Re: [PATCH] linux-user: Implement copy_file_range

[Laurent Vivier]

Le 12/11/2020 à 12:45, Andreas Schwab a écrit :
> Signed-off-by: Andreas Schwab <schwab@suse.de>
> ---
>  linux-user/syscall.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 3160a9ba06..c3373af4c7 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -813,6 +813,12 @@ safe_syscall5(int, mq_timedsend, int, mqdes, const char 
> *, msg_ptr,
>  safe_syscall5(int, mq_timedreceive, int, mqdes, char *, msg_ptr,
>                size_t, len, unsigned *, prio, const struct timespec *, 
> timeout)
>  #endif
> +#if defined(TARGET_NR_copy_file_range) && defined(__NR_copy_file_range)
> +safe_syscall6(ssize_t, copy_file_range, int, infd, loff_t *, pinoff,
> +              int, outfd, loff_t *, poutoff, size_t, length,
> +              unsigned int, flags)
> +#endif
> +
>  /* We do ioctl like this rather than via safe_syscall3 to preserve the
>   * "third argument might be integer or pointer or not present" behaviour of
>   * the libc function.
> @@ -13057,6 +13063,40 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>          return get_errno(membarrier(arg1, arg2));
>  #endif
>  
> +#if defined(TARGET_NR_copy_file_range) && defined(__NR_copy_file_range)
> +    case TARGET_NR_copy_file_range:
> +        {
> +            loff_t inoff, outoff;
> +            loff_t *pinoff = NULL, *poutoff = NULL;
> +
> +            if (arg2) {
> +                if (get_user_u64(inoff, arg2)) {
> +                    return -TARGET_EFAULT;
> +                }
> +                pinoff = &inoff;
> +            }
> +            if (arg4) {
> +                if (get_user_u64(outoff, arg4)) {
> +                    return -TARGET_EFAULT;
> +                }
> +                poutoff = &outoff;
> +            }
> +            ret = get_errno(safe_copy_file_range(arg1, pinoff, arg3, poutoff,
> +                                                 arg5, arg6));
> +            if (arg2) {
> +                if (put_user_u64(inoff, arg2)) {
> +                    return -TARGET_EFAULT;
> +                }
> +            }
> +            if (arg4) {
> +                if (put_user_u64(outoff, arg4)) {
> +                    return -TARGET_EFAULT;
> +                }
> +            }
> +        }
> +        return ret;
> +#endif
> +
>      default:
>          qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
>          return -TARGET_ENOSYS;
> 

Applied to my branch linux-user-for-6.0, modified not to copy back offset when 
there is an error.

Thanks,
Laurent