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 3D861C0502A for ; Sat, 27 Aug 2022 02:11:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345429AbiH0CL0 (ORCPT ); Fri, 26 Aug 2022 22:11:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345428AbiH0CJx (ORCPT ); Fri, 26 Aug 2022 22:09:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 264B01147E for ; Fri, 26 Aug 2022 19:09:52 -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 dfw.source.kernel.org (Postfix) with ESMTPS id AD07661D14 for ; Sat, 27 Aug 2022 02:09:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 069EFC433D7; Sat, 27 Aug 2022 02:09:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1661566191; bh=7XKjzNAuzsSbxEtrR1hzcewlsbpvjsDlCAv1V775puU=; h=Date:To:From:Subject:From; b=SxBJ/hfNJcJj01q6czqswQFyQw4lujpIEUmAjKtKk3y1l0EbNjpfLhqmgUgv2q/CG 0Yvzg11viW3M2z+9IlR2B7suqxWXV6np/ORwVU9Dw5e77dAOXBlepCRToeFOnH4aj9 39b/iyrnbLmrAOZAaaURa4YClwUuQ3NPhXjlzxac= Date: Fri, 26 Aug 2022 19:09:50 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, viro@zeniv.linux.org.uk, vegard.nossum@oracle.com, vbabka@suse.cz, tglx@linutronix.de, rostedt@goodmis.org, rientjes@google.com, pmladek@suse.com, peterz@infradead.org, penberg@kernel.org, mst@redhat.com, mingo@redhat.com, mark.rutland@arm.com, luto@kernel.org, keescook@chromium.org, iii@linux.ibm.com, iamjoonsoo.kim@lge.com, herbert@gondor.apana.org.au, hch@lst.de, gregkh@linuxfoundation.org, gor@linux.ibm.com, elver@google.com, edumazet@google.com, ebiggers@google.com, dvyukov@google.com, cl@linux.com, bp@alien8.de, axboe@kernel.dk, ast@kernel.org, arnd@arndb.de, andreyknvl@google.com, andreyknvl@gmail.com, glider@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: + dma-kmsan-unpoison-dma-mappings.patch added to mm-unstable branch Message-Id: <20220827020951.069EFC433D7@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: dma: kmsan: unpoison DMA mappings has been added to the -mm mm-unstable branch. Its filename is dma-kmsan-unpoison-dma-mappings.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/dma-kmsan-unpoison-dma-mappings.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Alexander Potapenko Subject: dma: kmsan: unpoison DMA mappings Date: Fri, 26 Aug 2022 17:07:45 +0200 KMSAN doesn't know about DMA memory writes performed by devices. We unpoison such memory when it's mapped to avoid false positive reports. Link: https://lkml.kernel.org/r/20220826150807.723137-23-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/kmsan.h | 41 +++++++++++++++++++++++++++ kernel/dma/mapping.c | 9 ++++-- mm/kmsan/hooks.c | 59 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 106 insertions(+), 3 deletions(-) --- a/include/linux/kmsan.h~dma-kmsan-unpoison-dma-mappings +++ a/include/linux/kmsan.h @@ -9,6 +9,7 @@ #ifndef _LINUX_KMSAN_H #define _LINUX_KMSAN_H +#include #include #include #include @@ -17,6 +18,7 @@ struct page; struct kmem_cache; struct task_struct; +struct scatterlist; #ifdef CONFIG_KMSAN @@ -196,6 +198,35 @@ void kmsan_ioremap_page_range(unsigned l */ void kmsan_iounmap_page_range(unsigned long start, unsigned long end); +/** + * kmsan_handle_dma() - Handle a DMA data transfer. + * @page: first page of the buffer. + * @offset: offset of the buffer within the first page. + * @size: buffer size. + * @dir: one of possible dma_data_direction values. + * + * Depending on @direction, KMSAN: + * * checks the buffer, if it is copied to device; + * * initializes the buffer, if it is copied from device; + * * does both, if this is a DMA_BIDIRECTIONAL transfer. + */ +void kmsan_handle_dma(struct page *page, size_t offset, size_t size, + enum dma_data_direction dir); + +/** + * kmsan_handle_dma_sg() - Handle a DMA transfer using scatterlist. + * @sg: scatterlist holding DMA buffers. + * @nents: number of scatterlist entries. + * @dir: one of possible dma_data_direction values. + * + * Depending on @direction, KMSAN: + * * checks the buffers in the scatterlist, if they are copied to device; + * * initializes the buffers, if they are copied from device; + * * does both, if this is a DMA_BIDIRECTIONAL transfer. + */ +void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, + enum dma_data_direction dir); + #else static inline void kmsan_init_shadow(void) @@ -278,6 +309,16 @@ static inline void kmsan_iounmap_page_ra { } +static inline void kmsan_handle_dma(struct page *page, size_t offset, + size_t size, enum dma_data_direction dir) +{ +} + +static inline void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ +} + #endif #endif /* _LINUX_KMSAN_H */ --- a/kernel/dma/mapping.c~dma-kmsan-unpoison-dma-mappings +++ a/kernel/dma/mapping.c @@ -156,6 +156,7 @@ dma_addr_t dma_map_page_attrs(struct dev addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else addr = ops->map_page(dev, page, offset, size, dir, attrs); + kmsan_handle_dma(page, offset, size, dir); debug_dma_map_page(dev, page, offset, size, dir, addr, attrs); return addr; @@ -194,11 +195,13 @@ static int __dma_map_sg_attrs(struct dev else ents = ops->map_sg(dev, sg, nents, dir, attrs); - if (ents > 0) + if (ents > 0) { + kmsan_handle_dma_sg(sg, nents, dir); debug_dma_map_sg(dev, sg, nents, ents, dir, attrs); - else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM && - ents != -EIO && ents != -EREMOTEIO)) + } else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM && + ents != -EIO && ents != -EREMOTEIO)) { return -EIO; + } return ents; } --- a/mm/kmsan/hooks.c~dma-kmsan-unpoison-dma-mappings +++ a/mm/kmsan/hooks.c @@ -10,9 +10,11 @@ */ #include +#include #include #include #include +#include #include #include @@ -242,6 +244,63 @@ void kmsan_copy_to_user(void __user *to, } EXPORT_SYMBOL(kmsan_copy_to_user); +static void kmsan_handle_dma_page(const void *addr, size_t size, + enum dma_data_direction dir) +{ + switch (dir) { + case DMA_BIDIRECTIONAL: + kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0, + REASON_ANY); + kmsan_internal_unpoison_memory((void *)addr, size, + /*checked*/ false); + break; + case DMA_TO_DEVICE: + kmsan_internal_check_memory((void *)addr, size, /*user_addr*/ 0, + REASON_ANY); + break; + case DMA_FROM_DEVICE: + kmsan_internal_unpoison_memory((void *)addr, size, + /*checked*/ false); + break; + case DMA_NONE: + break; + } +} + +/* Helper function to handle DMA data transfers. */ +void kmsan_handle_dma(struct page *page, size_t offset, size_t size, + enum dma_data_direction dir) +{ + u64 page_offset, to_go, addr; + + if (PageHighMem(page)) + return; + addr = (u64)page_address(page) + offset; + /* + * The kernel may occasionally give us adjacent DMA pages not belonging + * to the same allocation. Process them separately to avoid triggering + * internal KMSAN checks. + */ + while (size > 0) { + page_offset = addr % PAGE_SIZE; + to_go = min(PAGE_SIZE - page_offset, (u64)size); + kmsan_handle_dma_page((void *)addr, to_go, dir); + addr += to_go; + size -= to_go; + } +} + +void kmsan_handle_dma_sg(struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + struct scatterlist *item; + int i; + + for_each_sg(sg, item, nents, i) + kmsan_handle_dma(sg_page(item), item->offset, item->length, + dir); +} + /* Functions from kmsan-checks.h follow. */ void kmsan_poison_memory(const void *address, size_t size, gfp_t flags) { _ Patches currently in -mm which might be from glider@google.com are stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t.patch instrumentedh-allow-instrumenting-both-sides-of-copy_from_user.patch x86-asm-instrument-usercopy-in-get_user-and-put_user.patch asm-generic-instrument-usercopy-in-cacheflushh.patch kmsan-add-rest-documentation.patch kmsan-introduce-__no_sanitize_memory-and-__no_kmsan_checks.patch kmsan-mark-noinstr-as-__no_sanitize_memory.patch x86-kmsan-pgtable-reduce-vmalloc-space.patch libnvdimm-pfn_dev-increase-max_struct_page_size.patch kmsan-add-kmsan-runtime-core.patch kmsan-disable-instrumentation-of-unsupported-common-kernel-code.patch maintainers-add-entry-for-kmsan.patch mm-kmsan-maintain-kmsan-metadata-for-page-operations.patch mm-kmsan-call-kmsan-hooks-from-slub-code.patch kmsan-handle-task-creation-and-exiting.patch init-kmsan-call-kmsan-initialization-routines.patch instrumentedh-add-kmsan-support.patch kmsan-unpoison-tlb-in-arch_tlb_gather_mmu.patch kmsan-add-iomap-support.patch input-libps2-mark-data-received-in-__ps2_command-as-initialized.patch dma-kmsan-unpoison-dma-mappings.patch virtio-kmsan-check-unpoison-scatterlist-in-vring_map_one_sg.patch kmsan-handle-memory-sent-to-from-usb.patch kmsan-add-tests-for-kmsan.patch kmsan-disable-strscpy-optimization-under-kmsan.patch crypto-kmsan-disable-accelerated-configs-under-kmsan.patch kmsan-disable-physical-page-merging-in-biovec.patch block-kmsan-skip-bio-block-merging-logic-for-kmsan.patch kcov-kmsan-unpoison-area-list-in-kcov_remote_area_put.patch security-kmsan-fix-interoperability-with-auto-initialization.patch objtool-kmsan-list-kmsan-api-functions-as-uaccess-safe.patch x86-kmsan-disable-instrumentation-of-unsupported-code.patch x86-kmsan-skip-shadow-checks-in-__switch_to.patch x86-kmsan-handle-open-coded-assembly-in-lib-iomemc.patch x86-kmsan-use-__msan_-string-functions-where-possible.patch x86-kmsan-sync-metadata-pages-on-page-fault.patch x86-kasan-kmsan-support-config_generic_csum-on-x86-enable-it-for-kasan-kmsan.patch x86-fs-kmsan-disable-config_dcache_word_access.patch x86-kmsan-dont-instrument-stack-walking-functions.patch entry-kmsan-introduce-kmsan_unpoison_entry_regs.patch bpf-kmsan-initialize-bpf-registers-with-zeroes.patch mm-fs-initialize-fsdata-passed-to-write_begin-write_end-interface.patch x86-kmsan-enable-kmsan-builds-for-x86.patch