Re: [Qemu-devel] [PATCH] mmap: add check if requested memory area fits target address space

["Edgar E. Iglesias" <edgar.iglesias@axis.com>]

On Wed, Dec 03, 2008 at 01:29:43PM +0200, Kirill A. Shutemov wrote:
> Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
> ---
>  linux-user/mmap.c |   10 ++++++++++
>  1 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index d96917d..52e2dc8 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -389,6 +389,16 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
>          end = start + len;
>          real_end = HOST_PAGE_ALIGN(end);
>  
> +	/*
> +	 * Test if requested memory area fits target address space
> +	 * It can fail only on 64-bit host with 32-bit target.
> +	 * On any other target/host host mmap() handles this error correctly.
> +	 */
> +        if ((unsigned long)start + len - 1 > (abi_ulong) -1) {
> +            errno = EINVAL;
> +            goto fail;
> +        }
> +
>          for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) {
>              flg = page_get_flags(addr);
>              if (flg & PAGE_RESERVED) {

Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>