The patch titled
Subject: PCI/P2PDMA: fix the gen_pool_add_virt() failure path
has been added to the -mm tree. Its filename is
pci-p2pdma-fix-the-gen_pool_add_virt-failure-path.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/pci-p2pdma-fix-the-gen_pool_add_virt-failure-path.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/pci-p2pdma-fix-the-gen_pool_add_virt-failure-path.patch
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------------------------------------------------------
From: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: PCI/P2PDMA: fix the gen_pool_add_virt() failure path
The pci_p2pdma_add_resource() implementation immediately frees the pgmap
if gen_pool_add_virt() fails. However, that means that when @dev triggers
a devres release devm_memremap_pages_release() will crash trying to access
the freed @pgmap.
Use the new devm_memunmap_pages() to manually free the mapping in the
error path.
Link: http://lkml.kernel.org/r/155727337603.292046.13101332703665246702.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory")
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/pci/p2pdma.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/pci/p2pdma.c~pci-p2pdma-fix-the-gen_pool_add_virt-failure-path
+++ a/drivers/pci/p2pdma.c
@@ -208,13 +208,15 @@ int pci_p2pdma_add_resource(struct pci_d
pci_bus_address(pdev, bar) + offset,
resource_size(&pgmap->res), dev_to_node(&pdev->dev));
if (error)
- goto pgmap_free;
+ goto pages_free;
pci_info(pdev, "added peer-to-peer DMA memory %pR\n",
&pgmap->res);
return 0;
+pages_free:
+ devm_memunmap_pages(&pdev->dev, pgmap);
pgmap_free:
devm_kfree(&pdev->dev, pgmap);
return error;
_
Patches currently in -mm which might be from dan.j.williams@xxxxxxxxx are
drivers-base-devres-introduce-devm_release_action.patch
mm-devm_memremap_pages-introduce-devm_memunmap_pages.patch
pci-p2pdma-fix-the-gen_pool_add_virt-failure-path.patch
lib-genalloc-introduce-chunk-owners.patch
pci-p2pdma-track-pgmap-references-per-resource-not-globally.patch
mm-devm_memremap_pages-fix-final-page-put-race.patch
