Re: [PATCH 2/2] linux-user: Fix erroneous conversion in copy_file_range

[Laurent Vivier]

Le 03/05/2021 à 19:41, LemonBoy a écrit :
> From: Giuseppe Musacchio <thatlemon@gmail.com>
> 
> The implicit cast from abi_long to size_t may introduce an intermediate
> unwanted sign-extension of the value for 32bit targets running on 64bit
> hosts.
> 
> Signed-off-by: Giuseppe Musacchio <thatlemon@gmail.com>
> ---
>  linux-user/syscall.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 95d79ddc43..c425dfa278 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -13245,8 +13245,9 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>                  }
>                  poutoff = &outoff;
>              }
> +            /* Do not sign-extend the count parameter. */
>              ret = get_errno(safe_copy_file_range(arg1, pinoff, arg3, poutoff,
> -                                                 arg5, arg6));
> +                                                 (abi_ulong)arg5, arg6));
>              if (!is_error(ret) && ret > 0) {
>                  if (arg2) {
>                      if (put_user_u64(inoff, arg2)) {
> 

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