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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29309C71150 for ; Wed, 28 Aug 2024 21:40:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AE1E66B008C; Wed, 28 Aug 2024 17:40:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A91316B0092; Wed, 28 Aug 2024 17:40:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 90B4A6B0093; Wed, 28 Aug 2024 17:40:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 688B26B008C for ; Wed, 28 Aug 2024 17:40:05 -0400 (EDT) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id E83F61407D4 for ; Wed, 28 Aug 2024 21:40:04 +0000 (UTC) X-FDA: 82502972328.17.A65D36E Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) by imf19.hostedemail.com (Postfix) with ESMTP id E2EAD1A000B for ; Wed, 28 Aug 2024 21:40:01 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=q4Wp6yjU; dmarc=none; spf=pass (imf19.hostedemail.com: domain of charlie@rivosinc.com designates 209.85.210.177 as permitted sender) smtp.mailfrom=charlie@rivosinc.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1724881103; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=XeNJBfO0ja/8g6kzTOhNFElQs2waKVPJgdUV/DsW4nc=; b=emCoskxVysJxfd1QWgBbc/tBnD52zPTDSOY4uTlpUMl4ykwml9XU5dMlPMKSn8PydQiqdl rMjvC2JH07GG0x/ly1wOFRtBWvpOo84qCifDK8uaInQlqTjVKssKybXiOE4TU33BjXHZ/g StHJkKl0rhj7aY1WMsel/O8m8p/lEWo= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1724881103; a=rsa-sha256; cv=none; b=VbY0lx8u5Y211GdWmE/BcKQhsGPZP8MJZ0+nyfMEVheXGRCD4KlvzT0gfj3Gnbu5Xjirlm HMNHsrrBp4pZLLGxsRPvKSsWZtiZqet7E3aSMW7Q2EUNH7ny3vr9ICGe6mlLW7Nfp3nCkB 5UyErVEk/Lf4d6fTFgsOQw2PnbeZb2E= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=q4Wp6yjU; dmarc=none; spf=pass (imf19.hostedemail.com: domain of charlie@rivosinc.com designates 209.85.210.177 as permitted sender) smtp.mailfrom=charlie@rivosinc.com Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-714186ce2f2so12285b3a.0 for ; Wed, 28 Aug 2024 14:40:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1724881200; x=1725486000; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=XeNJBfO0ja/8g6kzTOhNFElQs2waKVPJgdUV/DsW4nc=; b=q4Wp6yjUEsR/FqXH/FbIF+Az3dzrMzoMDZVvnmD2xK4YAmT/4XeVmxubeZKSBLzQI/ 7ccRO1Rc26oBsR+1GcPm34NcmW7NvfxBonwKL9Cww4DA2pzJv473c+iDKLqFRbl1rlCo BviaC3fr9k1MWrDEiDtYgbCleJnQdJynr5YXl3E70oF3bZeIzUHymGOUdw3TQHSEduor KrryHlsmSfm9C58Qrz+z6LEqBtfN2KR13bOtEPgpTfgbG7e/0/tOymNkkw1+S6WNNwI0 q5Ze6/kLyc1z1lWKG99UhP/FJWbBKxV1ncNVJAgSu+dH0cCB6XTSsd2y8m4VvlQeTPRn hq6g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724881200; x=1725486000; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=XeNJBfO0ja/8g6kzTOhNFElQs2waKVPJgdUV/DsW4nc=; b=R2EyCrpfWN924puMZxYKcz5tsgSCZ+bcTVdgDk7+Sz4d26f2K2cqXKfBXgneYAklbk JJq2VJRbQ90SkqSVPCR5/kkCM56fORpA3328QCcuKtnxFs3zAJNHnxeGnCSwnTebpete 53xji4wN9O5DDOJ+MGalkJ7QZjwLS8LzO2Tpz/3flqZvVe0wFlYTsdlf49SsEMH9ldMw nbrq1h3OujLnVSNFo7nRTIgYxuOHftafVdwD7Y1ea92R40xfbfjEsyHJDzcHq1UUKfN1 ImbOwFywqbFfmNGWA+acjvbU55SguJYhM42dr8jruTQTxLZgK/qjsm/rTwOAR4yxAXn8 3egw== X-Forwarded-Encrypted: i=1; AJvYcCWmtCZzAdd3D+/+DV0HL+Fjx0R7Qm46N230fQqF9BfpyhtDD/lUpyyaujSUKt5j9P811zCUeJfumg==@kvack.org X-Gm-Message-State: AOJu0YyNpcTo5Dcx3NQqStZ+KUpHys6UT6bbWqMroRxMxbdRcfeo6TE+ pHGiO+VVzcdSjoAiwVtrUgq98zKS3ZC3D4/aYZtPOglJWpvkyPTAh6gMu0ezODI= X-Google-Smtp-Source: AGHT+IFaC7yLAKucAQ+jfC2ojeS1SzrNuL0Qf0TeCvZ+3dsJBG9fozmVtsZvCPOeq6REFPvrFRD1LQ== X-Received: by 2002:a05:6a00:2e87:b0:714:2ba6:e5c9 with SMTP id d2e1a72fcca58-715dfaf1fddmr1045535b3a.7.1724881200137; Wed, 28 Aug 2024 14:40:00 -0700 (PDT) Received: from ghost ([50.145.13.30]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7cd9ac98286sm9939173a12.5.2024.08.28.14.39.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Aug 2024 14:39:59 -0700 (PDT) Date: Wed, 28 Aug 2024 14:39:55 -0700 From: Charlie Jenkins To: "Liam R. Howlett" Cc: Arnd Bergmann , Paul Walmsley , Palmer Dabbelt , Albert Ou , Catalin Marinas , Will Deacon , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Muchun Song , Andrew Morton , Vlastimil Babka , Lorenzo Stoakes , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Huacai Chen , WANG Xuerui , Russell King , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Yoshinori Sato , Rich Felker , John Paul Adrian Glaubitz , "David S. Miller" , Andreas Larsson , Shuah Khan , Alexandre Ghiti , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH 00/16] mm: Introduce MAP_BELOW_HINT Message-ID: References: <20240827-patches-below_hint_mmap-v1-0-46ff2eb9022d@rivosinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: E2EAD1A000B X-Stat-Signature: bfywhrj5qxawbi93q7sor3hxufcwuqrw X-Rspam-User: X-HE-Tag: 1724881201-338168 X-HE-Meta: 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 PaaGIK6h 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 xdSc9mto 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Aug 28, 2024 at 01:59:18PM -0700, Charlie Jenkins wrote: > On Wed, Aug 28, 2024 at 02:31:42PM -0400, Liam R. Howlett wrote: > > * Charlie Jenkins [240828 01:49]: > > > Some applications rely on placing data in free bits addresses allocated > > > by mmap. Various architectures (eg. x86, arm64, powerpc) restrict the > > > address returned by mmap to be less than the maximum address space, > > > unless the hint address is greater than this value. > > > > Wait, what arch(s) allows for greater than the max? The passed hint > > should be where we start searching, but we go to the lower limit then > > start at the hint and search up (or vice-versa on the directions). > > > > I worded this awkwardly. On arm64 there is a page-table boundary at 48 > bits and at 52 bits. On x86 the boundaries are at 48 bits and 57 bits. > The max value mmap is able to return on arm64 is 48 bits if the hint > address uses 48 bits or less, even if the architecture supports 5-level > paging and thus addresses can be 52 bits. Applications can opt-in to > using up to 52-bits in an address by using a hint address greater than > 48 bits. x86 has the same behavior but with 57 bits instead of 52. > > This reason this exists is because some applications arbitrarily replace > bits in virtual addresses with data with an assumption that the address > will not be using any of the bits above bit 48 in the virtual address. > As hardware with larger address spaces was released, x86 decided to > build safety guards into the kernel to allow the applications that made > these assumptions to continue to work on this different hardware. > > This causes all application that use a hint address to silently be > restricted to 48-bit addresses. The goal of this flag is to have a way > for applications to explicitly request how many bits they want mmap to > use. > > > I don't understand how unmapping works on a higher address; we would > > fail to free it on termination of the application. > > > > Also, there are archs that map outside of the VMAs, which are freed by > > freeing from the prev->vm_end to next->vm_start, so I don't understand > > what that looks like in this reality as well. > > > > > > > > On arm64 this barrier is at 52 bits and on x86 it is at 56 bits. This > > > flag allows applications a way to specify exactly how many bits they > > > want to be left unused by mmap. This eliminates the need for > > > applications to know the page table hierarchy of the system to be able > > > to reason which addresses mmap will be allowed to return. > > > > But, why do they need to know today? We have a limit for this don't we? > > The limit is different for different architectures. On x86 the limit is > 57 bits, and on arm64 it is 52 bits. So in the theoretical case that an > application requires 10 bits free in a virtual address, the application > would always work on arm64 regardless of the hint address, but on x86 if > the hint address is greater than 48 bits then the application will not > work. > > The goal of this flag is to have consistent and tunable behavior of > mmap() when it is desired to ensure that mmap() only returns addresses > that use some number of bits. > > > > > Also, these upper limits are how some archs use the upper bits that you > > are trying to use. > > > > It does not eliminate the existing behavior of the architectures to > place this upper limits, it instead provides a way to have consistent > behavior across all architectures. > > > > > > > --- > > > riscv made this feature of mmap returning addresses less than the hint > > > address the default behavior. This was in contrast to the implementation > > > of x86/arm64 that have a single boundary at the 5-level page table > > > region. However this restriction proved too great -- the reduced > > > address space when using a hint address was too small. > > > > Yes, the hint is used to group things close together so it would > > literally be random chance on if you have enough room or not (aslr and > > all). > > > > > > > > A patch for riscv [1] reverts the behavior that broke userspace. This > > > series serves to make this feature available to all architectures. > > > > I don't fully understand this statement, you say it broke userspace so > > now you are porting it to everyone? This reads as if you are braking > > the userspace on all architectures :) > > It was the default for mmap on riscv. The difference here is that it is now > enabled by a flag instead. Instead of making the flag specific to riscv, > I figured that other architectures might find it useful as well. > > > > > If you fail to find room below, then your application fails as there is > > no way to get the upper bits you need. It would be better to fix this > > in userspace - if your application is returned too high an address, then > > free it and exit because it's going to fail anyways. > > > > This flag is trying to define an API that is more robust than the > current behavior on that x86 and arm64 which implicitly restricts mmap() > addresses to 48 bits. A solution could be to just write in the docs that > mmap() will always exhaust all addresses below the hint address before > returning an address that is above the hint address. However a flag that > defines this behavior seems more intuitive. > > > > > > > I have only tested on riscv and x86. > > > > This should be an RFC then. > > Fair enough. > > > > > > There is a tremendous amount of > > > duplicated code in mmap so the implementations across architectures I > > > believe should be mostly consistent. I added this feature to all > > > architectures that implement either > > > arch_get_mmap_end()/arch_get_mmap_base() or > > > arch_get_unmapped_area_topdown()/arch_get_unmapped_area(). I also added > > > it to the default behavior for arch_get_mmap_end()/arch_get_mmap_base(). > > > > Way too much duplicate code. We should be figuring out how to make this > > all work with the same code. > > > > This is going to make the cloned code problem worse. > > That would require standardizing every architecture with the generic > mmap() framework that arm64 has developed. That is far outside the scope > of this patch, but would be a great area to research for each of the > architectures that do not use the generic framework. Thinking about this again, I could drop support for all architectures that do not implement arch_get_mmap_base()/arch_get_mmap_end(). > > - Charlie > > > > > > > > > Link: https://lore.kernel.org/lkml/20240826-riscv_mmap-v1-2-cd8962afe47f@rivosinc.com/T/ [1] > > > > > > To: Arnd Bergmann > > > To: Paul Walmsley > > > To: Palmer Dabbelt > > > To: Albert Ou > > > To: Catalin Marinas > > > To: Will Deacon > > > To: Michael Ellerman > > > To: Nicholas Piggin > > > To: Christophe Leroy > > > To: Naveen N Rao > > > To: Muchun Song > > > To: Andrew Morton > > > To: Liam R. Howlett > > > To: Vlastimil Babka > > > To: Lorenzo Stoakes > > > To: Thomas Gleixner > > > To: Ingo Molnar > > > To: Borislav Petkov > > > To: Dave Hansen > > > To: x86@kernel.org > > > To: H. Peter Anvin > > > To: Huacai Chen > > > To: WANG Xuerui > > > To: Russell King > > > To: Thomas Bogendoerfer > > > To: James E.J. Bottomley > > > To: Helge Deller > > > To: Alexander Gordeev > > > To: Gerald Schaefer > > > To: Heiko Carstens > > > To: Vasily Gorbik > > > To: Christian Borntraeger > > > To: Sven Schnelle > > > To: Yoshinori Sato > > > To: Rich Felker > > > To: John Paul Adrian Glaubitz > > > To: David S. Miller > > > To: Andreas Larsson > > > To: Shuah Khan > > > To: Alexandre Ghiti > > > Cc: linux-arch@vger.kernel.org > > > Cc: linux-kernel@vger.kernel.org > > > Cc: Palmer Dabbelt > > > Cc: linux-riscv@lists.infradead.org > > > Cc: linux-arm-kernel@lists.infradead.org > > > Cc: linuxppc-dev@lists.ozlabs.org > > > Cc: linux-mm@kvack.org > > > Cc: loongarch@lists.linux.dev > > > Cc: linux-mips@vger.kernel.org > > > Cc: linux-parisc@vger.kernel.org > > > Cc: linux-s390@vger.kernel.org > > > Cc: linux-sh@vger.kernel.org > > > Cc: sparclinux@vger.kernel.org > > > Cc: linux-kselftest@vger.kernel.org > > > Signed-off-by: Charlie Jenkins > > > > > > --- > > > Charlie Jenkins (16): > > > mm: Add MAP_BELOW_HINT > > > riscv: mm: Do not restrict mmap address based on hint > > > mm: Add flag and len param to arch_get_mmap_base() > > > mm: Add generic MAP_BELOW_HINT > > > riscv: mm: Support MAP_BELOW_HINT > > > arm64: mm: Support MAP_BELOW_HINT > > > powerpc: mm: Support MAP_BELOW_HINT > > > x86: mm: Support MAP_BELOW_HINT > > > loongarch: mm: Support MAP_BELOW_HINT > > > arm: mm: Support MAP_BELOW_HINT > > > mips: mm: Support MAP_BELOW_HINT > > > parisc: mm: Support MAP_BELOW_HINT > > > s390: mm: Support MAP_BELOW_HINT > > > sh: mm: Support MAP_BELOW_HINT > > > sparc: mm: Support MAP_BELOW_HINT > > > selftests/mm: Create MAP_BELOW_HINT test > > > > > > arch/arm/mm/mmap.c | 10 ++++++++ > > > arch/arm64/include/asm/processor.h | 34 ++++++++++++++++++++++---- > > > arch/loongarch/mm/mmap.c | 11 +++++++++ > > > arch/mips/mm/mmap.c | 9 +++++++ > > > arch/parisc/include/uapi/asm/mman.h | 1 + > > > arch/parisc/kernel/sys_parisc.c | 9 +++++++ > > > arch/powerpc/include/asm/task_size_64.h | 36 +++++++++++++++++++++++----- > > > arch/riscv/include/asm/processor.h | 32 ------------------------- > > > arch/s390/mm/mmap.c | 10 ++++++++ > > > arch/sh/mm/mmap.c | 10 ++++++++ > > > arch/sparc/kernel/sys_sparc_64.c | 8 +++++++ > > > arch/x86/kernel/sys_x86_64.c | 25 ++++++++++++++++--- > > > fs/hugetlbfs/inode.c | 2 +- > > > include/linux/sched/mm.h | 34 ++++++++++++++++++++++++-- > > > include/uapi/asm-generic/mman-common.h | 1 + > > > mm/mmap.c | 2 +- > > > tools/arch/parisc/include/uapi/asm/mman.h | 1 + > > > tools/include/uapi/asm-generic/mman-common.h | 1 + > > > tools/testing/selftests/mm/Makefile | 1 + > > > tools/testing/selftests/mm/map_below_hint.c | 29 ++++++++++++++++++++++ > > > 20 files changed, 216 insertions(+), 50 deletions(-) > > > --- > > > base-commit: 5be63fc19fcaa4c236b307420483578a56986a37 > > > change-id: 20240827-patches-below_hint_mmap-b13d79ae1c55 > > > -- > > > - Charlie > > >