FAILED: patch "[PATCH] mm/mremap: fix BUILD_BUG_ON() error in get_extent" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

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;