[Devel] Re: [RFC][PATCH 4/5] utsname namespaces: sysctl hack

[Kirill Korotaev]

Serge,

can we do nothing with sysctls at this moment, instead of commiting hacks?

Thanks,
Kirill

> Sysctl uts patch.  This clearly will need to be done another way, but
> since sysctl itself needs to be container aware, 'the right thing' is
> a separate patchset.
> 
> Signed-off-by: Serge E. Hallyn <serue at us.ibm.com>
> ---
>  kernel/sysctl.c |   38 ++++++++++++++++++++++++++++----------
>  1 files changed, 28 insertions(+), 10 deletions(-)
> 
> 40f7e1320c82efb6e875fc3bf44408cdfd093f21
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index e82726f..c2b18ef 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -233,8 +233,8 @@ static ctl_table kern_table[] = {
>  	{
>  		.ctl_name	= KERN_OSTYPE,
>  		.procname	= "ostype",
> -		.data		= system_utsname.sysname,
> -		.maxlen		= sizeof(system_utsname.sysname),
> +		.data		= init_uts_ns.name.sysname,
> +		.maxlen		= sizeof(init_uts_ns.name.sysname),
>  		.mode		= 0444,
>  		.proc_handler	= &proc_doutsstring,
>  		.strategy	= &sysctl_string,
> @@ -242,8 +242,8 @@ static ctl_table kern_table[] = {
>  	{
>  		.ctl_name	= KERN_OSRELEASE,
>  		.procname	= "osrelease",
> -		.data		= system_utsname.release,
> -		.maxlen		= sizeof(system_utsname.release),
> +		.data		= init_uts_ns.name.release,
> +		.maxlen		= sizeof(init_uts_ns.name.release),
>  		.mode		= 0444,
>  		.proc_handler	= &proc_doutsstring,
>  		.strategy	= &sysctl_string,
> @@ -251,8 +251,8 @@ static ctl_table kern_table[] = {
>  	{
>  		.ctl_name	= KERN_VERSION,
>  		.procname	= "version",
> -		.data		= system_utsname.version,
> -		.maxlen		= sizeof(system_utsname.version),
> +		.data		= init_uts_ns.name.version,
> +		.maxlen		= sizeof(init_uts_ns.name.version),
>  		.mode		= 0444,
>  		.proc_handler	= &proc_doutsstring,
>  		.strategy	= &sysctl_string,
> @@ -260,8 +260,8 @@ static ctl_table kern_table[] = {
>  	{
>  		.ctl_name	= KERN_NODENAME,
>  		.procname	= "hostname",
> -		.data		= system_utsname.nodename,
> -		.maxlen		= sizeof(system_utsname.nodename),
> +		.data		= init_uts_ns.name.nodename,
> +		.maxlen		= sizeof(init_uts_ns.name.nodename),
>  		.mode		= 0644,
>  		.proc_handler	= &proc_doutsstring,
>  		.strategy	= &sysctl_string,
> @@ -269,8 +269,8 @@ static ctl_table kern_table[] = {
>  	{
>  		.ctl_name	= KERN_DOMAINNAME,
>  		.procname	= "domainname",
> -		.data		= system_utsname.domainname,
> -		.maxlen		= sizeof(system_utsname.domainname),
> +		.data		= init_uts_ns.name.domainname,
> +		.maxlen		= sizeof(init_uts_ns.name.domainname),
>  		.mode		= 0644,
>  		.proc_handler	= &proc_doutsstring,
>  		.strategy	= &sysctl_string,
> @@ -1619,6 +1619,24 @@ static int proc_doutsstring(ctl_table *t
>  {
>  	int r;
>  
> +	switch (table->ctl_name) {
> +		case KERN_OSTYPE:
> +			table->data = utsname()->sysname;
> +			break;
> +		case KERN_OSRELEASE:
> +			table->data = utsname()->release;
> +			break;
> +		case KERN_VERSION:
> +			table->data = utsname()->version;
> +			break;
> +		case KERN_NODENAME:
> +			table->data = utsname()->nodename;
> +			break;
> +		case KERN_DOMAINNAME:
> +			table->data = utsname()->domainname;
> +			break;
> +	}
> +
>  	if (!write) {
>  		down_read(&uts_sem);
>  		r=proc_dostring(table,0,filp,buffer,lenp, ppos);