Commit 808153e1 authored Dec 28, 2018 by Dan Williams Committed by Linus Torvalds Dec 28, 2018

mm, devm_memremap_pages: mark devm_memremap_pages() EXPORT_SYMBOL_GPL

devm_memremap_pages() is a facility that can create struct page entries
for any arbitrary range and give drivers the ability to subvert core
aspects of page management.

Specifically the facility is tightly integrated with the kernel's memory
hotplug functionality.  It injects an altmap argument deep into the
architecture specific vmemmap implementation to allow allocating from
specific reserved pages, and it has Linux specific assumptions about page
structure reference counting relative to get_user_pages() and
get_user_pages_fast().  It was an oversight and a mistake that this was
not marked EXPORT_SYMBOL_GPL from the outset.

Again, devm_memremap_pagex() exposes and relies upon core kernel internal
assumptions and will continue to evolve along with 'struct page', memory
hotplug, and support for new memory types / topologies.  Only an in-kernel
GPL-only driver is expected to keep up with this ongoing evolution.  This
interface, and functionality derived from this interface, is not suitable
for kernel-external drivers.

Link: http://lkml.kernel.org/r/154275557457.76910.16923571232582744134.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7ead3342

kernel/memremap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -233,7 +233,7 @@ void devm_memremap_pages(struct device dev, struct dev_pagemap *pgmap)
		err_array:
		return ERR_PTR(error);
		}
		EXPORT_SYMBOL(devm_memremap_pages);
		EXPORT_SYMBOL_GPL(devm_memremap_pages);

		unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
		{

tools/testing/nvdimm/test/iomap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -113,7 +113,7 @@ void __wrap_devm_memremap_pages(struct device dev, struct dev_pagemap *pgmap)
		return nfit_res->buf + offset - nfit_res->res.start;
		return devm_memremap_pages(dev, pgmap);
		}
		EXPORT_SYMBOL(__wrap_devm_memremap_pages);
		EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);

		pfn_t __wrap_phys_to_pfn_t(phys_addr_t addr, unsigned long flags)
		{

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