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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58643C433FE for ; Fri, 25 Mar 2022 22:43:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233991AbiCYWoc (ORCPT ); Fri, 25 Mar 2022 18:44:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53974 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233992AbiCYWoM (ORCPT ); Fri, 25 Mar 2022 18:44:12 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A57E20C186 for ; Fri, 25 Mar 2022 15:42:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 47C13B82A2F for ; Fri, 25 Mar 2022 22:42:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02262C340ED; Fri, 25 Mar 2022 22:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648248155; bh=uCnysLNWD+wHsJelLpsl1LSanDrUxNQuNT+AhaxFcP4=; h=Date:To:From:Subject:From; b=rKJCO6Pre4JRC81p+hGrx9/AC0ZXr/xUruxFc9Ol9gzMbX6UxhpPIenYnP+K0iAyU SyrkLJ1MYGqxZrQ/xYdsSVlimUvGsv7cs1qRhLkTW1cDJKPRC0d/mQDGyk/h7VjN/A q3godemid+2FXUZW/+uikBbtkspi6kypby9bSOOo= Date: Fri, 25 Mar 2022 15:42:34 -0700 To: mm-commits@vger.kernel.org, will@kernel.org, vincenzo.frascino@arm.com, ryabinin.a.a@gmail.com, pcc@google.com, mark.rutland@arm.com, glider@google.com, eugenis@google.com, elver@google.com, dvyukov@google.com, catalin.marinas@arm.com, andreyknvl@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged] kasan-documentation-updates.patch removed from -mm tree Message-Id: <20220325224235.02262C340ED@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: kasan: documentation updates has been removed from the -mm tree. Its filename was kasan-documentation-updates.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Andrey Konovalov Subject: kasan: documentation updates Update KASAN documentation: - Bump Clang version requirement for HW_TAGS as ARM64_MTE depends on AS_HAS_LSE_ATOMICS as of commit 2decad92f4731 ("arm64: mte: Ensure TIF_MTE_ASYNC_FAULT is set atomically"), which requires Clang 12. - Add description of the new kasan.vmalloc command line flag. - Mention that SW_TAGS and HW_TAGS modes now support vmalloc tagging. - Explicitly say that the "Shadow memory" section is only applicable to software KASAN modes. - Mention that shadow-based KASAN_VMALLOC is supported on arm64. Link: https://lkml.kernel.org/r/a61189128fa3f9fbcfd9884ff653d401864b8e74.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Acked-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Mark Rutland Cc: Peter Collingbourne Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton --- Documentation/dev-tools/kasan.rst | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) --- a/Documentation/dev-tools/kasan.rst~kasan-documentation-updates +++ a/Documentation/dev-tools/kasan.rst @@ -30,7 +30,7 @@ Software tag-based KASAN mode is only su The hardware KASAN mode (#3) relies on hardware to perform the checks but still requires a compiler version that supports memory tagging instructions. -This mode is supported in GCC 10+ and Clang 11+. +This mode is supported in GCC 10+ and Clang 12+. Both software KASAN modes work with SLUB and SLAB memory allocators, while the hardware tag-based KASAN currently only supports SLUB. @@ -206,6 +206,9 @@ additional boot parameters that allow di Asymmetric mode: a bad access is detected synchronously on reads and asynchronously on writes. +- ``kasan.vmalloc=off`` or ``=on`` disables or enables tagging of vmalloc + allocations (default: ``on``). + - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack traces collection (default: ``on``). @@ -279,8 +282,8 @@ Software tag-based KASAN uses 0xFF as a pointers with the 0xFF pointer tag are not checked). The value 0xFE is currently reserved to tag freed memory regions. -Software tag-based KASAN currently only supports tagging of slab and page_alloc -memory. +Software tag-based KASAN currently only supports tagging of slab, page_alloc, +and vmalloc memory. Hardware tag-based KASAN ~~~~~~~~~~~~~~~~~~~~~~~~ @@ -303,8 +306,8 @@ Hardware tag-based KASAN uses 0xFF as a pointers with the 0xFF pointer tag are not checked). The value 0xFE is currently reserved to tag freed memory regions. -Hardware tag-based KASAN currently only supports tagging of slab and page_alloc -memory. +Hardware tag-based KASAN currently only supports tagging of slab, page_alloc, +and VM_ALLOC-based vmalloc memory. If the hardware does not support MTE (pre ARMv8.5), hardware tag-based KASAN will not be enabled. In this case, all KASAN boot parameters are ignored. @@ -319,6 +322,8 @@ checking gets disabled. Shadow memory ------------- +The contents of this section are only applicable to software KASAN modes. + The kernel maps memory in several different parts of the address space. The range of kernel virtual addresses is large: there is not enough real memory to support a real shadow region for every address that could be @@ -349,7 +354,7 @@ CONFIG_KASAN_VMALLOC With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the cost of greater memory usage. Currently, this is supported on x86, -riscv, s390, and powerpc. +arm64, riscv, s390, and powerpc. This works by hooking into vmalloc and vmap and dynamically allocating real shadow memory to back the mappings. _ Patches currently in -mm which might be from andreyknvl@google.com are stacktrace-add-interface-based-on-shadow-call-stack.patch arm64-scs-save-scs_sp-values-per-cpu-when-switching-stacks.patch arm64-implement-stack_trace_save_shadow.patch kasan-use-stack_trace_save_shadow.patch