The devm_memremap_pages() 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 that
this was not marked EXPORT_SYMBOL_GPL from the outset.
It exposes and relies upon core kernel internal assumptions and will
continue to evolve as memory hotplug and support for new memory types
and topologies is required. Only an in kernel GPL-only driver is
expected to keep up with this ongoing evolution.
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
kernel/memremap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 5857267a4af5..4478e4688bb7 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -257,7 +257,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
pgmap_radix_release(res, pgoff);
return ERR_PTR(error);
}
-EXPORT_SYMBOL(devm_memremap_pages);
+EXPORT_SYMBOL_GPL(devm_memremap_pages);
unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
{
