[CRIU] [PATCH] vdso: Defer handling untill all zones are restored

[Andrew Vagin]

On Mon, Aug 04, 2014 at 04:55:32PM +0400, Cyrill Gorcunov wrote:
> In worst case we might be tryin to proxify vdso zone
> when vvar only is remmaped but vdso itself is not yet
> (left and right zones shifting). Thus vdso_proxify
> will complain that vdso is not yet mapped refusing
> to restore.
> 
> Thus wait until everything is re-mapped then call
> for proxification helper.

Acked-by: Andrew Vagin <avagin at parallels.com>

> 
> Reported: Mr. Jenkins
> Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
> ---
>  pie/restorer.c | 34 ++++++++++++++++------------------
>  1 file changed, 16 insertions(+), 18 deletions(-)
> 
> diff --git a/pie/restorer.c b/pie/restorer.c
> index 1b05f59edefe..16a75bf0c0d0 100644
> --- a/pie/restorer.c
> +++ b/pie/restorer.c
> @@ -728,15 +728,6 @@ long __export_restore_task(struct task_restore_args *args)
>  		if (vma_remap(vma_premmaped_start(vma_entry),
>  				vma_entry->start, vma_entry_len(vma_entry)))
>  			goto core_restore_end;
> -#ifdef CONFIG_VDSO
> -		if (vma_entry_is(vma_entry, VMA_AREA_VDSO) ||
> -		    vma_entry_is(vma_entry, VMA_AREA_VVAR)) {
> -			if (vdso_proxify("left dumpee", &args->vdso_sym_rt,
> -					 args->vdso_rt_parked_at,
> -					 i, args->tgt_vmas, args->nr_vmas))
> -				goto core_restore_end;
> -		}
> -#endif
>  	}
>  
>  	/* Shift private vma-s to the right */
> @@ -758,15 +749,6 @@ long __export_restore_task(struct task_restore_args *args)
>  		if (vma_remap(vma_premmaped_start(vma_entry),
>  				vma_entry->start, vma_entry_len(vma_entry)))
>  			goto core_restore_end;
> -#ifdef CONFIG_VDSO
> -		if (vma_entry_is(vma_entry, VMA_AREA_VDSO) ||
> -		    vma_entry_is(vma_entry, VMA_AREA_VVAR)) {
> -			if (vdso_proxify("right dumpee", &args->vdso_sym_rt,
> -					 args->vdso_rt_parked_at,
> -					 i, args->tgt_vmas, args->nr_vmas))
> -				goto core_restore_end;
> -		}
> -#endif
>  	}
>  
>  	/*
> @@ -789,6 +771,22 @@ long __export_restore_task(struct task_restore_args *args)
>  		}
>  	}
>  
> +#ifdef CONFIG_VDSO
> +	/*
> +	 * Proxify vDSO.
> +	 */
> +	for (i = 0; i < args->nr_vmas; i++) {
> +		if (vma_entry_is(vma_entry, VMA_AREA_VDSO) ||
> +		    vma_entry_is(vma_entry, VMA_AREA_VVAR)) {
> +			if (vdso_proxify("dumpee", &args->vdso_sym_rt,
> +					 args->vdso_rt_parked_at,
> +					 i, args->tgt_vmas, args->nr_vmas))
> +				goto core_restore_end;
> +			break;
> +		}
> +	}
> +#endif
> +
>  	/*
>  	 * Walk though all VMAs again to drop PROT_WRITE
>  	 * if it was not there.
> -- 
> 1.9.3
>