Re: [PATCH] KVM/MIPS32: Export min_low_pfn.

[David Daney <ddaney.cavm@gmail.com>]

On 05/17/2013 02:06 PM, Sanjay Lal wrote:
> The KVM module uses the standard MIPS cache management routines, which use min_low_pfn.
> This creates and indirect dependency, requiring min_low_pfn to be exported.
>
> Signed-off-by: Sanjay Lal <sanjayl@kymasys.com>
> ---
>   arch/mips/kernel/mips_ksyms.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/arch/mips/kernel/mips_ksyms.c b/arch/mips/kernel/mips_ksyms.c
> index 6e58e97..0299472 100644
> --- a/arch/mips/kernel/mips_ksyms.c
> +++ b/arch/mips/kernel/mips_ksyms.c
> @@ -14,6 +14,7 @@
>   #include <linux/mm.h>
>   #include <asm/uaccess.h>
>   #include <asm/ftrace.h>
> +#include <linux/bootmem.h>
>
>   extern void *__bzero(void *__s, size_t __count);
>   extern long __strncpy_from_user_nocheck_asm(char *__to,
> @@ -60,3 +61,8 @@ EXPORT_SYMBOL(invalid_pte_table);
>   /* _mcount is defined in arch/mips/kernel/mcount.S */
>   EXPORT_SYMBOL(_mcount);
>   #endif
> +
> +/* The KVM module uses the standard MIPS cache functions which use
> + * min_low_pfn, requiring it to be exported.
> + */
> +EXPORT_SYMBOL(min_low_pfn);

I think I asked this before, but I don't remember the answer:

Why not put EXPORT_SYMBOL(min_low_pfn) in mm/bootmem.c adjacent to where 
the symbol is defined?

Cluttering up the kernel with multiple architectures all doing 
architecture specific exports of the same symbol is not a clean way of 
doing things.

The second time something needs to be done, it should be factored out 
into common code.

David Daney

>