xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

memremap: move dev_pagemap callbacks into a separate structure

Browse Source 
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>
This commit is contained in:
Christoph Hellwig
2019-06-26 14:27:08 +02:00
committed by Jason Gunthorpe
parent 3ed2dcdf54
commit 1e240e8d4a
8 changed files with 65 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
kernel/memremap.c
View File

@@ -92,10 +92,10 @@ static void devm_memremap_pages_release(void *data)
unsigned long pfn;
int nid;
pgmap->kill(pgmap->ref);
pgmap->ops->kill(pgmap->ref);
for_each_device_pfn(pfn, pgmap)
put_page(pfn_to_page(pfn));
pgmap->cleanup(pgmap->ref);
pgmap->ops->cleanup(pgmap->ref);
/* pages are dead and unused, undo the arch mapping */
align_start = res->start & ~(SECTION_SIZE - 1);
@@ -128,8 +128,8 @@ static void devm_memremap_pages_release(void *data)
* @pgmap: pointer to a struct dev_pagemap
*
* Notes:
* 1/ At a minimum the res, ref and type members of @pgmap must be initialized
* by the caller before passing it to this function
* 1/ At a minimum the res, ref and type and ops members of @pgmap must be
* initialized by the caller before passing it to this function
*
* 2/ The altmap field may optionally be initialized, in which case altmap_valid
* must be set to true
@@ -179,7 +179,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
break;
}
if (!pgmap->ref || !pgmap->kill || !pgmap->cleanup) {
if (!pgmap->ref || !pgmap->ops || !pgmap->ops->kill ||
!pgmap->ops->cleanup) {
WARN(1, "Missing reference count teardown definition\n");
return ERR_PTR(-EINVAL);
}
@@ -293,9 +294,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
err_pfn_remap:
pgmap_array_delete(res);
err_array:
pgmap->kill(pgmap->ref);
pgmap->cleanup(pgmap->ref);
pgmap->ops->kill(pgmap->ref);
pgmap->ops->cleanup(pgmap->ref);
return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(devm_memremap_pages);
@@ -388,7 +388,7 @@ void __put_devmap_managed_page(struct page *page)
mem_cgroup_uncharge(page);
page->pgmap->page_free(page, page->pgmap->data);
page->pgmap->ops->page_free(page, page->pgmap->data);
} else if (!count)
__put_page(page);
}