From: Alexander Potapenko <glider@google.com>
To: glider@google.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Konovalov <andreyknvl@google.com>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Borislav Petkov <bp@alien8.de>, Christoph Hellwig <hch@lst.de>,
Christoph Lameter <cl@linux.com>,
David Rientjes <rientjes@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
Eric Dumazet <edumazet@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Ilya Leoshkevich <iii@linux.ibm.com>,
Ingo Molnar <mingo@redhat.com>, Jens Axboe <axboe@kernel.dk>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Kees Cook <keescook@chromium.org>, Marco Elver <elver@google.com>,
Mark Rutland <mark.rutland@arm.com>,
Matthew Wilcox <willy@infradead.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Pekka Enberg <penberg@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vasily Gorbik <gor@linux.ibm.com>,
Vegard Nossum <vegard.nossum@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
linux-mm@kvack.org, linux-arch@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 25/48] kmsan: dma: unpoison DMA mappings
Date: Tue, 29 Mar 2022 14:39:54 +0200 [thread overview]
Message-ID: <20220329124017.737571-26-glider@google.com> (raw)
In-Reply-To: <20220329124017.737571-1-glider@google.com>
KMSAN doesn't know about DMA memory writes performed by devices.
We unpoison such memory when it's mapped to avoid false positive
reports.
Signed-off-by: Alexander Potapenko <glider@google.com>
---
v2:
-- move implementation of kmsan_handle_dma() and kmsan_handle_dma_sg() here
Link: https://linux-review.googlesource.com/id/Ia162dc4c5a92e74d4686c1be32a4dfeffc5c32cd
---
include/linux/kmsan.h | 41 +++++++++++++++++++++++++++++
kernel/dma/mapping.c | 9 ++++---
mm/kmsan/hooks.c | 61 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 108 insertions(+), 3 deletions(-)
diff --git a/include/linux/kmsan.h b/include/linux/kmsan.h
index a5767c728a46b..d8667161a10c8 100644
--- a/include/linux/kmsan.h
+++ b/include/linux/kmsan.h
@@ -9,6 +9,7 @@
#ifndef _LINUX_KMSAN_H
#define _LINUX_KMSAN_H
+#include <linux/dma-direction.h>
#include <linux/gfp.h>
#include <linux/kmsan-checks.h>
#include <linux/stackdepot.h>
@@ -18,6 +19,7 @@
struct page;
struct kmem_cache;
struct task_struct;
+struct scatterlist;
#ifdef CONFIG_KMSAN
@@ -205,6 +207,35 @@ void kmsan_ioremap_page_range(unsigned long addr, unsigned long end,
*/
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)
@@ -287,6 +318,16 @@ static inline void kmsan_iounmap_page_range(unsigned long start,
{
}
+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 */
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 9478eccd1c8e6..0560080813761 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -156,6 +156,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
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 device *dev, struct scatterlist *sg,
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))
+ } else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
+ ents != -EIO)) {
return -EIO;
+ }
return ents;
}
diff --git a/mm/kmsan/hooks.c b/mm/kmsan/hooks.c
index 365eedcb08953..cc3465bd69754 100644
--- a/mm/kmsan/hooks.c
+++ b/mm/kmsan/hooks.c
@@ -10,9 +10,11 @@
*/
#include <linux/cacheflush.h>
+#include <linux/dma-direction.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#include <linux/mm_types.h>
+#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -250,6 +252,65 @@ void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy,
}
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;
+ }
+}
+EXPORT_SYMBOL(kmsan_handle_dma);
+
+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);
+}
+EXPORT_SYMBOL(kmsan_handle_dma_sg);
+
/* Functions from kmsan-checks.h follow. */
void kmsan_poison_memory(const void *address, size_t size, gfp_t flags)
{
--
2.35.1.1021.g381101b075-goog
next prev parent reply other threads:[~2022-03-29 12:43 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-29 12:39 [PATCH v2 00/48] Add KernelMemorySanitizer infrastructure Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 01/48] x86: add missing include to sparsemem.h Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 02/48] stackdepot: reserve 5 extra bits in depot_stack_handle_t Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 03/48] kasan: common: adapt to the new prototype of __stack_depot_save() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 04/48] instrumented.h: allow instrumenting both sides of copy_from_user() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 05/48] x86: asm: instrument usercopy in get_user() and __put_user_size() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 06/48] asm-generic: instrument usercopy in cacheflush.h Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 07/48] kmsan: add ReST documentation Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 08/48] kmsan: introduce __no_sanitize_memory and __no_kmsan_checks Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 09/48] kmsan: mark noinstr as __no_sanitize_memory Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 10/48] x86: kmsan: pgtable: reduce vmalloc space Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 11/48] libnvdimm/pfn_dev: increase MAX_STRUCT_PAGE_SIZE Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 12/48] kcsan: clang: retire CONFIG_KCSAN_KCOV_BROKEN Alexander Potapenko
2022-03-30 6:00 ` Marco Elver
2022-03-29 12:39 ` [PATCH v2 13/48] kmsan: add KMSAN runtime core Alexander Potapenko
2022-03-30 8:58 ` Peter Zijlstra
2022-03-30 9:41 ` Peter Zijlstra
2022-04-04 14:39 ` Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 14/48] kmsan: implement kmsan_init(), initialize READ_ONCE_NOCHECK() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 15/48] kmsan: disable instrumentation of unsupported common kernel code Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 16/48] MAINTAINERS: add entry for KMSAN Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 17/48] kmsan: mm: maintain KMSAN metadata for page operations Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 18/48] kmsan: mm: call KMSAN hooks from SLUB code Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 19/48] kmsan: handle task creation and exiting Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 20/48] kmsan: init: call KMSAN initialization routines Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 21/48] instrumented.h: add KMSAN support Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 22/48] kmsan: unpoison @tlb in arch_tlb_gather_mmu() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 23/48] kmsan: add iomap support Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 24/48] Input: libps2: mark data received in __ps2_command() as initialized Alexander Potapenko
2022-03-29 12:39 ` Alexander Potapenko [this message]
2022-03-29 12:39 ` [PATCH v2 26/48] kmsan: virtio: check/unpoison scatterlist in vring_map_one_sg() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 27/48] kmsan: handle memory sent to/from USB Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 28/48] kmsan: instrumentation.h: add instrumentation_begin_with_regs() Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 29/48] kmsan: entry: handle register passing from uninstrumented code Alexander Potapenko
2022-03-29 12:39 ` [PATCH v2 30/48] kmsan: add tests for KMSAN Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 31/48] kernel: kmsan: don't instrument stacktrace.c Alexander Potapenko
2022-04-04 14:56 ` Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 32/48] kmsan: disable strscpy() optimization under KMSAN Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 33/48] crypto: kmsan: disable accelerated configs " Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 34/48] kmsan: disable physical page merging in biovec Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 35/48] kmsan: block: skip bio block merging logic for KMSAN Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 36/48] kmsan: kcov: unpoison area->list in kcov_remote_area_put() Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 37/48] security: kmsan: fix interoperability with auto-initialization Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 38/48] objtool: kmsan: list KMSAN API functions as uaccess-safe Alexander Potapenko
2022-03-30 8:46 ` Peter Zijlstra
[not found] ` <CAG_fn=UzshCuwbq7pZ93v7+eVUgFq1dZ4L_9nEWhYnotmyZtJg@mail.gmail.com>
2022-04-14 15:38 ` Peter Zijlstra
2022-03-29 12:40 ` [PATCH v2 39/48] x86: kmsan: make READ_ONCE_TASK_STACK() return initialized values Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 40/48] x86: kmsan: disable instrumentation of unsupported code Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 41/48] x86: kmsan: skip shadow checks in __switch_to() Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 42/48] x86: kmsan: handle open-coded assembly in lib/iomem.c Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 43/48] x86: kmsan: use __msan_ string functions where possible Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 44/48] x86: kmsan: sync metadata pages on page fault Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 45/48] x86: kasan: kmsan: support CONFIG_GENERIC_CSUM on x86, enable it for KASAN/KMSAN Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 46/48] x86: fs: kmsan: disable CONFIG_DCACHE_WORD_ACCESS Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 47/48] x86: kmsan: handle register passing from uninstrumented code Alexander Potapenko
2022-03-29 12:40 ` [PATCH v2 48/48] x86: kmsan: enable KMSAN builds for x86 Alexander Potapenko
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