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Message-ID: <20260124095628.668870-1-rppt@kernel.org>
Date: Sat, 24 Jan 2026 11:56:28 +0200
From: Mike Rapoport <rppt@...nel.org>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Andreas Larsson <andreas@...sler.com>,
Borislav Petkov <bp@...en8.de>,
Brian Cain <bcain@...nel.org>,
Catalin Marinas <catalin.marinas@....com>,
"David S. Miller" <davem@...emloft.net>,
Dave Hansen <dave.hansen@...ux.intel.com>,
David Hildenbrand <david@...nel.org>,
Dinh Nguyen <dinguyen@...nel.org>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
Guo Ren <guoren@...nel.org>,
Helge Deller <deller@....de>,
Huacai Chen <chenhuacai@...nel.org>,
Ingo Molnar <mingo@...hat.com>,
Johannes Berg <johannes@...solutions.net>,
John Paul Adrian Glaubitz <glaubitz@...sik.fu-berlin.de>,
"Liam R. Howlett" <Liam.Howlett@...cle.com>,
Lorenzo Stoakes <lorenzo.stoakes@...cle.com>,
Madhavan Srinivasan <maddy@...ux.ibm.com>,
Magnus Lindholm <linmag7@...il.com>,
Matt Turner <mattst88@...il.com>,
Max Filippov <jcmvbkbc@...il.com>,
Michael Ellerman <mpe@...erman.id.au>,
Michal Hocko <mhocko@...e.com>,
Michal Simek <monstr@...str.eu>,
Mike Rapoport <rppt@...nel.org>,
Palmer Dabbelt <palmer@...belt.com>,
Richard Weinberger <richard@....at>,
Russell King <linux@...linux.org.uk>,
Stafford Horne <shorne@...il.com>,
Suren Baghdasaryan <surenb@...gle.com>,
Thomas Gleixner <tglx@...nel.org>,
Vineet Gupta <vgupta@...nel.org>,
Vlastimil Babka <vbabka@...e.cz>,
Will Deacon <will@...nel.org>,
linux-alpha@...r.kernel.org,
linux-kernel@...r.kernel.org,
linux-snps-arc@...ts.infradead.org,
linux-arm-kernel@...ts.infradead.org,
linux-csky@...r.kernel.org,
linux-hexagon@...r.kernel.org,
loongarch@...ts.linux.dev,
linux-m68k@...ts.linux-m68k.org,
linux-openrisc@...r.kernel.org,
linux-parisc@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org,
linux-riscv@...ts.infradead.org,
linux-sh@...r.kernel.org,
sparclinux@...r.kernel.org,
linux-um@...ts.infradead.org,
linux-mm@...ck.org,
x86@...nel.org
Subject: [PATCH mm-unstable] arch, mm: consolidate empty_zero_page
From: "Mike Rapoport (Microsoft)" <rppt@...nel.org>
Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of
ZERO_PAGE() to 4.
Every architecture defines empty_zero_page that way or another, but for the
most of them it is always a page aligned page in BSS and most definitions
of ZERO_PAGE do virt_to_page(empty_zero_page).
Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the
core MM and drop these definitions in architectures that do not implement
colored zero page (MIPS and s390).
ZERO_PAGE() remains a macro because turning it to a wrapper for a static
inline causes severe pain in header dependencies.
For the most part the change is mechanical, with these being noteworthy:
* alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot
parameters. Switching to a generic empty_zero_page removes the aliasing
and keeps ZERO_PGE for boot parameters only
* arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of
ZERO_PAGE() is kept intact.
* m68k/parisc/sparc64/um: allocated empty_zero_page from memblock,
although they do not support zero page coloring and having it in BSS
will work fine.
* sh: used empty_zero_page for boot parameters at the very early boot.
Rename the parameters page to boot_params_page and let sh use the generic
empty_zero_page.
* hexagon: had an amusing comment about empty_zero_page
/* A handy thing to have if one has the RAM. Declared in head.S */
that unfortunately had to go :)
Signed-off-by: Mike Rapoport (Microsoft) <rppt@...nel.org>
---
arch/alpha/include/asm/pgtable.h | 6 ------
arch/arc/include/asm/pgtable.h | 3 ---
arch/arc/mm/init.c | 2 --
arch/arm/include/asm/pgtable.h | 9 ---------
arch/arm/mm/mmu.c | 7 -------
arch/arm/mm/nommu.c | 7 -------
arch/arm64/include/asm/pgtable.h | 1 -
arch/arm64/mm/mmu.c | 7 -------
arch/csky/include/asm/pgtable.h | 3 ---
arch/csky/mm/init.c | 3 ---
arch/hexagon/include/asm/pgtable.h | 6 ------
arch/hexagon/kernel/head.S | 5 -----
arch/hexagon/kernel/hexagon_ksyms.c | 1 -
arch/loongarch/include/asm/pgtable.h | 9 ---------
arch/loongarch/mm/init.c | 3 ---
arch/m68k/include/asm/pgtable_mm.h | 9 ---------
arch/m68k/include/asm/pgtable_no.h | 7 -------
arch/m68k/mm/init.c | 9 ---------
arch/m68k/mm/mcfmmu.c | 2 --
arch/m68k/mm/motorola.c | 6 ------
arch/m68k/mm/sun3mmu.c | 2 --
arch/microblaze/include/asm/pgtable.h | 10 ----------
arch/microblaze/kernel/head.S | 4 ----
arch/microblaze/kernel/microblaze_ksyms.c | 2 --
arch/nios2/include/asm/pgtable.h | 7 -------
arch/nios2/kernel/head.S | 10 ----------
arch/nios2/kernel/nios2_ksyms.c | 1 -
arch/openrisc/include/asm/pgtable.h | 4 ----
arch/openrisc/kernel/head.S | 3 ---
arch/openrisc/kernel/or32_ksyms.c | 1 -
arch/openrisc/mm/init.c | 3 ---
arch/parisc/include/asm/pgtable.h | 11 -----------
arch/parisc/mm/init.c | 6 ------
arch/powerpc/include/asm/pgtable.h | 6 ------
arch/powerpc/mm/mem.c | 3 ---
arch/riscv/include/asm/pgtable.h | 7 -------
arch/riscv/mm/init.c | 4 ----
arch/sh/include/asm/pgtable.h | 8 --------
arch/sh/include/asm/setup.h | 3 ++-
arch/sh/kernel/head_32.S | 4 ++--
arch/sh/kernel/sh_ksyms_32.c | 1 -
arch/sh/mm/init.c | 1 -
arch/sparc/include/asm/pgtable_32.h | 8 --------
arch/sparc/include/asm/pgtable_64.h | 3 ---
arch/sparc/include/asm/setup.h | 2 --
arch/sparc/kernel/head_32.S | 7 -------
arch/sparc/mm/init_32.c | 4 ----
arch/sparc/mm/init_64.c | 15 ---------------
arch/um/include/asm/pgtable.h | 9 ---------
arch/um/include/shared/kern_util.h | 1 -
arch/um/kernel/mem.c | 16 ----------------
arch/um/kernel/um_arch.c | 1 -
arch/x86/include/asm/pgtable.h | 8 --------
arch/x86/kernel/head_32.S | 4 ----
arch/x86/kernel/head_64.S | 7 -------
arch/xtensa/include/asm/pgtable.h | 4 ----
arch/xtensa/kernel/head.S | 3 ---
arch/xtensa/kernel/xtensa_ksyms.c | 2 --
include/linux/pgtable.h | 8 ++++++++
mm/mm_init.c | 9 +++++++++
60 files changed, 21 insertions(+), 296 deletions(-)
diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index 90e7a9539102..12a3c5f8ece8 100644
--- a/arch/alpha/include/asm/pgtable.h
+++ b/arch/alpha/include/asm/pgtable.h
@@ -125,12 +125,6 @@ struct vm_area_struct;
*/
#define pgprot_noncached(prot) (prot)
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-#define ZERO_PAGE(vaddr) (virt_to_page(ZERO_PGE))
-
/*
* On certain platforms whose physical address space can overlap KSEG,
* namely EV6 and above, we must re-twiddle the physaddr to restore the
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
index bd580e2b62d7..0fdaea81b5fa 100644
--- a/arch/arc/include/asm/pgtable.h
+++ b/arch/arc/include/asm/pgtable.h
@@ -21,9 +21,6 @@
#ifndef __ASSEMBLER__
-extern char empty_zero_page[PAGE_SIZE];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE);
/* to cope with aliasing VIPT cache */
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
index a5e92f46e5d1..d6b5c27a0098 100644
--- a/arch/arc/mm/init.c
+++ b/arch/arc/mm/init.c
@@ -19,8 +19,6 @@
#include <asm/arcregs.h>
pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
-char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
-EXPORT_SYMBOL(empty_zero_page);
static const unsigned long low_mem_start = CONFIG_LINUX_RAM_BASE;
static unsigned long low_mem_sz;
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 6fa9acd6a7f5..982795cf4563 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -10,15 +10,6 @@
#include <linux/const.h>
#include <asm/proc-fns.h>
-#ifndef __ASSEMBLY__
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-#endif
-
#include <asm-generic/pgtable-nopud.h>
#ifndef CONFIG_MMU
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 518def8314e7..23b87b5ef7f1 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -41,13 +41,6 @@
extern unsigned long __atags_pointer;
-/*
- * empty_zero_page is a special page that is used for
- * zero-initialized data and COW.
- */
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
/*
* The pmd table for the upper-most set of pages.
*/
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 7e42d8accec6..040ea43cce32 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -27,13 +27,6 @@
unsigned long vectors_base;
-/*
- * empty_zero_page is a special page that is used for
- * zero-initialized data and COW.
- */
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
#ifdef CONFIG_ARM_MPU
struct mpu_rgn_info mpu_rgn_info;
#endif
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index a17eb8a76788..516147f06fe8 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -110,7 +110,6 @@ static inline void arch_leave_lazy_mmu_mode(void)
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
*/
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
#define ZERO_PAGE(vaddr) phys_to_page(__pa_symbol(empty_zero_page))
#define pte_ERROR(e) \
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index a6a00accf4f9..0f6a171faf1f 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -64,13 +64,6 @@ static bool rodata_is_rw __ro_after_init = true;
*/
long __section(".mmuoff.data.write") __early_cpu_boot_status;
-/*
- * Empty_zero_page is a special page that is used for zero-initialized data
- * and COW.
- */
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
static DEFINE_SPINLOCK(swapper_pgdir_lock);
static DEFINE_MUTEX(fixmap_lock);
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index d606afbabce1..bafcd5823531 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -76,9 +76,6 @@
#define MAX_SWAPFILES_CHECK() \
BUILD_BUG_ON(MAX_SWAPFILES_SHIFT != 5)
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
extern void load_pgd(unsigned long pg_dir);
extern pte_t invalid_pte_table[PTRS_PER_PTE];
diff --git a/arch/csky/mm/init.c b/arch/csky/mm/init.c
index 573da66b2543..fa16015ea1c0 100644
--- a/arch/csky/mm/init.c
+++ b/arch/csky/mm/init.c
@@ -38,9 +38,6 @@ pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss;
EXPORT_SYMBOL(invalid_pte_table);
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
- __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
void free_initmem(void)
{
diff --git a/arch/hexagon/include/asm/pgtable.h b/arch/hexagon/include/asm/pgtable.h
index fbf24d1d1ca6..27b269e2870d 100644
--- a/arch/hexagon/include/asm/pgtable.h
+++ b/arch/hexagon/include/asm/pgtable.h
@@ -14,9 +14,6 @@
#include <asm/page.h>
#include <asm-generic/pgtable-nopmd.h>
-/* A handy thing to have if one has the RAM. Declared in head.S */
-extern unsigned long empty_zero_page;
-
/*
* The PTE model described here is that of the Hexagon Virtual Machine,
* which autonomously walks 2-level page tables. At a lower level, we
@@ -348,9 +345,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
return (unsigned long)__va(pmd_val(pmd) & PAGE_MASK);
}
-/* ZERO_PAGE - returns the globally shared zero page */
-#define ZERO_PAGE(vaddr) (virt_to_page(&empty_zero_page))
-
/*
* Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
* are !pte_none() && !pte_present().
diff --git a/arch/hexagon/kernel/head.S b/arch/hexagon/kernel/head.S
index 0b016308cc79..908ffece9132 100644
--- a/arch/hexagon/kernel/head.S
+++ b/arch/hexagon/kernel/head.S
@@ -216,8 +216,3 @@ __head_s_vaddr_target:
.p2align PAGE_SHIFT
ENTRY(external_cmdline_buffer)
.fill _PAGE_SIZE,1,0
-
-.data
-.p2align PAGE_SHIFT
-ENTRY(empty_zero_page)
- .fill _PAGE_SIZE,1,0
diff --git a/arch/hexagon/kernel/hexagon_ksyms.c b/arch/hexagon/kernel/hexagon_ksyms.c
index 36a80e31d187..81bc6f81e200 100644
--- a/arch/hexagon/kernel/hexagon_ksyms.c
+++ b/arch/hexagon/kernel/hexagon_ksyms.c
@@ -17,7 +17,6 @@ EXPORT_SYMBOL(raw_copy_to_user);
EXPORT_SYMBOL(__vmgetie);
EXPORT_SYMBOL(__vmsetie);
EXPORT_SYMBOL(__vmyield);
-EXPORT_SYMBOL(empty_zero_page);
EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memset);
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index c33b3bcb733e..a244de27a03e 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -74,15 +74,6 @@
struct mm_struct;
struct vm_area_struct;
-/*
- * ZERO_PAGE is a global shared page that is always zero; used
- * for zero-mapped memory areas etc..
- */
-
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-
-#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
-
#ifdef CONFIG_32BIT
#define VMALLOC_START (vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE))
diff --git a/arch/loongarch/mm/init.c b/arch/loongarch/mm/init.c
index c331bf69d2ec..00f3822b6e47 100644
--- a/arch/loongarch/mm/init.c
+++ b/arch/loongarch/mm/init.c
@@ -36,9 +36,6 @@
#include <asm/pgalloc.h>
#include <asm/tlb.h>
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h
index bba64a9c49ac..7501ff030c63 100644
--- a/arch/m68k/include/asm/pgtable_mm.h
+++ b/arch/m68k/include/asm/pgtable_mm.h
@@ -110,15 +110,6 @@ extern unsigned long m68k_vmalloc_end;
#define VMALLOC_END KMAP_START
#endif
-/* zero page used for uninitialized stuff */
-extern void *empty_zero_page;
-
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);
/*
diff --git a/arch/m68k/include/asm/pgtable_no.h b/arch/m68k/include/asm/pgtable_no.h
index 1a86c15b9008..11751807a3f3 100644
--- a/arch/m68k/include/asm/pgtable_no.h
+++ b/arch/m68k/include/asm/pgtable_no.h
@@ -30,13 +30,6 @@
#define swapper_pg_dir ((pgd_t *) 0)
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern void *empty_zero_page;
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
/*
* All 32bit addresses are effectively valid for vmalloc...
* Sort of meaningless for non-VM targets.
diff --git a/arch/m68k/mm/init.c b/arch/m68k/mm/init.c
index 53b71f786c27..3b88c0dd1616 100644
--- a/arch/m68k/mm/init.c
+++ b/arch/m68k/mm/init.c
@@ -33,13 +33,6 @@
#include <asm/sections.h>
#include <asm/tlb.h>
-/*
- * ZERO_PAGE is a special page that is used for zero-initialized
- * data and COW.
- */
-void *empty_zero_page;
-EXPORT_SYMBOL(empty_zero_page);
-
void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
{
max_zone_pfns[ZONE_DMA] = PFN_DOWN(memblock_end_of_DRAM());
@@ -71,8 +64,6 @@ void __init paging_init(void)
unsigned long end_mem = memory_end & PAGE_MASK;
high_memory = (void *) end_mem;
-
- empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
}
#endif /* CONFIG_MMU */
diff --git a/arch/m68k/mm/mcfmmu.c b/arch/m68k/mm/mcfmmu.c
index 3418fd864237..4924f2ff8ef8 100644
--- a/arch/m68k/mm/mcfmmu.c
+++ b/arch/m68k/mm/mcfmmu.c
@@ -41,8 +41,6 @@ void __init paging_init(void)
unsigned long next_pgtable;
int i;
- empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
-
pg_dir = swapper_pg_dir;
memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 127a3fa69f4c..b30aa69a73a6 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -498,12 +498,6 @@ void __init paging_init(void)
early_memtest(min_addr, max_addr);
- /*
- * initialize the bad page table and bad page to point
- * to a couple of allocated pages
- */
- empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
-
/*
* Set up SFC/DFC registers
*/
diff --git a/arch/m68k/mm/sun3mmu.c b/arch/m68k/mm/sun3mmu.c
index c801677f7df8..f139cc15753a 100644
--- a/arch/m68k/mm/sun3mmu.c
+++ b/arch/m68k/mm/sun3mmu.c
@@ -43,8 +43,6 @@ void __init paging_init(void)
unsigned long bootmem_end;
unsigned long size;
- empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
-
address = PAGE_OFFSET;
pg_dir = swapper_pg_dir;
memset (swapper_pg_dir, 0, sizeof (swapper_pg_dir));
diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
index 4eb76de6be4a..ea72291de553 100644
--- a/arch/microblaze/include/asm/pgtable.h
+++ b/arch/microblaze/include/asm/pgtable.h
@@ -207,16 +207,6 @@ extern pte_t *va_to_pte(unsigned long address);
* Also, write permissions imply read permissions.
*/
-#ifndef __ASSEMBLER__
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[1024];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
-#endif /* __ASSEMBLER__ */
-
#define pte_none(pte) ((pte_val(pte) & ~_PTE_NONE_MASK) == 0)
#define pte_present(pte) (pte_val(pte) & _PAGE_PRESENT)
#define pte_clear(mm, addr, ptep) \
diff --git a/arch/microblaze/kernel/head.S b/arch/microblaze/kernel/head.S
index ec2fcb545e64..808019c3b7ac 100644
--- a/arch/microblaze/kernel/head.S
+++ b/arch/microblaze/kernel/head.S
@@ -39,10 +39,6 @@
#include <asm/processor.h>
.section .data
-.global empty_zero_page
-.align 12
-empty_zero_page:
- .space PAGE_SIZE
.global swapper_pg_dir
swapper_pg_dir:
.space PAGE_SIZE
diff --git a/arch/microblaze/kernel/microblaze_ksyms.c b/arch/microblaze/kernel/microblaze_ksyms.c
index a8553f54152b..ad7596d7ba07 100644
--- a/arch/microblaze/kernel/microblaze_ksyms.c
+++ b/arch/microblaze/kernel/microblaze_ksyms.c
@@ -33,8 +33,6 @@ EXPORT_SYMBOL(memcpy);
EXPORT_SYMBOL(memmove);
#endif
-EXPORT_SYMBOL(empty_zero_page);
-
EXPORT_SYMBOL(mbc);
extern void __divsi3(void);
diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
index 844dce55569f..d389aa9ca57c 100644
--- a/arch/nios2/include/asm/pgtable.h
+++ b/arch/nios2/include/asm/pgtable.h
@@ -65,13 +65,6 @@ struct mm_struct;
#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
#define PGDIR_MASK (~(PGDIR_SIZE-1))
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
diff --git a/arch/nios2/kernel/head.S b/arch/nios2/kernel/head.S
index 372ce4a33018..613212e1a63a 100644
--- a/arch/nios2/kernel/head.S
+++ b/arch/nios2/kernel/head.S
@@ -23,16 +23,6 @@
#include <asm/asm-offsets.h>
#include <asm/asm-macros.h>
-/*
- * ZERO_PAGE is a special page that is used for zero-initialized
- * data and COW.
- */
-.data
-.global empty_zero_page
-.align 12
-empty_zero_page:
- .space PAGE_SIZE
-
/*
* This global variable is used as an extension to the nios'
* STATUS register to emulate a user/supervisor mode.
diff --git a/arch/nios2/kernel/nios2_ksyms.c b/arch/nios2/kernel/nios2_ksyms.c
index 54f7b23df1bf..c40aa39e8658 100644
--- a/arch/nios2/kernel/nios2_ksyms.c
+++ b/arch/nios2/kernel/nios2_ksyms.c
@@ -20,7 +20,6 @@ EXPORT_SYMBOL(memmove);
/* memory management */
-EXPORT_SYMBOL(empty_zero_page);
EXPORT_SYMBOL(flush_icache_range);
/*
diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
index b218050e2f6d..6b89996d0b62 100644
--- a/arch/openrisc/include/asm/pgtable.h
+++ b/arch/openrisc/include/asm/pgtable.h
@@ -179,10 +179,6 @@ extern void paging_init(void);
__pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \
| _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI)
-/* zero page used for uninitialized stuff */
-extern unsigned long empty_zero_page[2048];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
#define pte_none(x) (!pte_val(x))
#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
#define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0)
diff --git a/arch/openrisc/kernel/head.S b/arch/openrisc/kernel/head.S
index bd760066f1cd..45890393947d 100644
--- a/arch/openrisc/kernel/head.S
+++ b/arch/openrisc/kernel/head.S
@@ -1563,9 +1563,6 @@ _string_nl:
*/
.section .data,"aw"
.align 8192
- .global empty_zero_page
-empty_zero_page:
- .space 8192
.global swapper_pg_dir
swapper_pg_dir:
diff --git a/arch/openrisc/kernel/or32_ksyms.c b/arch/openrisc/kernel/or32_ksyms.c
index 212e5f85004c..84a937a64e2a 100644
--- a/arch/openrisc/kernel/or32_ksyms.c
+++ b/arch/openrisc/kernel/or32_ksyms.c
@@ -40,7 +40,6 @@ DECLARE_EXPORT(__ashldi3);
DECLARE_EXPORT(__lshrdi3);
DECLARE_EXPORT(__ucmpdi2);
-EXPORT_SYMBOL(empty_zero_page);
EXPORT_SYMBOL(__copy_tofrom_user);
EXPORT_SYMBOL(__clear_user);
EXPORT_SYMBOL(memset);
diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c
index 78fb0734cdbc..89d8c6df8855 100644
--- a/arch/openrisc/mm/init.c
+++ b/arch/openrisc/mm/init.c
@@ -188,9 +188,6 @@ void __init mem_init(void)
{
BUG_ON(!mem_map);
- /* clear the zero-page */
- memset((void *)empty_zero_page, 0, PAGE_SIZE);
-
printk("mem_init_done ...........................................\n");
mem_init_done = 1;
return;
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index 2c139a4dbf4b..cbdc01a26ea0 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -262,17 +262,6 @@ extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */
extern pte_t pg0[];
-/* zero page used for uninitialized stuff */
-
-extern unsigned long *empty_zero_page;
-
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
#define pte_none(x) (pte_val(x) == 0)
#define pte_present(x) (pte_val(x) & _PAGE_PRESENT)
#define pte_user(x) (pte_val(x) & _PAGE_USER)
diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index 6a39e031e5ff..be3380c9bcda 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -604,9 +604,6 @@ void __init mem_init(void)
#endif
}
-unsigned long *empty_zero_page __ro_after_init;
-EXPORT_SYMBOL(empty_zero_page);
-
/*
* pagetable_init() sets up the page tables
*
@@ -639,9 +636,6 @@ static void __init pagetable_init(void)
initrd_end - initrd_start, PAGE_KERNEL, 0);
}
#endif
-
- empty_zero_page = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
-
}
static void __init gateway_init(void)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index dcd3a88caaf6..b27d94c06d0e 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -76,12 +76,6 @@ static inline const void *pmd_page_vaddr(pmd_t pmd)
}
#define pmd_page_vaddr pmd_page_vaddr
#endif
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
extern pgd_t swapper_pg_dir[];
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 3789a51bdaae..85508392a6b6 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -34,9 +34,6 @@
unsigned long long memory_limit __initdata;
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
pgprot_t __phys_mem_access_prot(unsigned long pfn, unsigned long size,
pgprot_t vma_prot)
{
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 9ecbf0366719..a6b496f4944f 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -1258,13 +1258,6 @@ extern u64 satp_mode;
void paging_init(void);
void misc_mem_init(void);
-/*
- * ZERO_PAGE is a global shared page that is always zero,
- * used for zero-mapped memory areas, etc.
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
/*
* Use set_p*_safe(), and elide TLB flushing, when confident that *no*
* TLB flush will be required as a result of the "set". For example, use
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 848efeb9e163..95ac79c62067 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -69,10 +69,6 @@ unsigned long vmemmap_start_pfn __ro_after_init;
EXPORT_SYMBOL(vmemmap_start_pfn);
#endif
-unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
- __page_aligned_bss;
-EXPORT_SYMBOL(empty_zero_page);
-
extern char _start[];
void *_dtb_early_va __initdata;
uintptr_t _dtb_early_pa __initdata;
diff --git a/arch/sh/include/asm/pgtable.h b/arch/sh/include/asm/pgtable.h
index 10fa8f2bb8d1..d5ce0950a323 100644
--- a/arch/sh/include/asm/pgtable.h
+++ b/arch/sh/include/asm/pgtable.h
@@ -20,14 +20,6 @@
#ifndef __ASSEMBLER__
#include <asm/addrspace.h>
#include <asm/fixmap.h>
-
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
#endif /* !__ASSEMBLER__ */
/*
diff --git a/arch/sh/include/asm/setup.h b/arch/sh/include/asm/setup.h
index 84bb23a771f3..63c9efc06348 100644
--- a/arch/sh/include/asm/setup.h
+++ b/arch/sh/include/asm/setup.h
@@ -7,7 +7,8 @@
/*
* This is set up by the setup-routine at boot-time
*/
-#define PARAM ((unsigned char *)empty_zero_page)
+extern unsigned char *boot_params_page;
+#define PARAM boot_params_page
#define MOUNT_ROOT_RDONLY (*(unsigned long *) (PARAM+0x000))
#define RAMDISK_FLAGS (*(unsigned long *) (PARAM+0x004))
diff --git a/arch/sh/kernel/head_32.S b/arch/sh/kernel/head_32.S
index b603b7968b38..0b91bb85d40a 100644
--- a/arch/sh/kernel/head_32.S
+++ b/arch/sh/kernel/head_32.S
@@ -26,7 +26,7 @@
#endif
.section .empty_zero_page, "aw"
-ENTRY(empty_zero_page)
+ENTRY(boot_params_page)
.long 1 /* MOUNT_ROOT_RDONLY */
.long 0 /* RAMDISK_FLAGS */
.long 0x0200 /* ORIG_ROOT_DEV */
@@ -39,7 +39,7 @@ ENTRY(empty_zero_page)
.long 0x53453f00 + 29 /* "SE?" = 29 bit */
#endif
1:
- .skip PAGE_SIZE - empty_zero_page - 1b
+ .skip PAGE_SIZE - boot_params_page - 1b
__HEAD
diff --git a/arch/sh/kernel/sh_ksyms_32.c b/arch/sh/kernel/sh_ksyms_32.c
index 5858936cb431..041191002e2e 100644
--- a/arch/sh/kernel/sh_ksyms_32.c
+++ b/arch/sh/kernel/sh_ksyms_32.c
@@ -20,7 +20,6 @@ EXPORT_SYMBOL(csum_partial);
EXPORT_SYMBOL(csum_partial_copy_generic);
EXPORT_SYMBOL(copy_page);
EXPORT_SYMBOL(__clear_user);
-EXPORT_SYMBOL(empty_zero_page);
#ifdef CONFIG_FLATMEM
/* need in pfn_valid macro */
EXPORT_SYMBOL(min_low_pfn);
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 464a3a63e2fa..4e40d5e96be9 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -332,7 +332,6 @@ void __init mem_init(void)
cpu_cache_init();
/* clear the zero-page */
- memset(empty_zero_page, 0, PAGE_SIZE);
__flush_wback_region(empty_zero_page, PAGE_SIZE);
vsyscall_init();
diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
index a9f802d1dd64..f89b1250661d 100644
--- a/arch/sparc/include/asm/pgtable_32.h
+++ b/arch/sparc/include/asm/pgtable_32.h
@@ -71,14 +71,6 @@ extern unsigned long ptr_in_current_pgd;
extern unsigned long phys_base;
extern unsigned long pfn_base;
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
/*
* In general all page table modifications should use the V8 atomic
* swap instruction. This insures the mmu and the cpu are in sync
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 615f460c50af..74ede706fb32 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -210,9 +210,6 @@ extern unsigned long _PAGE_CACHE;
extern unsigned long pg_iobits;
extern unsigned long _PAGE_ALL_SZ_BITS;
-extern struct page *mem_map_zero;
-#define ZERO_PAGE(vaddr) (mem_map_zero)
-
/* PFNs are real physical page numbers. However, mem_map only begins to record
* per-page information starting at pfn_base. This is to handle systems where
* the first physical page in the machine is at some huge physical address,
diff --git a/arch/sparc/include/asm/setup.h b/arch/sparc/include/asm/setup.h
index 72205684e51e..21bed5514028 100644
--- a/arch/sparc/include/asm/setup.h
+++ b/arch/sparc/include/asm/setup.h
@@ -17,8 +17,6 @@ extern char reboot_command[];
*/
extern unsigned char boot_cpu_id;
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
-
extern int serial_console;
static inline int con_is_present(void)
{
diff --git a/arch/sparc/kernel/head_32.S b/arch/sparc/kernel/head_32.S
index 38345460d542..8c320fa25a67 100644
--- a/arch/sparc/kernel/head_32.S
+++ b/arch/sparc/kernel/head_32.S
@@ -57,13 +57,6 @@ sun4e_notsup:
.align PAGE_SIZE
-/* This was the only reasonable way I could think of to properly align
- * these page-table data structures.
- */
- .globl empty_zero_page
-empty_zero_page: .skip PAGE_SIZE
-EXPORT_SYMBOL(empty_zero_page)
-
.global root_flags
.global ram_flags
.global root_dev
diff --git a/arch/sparc/mm/init_32.c b/arch/sparc/mm/init_32.c
index fdc93dd12c3e..e0e66f91ceeb 100644
--- a/arch/sparc/mm/init_32.c
+++ b/arch/sparc/mm/init_32.c
@@ -246,10 +246,6 @@ void __init arch_mm_preinit(void)
prom_halt();
}
-
- /* Saves us work later. */
- memset((void *)empty_zero_page, 0, PAGE_SIZE);
-
i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
i += 1;
sparc_valid_addr_bitmap = (unsigned long *)
diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index c2d19c9a9244..2bd99944176d 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -177,9 +177,6 @@ extern unsigned long sparc_ramdisk_image64;
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;
-struct page *mem_map_zero __read_mostly;
-EXPORT_SYMBOL(mem_map_zero);
-
unsigned int sparc64_highest_unlocked_tlb_ent __read_mostly;
unsigned long sparc64_kern_pri_context __read_mostly;
@@ -2506,18 +2503,6 @@ void __init mem_init(void)
*/
register_page_bootmem_info();
- /*
- * Set up the zero page, mark it reserved, so that page count
- * is not manipulated when freeing the page from user ptes.
- */
- mem_map_zero = alloc_pages(GFP_KERNEL|__GFP_ZERO, 0);
- if (mem_map_zero == NULL) {
- prom_printf("paging_init: Cannot alloc zero page.\n");
- prom_halt();
- }
- mark_page_reserved(mem_map_zero);
-
-
if (tlb_type == cheetah || tlb_type == cheetah_plus)
cheetah_ecache_flush_init();
}
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index 3b42b0f45bf6..19e0608fb649 100644
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -34,9 +34,6 @@
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
-/* zero page used for uninitialized stuff */
-extern unsigned long *empty_zero_page;
-
/* Just any arbitrary offset to the start of the vmalloc VM area: the
* current 8MB value just means that there will be a 8MB "hole" after the
* physical memory until the kernel virtual memory starts. That means that
@@ -74,12 +71,6 @@ extern unsigned long *empty_zero_page;
* get..
*/
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-#define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
-
#define pte_clear(mm, addr, xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEEDSYNC))
#define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEEDSYNC))
diff --git a/arch/um/include/shared/kern_util.h b/arch/um/include/shared/kern_util.h
index 38321188c04c..9812efd14ec0 100644
--- a/arch/um/include/shared/kern_util.h
+++ b/arch/um/include/shared/kern_util.h
@@ -38,7 +38,6 @@ extern void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs
extern void uml_pm_wake(void);
extern int start_uml(void);
-extern void paging_init(void);
extern void uml_cleanup(void);
extern void do_uml_exitcalls(void);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 89c8c8b94a79..1eef0e42ef5d 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -44,10 +44,6 @@ __section(".kasan_init") __used
= kasan_init;
#endif
-/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
-unsigned long *empty_zero_page = NULL;
-EXPORT_SYMBOL(empty_zero_page);
-
/*
* Initialized during boot, and readonly for initializing page tables
* afterwards
@@ -65,9 +61,6 @@ void __init arch_mm_preinit(void)
/* Safe to call after jump_label_init(). Enables KASAN. */
kasan_init_generic();
- /* clear the zero-page */
- memset(empty_zero_page, 0, PAGE_SIZE);
-
/* Map in the area just after the brk now that kmalloc is about
* to be turned on.
*/
@@ -89,15 +82,6 @@ void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
max_zone_pfns[ZONE_NORMAL] = high_physmem >> PAGE_SHIFT;
}
-void __init paging_init(void)
-{
- empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
- PAGE_SIZE);
- if (!empty_zero_page)
- panic("%s: Failed to allocate %lu bytes align=%lx\n",
- __func__, PAGE_SIZE, PAGE_SIZE);
-}
-
/*
* This can't do anything because nothing in the kernel image can be freed
* since it's not in kernel physical memory.
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index e2b24e1ecfa6..2141f5f1f5a2 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -413,7 +413,6 @@ void __init setup_arch(char **cmdline_p)
uml_dtb_init();
read_initrd();
- paging_init();
strscpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
setup_hostinfo(host_info, sizeof host_info);
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 1662c5a8f445..54289f4587a4 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -47,14 +47,6 @@ void ptdump_walk_user_pgd_level_checkwx(void);
#define debug_checkwx_user() do { } while (0)
#endif
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
- __visible;
-#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page))
-
extern spinlock_t pgd_lock;
extern struct list_head pgd_list;
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 80ef5d386b03..5171cb746444 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -441,10 +441,6 @@ initial_pg_fixmap:
swapper_pg_dir:
.fill 1024,4,0
.fill PTI_USER_PGD_FILL,4,0
-.globl empty_zero_page
-empty_zero_page:
- .fill 4096,1,0
-EXPORT_SYMBOL(empty_zero_page)
/*
* This starts the data section.
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 21816b48537c..cbf7647a25d8 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -712,10 +712,3 @@ SYM_PIC_ALIAS(phys_base);
EXPORT_SYMBOL(phys_base)
#include "../xen/xen-head.S"
-
- __PAGE_ALIGNED_BSS
-SYM_DATA_START_PAGE_ALIGNED(empty_zero_page)
- .skip PAGE_SIZE
-SYM_DATA_END(empty_zero_page)
-EXPORT_SYMBOL(empty_zero_page)
-
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 50a136213b2b..61f07d981a94 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -209,10 +209,6 @@
#define pgd_ERROR(e) \
printk("%s:%d: bad pgd entry %08lx.\n", __FILE__, __LINE__, pgd_val(e))
-extern unsigned long empty_zero_page[1024];
-
-#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
-
#ifdef CONFIG_MMU
extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)];
extern void paging_init(void);
diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index 8484294bc623..4b0c5c5e685a 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -381,6 +381,3 @@ ENTRY(swapper_pg_dir)
.fill PAGE_SIZE, 1, 0
END(swapper_pg_dir)
#endif
-ENTRY(empty_zero_page)
- .fill PAGE_SIZE, 1, 0
-END(empty_zero_page)
diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c
index 62d81e76e18e..ced335b4df5f 100644
--- a/arch/xtensa/kernel/xtensa_ksyms.c
+++ b/arch/xtensa/kernel/xtensa_ksyms.c
@@ -15,8 +15,6 @@
#include <linux/module.h>
#include <asm/pgtable.h>
-EXPORT_SYMBOL(empty_zero_page);
-
unsigned int __sync_fetch_and_and_4(volatile void *p, unsigned int v)
{
BUG();
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 4f063438a4fc..3687ea2ddedb 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -2188,6 +2188,14 @@ static inline const char *pgtable_level_to_str(enum pgtable_level level)
}
}
+#ifndef __HAVE_COLOR_ZERO_PAGE
+extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
+#endif
+
+#ifndef ZERO_PAGE
+#define ZERO_PAGE(vaddr) ((void)(vaddr),virt_to_page(empty_zero_page))
+#endif
+
#endif /* !__ASSEMBLY__ */
#if !defined(MAX_POSSIBLE_PHYSMEM_BITS) && !defined(CONFIG_64BIT)
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 1a29a719af58..8ea5b76f317f 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -53,6 +53,15 @@ EXPORT_SYMBOL(mem_map);
void *high_memory;
EXPORT_SYMBOL(high_memory);
+#ifndef __HAVE_COLOR_ZERO_PAGE
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss;
+EXPORT_SYMBOL(empty_zero_page);
+#endif
+
#ifdef CONFIG_DEBUG_MEMORY_INIT
int __meminitdata mminit_loglevel;
base-commit: 10de4550639e9df9242e32e9affc90ed75a27c7d
--
2.51.0
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