From patchwork Tue Nov 30 21:39:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12648173 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 6EED6C433EF for ; Tue, 30 Nov 2021 21:41:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D9F516B0074; Tue, 30 Nov 2021 16:40:51 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id D4E006B0075; Tue, 30 Nov 2021 16:40:51 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BCFB76B007B; Tue, 30 Nov 2021 16:40:51 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 9A0716B0075 for ; Tue, 30 Nov 2021 16:40:51 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4FFAB8954E for ; Tue, 30 Nov 2021 21:40:41 +0000 (UTC) X-FDA: 78866916282.15.10CE019 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by imf06.hostedemail.com (Postfix) with ESMTP id 24696801A8A0 for ; Tue, 30 Nov 2021 21:40:38 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1638308438; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Rcspyw3aJSs9x/mVwJKJ/FdDOElM4iaddbIoQBCce4s=; b=gni20/GnmdqNCy/t7JZgLCPTaUWKmqmwegB9OeXRMlKYtEeroZthHsvwu+NnCfAKsJdgrr UQ9gav+YKIGqDmWpPO5WPb3a0BkAhEvPAkKIyg2J2mqK770A/PYB5XsVGwf8h5w1GShu1h hejV8Bh2Dj3+cJ4AEK5F6PxyLvxERxo= From: andrey.konovalov@linux.dev To: Marco Elver , Alexander Potapenko , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne Cc: Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH 00/31] kasan, vmalloc, arm64: add vmalloc tagging support for SW/HW_TAGS Date: Tue, 30 Nov 2021 22:39:06 +0100 Message-Id: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Stat-Signature: ucdgg1rn6d3sckwtocqnoyo1ct4htnxo X-Rspamd-Queue-Id: 24696801A8A0 X-Rspamd-Server: rspam07 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b="gni20/Gn"; spf=pass (imf06.hostedemail.com: domain of andrey.konovalov@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-HE-Tag: 1638308438-435258 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: From: Andrey Konovalov Hi, This patchset adds vmalloc tagging support for SW_TAGS and HW_TAGS KASAN modes. About half of patches are cleanups I went for along the way. None of them seem to be important enough to go through stable, so I decided not to split them out into separate patches/series. I'll keep the patchset based on the mainline for now. Once the high-level issues are resolved, I'll rebase onto mm - there might be a few conflicts right now. The patchset is partially based on an early version of the HW_TAGS patchset by Vincenzo that had vmalloc support. Thus, I added a Co-developed-by tag into a few patches. SW_TAGS vmalloc tagging support is straightforward. It reuses all of the generic KASAN machinery, but uses shadow memory to store tags instead of magic values. Naturally, vmalloc tagging requires adding a few kasan_reset_tag() annotations to the vmalloc code. HW_TAGS vmalloc tagging support stands out. HW_TAGS KASAN is based on Arm MTE, which can only assigns tags to physical memory. As a result, HW_TAGS KASAN only tags vmalloc() allocations, which are backed by page_alloc memory. It ignores vmap() and others. Two things about the patchset that might be questionable, and I'd like to get input on: 1. In this version of the pathset, if both HW_TAGS KASAN and memory initialization are enabled, the memory for vmalloc() allocations is initialized by page_alloc, while the tags are assigned in vmalloc. Initially I thought that moving memory initialization into vmalloc would be confusing, but I don't have any good arguments to support that. So unless anyone has objecttions, I will move memory initialization for HW_TAGS KASAN into vmalloc in v2. 2. In this version of the patchset, when VMAP_STACK is enabled, pointer tags of stacks allocated via vmalloc() are reset, see the "kasan, fork: don't tag stacks allocated with vmalloc" patch. However, allowing sp to be tagged works just fine in my testing setup. Does anyone has an idea of why having a tagged sp in the kernel could be bad? If not, I can drop the mentioned patch. Thanks! Andrey Konovalov (31): kasan, page_alloc: deduplicate should_skip_kasan_poison kasan, page_alloc: move tag_clear_highpage out of kernel_init_free_pages kasan, page_alloc: merge kasan_free_pages into free_pages_prepare kasan, page_alloc: simplify kasan_poison_pages call site kasan, page_alloc: init memory of skipped pages on free mm: clarify __GFP_ZEROTAGS comment kasan: only apply __GFP_ZEROTAGS when memory is zeroed kasan, page_alloc: refactor init checks in post_alloc_hook kasan, page_alloc: merge kasan_alloc_pages into post_alloc_hook kasan, page_alloc: combine tag_clear_highpage calls in post_alloc_hook kasan, page_alloc: move SetPageSkipKASanPoison in post_alloc_hook kasan, page_alloc: move kernel_init_free_pages in post_alloc_hook kasan, page_alloc: simplify kasan_unpoison_pages call site kasan: clean up metadata byte definitions kasan: define KASAN_VMALLOC_INVALID for SW_TAGS kasan, x86, arm64, s390: rename functions for modules shadow kasan, vmalloc: drop outdated VM_KASAN comment kasan: reorder vmalloc hooks kasan: add wrappers for vmalloc hooks kasan, vmalloc: reset tags in vmalloc functions kasan, fork: don't tag stacks allocated with vmalloc kasan, vmalloc: add vmalloc support to SW_TAGS kasan, arm64: allow KASAN_VMALLOC with SW_TAGS kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged kasan, vmalloc: don't unpoison VM_ALLOC pages before mapping kasan, page_alloc: allow skipping unpoisoning for HW_TAGS kasan, vmalloc: add vmalloc support to HW_TAGS kasan: add kasan.vmalloc command line flag kasan, arm64: allow KASAN_VMALLOC with HW_TAGS kasan: documentation updates kasan: improve vmalloc tests Documentation/dev-tools/kasan.rst | 17 ++- arch/arm64/Kconfig | 2 +- arch/arm64/include/asm/vmalloc.h | 10 ++ arch/arm64/kernel/module.c | 2 +- arch/s390/kernel/module.c | 2 +- arch/x86/kernel/module.c | 2 +- include/linux/gfp.h | 17 ++- include/linux/kasan.h | 90 +++++++++------ include/linux/vmalloc.h | 18 ++- kernel/fork.c | 1 + lib/Kconfig.kasan | 20 ++-- lib/test_kasan.c | 181 +++++++++++++++++++++++++++++- mm/kasan/common.c | 4 +- mm/kasan/hw_tags.c | 142 +++++++++++++++++++---- mm/kasan/kasan.h | 16 ++- mm/kasan/shadow.c | 54 +++++---- mm/page_alloc.c | 138 +++++++++++++++-------- mm/vmalloc.c | 65 +++++++++-- 18 files changed, 597 insertions(+), 184 deletions(-)