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 6FE04C3DA4A for ; Thu, 22 Aug 2024 10:20:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id EFB6180026; Thu, 22 Aug 2024 06:20:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E837C8001E; Thu, 22 Aug 2024 06:20:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CFD6E80026; Thu, 22 Aug 2024 06:20:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id AE59E8001E for ; Thu, 22 Aug 2024 06:20:01 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5D181C145C for ; Thu, 22 Aug 2024 10:20:01 +0000 (UTC) X-FDA: 82479485802.14.E230AE5 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf11.hostedemail.com (Postfix) with ESMTP id BEEC640020 for ; Thu, 22 Aug 2024 10:19:59 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1724321936; 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; bh=zl8RgCnyocUrg5HplpCJh2cr2oO2gB1NJjTN9ft3YeM=; b=8jHcKLPuUf2ptRXvsm8wWt/J7mR82RvYwXxuFZx59fZhKgF5ZhjDHl2QnelyOV+QhAYO2l 6wAMveQvcm41wxiAi2lE6W+VAt4pHK/t0s4hvDlr4M+6Hj6GBkghhvxKQDBASZYX9fdNX3 Myma7jnsU/aPd+tM0RW59FhzXOYI0Vc= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=none; spf=pass (imf11.hostedemail.com: domain of cmarinas@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=cmarinas@kernel.org; dmarc=fail reason="SPF not aligned (relaxed), No valid DKIM" header.from=arm.com (policy=none) ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1724321936; a=rsa-sha256; cv=none; b=plWWcPV5SYoISMsG9xZY6lDrRU1UvcN7jDerR69jPdbC9Vyf0RhMzcL4CKV+x8mFFY0Y86 2FjKDgDdNrULHglNCBc7lTqkQ5MC4NlcaTacNw4TSzYetbdoYCgeyzwj7RsJfEhe4OZD6m mCkJMShMnPkALtFmvTa4ayw8Pkgd9J4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id E27FA60FF3; Thu, 22 Aug 2024 10:19:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEBE0C32782; Thu, 22 Aug 2024 10:19:52 +0000 (UTC) Date: Thu, 22 Aug 2024 11:19:50 +0100 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , Jonathan Corbet , Andrew Morton , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Arnd Bergmann , Oleg Nesterov , Eric Biederman , Shuah Khan , "Rick P. Edgecombe" , Deepak Gupta , Ard Biesheuvel , Szabolcs Nagy , Kees Cook , "H.J. Lu" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Florian Weimer , Christian Brauner , Thiago Jung Bauermann , Ross Burton , Yury Khrustalev , Wilco Dijkstra , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v11 14/39] arm64/mm: Map pages for guarded control stack Message-ID: References: <20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org> <20240822-arm64-gcs-v11-14-41b81947ecb5@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240822-arm64-gcs-v11-14-41b81947ecb5@kernel.org> X-Stat-Signature: wnc6pywxnb5f9ohjmb968hcm51747fzo X-Rspam-User: X-Rspamd-Queue-Id: BEEC640020 X-Rspamd-Server: rspam02 X-HE-Tag: 1724321999-140327 X-HE-Meta: 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 8xk3bX7C M7TFvBCWF6G4kZvr/cA2t+SuZp1xwdAsjrTY4Xi9IAuC8lZN5cVRLoTpZRjHpRPFs2wTcPKFRXDzsYdu6DUvTrrCf5WPTUcBfHqq7Mek1F4LRrwMn7kGWcC6BHcGnzL5TlZHE3ASavIDpuDN3tBCSexfAEaELTJGymeJpxAU4iu1fYX1X25237K1q1eMXwFCfy2FocKJzaegTwO6naEua4RiTALNCFKMDfOJgklz3n5u7WzUgdJhjtevb2qFGR6HIb9QIYKvr+gpN4JzXYakuAnugWfxvMJZpH2RGu5tkoMxw1lkrTOA/+BcML41vFAoYltvDFyyOuiGpZUk5VAhJWuWurGXN5DnjRrksngZD0jR0OMfnqi9Ei7X/vYuDnEYeBjY8XcD5GtxumlgMBWGW2B7mGK9IrLFfjxEimyGLLA7y51cC3P38lfz8p2Hv9RWk+N/fN1kM6Z95VuQQwWOuquhC67Lnp9AK3Jw4 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 Thu, Aug 22, 2024 at 02:15:17AM +0100, Mark Brown wrote: > diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h > index c21849ffdd88..37dfd2882f04 100644 > --- a/arch/arm64/include/asm/mman.h > +++ b/arch/arm64/include/asm/mman.h > @@ -61,6 +61,15 @@ static inline bool arch_validate_flags(unsigned long vm_flags) > return false; > } > > + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { > + /* An executable GCS isn't a good idea. */ > + if (vm_flags & VM_EXEC) > + return false; Later we should look at clear VM_MAYEXEC in the core code (if the x86 folk agree). > + > + /* The memory management core should prevent this */ > + VM_WARN_ON(vm_flags & VM_SHARED); > + } > + > return true; > > } > diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c > index 642bdf908b22..3ed63fc8cd0a 100644 > --- a/arch/arm64/mm/mmap.c > +++ b/arch/arm64/mm/mmap.c > @@ -83,9 +83,17 @@ arch_initcall(adjust_protection_map); > > pgprot_t vm_get_page_prot(unsigned long vm_flags) > { > - pteval_t prot = pgprot_val(protection_map[vm_flags & > + pteval_t prot; > + > + /* Short circuit GCS to avoid bloating the table. */ > + if (system_supports_gcs() && (vm_flags & VM_SHADOW_STACK)) { > + prot = _PAGE_GCS_RO; > + } else { > + prot = pgprot_val(protection_map[vm_flags & > (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]); > + } > > + /* VM_ARM64_BTI on a GCS is rejected in arch_validate_flags() */ Not anymore. > if (vm_flags & VM_ARM64_BTI) > prot |= PTE_GP; Other than the comment above, it looks good. Reviewed-by: Catalin Marinas