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author | Christoph Hellwig <hch@lst.de> | 2019-06-26 14:27:08 +0200 |
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committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-07-02 14:32:44 -0300 |
commit | 1e240e8d4a7d92232b6214e02a0a4197a53afd6c (patch) | |
tree | 79627ced555b058e23eedd971352ee51918e5dcd /include/linux/memremap.h | |
parent | 3ed2dcdf54d5bf1f9823b5faf1a702e7cee53982 (diff) | |
download | linux-1e240e8d4a7d92232b6214e02a0a4197a53afd6c.tar.gz linux-1e240e8d4a7d92232b6214e02a0a4197a53afd6c.tar.bz2 linux-1e240e8d4a7d92232b6214e02a0a4197a53afd6c.zip |
memremap: move dev_pagemap callbacks into a separate structure
The dev_pagemap is a growing too many callbacks. Move them into a
separate ops structure so that they are not duplicated for multiple
instances, and an attacker can't easily overwrite them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'include/linux/memremap.h')
-rw-r--r-- | include/linux/memremap.h | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 0c86f2c5ac9c..919755f48c7e 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -63,41 +63,45 @@ enum memory_type { MEMORY_DEVICE_PCI_P2PDMA, }; -/* - * Additional notes about MEMORY_DEVICE_PRIVATE may be found in - * include/linux/hmm.h and Documentation/vm/hmm.rst. There is also a brief - * explanation in include/linux/memory_hotplug.h. - * - * The page_free() callback is called once the page refcount reaches 1 - * (ZONE_DEVICE pages never reach 0 refcount unless there is a refcount bug. - * This allows the device driver to implement its own memory management.) - */ -typedef void (*dev_page_free_t)(struct page *page, void *data); +struct dev_pagemap_ops { + /* + * Called once the page refcount reaches 1. (ZONE_DEVICE pages never + * reach 0 refcount unless there is a refcount bug. This allows the + * device driver to implement its own memory management.) + */ + void (*page_free)(struct page *page, void *data); + + /* + * Transition the refcount in struct dev_pagemap to the dead state. + */ + void (*kill)(struct percpu_ref *ref); + + /* + * Wait for refcount in struct dev_pagemap to be idle and reap it. + */ + void (*cleanup)(struct percpu_ref *ref); +}; /** * struct dev_pagemap - metadata for ZONE_DEVICE mappings - * @page_free: free page callback when page refcount reaches 1 * @altmap: pre-allocated/reserved memory for vmemmap allocations * @res: physical address range covered by @ref * @ref: reference count that pins the devm_memremap_pages() mapping - * @kill: callback to transition @ref to the dead state - * @cleanup: callback to wait for @ref to be idle and reap it * @dev: host device of the mapping for debug * @data: private data pointer for page_free() * @type: memory type: see MEMORY_* in memory_hotplug.h + * @ops: method table */ struct dev_pagemap { - dev_page_free_t page_free; struct vmem_altmap altmap; bool altmap_valid; struct resource res; struct percpu_ref *ref; - void (*kill)(struct percpu_ref *ref); - void (*cleanup)(struct percpu_ref *ref); struct device *dev; void *data; enum memory_type type; u64 pci_p2pdma_bus_offset; + const struct dev_pagemap_ops *ops; }; #ifdef CONFIG_ZONE_DEVICE |