From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
iommu@lists.linux-foundation.org
Cc: konrad.wilk@oracle.com, boris.ostrovsky@oracle.com,
sstabellini@kernel.org, Juergen Gross <jgross@suse.com>,
stable@vger.kernel.org
Subject: [PATCH 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()
Date: Tue, 23 Apr 2019 12:54:55 +0200 [thread overview]
Message-ID: <20190423105457.17502-2-jgross@suse.com> (raw)
In-Reply-To: <20190423105457.17502-1-jgross@suse.com>
The condition in xen_swiotlb_free_coherent() for deciding whether to
call xen_destroy_contiguous_region() is wrong: in case the region to
be freed is not contiguous calling xen_destroy_contiguous_region() is
the wrong thing to do: it would result in inconsistent mappings of
multiple PFNs to the same MFN. This will lead to various strange
crashes or data corruption.
Instead of calling xen_destroy_contiguous_region() in that case a
warning should be issued as that situation should never occur.
Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/xen/swiotlb-xen.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 877baf2a94f4..42a3924e6d91 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -360,8 +360,8 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
/* Convert the size to actually allocated. */
size = 1UL << (order + XEN_PAGE_SHIFT);
- if (((dev_addr + size - 1 <= dma_mask)) ||
- range_straddles_page_boundary(phys, size))
+ if ((dev_addr + size - 1 <= dma_mask) &&
+ !WARN_ON(range_straddles_page_boundary(phys, size)))
xen_destroy_contiguous_region(phys, order);
xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
--
2.16.4
next prev parent reply other threads:[~2019-04-23 10:55 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-23 10:54 [PATCH 0/3] xen/swiotlb: fix an issue and improve swiotlb-xen Juergen Gross
2019-04-23 10:54 ` Juergen Gross [this message]
2019-04-23 14:20 ` [PATCH 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region() Boris Ostrovsky
2019-04-25 8:53 ` [Xen-devel] " Jan Beulich
2019-04-23 10:54 ` [PATCH 2/3] xen/swiotlb: simplify range_straddles_page_boundary() Juergen Gross
2019-04-23 14:25 ` Boris Ostrovsky
2019-04-23 10:54 ` [PATCH 3/3] xen/swiotlb: remember having called xen_create_contiguous_region() Juergen Gross
2019-04-23 14:31 ` Boris Ostrovsky
2019-04-23 17:05 ` Stefano Stabellini
2019-04-23 18:36 ` Juergen Gross
2019-04-25 9:01 ` [Xen-devel] " Jan Beulich
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