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 766B5EB64DB for ; Sat, 17 Jun 2023 20:38:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229816AbjFQUi4 (ORCPT ); Sat, 17 Jun 2023 16:38:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346515AbjFQUiz (ORCPT ); Sat, 17 Jun 2023 16:38:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92DFAE68; Sat, 17 Jun 2023 13:38:54 -0700 (PDT) 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 289A4612EC; Sat, 17 Jun 2023 20:38:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FD68C433C9; Sat, 17 Jun 2023 20:38:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687034333; bh=WVP/rhexoYDXJAhdCS8+aXf4gLUVAzDkioEZAL3bkuY=; h=In-Reply-To:References:Date:From:To:Cc:Subject:From; b=JKzE4z2tSEoLkc7ndZWnN4X7rPbZEhhlfrZyLWi07NSuE063OnjnC6kfUU9bDE7Q9 dYA+ZpDXUBD2TgjoWFjLAe+1VQ5WrMEQP2Oc9RGbVW9Wm4fut1k9el1xGXrGAH5XMV Vnj1FFJmE2x7cDhuvv0urvwR7eE2IJsG6wxHbKmZVXtzDiEbQttYBzKZysC9OE/47n JBkqqNwFgve/J61DF6GlrPrdaUiX2HWbrE8tfOts8C1LTzC7qOduTMdCt7JxlC8PRU FJrqMxXtr7sBOMLN0/Tey+NujGr9peRqjts6e1zOlWFY5KMatDCGIXdhGrkirNWaIE ASCBN9CMJq/6w== Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailauth.nyi.internal (Postfix) with ESMTP id 4D15627C005B; Sat, 17 Jun 2023 16:38:51 -0400 (EDT) Received: from imap48 ([10.202.2.98]) by compute3.internal (MEProxy); Sat, 17 Jun 2023 16:38:51 -0400 X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgedvjedgudehudcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefofgggkfgjfhffhffvvefutgesthdtredtreertdenucfhrhhomhepfdet nhguhicunfhuthhomhhirhhskhhifdcuoehluhhtoheskhgvrhhnvghlrdhorhhgqeenuc ggtffrrghtthgvrhhnpeevfffgvefhieetudeuteegvedvveduveetfeevffduieevfedu tdeliedtledugfenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecuvehluhhsthgvrh fuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomheprghnugihodhmvghsmhhtphgr uhhthhhpvghrshhonhgrlhhithihqdduudeiudekheeifedvqddvieefudeiiedtkedqlh huthhopeepkhgvrhhnvghlrdhorhhgsehlihhnuhigrdhluhhtohdruhhs X-ME-Proxy: Feedback-ID: ieff94742:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id E1AA531A0063; Sat, 17 Jun 2023 16:38:49 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.9.0-alpha0-496-g8c46984af0-fm-20230615.001-g8c46984a Mime-Version: 1.0 Message-Id: In-Reply-To: <20230616085038.4121892-3-rppt@kernel.org> References: <20230616085038.4121892-1-rppt@kernel.org> <20230616085038.4121892-3-rppt@kernel.org> Date: Sat, 17 Jun 2023 13:38:29 -0700 From: "Andy Lutomirski" To: "Mike Rapoport" , "Linux Kernel Mailing List" Cc: "Andrew Morton" , "Catalin Marinas" , "Christophe Leroy" , "David S. Miller" , "Dinh Nguyen" , "Heiko Carstens" , "Helge Deller" , "Huacai Chen" , "Kent Overstreet" , "Luis Chamberlain" , "Mark Rutland" , "Michael Ellerman" , "Nadav Amit" , "Naveen N. Rao" , "Palmer Dabbelt" , "Puranjay Mohan" , "Rick P Edgecombe" , "Russell King (Oracle)" , "Song Liu" , "Steven Rostedt" , "Thomas Bogendoerfer" , "Thomas Gleixner" , "Will Deacon" , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, "the arch/x86 maintainers" Subject: Re: [PATCH v2 02/12] mm: introduce execmem_text_alloc() and jit_text_alloc() Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org 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: https://lore.kernel.org/linux-fsdevel/cb6533c6-cea0-4f04-95cf-b8240c6ab405@app.fastmail.com/T/#u