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: 12694211 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 54E39C433EF for ; Tue, 30 Nov 2021 21:42:32 +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:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=AP9TQM+jNt3ryrVx1yVlTPDVMYMcggrhYLEm3LXj5MY=; b=Y8A8R0teRRHWiG bhudf9i0cl0XLOKkVjIc0nnEGDxs9o+qcUB9ggndQ1wQVG33Hw+K4nGH9UCU2Hq/mMeCN0IvI+FMw zBDoq4pUxu/5aY82xNOFwU+gv1RyCmOQTT3LtBwCl9DSAhW9vfFIwMWsOt77N4Xuo33LXV8etFKfu k3n4jVVpoQEgQyu3tSjHrnxk9XxY+L+JAdONnnnQRAa/m4++5hShpqoDhrH3hsqFT9r2XQiFLQHLj ByalOxorOueoTh9lqGSkiLbH783Bsidkx60jWPgkTNBx5fXiKbWzStCD0tSZXXS+ia7EssW6S4PSg dG0ze0ayvHGxxpebFmDg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1msArq-006lwf-Pi; Tue, 30 Nov 2021 21:40:51 +0000 Received: from out0.migadu.com ([94.23.1.103]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1msArl-006ltg-Hj for linux-arm-kernel@lists.infradead.org; Tue, 30 Nov 2021 21:40:47 +0000 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211130_134045_912574_6E6B7F84 X-CRM114-Status: GOOD ( 15.55 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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(-)