[CRIU] [PATCH 2/2] cr-check: add compat_restore check

[Pavel Emelyanov]

On 01/09/2017 07:59 PM, Dmitry Safonov wrote:
> Initialy, I thought to name it "compat_restore", but after I've dropped
> the second 32-bit parasite (which surely made compat code lesser and
> easier), our parasite works in 64-bit in 32-bit task and ptrace()
> for setting registers in this long-jumped situation will work correctly
> only after v4.9 kernel. Maybe it can be work-arounded if needed,
> but yet no compatible dump for pre-v4.9 kernels.
> 
> Requested-by: Andrei Vagin <avagin at virtuozzo.com>
> Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
> ---
>  criu/cr-check.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/criu/cr-check.c b/criu/cr-check.c
> index 60279e135dfa..94c5074557ce 100644
> --- a/criu/cr-check.c
> +++ b/criu/cr-check.c
> @@ -48,6 +48,7 @@
>  #include "libnetlink.h"
>  #include "net.h"
>  #include "linux/userfaultfd.h"
> +#include "restorer.h"
>  
>  static char *feature_name(int (*func)());
>  
> @@ -1134,6 +1135,14 @@ static int check_loginuid(void)
>  	return 0;
>  }
>  
> +static int check_compat_cr(void)

Call for this should also be added to cr_check()

> +{
> +	if (kdat_compat_sigreturn_test())
> +		return 0;
> +	pr_err("compat_cr is not supported. Requires kernel >= v4.9\n");
> +	return -1;
> +}
> +
>  struct feature_list {
>  	char *name;
>  	int (*func)();
> @@ -1154,6 +1163,7 @@ static struct feature_list feature_list[] = {
>  	{ "autofs", check_autofs },
>  	{ "tcp_half_closed", check_tcp_halt_closed },
>  	{ "lazy_pages", check_uffd },
> +	{ "compat_cr", check_compat_cr },
>  	{ NULL, NULL },
>  };
>  
>