Re: [PATCH 2/3] mmap: round mmap hint address above mmap_min_addr

From: James Morris
Date: Fri Nov 16 2007 - 16:43:33 EST


On Fri, 16 Nov 2007, Eric Paris wrote:

> +#ifdef CONFIG_SECURITY
> + /*
> + * If a hint addr is less than mmap_min_addr change addr to be as
> + * low as possible but still greater than mmap_min_addr
> + */
> + if (!(flags & MAP_FIXED) && ((void *)addr != NULL) &&
> + (addr < mmap_min_addr))
> + addr = PAGE_ALIGN(mmap_min_addr);
> +#endif

Please make this a static inline which is optimized away with
!CONFIG_SECURITY.


> +
> error = arch_mmap_check(addr, len, flags);
> if (error)
> return error;
> diff --git a/mm/nommu.c b/mm/nommu.c
> index 35622c5..ea4d20a 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -829,6 +829,16 @@ unsigned long do_mmap_pgoff(struct file *file,
> void *result;
> int ret;
>
> +#ifdef CONFIG_SECURITY
> + /*
> + * If a hint addr is less than mmap_min_addr change addr to be as
> + * low as possible, but still greater than mmap_min_addr
> + */
> + if (!(flags & MAP_FIXED) && ((void *)addr != NULL) &&
> + (addr < mmap_min_addr))
> + addr = PAGE_ALIGN(mmap_min_addr);
> +#endif
> +
> /* decide whether we should attempt the mapping, and if so what sort of
> * mapping */
> ret = validate_mmap_request(file, addr, len, prot, flags, pgoff,
>
>

--
James Morris
<jmorris@xxxxxxxxx>
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