From: Arnd Bergmann <arnd@xxxxxxxx> Subject: memblock: fix section mismatch warning The inlining logic in clang-13 is rewritten to often not inline some functions that were inlined by all earlier compilers. In case of the memblock interfaces, this exposed a harmless bug of a missing __init annotation: WARNING: modpost: vmlinux.o(.text+0x507c0a): Section mismatch in reference from the function memblock_bottom_up() to the variable .meminit.data:memblock The function memblock_bottom_up() references the variable __meminitdata memblock. This is often because memblock_bottom_up lacks a __meminitdata annotation or the annotation of memblock is wrong. Interestingly, these annotations were present originally, but got removed with the explanation that the __init annotation prevents the function from getting inlined. I checked this again and found that while this is the case with clang, gcc (version 7 through 10, did not test others) does inline the functions regardless. As the previous change was apparently intended to help the clang builds, reverting it to help the newer clang versions seems appropriate as well. gcc builds don't seem to care either way. Link: https://lkml.kernel.org/r/20210225133808.2188581-1-arnd@xxxxxxxxxx Fixes: 5bdba520c1b3 ("mm: memblock: drop __init from memblock functions to make it inline") Reference: 2cfb3665e864 ("include/linux/memblock.h: add __init to memblock_set_bottom_up()") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Nathan Chancellor <nathan@xxxxxxxxxx> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Cc: Faiyaz Mohammed <faiyazm@xxxxxxxxxxxxxx> Cc: Baoquan He <bhe@xxxxxxxxxx> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Cc: Aslan Bakirov <aslan@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memblock.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/include/linux/memblock.h~memblock-fix-section-mismatch-warning +++ a/include/linux/memblock.h @@ -460,7 +460,7 @@ static inline void memblock_free_late(ph /* * Set the allocation direction to bottom-up or top-down. */ -static inline void memblock_set_bottom_up(bool enable) +static inline __init void memblock_set_bottom_up(bool enable) { memblock.bottom_up = enable; } @@ -470,7 +470,7 @@ static inline void memblock_set_bottom_u * if this is true, that said, memblock will allocate memory * in bottom-up direction. */ -static inline bool memblock_bottom_up(void) +static inline __init bool memblock_bottom_up(void) { return memblock.bottom_up; } _
