Re: [git pull] x86 fix

[Harvey Harrison <harvey.harrison@gmail.com>]

On Sat, 2008-04-26 at 21:47 +0200, Ingo Molnar wrote:
> Linus, please pull this x86 fix from:
> 
>    git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-fixes2.git for-linus
> 
> Thanks,
> 
> 	Ingo
> 
> ------------------>
> Venki Pallipadi (1):
>       x86, PAT: disable /dev/mem mmap RAM with PAT
> 
>  arch/x86/mm/pat.c |   31 +++++++++++++++++++++++++++++++
>  1 files changed, 31 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
> index 9851265..e7ca7fc 100644
> --- a/arch/x86/mm/pat.c
> +++ b/arch/x86/mm/pat.c
> @@ -16,6 +16,7 @@
>  #include <asm/msr.h>
>  #include <asm/tlbflush.h>
>  #include <asm/processor.h>
> +#include <asm/page.h>
>  #include <asm/pgtable.h>
>  #include <asm/pat.h>
>  #include <asm/e820.h>
> @@ -477,6 +478,33 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
>  	return vma_prot;
>  }
>  
> +#ifdef CONFIG_NONPROMISC_DEVMEM
> +/* This check is done in drivers/char/mem.c in case of NONPROMISC_DEVMEM*/
> +static inline int range_is_allowed(unsigned long pfn, unsigned long size)
> +{
> +	return 1;
> +}
> +#else
> +static inline int range_is_allowed(unsigned long pfn, unsigned long size)

inline?  Seems a bit big to me.

> +{
> +	u64 from = ((u64)pfn) << PAGE_SHIFT;
> +	u64 to = from + size;
> +	u64 cursor = from;
> +
> +	while (cursor < to) {
> +		if (!devmem_is_allowed(pfn)) {
> +			printk(KERN_INFO
> +		"Program %s tried to access /dev/mem between %Lx->%Lx.\n",
> +				current->comm, from, to);
> +			return 0;
> +		}
> +		cursor += PAGE_SIZE;
> +		pfn++;
> +	}
> +	return 1;
> +}
> +#endif /* CONFIG_NONPROMISC_DEVMEM */
> +

Cheers,

Harvey