Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp1672465yba; Thu, 9 May 2019 22:08:17 -0700 (PDT) X-Google-Smtp-Source: APXvYqwhNKoBlUXyQRS5eR6nSWwS3Y2qgLy5A66HzFPldJGdjxz31DXTYYTLOSIL4E5YDRtiSbs4 X-Received: by 2002:a63:295:: with SMTP id 143mr11110162pgc.279.1557464897741; Thu, 09 May 2019 22:08:17 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1557464897; cv=none; d=google.com; s=arc-20160816; b=lNN+KOpg7HaVYsn3fgDpQhRvM44rd5oN5xQfh+Pdm7p3BLIv7BDKW1i5VnXCiZq3x2 XItkU37+sYJYL2Ni+S5S5I+4Vwg6wCweo1P0F/Tccmd623Q+m+yHjR4EwqEOARPCniEK Bh56zvYwtf1npjrvyP47LmQ505roy2USPddQt+VHjmoeCdDA+T0D/qnVbmBfWmOGQIkG AccljMVbn4Hetzl3k4cF2haq8nN6sbnuxtGSh94ym3Bv25rEg8zseSF0OI6NNd6d79zO NG/0is6GFFE1nFhAcf70ajdeMs7cNNvstjrg+2dNc0gk5m7ibea1uioMnTEA31H687CJ eY2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=FjMDX6OXptCPbOEPZorERjXrFHT+sQLeZXg4fcoOVO4=; b=e4OJhZ5iT1zcihFlM2GfzIO1Fchv/kHQ7zv4El/oLiRHtwAydO/+SvOYw6xxsOyOyz YaCWpT+tB0lm4C7nKPRNq2m8izGHpVISJBgEs8k7cyq22J3aOijI9qn0uohmjMaUR9Sy SpidfcR6s8xYVaLRBw38G8UKbawzBXcinGiIg6+7slzm3Wz3Aj7fMXJxGCJ8IVRNYjEQ WgVx1R8Ug7PjFGFkh6t2YrOYVPkD/kju53G5SQHrSvSpBFfK7q2o9t0c1ByBTDomqtJl Dfn7NSCh9NAMHPbBrfCPy9WQnwhQh3MPHhIS/aysX/YQICyA+hkDfOIFlhgT2cncGTSX lRNg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=c0UMDkfB; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id y6si6875621pgq.374.2019.05.09.22.08.01; Thu, 09 May 2019 22:08:17 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=c0UMDkfB; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726984AbfEJFHP (ORCPT + 99 others); Fri, 10 May 2019 01:07:15 -0400 Received: from mail-pl1-f195.google.com ([209.85.214.195]:45334 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726587AbfEJFHO (ORCPT ); Fri, 10 May 2019 01:07:14 -0400 Received: by mail-pl1-f195.google.com with SMTP id a5so2226545pls.12; Thu, 09 May 2019 22:07:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=FjMDX6OXptCPbOEPZorERjXrFHT+sQLeZXg4fcoOVO4=; b=c0UMDkfB6tTjOuuL7w77f9bWKLRAazsReBhnmqpNGDM0k59e6X/kl3C4Pe6J9eHUen VFAkbAqGjUIJBx7hvW7Fh6dqtrYSHH9XX2PvuEVj32Jy9VNtfv95QPZNAgVJgPRL3BKO OyB6K6sIcnJOt80RK+9Kgdu4JyMQCO4sdI1JvFP7WzWDVWm7oHYsqPIL5NCA8RM1tJ12 ggKw4hwLADwL4j8sXY2gT6/wneNWSju7qCVIsYvNXQPH+QrW25KdR1AYG7U4Rz8in6rI qNWUTknwUpjjpgfRE8r4QpfQla/BLjPtT0IOYTbpCwB99LwTtNvLRfDE7OPzwXu3cz1B Lx1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=FjMDX6OXptCPbOEPZorERjXrFHT+sQLeZXg4fcoOVO4=; b=qP0NRHx+jxEvRyzVqhIgI8yrfGIw9S+AyBlNh6wYpKYOvQAkGiCRNOWtPUIEvl9Yz3 pDPrg5z4P6992n747ySDUd7zKsScagwK1PLzctMf6g0LUoJM0y/ehmrCa67P3IbSDspq p0X+fDRdju5GguLGKLJ0Y+I0IkHpWqSu5e6+rsHeQx5xyVfEbRyJw6Y9ersmj50DBkA+ qTgyWJVlP0Y+AZj+yWUKCATyO9xvtdl/vLyfOdRua+1efSLtRrVOOZuN0dY5criaXAg5 zHgdB4+fbG22Hbd9dSUxW9Li6zeyasWejB80NjnhBQ9eWouTemxtLZ/yYKo4zAgi+i+S x78g== X-Gm-Message-State: APjAAAVRjkQ4g/n489TF531osDJFiVkMdMixsQCctb6etXmiNbU8gqvf ZPtNBWsQYjT3PuuDvLZkw0g= X-Received: by 2002:a17:902:8c85:: with SMTP id t5mr10664151plo.23.1557464834204; Thu, 09 May 2019 22:07:14 -0700 (PDT) Received: from localhost ([39.7.15.25]) by smtp.gmail.com with ESMTPSA id d67sm5741186pfa.35.2019.05.09.22.07.12 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 09 May 2019 22:07:13 -0700 (PDT) Date: Fri, 10 May 2019 14:07:09 +0900 From: Sergey Senozhatsky To: Linus Torvalds Cc: Sergey Senozhatsky , Petr Mladek , Andy Shevchenko , Rasmus Villemoes , "Tobin C . Harding" , Michal Hocko , Sergey Senozhatsky , Steven Rostedt , linux-kernel@vger.kernel.org, Michael Ellerman , linuxppc-dev@lists.ozlabs.org, Russell Currey , Christophe Leroy , Stephen Rothwell , Heiko Carstens , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Martin Schwidefsky Subject: Re: [PATCH] vsprintf: Do not break early boot with probing addresses Message-ID: <20190510050709.GA1831@jagdpanzerIV> References: <20190509121923.8339-1-pmladek@suse.com> <20190510043200.GC15652@jagdpanzerIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (05/09/19 21:47), Linus Torvalds wrote: > [ Sorry about html and mobile crud, I'm not at the computer right now ] > How about we just undo the whole misguided probe_kernel_address() thing? But the problem will remain - %pS/%pF on PPC (and some other arch-s) do dereference_function_descriptor(), which calls probe_kernel_address(). So if probe_kernel_address() starts to dump_stack(), then we are heading towards stack overflow. Unless I'm totally missing something. -ss