The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a30a29091b5a6d4c64b5fc77040720a65e2dd4e6 Mon Sep 17 00:00:00 2001

From: Arnd Bergmann arnd@arndb.de Date: Tue, 9 Feb 2021 13:42:10 -0800 Subject: [PATCH] mm/mremap: fix BUILD_BUG_ON() error in get_extent

clang can't evaluate this function argument at compile time when the function is not inlined, which leads to a link time failure:

ld.lld: error: undefined symbol: __compiletime_assert_414

...

...

referenced by mremap.c mremap.o:(get_extent) in archive mm/built-in.a

Mark the function as __always_inline to avoid it.

Link: https://lkml.kernel.org/r/20201230154104.522605-1-arnd@kernel.org Fixes: 9ad9718bfa41 ("mm/mremap: calculate extent in one place") Signed-off-by: Arnd Bergmann arnd@arndb.de Tested-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Nathan Chancellor natechancellor@gmail.com Tested-by: Sedat Dilek sedat.dilek@gmail.com Cc: Kirill A. Shutemov" kirill.shutemov@linux.intel.com Cc: Wei Yang richard.weiyang@linux.alibaba.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Dmitry Safonov 0x7f454c46@gmail.com Cc: Brian Geffon bgeffon@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org

diff --git a/mm/mremap.c b/mm/mremap.c index f554320281cc..aa63bfd3cad2 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -336,8 +336,9 @@ enum pgt_entry { * valid. Else returns a smaller extent bounded by the end of the source and * destination pgt_entry. */ -static unsigned long get_extent(enum pgt_entry entry, unsigned long old_addr, - unsigned long old_end, unsigned long new_addr) +static __always_inline unsigned long get_extent(enum pgt_entry entry, + unsigned long old_addr, unsigned long old_end, + unsigned long new_addr) { unsigned long next, extent, mask, size;