[PATCH] arm: Export needed symbol for ZERO_PAGE usage in modules.

[PATCH] arm: Export needed symbol for ZERO_PAGE usage in modules.

[Aneesh Kumar K.V]

ext4 use ZERO_PAGE(0) to zero out blocks. We need to export
different symbols in different arch for the usage of ZERO_PAGE
in modules.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/arm/mm/mmu.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index d41a75e..2d6d682 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -35,6 +35,7 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  * zero-initialized data and COW.
  */
 struct page *empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
 
 /*
  * The pmd table for the upper-most set of pages.
-- 
1.5.5.rc0.16.g02b00.dirty

Re: [PATCH] arm: Export needed symbol for ZERO_PAGE usage in modules.

[Andrew Morton]

On Mon, 24 Mar 2008 23:31:29 +0530
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> wrote:

> ext4 use ZERO_PAGE(0) to zero out blocks. We need to export
> different symbols in different arch for the usage of ZERO_PAGE
> in modules.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> ---
>  arch/arm/mm/mmu.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index d41a75e..2d6d682 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -35,6 +35,7 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
>   * zero-initialized data and COW.
>   */
>  struct page *empty_zero_page;
> +EXPORT_SYMBOL(empty_zero_page);
>  
>  /*

I wonder if it would be better to do this export in generic code.

Architectures which don't implement empty_zero_page:

alpha:		seems to do something fancy
sparc64: 	need to rename mem_map_zero to empty_zero_page
v850:		#define ZERO_PAGE(vaddr) ((void *)0x87654321)  (wtf?)