+ mm-export-pageheadhuge-fix.patch added to -mm tree

+ mm-export-pageheadhuge-fix.patch added to -mm tree

[Andrew Morton]

The patch titled
     Subject: mm-export-pageheadhuge-fix
has been added to the -mm tree.  Its filename is
     mm-export-pageheadhuge-fix.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-export-pageheadhuge-fix.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-export-pageheadhuge-fix.patch

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------------------------------------------------------
From: Andrew Morton <akpm@linux-foundation.org>
Subject: mm-export-pageheadhuge-fix

s/EXPORT_SYMBOL/EXPORT_SYMBOL_GPL/, per Christoph

Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/hugetlb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/hugetlb.c~mm-export-pageheadhuge-fix
+++ a/mm/hugetlb.c
@@ -1855,7 +1855,7 @@ int PageHeadHuge(struct page *page_head)
 
 	return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR;
 }
-EXPORT_SYMBOL(PageHeadHuge);
+EXPORT_SYMBOL_GPL(PageHeadHuge);
 
 /*
  * Find and lock address space (mapping) in write mode.
_

Patches currently in -mm which might be from akpm@linux-foundation.org are

remove-bdi_congested-and-wb_congested-and-related-functions-fix.patch
mm.patch
documentation-vm-page_ownerrst-update-the-documentation-fix.patch
x86-mm-enable-arch_has_vm_get_page_prot-fix.patch
mm-hwpoison-inject-support-injecting-hwpoison-to-free-page-fix.patch
mm-export-pageheadhuge-fix.patch
mm-mempolicy-convert-from-atomic_t-to-refcount_t-on-mempolicy-refcnt-fix.patch
mm-handle-uninitialized-numa-nodes-gracefully-fix.patch
mm-memory_hotplug-remove-obsolete-comment-of-__add_pages-fix.patch
proc-alloc-path_max-bytes-for-proc-pid-fd-symlinks-fix.patch
linux-next-rejects.patch
drivers-gpu-drm-dp-drm_dpc-fix-build.patch
arch-x86-kernel-resourcec-needs-spinlockh.patch
kasan-improve-vmalloc-tests-fix-3-fix.patch
mutex-subsystem-synchro-test-module-fix.patch
kernel-forkc-export-kernel_thread-to-modules.patch

Re: + mm-export-pageheadhuge-fix.patch added to -mm tree

[David Howells]

Andrew Morton <akpm@linux-foundation.org> wrote:

> -EXPORT_SYMBOL(PageHeadHuge);
> +EXPORT_SYMBOL_GPL(PageHeadHuge);

Does this mean that we're moving towards forbidding use of the pagecache in
non-GPL drivers?  'Standard' bits of the folio API use this function
implicitly.

David

Re: + mm-export-pageheadhuge-fix.patch added to -mm tree

[Matthew Wilcox]

On Mon, Feb 28, 2022 at 07:08:44PM +0000, David Howells wrote:
> Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > -EXPORT_SYMBOL(PageHeadHuge);
> > +EXPORT_SYMBOL_GPL(PageHeadHuge);
> 
> Does this mean that we're moving towards forbidding use of the pagecache in
> non-GPL drivers?  'Standard' bits of the folio API use this function
> implicitly.

Check out the definition of PageHuge() directly above.  Same usage in
pre-folio times.