Re: [Qemu-devel] [PATCH] linux-user: Implement renameat2 when defined

[Peter Maydell]

On 20 December 2017 at 00:29, Palmer Dabbelt <address@hidden> wrote:
> +#if defined(TARGET_NR_renameat2) && defined(__NR_renameat2)
> +    case TARGET_NR_renameat2:
> +        {
> +            void *p2;
> +            p  = lock_user_string(arg2);
> +            p2 = lock_user_string(arg4);
> +            if (!p || !p2)
> +                ret = -TARGET_EFAULT;
> +            else
> +                ret = get_errno(syscall(__NR_renameat2, arg1, p, arg3, p2, 
> arg5));
> +            unlock_user(p2, arg4, 0);
> +            unlock_user(p, arg2, 0);
> +        }
> +        break;
> +#endif

Should we have code to handle using plain renameat for flags==0
calls? renameat2() only arrived in 3.15 kernels, so as it stands
this patch will work on a smaller set of hosts than it might.

thanks
-- PMM