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 B0327EB64D7 for ; Sun, 18 Jun 2023 08:02:12 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=sRSVsUz+; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QkQNM0sTsz30G1 for ; Sun, 18 Jun 2023 18:02:11 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=sRSVsUz+; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=2604:1380:4641:c500::1; helo=dfw.source.kernel.org; envelope-from=rppt@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) (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 4QkQMN0MHwz2xdn for ; Sun, 18 Jun 2023 18:01:19 +1000 (AEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id ADABC60F01; Sun, 18 Jun 2023 08:01:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DA1EC433C0; Sun, 18 Jun 2023 08:01:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687075275; bh=JOdF7gdXvqBjASqKs6SWBkQKDgB3N69nrNaZPukvaeM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sRSVsUz+8qwPDTD+DbQ8ZGj3oxWbs6Q2yclpQ5oA01FgfO3x99AMq57vy9vTmKGCz zxsNFAk2tsVXc2/ZMKN5WrqHKwwq7cFYa5f3HPOYIxlAVh8JcIK7E8a/4ukOQRZ4nx MkY7brx+YmsqJJOWjKI+esA6758vzynczNeZM28mb8D2036W2Ac3dVaBq4RYIRm2lO UwBKETxVcKwPW5jcSjXTb+3J9p7JSrJABXAw2lEoobsEXKewtbcSu8Iyl/ROefguVb JB6NowqZPjsvgPvrW3+OErG+qxYX7mjk/nhQmoo1FPg/indEYGUiochf7rWuDn85yN s8jpvUG70jw+A== Date: Sun, 18 Jun 2023 11:00:27 +0300 From: Mike Rapoport To: Andy Lutomirski Subject: Re: [PATCH v2 02/12] mm: introduce execmem_text_alloc() and jit_text_alloc() Message-ID: <20230618080027.GA52412@kernel.org> References: <20230616085038.4121892-1-rppt@kernel.org> <20230616085038.4121892-3-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: Mark Rutland , the arch/x86 maintainers , Catalin Marinas , linux-mips@vger.kernel.org, Song Liu , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Nadav Amit , linux-s390@vger.kernel.org, Helge Deller , Huacai Chen , "Russell King \(Oracle\)" , "Naveen N. Rao" , linux-trace-kernel@vger.kernel.org, Will Deacon , Heiko Carstens , Steven Rostedt , loongarch@lists.linux.dev, Thomas Gleixner , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Thomas Bogendoerfer , linux-parisc@vger.kernel.org, Puranjay Mohan , linux-mm@kvack.org, netdev@vger.kernel.org, Kent Overstreet , Linux Kernel Mailing List , Dinh Nguyen , Luis Chamberlain , Palmer Dabbelt , Andrew Morton , Rick P Edgecombe , linuxppc-dev@lists.ozlabs.org, "David S. Miller" , linux-modules@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sat, Jun 17, 2023 at 01:38:29PM -0700, Andy Lutomirski wrote: > On Fri, Jun 16, 2023, at 1:50 AM, Mike Rapoport wrote: > > From: "Mike Rapoport (IBM)" > > > > module_alloc() is used everywhere as a mean to allocate memory for code. > > > > Beside being semantically wrong, this unnecessarily ties all subsystems > > that need to allocate code, such as ftrace, kprobes and BPF to modules > > and puts the burden of code allocation to the modules code. > > > > Several architectures override module_alloc() because of various > > constraints where the executable memory can be located and this causes > > additional obstacles for improvements of code allocation. > > > > Start splitting code allocation from modules by introducing > > execmem_text_alloc(), execmem_free(), jit_text_alloc(), jit_free() APIs. > > > > Initially, execmem_text_alloc() and jit_text_alloc() are wrappers for > > module_alloc() and execmem_free() and jit_free() are replacements of > > module_memfree() to allow updating all call sites to use the new APIs. > > > > The intention semantics for new allocation APIs: > > > > * execmem_text_alloc() should be used to allocate memory that must reside > > close to the kernel image, like loadable kernel modules and generated > > code that is restricted by relative addressing. > > > > * jit_text_alloc() should be used to allocate memory for generated code > > when there are no restrictions for the code placement. For > > architectures that require that any code is within certain distance > > from the kernel image, jit_text_alloc() will be essentially aliased to > > execmem_text_alloc(). > > > > Is there anything in this series to help users do the appropriate > synchronization when the actually populate the allocated memory with > code? See here, for example: This series only factors out the executable allocations from modules and puts them in a central place. Anything else would go on top after this lands. > https://lore.kernel.org/linux-fsdevel/cb6533c6-cea0-4f04-95cf-b8240c6ab405@app.fastmail.com/T/#u -- Sincerely yours, Mike.