From 1e240e8d4a7d92232b6214e02a0a4197a53afd6c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 26 Jun 2019 14:27:08 +0200 Subject: 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 Reviewed-by: Logan Gunthorpe Reviewed-by: Jason Gunthorpe Reviewed-by: Dan Williams Tested-by: Dan Williams Signed-off-by: Jason Gunthorpe --- mm/hmm.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'mm/hmm.c') diff --git a/mm/hmm.c b/mm/hmm.c index 48574f8485bb..583a02a16872 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -1384,6 +1384,12 @@ static void hmm_devmem_free(struct page *page, void *data) devmem->ops->free(devmem, page); } +static const struct dev_pagemap_ops hmm_pagemap_ops = { + .page_free = hmm_devmem_free, + .kill = hmm_devmem_ref_kill, + .cleanup = hmm_devmem_ref_exit, +}; + /* * hmm_devmem_add() - hotplug ZONE_DEVICE memory for device memory * @@ -1438,12 +1444,10 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; devmem->pagemap.res = *devmem->resource; - devmem->pagemap.page_free = hmm_devmem_free; + devmem->pagemap.ops = &hmm_pagemap_ops; devmem->pagemap.altmap_valid = false; devmem->pagemap.ref = &devmem->ref; devmem->pagemap.data = devmem; - devmem->pagemap.kill = hmm_devmem_ref_kill; - devmem->pagemap.cleanup = hmm_devmem_ref_exit; result = devm_memremap_pages(devmem->device, &devmem->pagemap); if (IS_ERR(result)) -- cgit v1.2.3-55-g7522