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[2620:137:e000::1:20]) by mx.google.com with ESMTP id b13-20020a170902d50d00b001a6dc4ab8f3si23321564plg.574.2023.05.17.08.50.36; Wed, 17 May 2023 08:50:54 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=S8yqKPip; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231146AbjEQPon (ORCPT + 99 others); Wed, 17 May 2023 11:44:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43630 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231464AbjEQPoa (ORCPT ); Wed, 17 May 2023 11:44:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E441558B; Wed, 17 May 2023 08:44:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0BD1D63860; Wed, 17 May 2023 15:44:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4798C433EF; Wed, 17 May 2023 15:44:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684338266; bh=CWH2pztIOxMe+ekz7FPDOiiqxPpYYmkV6Bjtj8FaKhc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S8yqKPipt+vunH2g5aUufq37y/MGQZ4ijZGLIT3VzuwM9BzjnhxDZz471LRMl4jXD 8ZpG4eUF8dr8JxX99DI1OaxcFhorHnv4oWxGM8C8TNz9Fdj9vKgsX/TwvEN1MroAoJ sNc5C9I5qJDT5Mzh5bqUw499jLFaYAM67otU1Bl62J8WQfsEImW4sZ0PYuVoQVN+1Z fgRDJMMz1IYy7a9GV87WnXxyv7DjvDLCrZF7P7iLTGM6yCCrNObF2i1vrxco+JfEXT B2rZ417mW+tSWt7xZKCkfHnT8h7lmnqNksSLOUczAdTmQY5MAX60pTJGirG3bNKM2r WDdi6PFoLVdRw== Date: Wed, 17 May 2023 18:44:12 +0300 From: Mike Rapoport To: Kent Overstreet Cc: Matthew Wilcox , Kees Cook , Johannes Thumshirn , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-bcachefs@vger.kernel.org" , Kent Overstreet , Andrew Morton , Uladzislau Rezki , "hch@infradead.org" , "linux-mm@kvack.org" , "linux-hardening@vger.kernel.org" , song@kernel.org Subject: Re: [PATCH 07/32] mm: Bring back vmalloc_exec Message-ID: <20230517154412.GC4967@kernel.org> References: <20230509165657.1735798-8-kent.overstreet@linux.dev> <3508afc0-6f03-a971-e716-999a7373951f@wdc.com> <202305111525.67001E5C4@keescook> <202305161401.F1E3ACFAC@keescook> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 17, 2023 at 10:18:11AM -0400, Kent Overstreet wrote: > On Wed, May 17, 2023 at 05:04:27PM +0300, Mike Rapoport wrote: > > And I'm really curious why text_poke() is needed at all. Seems like we > could just use kmap_local() to create a temporary writeable mapping, On 64 bit kmap_local_page() is aliased to page_address() and does not map anything. text_poke() is needed to actually create a temporary writable mapping without touching page tables in vmalloc and/or direct map. -- Sincerely yours, Mike.