[PATCH] [v2] mm: make arch_has_descending_max_zone_pfns() static

From: Arnd Bergmann
Date: Sat Apr 15 2023 - 04:19:27 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

clang produces a build failure on x86 for some randconfig builds
after a change that moves around code to mm/mm_init.c:

Cannot find symbol for section 2: .text.
mm/mm_init.o: failed

I have not been able to figure out why this happens, but the __weak
annotation on arch_has_descending_max_zone_pfns() is the trigger here.

Removing the weak function in favor of an open-coded Kconfig option
check avoids the problem and becomes clearer as well as better to
optimize by the compiler.

Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c")
Cc: llvm@xxxxxxxxxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
v2: fix logic bug reported-by: kernel test robot <oliver.sang@xxxxxxxxx>,
see https://lore.kernel.org/oe-lkp/202304151422.5e4d380b-oliver.sang@xxxxxxxxx
---
arch/arc/mm/init.c | 5 -----
include/linux/mm.h | 1 -
mm/mm_init.c | 4 ++--
3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index ce4e939a7f07..2b89b6c53801 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -74,11 +74,6 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
base, TO_MB(size), !in_use ? "Not used":"");
}

-bool arch_has_descending_max_zone_pfns(void)
-{
- return !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
-}
-
/*
* First memory setup routine called from setup_arch()
* 1. setup swapper's mm @init_mm
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 63acf4a598fe..75d8adce0aee 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3061,7 +3061,6 @@ extern void setup_per_cpu_pageset(void);
extern int min_free_kbytes;
extern int watermark_boost_factor;
extern int watermark_scale_factor;
-extern bool arch_has_descending_max_zone_pfns(void);

/* nommu.c */
extern atomic_long_t mmap_pages_allocated;
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 35302b7bca83..7f7f9c677854 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -1754,9 +1754,9 @@ static void __init free_area_init_memoryless_node(int nid)
* Some architectures, e.g. ARC may have ZONE_HIGHMEM below ZONE_NORMAL. For
* such cases we allow max_zone_pfn sorted in the descending order
*/
-bool __weak arch_has_descending_max_zone_pfns(void)
+static bool arch_has_descending_max_zone_pfns(void)
{
- return false;
+ return IS_ENABLED(CONFIG_ARC) && !IS_ENABLED(CONFIG_ARC_HAS_PAE40);
}

/**
--
2.39.2