From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-184.mta1.migadu.com (out-184.mta1.migadu.com [95.215.58.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D213244391 for ; Thu, 11 Apr 2024 18:00:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712858435; cv=none; b=KnfJ9U7OKZ4HuGQw1EkhN7CudSFVsd6wAfkdrb2n3sGJUGdEFgZOrb++yehsg+9nwBp8Z0OJ0LeTtpL7b/vNVVYB906LVbuPELZitHfDmqLt/a5WBainXmVcs57CShnGFRWeauvsZANLA2XaLqFl/iuozcbLz5WVKKNnCX+vT9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712858435; c=relaxed/simple; bh=yh/ixDQ5eg6OWrim9+bm1G6d/37CpJ1/QL+beESG4jw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=e1qv4dEQQciknKQEmsEKmtgfI/VtHoyUgj+Pc2ICdIW7uBMgNQCKHGfOCD6xgaKxJLheYRrltqwbbTHc7Q6UxBx//SOMxbrWavs9Nyonjov0uaJOgHtI+E+axiemAIsI8gY1octo21OcRtctBq4E+LVe2DoyTfXXd35olQkwZkM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=F6A8Ql6Y; arc=none smtp.client-ip=95.215.58.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="F6A8Ql6Y" Date: Thu, 11 Apr 2024 14:00:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712858430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hugd8ugKeGXlWiLmTwUcSwxtoNqEbzFWRyiumV4I0QI=; b=F6A8Ql6YjuHeVhFhvCjRCHtt6+j5Zmavb6rBRVS2UPMjaUzBr8Uy9YMXKrMLS6Bdu93QAe +1JDwGCXhSmYXVX/GYkUtjra2ilUH2ndkI9p7bCt0GDxnXoAiXvPRveKB1Tl7czCP5mSyl LwnxqSrFPBMBfyHHV7aQPCs6G/4zVIs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Kent Overstreet To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, Alexandre Ghiti , Andrew Morton , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Donald Dutile , Eric Chanudet , Heiko Carstens , Helge Deller , Huacai Chen , Luis Chamberlain , Mark Rutland , Michael Ellerman , Nadav Amit , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arch@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, x86@kernel.org Subject: Re: [PATCH v4 00/15] mm: jit/text allocator Message-ID: References: <20240411160051.2093261-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240411160051.2093261-1-rppt@kernel.org> X-Migadu-Flow: FLOW_OUT On Thu, Apr 11, 2024 at 07:00:36PM +0300, Mike Rapoport wrote: > From: "Mike Rapoport (IBM)" > > Hi, > > Since v3 I looked into making execmem more of an utility toolbox, as we > discussed at LPC with Mark Rutland, but it was getting more hairier than > having a struct describing architecture constraints and a type identifying > the consumer of execmem. > > And I do think that having the description of architecture constraints for > allocations of executable memory in a single place is better that having it > spread all over the place. > > The patches available via git: > https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=execmem/v4 > > v4 changes: > * rebase on v6.9-rc2 > * rename execmem_params to execmem_info and execmem_arch_params() to > execmem_arch_setup() > * use single execmem_alloc() API instead of execmem_{text,data}_alloc() (Song) > * avoid extra copy of execmem parameters (Rick) > * run execmem_init() as core_initcall() except for the architectures that > may allocated text really early (currently only x86) (Will) > * add acks for some of arm64 and riscv changes, thanks Will and Alexandre > * new commits: > - drop call to kasan_alloc_module_shadow() on arm64 because it's not > needed anymore > - rename MODULE_START to MODULES_VADDR on MIPS > - use CONFIG_EXECMEM instead of CONFIG_MODULES on powerpc as per Christophe: > https://lore.kernel.org/all/79062fa3-3402-47b3-8920-9231ad05e964@csgroup.eu/ > > v3: https://lore.kernel.org/all/20230918072955.2507221-1-rppt@kernel.org > * add type parameter to execmem allocation APIs > * remove BPF dependency on modules > > v2: https://lore.kernel.org/all/20230616085038.4121892-1-rppt@kernel.org > * Separate "module" and "others" allocations with execmem_text_alloc() > and jit_text_alloc() > * Drop ROX entailment on x86 > * Add ack for nios2 changes, thanks Dinh Nguyen > > v1: https://lore.kernel.org/all/20230601101257.530867-1-rppt@kernel.org > > = Cover letter from v1 (sligtly updated) = > > module_alloc() is used everywhere as a mean to allocate memory for code. > > Beside being semantically wrong, this unnecessarily ties all subsystmes > 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. > > A centralized infrastructure for code allocation allows allocations of > executable memory as ROX, and future optimizations such as caching large > pages for better iTLB performance and providing sub-page allocations for > users that only need small jit code snippets. > > Rick Edgecombe proposed perm_alloc extension to vmalloc [1] and Song Liu > proposed execmem_alloc [2], but both these approaches were targeting BPF > allocations and lacked the ground work to abstract executable allocations > and split them from the modules core. > > Thomas Gleixner suggested to express module allocation restrictions and > requirements as struct mod_alloc_type_params [3] that would define ranges, > protections and other parameters for different types of allocations used by > modules and following that suggestion Song separated allocations of > different types in modules (commit ac3b43283923 ("module: replace > module_layout with module_memory")) and posted "Type aware module > allocator" set [4]. > > I liked the idea of parametrising code allocation requirements as a > structure, but I believe the original proposal and Song's module allocator > was too module centric, so I came up with these patches. > > This set splits code allocation from modules by introducing execmem_alloc() > and and execmem_free(), APIs, replaces call sites of module_alloc() and > module_memfree() with the new APIs and implements core text and related > allocations in a central place. > > Instead of architecture specific overrides for module_alloc(), the > architectures that require non-default behaviour for text allocation must > fill execmem_info structure and implement execmem_arch_setup() that returns > a pointer to that structure. If an architecture does not implement > execmem_arch_setup(), the defaults compatible with the current > modules::module_alloc() are used. > > Since architectures define different restrictions on placement, > permissions, alignment and other parameters for memory that can be used by > different subsystems that allocate executable memory, execmem APIs > take a type argument, that will be used to identify the calling subsystem > and to allow architectures to define parameters for ranges suitable for that > subsystem. > > The new infrastructure allows decoupling of BPF, kprobes and ftrace from > modules, and most importantly it paves the way for ROX allocations for > executable memory. It looks like you're just doing API cleanup first, then improving the implementation later? Patch set looks nice and clean; previous versions did seem to leak too much arch/module details (or perhaps we were just bikeshedding too much ;) - but the API first approach is nice. Looking forward to seeing this merged. 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 82F09C001CC for ; Thu, 11 Apr 2024 18:00:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=SNZ8K0RuD+QSEE7QG3GV3tpYoARThB1mudVGqxlKGQg=; b=LzjwgxkSaBLQiE UOJTLlZ3YjGMbCyDyrA7x/cacwNgN1RA9rAhGfVX8Ox6UvfQ3sikH/I4t4aTKBdAFAbk4Io33crYf 9lH42nScnOJmjSVFb4dixJPqSKm4A22fqez37Fto1NZY+Ru8NzZnxLgUnyej2Trg5fN+pA+08dDZG RgiQkNuAP+cmpO1L55fvRBwSokMsFazfLzdMGNF1Tr1cTYDOlCMvCVvZRotPXvT8SDPh6d8YLx+Er df8Um9QiaQGHhbiR3iQ27xPQdEDTyH/6xEtTwe7CAS/mMwpkRqoJWlN+jCzwnEMgv3wZDZ/9wlkYb hskNLBTbiDPMrjPut60g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1ruyj2-0000000DXZq-3on6; Thu, 11 Apr 2024 18:00:40 +0000 Received: from out-177.mta1.migadu.com ([2001:41d0:203:375::b1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1ruyiv-0000000DXUA-30RW for linux-riscv@lists.infradead.org; Thu, 11 Apr 2024 18:00:36 +0000 Date: Thu, 11 Apr 2024 14:00:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712858430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hugd8ugKeGXlWiLmTwUcSwxtoNqEbzFWRyiumV4I0QI=; b=F6A8Ql6YjuHeVhFhvCjRCHtt6+j5Zmavb6rBRVS2UPMjaUzBr8Uy9YMXKrMLS6Bdu93QAe +1JDwGCXhSmYXVX/GYkUtjra2ilUH2ndkI9p7bCt0GDxnXoAiXvPRveKB1Tl7czCP5mSyl LwnxqSrFPBMBfyHHV7aQPCs6G/4zVIs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Kent Overstreet To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, Alexandre Ghiti , Andrew Morton , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Donald Dutile , Eric Chanudet , Heiko Carstens , Helge Deller , Huacai Chen , Luis Chamberlain , Mark Rutland , Michael Ellerman , Nadav Amit , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arch@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, x86@kernel.org Subject: Re: [PATCH v4 00/15] mm: jit/text allocator Message-ID: References: <20240411160051.2093261-1-rppt@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240411160051.2093261-1-rppt@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240411_110034_166732_0013B8B2 X-CRM114-Status: GOOD ( 31.14 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, Apr 11, 2024 at 07:00:36PM +0300, Mike Rapoport wrote: > From: "Mike Rapoport (IBM)" > > Hi, > > Since v3 I looked into making execmem more of an utility toolbox, as we > discussed at LPC with Mark Rutland, but it was getting more hairier than > having a struct describing architecture constraints and a type identifying > the consumer of execmem. > > And I do think that having the description of architecture constraints for > allocations of executable memory in a single place is better that having it > spread all over the place. > > The patches available via git: > https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=execmem/v4 > > v4 changes: > * rebase on v6.9-rc2 > * rename execmem_params to execmem_info and execmem_arch_params() to > execmem_arch_setup() > * use single execmem_alloc() API instead of execmem_{text,data}_alloc() (Song) > * avoid extra copy of execmem parameters (Rick) > * run execmem_init() as core_initcall() except for the architectures that > may allocated text really early (currently only x86) (Will) > * add acks for some of arm64 and riscv changes, thanks Will and Alexandre > * new commits: > - drop call to kasan_alloc_module_shadow() on arm64 because it's not > needed anymore > - rename MODULE_START to MODULES_VADDR on MIPS > - use CONFIG_EXECMEM instead of CONFIG_MODULES on powerpc as per Christophe: > https://lore.kernel.org/all/79062fa3-3402-47b3-8920-9231ad05e964@csgroup.eu/ > > v3: https://lore.kernel.org/all/20230918072955.2507221-1-rppt@kernel.org > * add type parameter to execmem allocation APIs > * remove BPF dependency on modules > > v2: https://lore.kernel.org/all/20230616085038.4121892-1-rppt@kernel.org > * Separate "module" and "others" allocations with execmem_text_alloc() > and jit_text_alloc() > * Drop ROX entailment on x86 > * Add ack for nios2 changes, thanks Dinh Nguyen > > v1: https://lore.kernel.org/all/20230601101257.530867-1-rppt@kernel.org > > = Cover letter from v1 (sligtly updated) = > > module_alloc() is used everywhere as a mean to allocate memory for code. > > Beside being semantically wrong, this unnecessarily ties all subsystmes > 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. > > A centralized infrastructure for code allocation allows allocations of > executable memory as ROX, and future optimizations such as caching large > pages for better iTLB performance and providing sub-page allocations for > users that only need small jit code snippets. > > Rick Edgecombe proposed perm_alloc extension to vmalloc [1] and Song Liu > proposed execmem_alloc [2], but both these approaches were targeting BPF > allocations and lacked the ground work to abstract executable allocations > and split them from the modules core. > > Thomas Gleixner suggested to express module allocation restrictions and > requirements as struct mod_alloc_type_params [3] that would define ranges, > protections and other parameters for different types of allocations used by > modules and following that suggestion Song separated allocations of > different types in modules (commit ac3b43283923 ("module: replace > module_layout with module_memory")) and posted "Type aware module > allocator" set [4]. > > I liked the idea of parametrising code allocation requirements as a > structure, but I believe the original proposal and Song's module allocator > was too module centric, so I came up with these patches. > > This set splits code allocation from modules by introducing execmem_alloc() > and and execmem_free(), APIs, replaces call sites of module_alloc() and > module_memfree() with the new APIs and implements core text and related > allocations in a central place. > > Instead of architecture specific overrides for module_alloc(), the > architectures that require non-default behaviour for text allocation must > fill execmem_info structure and implement execmem_arch_setup() that returns > a pointer to that structure. If an architecture does not implement > execmem_arch_setup(), the defaults compatible with the current > modules::module_alloc() are used. > > Since architectures define different restrictions on placement, > permissions, alignment and other parameters for memory that can be used by > different subsystems that allocate executable memory, execmem APIs > take a type argument, that will be used to identify the calling subsystem > and to allow architectures to define parameters for ranges suitable for that > subsystem. > > The new infrastructure allows decoupling of BPF, kprobes and ftrace from > modules, and most importantly it paves the way for ROX allocations for > executable memory. It looks like you're just doing API cleanup first, then improving the implementation later? Patch set looks nice and clean; previous versions did seem to leak too much arch/module details (or perhaps we were just bikeshedding too much ;) - but the API first approach is nice. Looking forward to seeing this merged. _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A1DD6C41513 for ; Thu, 11 Apr 2024 18:00:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9YTugmwhaf3afdva2aF7po0GK5HalVwyF7DS8fb8dL8=; b=qbXN5TvC8RixYk McXVWdTqmax8BsoQsfAPQtZGUaOzro30VDYTijsLWp9RUqSbPqZZOUtSLJlxLxpKVGsh6Gzchsqev uFSr0WF2r93eSlRyYwNJRvmMtClxOjvlaXJ1+6/3R39DEK+nez4euiGHhf1c49cF9SdThLcGGTeSL IUCZkzr8i91YfAHdJR/8c5o88a4wmW9rWBOqzWggSwYu6GcIgIC6ZEevpgHpdbYAT2WWPaSF40i68 ndTswj19Onu6s/MUmJdkLsVSd1pcKhQWJRQR/WNCLQGpNLsISp0Hv++oyQ+tZixeaPWLIOaeVmuBU S2vTIi2sncLXu9pnTHNw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1ruyj0-0000000DXYb-37cE; Thu, 11 Apr 2024 18:00:38 +0000 Received: from out-170.mta1.migadu.com ([95.215.58.170]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1ruyiv-0000000DXUB-35HL for linux-arm-kernel@lists.infradead.org; Thu, 11 Apr 2024 18:00:36 +0000 Date: Thu, 11 Apr 2024 14:00:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712858430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hugd8ugKeGXlWiLmTwUcSwxtoNqEbzFWRyiumV4I0QI=; b=F6A8Ql6YjuHeVhFhvCjRCHtt6+j5Zmavb6rBRVS2UPMjaUzBr8Uy9YMXKrMLS6Bdu93QAe +1JDwGCXhSmYXVX/GYkUtjra2ilUH2ndkI9p7bCt0GDxnXoAiXvPRveKB1Tl7czCP5mSyl LwnxqSrFPBMBfyHHV7aQPCs6G/4zVIs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Kent Overstreet To: Mike Rapoport Cc: linux-kernel@vger.kernel.org, Alexandre Ghiti , Andrew Morton , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Donald Dutile , Eric Chanudet , Heiko Carstens , Helge Deller , Huacai Chen , Luis Chamberlain , Mark Rutland , Michael Ellerman , Nadav Amit , Palmer Dabbelt , Puranjay Mohan , Rick Edgecombe , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arch@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, x86@kernel.org Subject: Re: [PATCH v4 00/15] mm: jit/text allocator Message-ID: References: <20240411160051.2093261-1-rppt@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240411160051.2093261-1-rppt@kernel.org> X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240411_110034_354308_4C10FCD3 X-CRM114-Status: GOOD ( 32.22 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Apr 11, 2024 at 07:00:36PM +0300, Mike Rapoport wrote: > From: "Mike Rapoport (IBM)" > > Hi, > > Since v3 I looked into making execmem more of an utility toolbox, as we > discussed at LPC with Mark Rutland, but it was getting more hairier than > having a struct describing architecture constraints and a type identifying > the consumer of execmem. > > And I do think that having the description of architecture constraints for > allocations of executable memory in a single place is better that having it > spread all over the place. > > The patches available via git: > https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=execmem/v4 > > v4 changes: > * rebase on v6.9-rc2 > * rename execmem_params to execmem_info and execmem_arch_params() to > execmem_arch_setup() > * use single execmem_alloc() API instead of execmem_{text,data}_alloc() (Song) > * avoid extra copy of execmem parameters (Rick) > * run execmem_init() as core_initcall() except for the architectures that > may allocated text really early (currently only x86) (Will) > * add acks for some of arm64 and riscv changes, thanks Will and Alexandre > * new commits: > - drop call to kasan_alloc_module_shadow() on arm64 because it's not > needed anymore > - rename MODULE_START to MODULES_VADDR on MIPS > - use CONFIG_EXECMEM instead of CONFIG_MODULES on powerpc as per Christophe: > https://lore.kernel.org/all/79062fa3-3402-47b3-8920-9231ad05e964@csgroup.eu/ > > v3: https://lore.kernel.org/all/20230918072955.2507221-1-rppt@kernel.org > * add type parameter to execmem allocation APIs > * remove BPF dependency on modules > > v2: https://lore.kernel.org/all/20230616085038.4121892-1-rppt@kernel.org > * Separate "module" and "others" allocations with execmem_text_alloc() > and jit_text_alloc() > * Drop ROX entailment on x86 > * Add ack for nios2 changes, thanks Dinh Nguyen > > v1: https://lore.kernel.org/all/20230601101257.530867-1-rppt@kernel.org > > = Cover letter from v1 (sligtly updated) = > > module_alloc() is used everywhere as a mean to allocate memory for code. > > Beside being semantically wrong, this unnecessarily ties all subsystmes > 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. > > A centralized infrastructure for code allocation allows allocations of > executable memory as ROX, and future optimizations such as caching large > pages for better iTLB performance and providing sub-page allocations for > users that only need small jit code snippets. > > Rick Edgecombe proposed perm_alloc extension to vmalloc [1] and Song Liu > proposed execmem_alloc [2], but both these approaches were targeting BPF > allocations and lacked the ground work to abstract executable allocations > and split them from the modules core. > > Thomas Gleixner suggested to express module allocation restrictions and > requirements as struct mod_alloc_type_params [3] that would define ranges, > protections and other parameters for different types of allocations used by > modules and following that suggestion Song separated allocations of > different types in modules (commit ac3b43283923 ("module: replace > module_layout with module_memory")) and posted "Type aware module > allocator" set [4]. > > I liked the idea of parametrising code allocation requirements as a > structure, but I believe the original proposal and Song's module allocator > was too module centric, so I came up with these patches. > > This set splits code allocation from modules by introducing execmem_alloc() > and and execmem_free(), APIs, replaces call sites of module_alloc() and > module_memfree() with the new APIs and implements core text and related > allocations in a central place. > > Instead of architecture specific overrides for module_alloc(), the > architectures that require non-default behaviour for text allocation must > fill execmem_info structure and implement execmem_arch_setup() that returns > a pointer to that structure. If an architecture does not implement > execmem_arch_setup(), the defaults compatible with the current > modules::module_alloc() are used. > > Since architectures define different restrictions on placement, > permissions, alignment and other parameters for memory that can be used by > different subsystems that allocate executable memory, execmem APIs > take a type argument, that will be used to identify the calling subsystem > and to allow architectures to define parameters for ranges suitable for that > subsystem. > > The new infrastructure allows decoupling of BPF, kprobes and ftrace from > modules, and most importantly it paves the way for ROX allocations for > executable memory. It looks like you're just doing API cleanup first, then improving the implementation later? Patch set looks nice and clean; previous versions did seem to leak too much arch/module details (or perhaps we were just bikeshedding too much ;) - but the API first approach is nice. Looking forward to seeing this merged. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 A7BDCC001CC for ; Thu, 11 Apr 2024 18:07:41 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=F6A8Ql6Y; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4VFnjS2J4Jz3vcW for ; Fri, 12 Apr 2024 04:07:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=F6A8Ql6Y; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=2001:41d0:203:375::b2; helo=out-178.mta1.migadu.com; envelope-from=kent.overstreet@linux.dev; receiver=lists.ozlabs.org) X-Greylist: delayed 357 seconds by postgrey-1.37 at boromir; Fri, 12 Apr 2024 04:06:53 AEST Received: from out-178.mta1.migadu.com (out-178.mta1.migadu.com [IPv6:2001:41d0:203:375::b2]) (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 4VFnhY1hlBz3d2c for ; Fri, 12 Apr 2024 04:06:52 +1000 (AEST) Date: Thu, 11 Apr 2024 14:00:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712858430; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hugd8ugKeGXlWiLmTwUcSwxtoNqEbzFWRyiumV4I0QI=; b=F6A8Ql6YjuHeVhFhvCjRCHtt6+j5Zmavb6rBRVS2UPMjaUzBr8Uy9YMXKrMLS6Bdu93QAe +1JDwGCXhSmYXVX/GYkUtjra2ilUH2ndkI9p7bCt0GDxnXoAiXvPRveKB1Tl7czCP5mSyl LwnxqSrFPBMBfyHHV7aQPCs6G/4zVIs= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Kent Overstreet To: Mike Rapoport Subject: Re: [PATCH v4 00/15] mm: jit/text allocator Message-ID: References: <20240411160051.2093261-1-rppt@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240411160051.2093261-1-rppt@kernel.org> X-Migadu-Flow: FLOW_OUT 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 , x86@kernel.org, Catalin Marinas , linux-mips@vger.kernel.org, Song Liu , Donald Dutile , Luis Chamberlain , sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Nadav Amit , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Helge Deller , Huacai Chen , Russell King , linux-trace-kernel@vger.kernel.org, Alexandre Ghiti , 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, linux-kernel@vger.kernel.org, Dinh Nguyen , =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= , Eric Chanudet , Palmer Dabbelt , Andrew Morton , Rick 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 Thu, Apr 11, 2024 at 07:00:36PM +0300, Mike Rapoport wrote: > From: "Mike Rapoport (IBM)" > > Hi, > > Since v3 I looked into making execmem more of an utility toolbox, as we > discussed at LPC with Mark Rutland, but it was getting more hairier than > having a struct describing architecture constraints and a type identifying > the consumer of execmem. > > And I do think that having the description of architecture constraints for > allocations of executable memory in a single place is better that having it > spread all over the place. > > The patches available via git: > https://git.kernel.org/pub/scm/linux/kernel/git/rppt/linux.git/log/?h=execmem/v4 > > v4 changes: > * rebase on v6.9-rc2 > * rename execmem_params to execmem_info and execmem_arch_params() to > execmem_arch_setup() > * use single execmem_alloc() API instead of execmem_{text,data}_alloc() (Song) > * avoid extra copy of execmem parameters (Rick) > * run execmem_init() as core_initcall() except for the architectures that > may allocated text really early (currently only x86) (Will) > * add acks for some of arm64 and riscv changes, thanks Will and Alexandre > * new commits: > - drop call to kasan_alloc_module_shadow() on arm64 because it's not > needed anymore > - rename MODULE_START to MODULES_VADDR on MIPS > - use CONFIG_EXECMEM instead of CONFIG_MODULES on powerpc as per Christophe: > https://lore.kernel.org/all/79062fa3-3402-47b3-8920-9231ad05e964@csgroup.eu/ > > v3: https://lore.kernel.org/all/20230918072955.2507221-1-rppt@kernel.org > * add type parameter to execmem allocation APIs > * remove BPF dependency on modules > > v2: https://lore.kernel.org/all/20230616085038.4121892-1-rppt@kernel.org > * Separate "module" and "others" allocations with execmem_text_alloc() > and jit_text_alloc() > * Drop ROX entailment on x86 > * Add ack for nios2 changes, thanks Dinh Nguyen > > v1: https://lore.kernel.org/all/20230601101257.530867-1-rppt@kernel.org > > = Cover letter from v1 (sligtly updated) = > > module_alloc() is used everywhere as a mean to allocate memory for code. > > Beside being semantically wrong, this unnecessarily ties all subsystmes > 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. > > A centralized infrastructure for code allocation allows allocations of > executable memory as ROX, and future optimizations such as caching large > pages for better iTLB performance and providing sub-page allocations for > users that only need small jit code snippets. > > Rick Edgecombe proposed perm_alloc extension to vmalloc [1] and Song Liu > proposed execmem_alloc [2], but both these approaches were targeting BPF > allocations and lacked the ground work to abstract executable allocations > and split them from the modules core. > > Thomas Gleixner suggested to express module allocation restrictions and > requirements as struct mod_alloc_type_params [3] that would define ranges, > protections and other parameters for different types of allocations used by > modules and following that suggestion Song separated allocations of > different types in modules (commit ac3b43283923 ("module: replace > module_layout with module_memory")) and posted "Type aware module > allocator" set [4]. > > I liked the idea of parametrising code allocation requirements as a > structure, but I believe the original proposal and Song's module allocator > was too module centric, so I came up with these patches. > > This set splits code allocation from modules by introducing execmem_alloc() > and and execmem_free(), APIs, replaces call sites of module_alloc() and > module_memfree() with the new APIs and implements core text and related > allocations in a central place. > > Instead of architecture specific overrides for module_alloc(), the > architectures that require non-default behaviour for text allocation must > fill execmem_info structure and implement execmem_arch_setup() that returns > a pointer to that structure. If an architecture does not implement > execmem_arch_setup(), the defaults compatible with the current > modules::module_alloc() are used. > > Since architectures define different restrictions on placement, > permissions, alignment and other parameters for memory that can be used by > different subsystems that allocate executable memory, execmem APIs > take a type argument, that will be used to identify the calling subsystem > and to allow architectures to define parameters for ranges suitable for that > subsystem. > > The new infrastructure allows decoupling of BPF, kprobes and ftrace from > modules, and most importantly it paves the way for ROX allocations for > executable memory. It looks like you're just doing API cleanup first, then improving the implementation later? Patch set looks nice and clean; previous versions did seem to leak too much arch/module details (or perhaps we were just bikeshedding too much ;) - but the API first approach is nice. Looking forward to seeing this merged.