+ mm-page_poison-always-declare-__kernel_map_pages-function.patch added to mm-nonmm-unstable branch

+ mm-page_poison-always-declare-__kernel_map_pages-function.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: page_poison: always declare __kernel_map_pages() function
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     mm-page_poison-always-declare-__kernel_map_pages-function.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_poison-always-declare-__kernel_map_pages-function.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Arnd Bergmann <arnd@arndb.de>
Subject: mm: page_poison: always declare __kernel_map_pages() function
Date: Wed, 17 May 2023 15:10:50 +0200

The __kernel_map_pages() function is mainly used for
CONFIG_DEBUG_PAGEALLOC, but has a number of architecture specific
definitions that may also be used in other configurations, as well as a
global fallback definition for architectures that do not support
DEBUG_PAGEALLOC.

When the option is disabled, any definitions without the prototype cause a
warning:

mm/page_poison.c:102:6: error: no previous prototype for '__kernel_map_pages' [-Werror=missing-prototypes]

The function is a trivial nop here, so just declare it anyway
to avoid the warning.

Link: https://lkml.kernel.org/r/20230517131102.934196-3-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/mm.h |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/include/linux/mm.h~mm-page_poison-always-declare-__kernel_map_pages-function
+++ a/include/linux/mm.h
@@ -3482,13 +3482,12 @@ static inline bool debug_pagealloc_enabl
 	return static_branch_unlikely(&_debug_pagealloc_enabled);
 }
 
-#ifdef CONFIG_DEBUG_PAGEALLOC
 /*
  * To support DEBUG_PAGEALLOC architecture must ensure that
  * __kernel_map_pages() never fails
  */
 extern void __kernel_map_pages(struct page *page, int numpages, int enable);
-
+#ifdef CONFIG_DEBUG_PAGEALLOC
 static inline void debug_pagealloc_map_pages(struct page *page, int numpages)
 {
 	if (debug_pagealloc_enabled_static())
_

Patches currently in -mm which might be from arnd@arndb.de are

radix-tree-move-declarations-to-header.patch
decompressor-provide-missing-prototypes.patch
kasan-add-kasan_tag_mismatch-prototype.patch
kasan-use-internal-prototypes-matching-gcc-13-builtins.patch
mm-percpu-unhide-pcpu_embed_first_chunk-prototype.patch
mm-page_poison-always-declare-__kernel_map_pages-function.patch
mm-sparse-mark-populate_section_memmap-static.patch
lib-devmem_is_allowed-include-linux-ioh.patch
locking-add-lockevent_read-prototype.patch
panic-hide-unused-global-functions.patch
panic-make-function-declarations-visible.patch
kunit-include-debugfs-header-file.patch
init-consolidate-prototypes-in-linux-inith.patch
init-move-cifs_root_data-prototype-into-linux-mounth.patch
thread_info-move-function-declarations-to-linux-thread_infoh.patch
time_namespace-always-provide-arch_get_vdso_data-prototype-for-vdso.patch