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 92748C02199 for ; Fri, 7 Feb 2025 23:44:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0A690280004; Fri, 7 Feb 2025 18:44:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 02EFB280001; Fri, 7 Feb 2025 18:44:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DC44F280004; Fri, 7 Feb 2025 18:44:34 -0500 (EST) 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 BDDB8280001 for ; Fri, 7 Feb 2025 18:44:34 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 1B1D280F31 for ; Fri, 7 Feb 2025 23:44:34 +0000 (UTC) X-FDA: 83094780468.18.ADF953A Received: from mail-pj1-f46.google.com (mail-pj1-f46.google.com [209.85.216.46]) by imf28.hostedemail.com (Postfix) with ESMTP id 1A4C6C0003 for ; Fri, 7 Feb 2025 23:44:31 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=XMJi4Q5g; spf=pass (imf28.hostedemail.com: domain of debug@rivosinc.com designates 209.85.216.46 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738971872; 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=sFQiCNrm30AFPGwQY6ts0jjT1ZeITQwhTZXh/92SdFM=; b=FtxXEQa1rOFrq0+gMc03ZKC6Yp8zG/QsO8Upajm/V4XCDC528zVYR3gSpi5HGfwfqdF958 GV+bwMRt6vJo/n5R7O5sAhJmvucGaXZ9IN19uRHdzN/YsQDuCfpg4UzX9Vt5XwASXTN9Ig FPx0r6AlLVl67caLZ50mnB1oZYPtBqs= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=rivosinc-com.20230601.gappssmtp.com header.s=20230601 header.b=XMJi4Q5g; spf=pass (imf28.hostedemail.com: domain of debug@rivosinc.com designates 209.85.216.46 as permitted sender) smtp.mailfrom=debug@rivosinc.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738971872; a=rsa-sha256; cv=none; b=aAXeciDgxSxycmPFDuuui+iVoVapZ1FDEN0mdUCrX6HaTSkke2K67B0xMWmWKNcM6xv0Yb 3ecUYsff+HsvflJrh9Ou+nS7gz2+13eNig4uLgHMpNgoUe3nqeT9roU7tdW+jzFJL3aFxO nAoYd/1L1TGp/y5qGJQf9AUwECIRwsQ= Received: by mail-pj1-f46.google.com with SMTP id 98e67ed59e1d1-2f9f5caa37cso5048982a91.0 for ; Fri, 07 Feb 2025 15:44:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1738971871; x=1739576671; 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=sFQiCNrm30AFPGwQY6ts0jjT1ZeITQwhTZXh/92SdFM=; b=XMJi4Q5grOiHenzN7vuLjoX3N2mglMeiIthYUdV/vhKYoGq5ZdhqKpgGdKp0nDSpQy SKYmdvyhY/g9G6p0XlqQxAWNi+ulBWWqKOpj8YKjBUoq+8xoHRk2Ar/MUgp5g1EOQjN+ uRb+E4eotpFxSRprHLx/BHwDQj559cxXCv4Zx6UtmlBM6FK+XTLWPRdex7sUOnEiiQ+r qqguypcEWv37SBkQFBRaOB81nkFSR5XZZgerHMogiYIvt5N/BodbDzxoqEhdoz5bD8z1 gGFs/LxBdVzTY6f5YynuKcODuDq0YPcLkXWivGs+N5bwFJvzw61Ia1xnbs1XSn6L19iU sOgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738971871; x=1739576671; 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=sFQiCNrm30AFPGwQY6ts0jjT1ZeITQwhTZXh/92SdFM=; b=oVJTbR1IZAeiDaG56nUvJzLUTiYWBVzZYBK4LTroCIr2i8yv0XQYUVbdiDH6gfTcrb tbiJq31N/82Lhv1Q1wiOcaS56PXTwiZpbNS2xgZqfBDKOkjKTjd7nHa0ZWgykeri2Qqh zYIUXhCeGWnj9Yc1CVrA1uwtZtWIlWWPrji64As4tCkY02TNxabj0PK+8rBnC/79oepj ALZWikI5aQIF/MjSWZ21TFu+bEaWurU8W5QhcCPB84IN8kt+U2aja8sRh6o2nDcWOTZc Shd+FxobN4eh0yAp0qV7q4FgnwyvbmB7XzO+Ph0VVJo5/6gNTNHTsk7j6iRY9I/h0Woy T0Rg== X-Forwarded-Encrypted: i=1; AJvYcCWOuURvpNV20veq09gbgcKElvryY3egkSBsD5bDcIVPQrN8L5UylNkAczxPPbIZHtkiUAO3kZHGow==@kvack.org X-Gm-Message-State: AOJu0YwQHDkGVuovWOei7ufxFeR9bflKWHve+udjEWJsxdqlComNsBzt iIVxywTQtTV7Wo0qc2DGDyMS4cLEYdGJi0thwDN5ZGBWda43UmN9OuTf0eUrICs= X-Gm-Gg: ASbGnct+XbnvgRxe1yJiMxwUdng0mv2Bx9v8Dz9afNrfP3s92JI1jzPxZLiA4FN1vW/ EzowGhnDyH2azBGESbvxPLA5gf34+WDkbSlo/hZcreS2O7c6M0VLE9yAFGas7C7HXMTVZJSyp+c 6A/j0hUwz2blTcodROsVgM0Mbleipc6qkg9i5wfh/AkJMFBCjTLfaXAZgB3RIp3L25QDVpFIQst 7qh2OlemXXLsjjElzbh0YODgREFRGDmpuB4Pp7y9qFVo4KOH+QtwogiTuboCtOYVJPGWGVddlZG ljJZx5M0rix2pz+DUPZbWNFiPA== X-Google-Smtp-Source: AGHT+IEu/BmgD+AgLAp2nKonkfG6/YX8d0cZZKASE/tVvqPiMWzUevWv2BoO4p6W9X0pvQWJ2zpYLw== X-Received: by 2002:a17:90b:380e:b0:2fa:2133:bc87 with SMTP id 98e67ed59e1d1-2fa2133bf2amr8657814a91.6.1738971870845; Fri, 07 Feb 2025 15:44:30 -0800 (PST) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21f3687d169sm36049505ad.202.2025.02.07.15.44.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Feb 2025 15:44:30 -0800 (PST) Date: Fri, 7 Feb 2025 15:44:27 -0800 From: Deepak Gupta To: Vlastimil Babka Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , "Liam R. Howlett" , Lorenzo Stoakes , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Arnd Bergmann , Christian Brauner , Peter Zijlstra , Oleg Nesterov , Eric Biederman , Kees Cook , Jonathan Corbet , Shuah Khan , Jann Horn , Conor Dooley , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, alistair.francis@wdc.com, richard.henderson@linaro.org, jim.shu@sifive.com, andybnac@gmail.com, kito.cheng@sifive.com, charlie@rivosinc.com, atishp@rivosinc.com, evan@rivosinc.com, cleger@rivosinc.com, alexghiti@rivosinc.com, samitolvanen@google.com, broonie@kernel.org, rick.p.edgecombe@intel.com Subject: Re: [PATCH v9 01/26] mm: helper `is_shadow_stack_vma` to check shadow stack vma Message-ID: References: <20250204-v5_user_cfi_series-v9-0-b37a49c5205c@rivosinc.com> <20250204-v5_user_cfi_series-v9-1-b37a49c5205c@rivosinc.com> <6543c6b6-da86-4c10-9b8c-e5fe6f6f7da9@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <6543c6b6-da86-4c10-9b8c-e5fe6f6f7da9@suse.cz> X-Rspamd-Queue-Id: 1A4C6C0003 X-Stat-Signature: p9ocfin8ui3nxh9b3j71wi4hjccxd33y X-Rspam-User: X-Rspamd-Server: rspam01 X-HE-Tag: 1738971871-461431 X-HE-Meta: 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 wCmDpUk3 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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 Fri, Feb 07, 2025 at 10:27:10AM +0100, Vlastimil Babka wrote: >On 2/5/25 02:21, Deepak Gupta wrote: >> VM_SHADOW_STACK (alias to VM_HIGH_ARCH_5) is used to encode shadow stack > >I see that arm GCS uses VM_HIGH_ARCH_6. > >> VMA on three architectures (x86 shadow stack, arm GCS and RISC-V shadow > >And RISC-V doesn't define it at all, not even in this patchset, or did I >miss it somewhere? > hmm... Something wrong in my workflow and rebasing. Thanks for catching this. >> stack). In case architecture doesn't implement shadow stack, it's VM_NONE >> Introducing a helper `is_shadow_stack_vma` to determine shadow stack vma >> or not. > >This looks like an unfinished sentence. As if it was to continue with "... >will allow us to ..." what? > >I'm not against a helper but this changelog is rather confusing and also >code in arch/x86 and arch/arm64 isn't converted to the helper but testing >VM_SHADOW_STACK still. > >> Signed-off-by: Deepak Gupta >> Reviewed-by: Mark Brown >> --- >> mm/gup.c | 2 +- >> mm/mmap.c | 2 +- >> mm/vma.h | 10 +++++++--- >> 3 files changed, 9 insertions(+), 5 deletions(-) >> >> diff --git a/mm/gup.c b/mm/gup.c >> index 3883b307780e..8c64f3ff34ab 100644 >> --- a/mm/gup.c >> +++ b/mm/gup.c >> @@ -1291,7 +1291,7 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags) >> !writable_file_mapping_allowed(vma, gup_flags)) >> return -EFAULT; >> >> - if (!(vm_flags & VM_WRITE) || (vm_flags & VM_SHADOW_STACK)) { >> + if (!(vm_flags & VM_WRITE) || is_shadow_stack_vma(vm_flags)) { >> if (!(gup_flags & FOLL_FORCE)) >> return -EFAULT; >> /* >> diff --git a/mm/mmap.c b/mm/mmap.c >> index cda01071c7b1..7b6be4eec35d 100644 >> --- a/mm/mmap.c >> +++ b/mm/mmap.c >> @@ -648,7 +648,7 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) >> */ >> static inline unsigned long stack_guard_placement(vm_flags_t vm_flags) >> { >> - if (vm_flags & VM_SHADOW_STACK) >> + if (is_shadow_stack_vma(vm_flags)) >> return PAGE_SIZE; >> >> return 0; >> diff --git a/mm/vma.h b/mm/vma.h >> index a2e8710b8c47..47482a25f5c3 100644 >> --- a/mm/vma.h >> +++ b/mm/vma.h >> @@ -278,7 +278,7 @@ static inline struct vm_area_struct *vma_prev_limit(struct vma_iterator *vmi, >> } >> >> /* >> - * These three helpers classifies VMAs for virtual memory accounting. >> + * These four helpers classifies VMAs for virtual memory accounting. >> */ >> >> /* >> @@ -289,6 +289,11 @@ static inline bool is_exec_mapping(vm_flags_t flags) >> return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC; >> } >> >> +static inline bool is_shadow_stack_vma(vm_flags_t vm_flags) >> +{ >> + return !!(vm_flags & VM_SHADOW_STACK); >> +} >> + >> /* >> * Stack area (including shadow stacks) >> * >> @@ -297,7 +302,7 @@ static inline bool is_exec_mapping(vm_flags_t flags) >> */ >> static inline bool is_stack_mapping(vm_flags_t flags) >> { >> - return ((flags & VM_STACK) == VM_STACK) || (flags & VM_SHADOW_STACK); >> + return ((flags & VM_STACK) == VM_STACK) || is_shadow_stack_vma(flags); >> } >> >> /* >> @@ -308,7 +313,6 @@ static inline bool is_data_mapping(vm_flags_t flags) >> return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE; >> } >> >> - >> static inline void vma_iter_config(struct vma_iterator *vmi, >> unsigned long index, unsigned long last) >> { >> >