Re: [Qemu-devel] [PATCH v3] linux-user/mmap.c: Always zero MAP_ANONYMOUS memory in mmap_frag()

[Laurent Vivier <laurent@vivier.eu>]

Le 30/12/2015 02:10, chengang@emindsoft.com.cn a écrit :
> From: Chen Gang <chengang@emindsoft.com.cn>
> 
> When mapping MAP_ANONYMOUS memory fragments, still need notice about to
> set it zero, or it will cause issues.
> 
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
>  linux-user/mmap.c |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index 7b459d5..c6c478e 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -186,10 +186,12 @@ static int mmap_frag(abi_ulong real_start,
>          if (prot_new != (prot1 | PROT_WRITE))
>              mprotect(host_start, qemu_host_page_size, prot_new);
>      } else {
> -        /* just update the protection */
>          if (prot_new != prot1) {
>              mprotect(host_start, qemu_host_page_size, prot_new);
>          }
> +        if (prot_new & PROT_WRITE) {
> +            memset(g2h(start), 0, end - start);
> +        }
>      }
>      return 0;
>  }
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>