQ8w1c016yR7KKWOhrJw2t8d6aUQtE42z+Rxm RveKztJihZnRcTAduqNqoN35Dbxsgh5KkmWKBkWlVjXHvbn28zgqRPkuvTxpINutI975 +kI/pW8I8LNvRhU0kxJV+tJTh3EfbDsWDG2w89Zpwf3MRnYHXjcD3M9t4xil29LIAuZY xd76leQg1IVX+e9E08qQSemyedhJAS6hygDhwXDSPYwdMD6tfMyYZK3nmPYvV/yIwUrl iyOyAx4sQV3RtGfxgwZNwEfCGxO1IeJAk/vJ5QMGYJiONs1oWwOetEpeinT/fVvVCPbG VHVQ== X-Gm-Message-State: AJIora8g+dbjSk1Ae5tqSkehuXjASZYAPHDyS1uYb/hjuTBmx5eKogIU 0/UO/qNcrc5L8UaKeeDfGUpEH6wqCZh75snblUU= 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 Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kees Cook , linux-kernel , Paul Mackerras , linux-hardening@vger.kernel.org, linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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