lkml.org 
[lkml]   [2014]   [May]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V2 1/6] namespaces: assign each namespace instance a serial number
On 14/05/13, Richard Guy Briggs wrote:
> On 14/05/10, Eric Paris wrote:
> > On Fri, 2014-05-09 at 20:27 -0400, Richard Guy Briggs wrote:
> > > Generate and assign a serial number per namespace instance since boot.
> > >
> > > Use a serial number per namespace (unique across one boot of one kernel)
> > > instead of the inode number (which is claimed to have had the right to change
> > > reserved and is not necessarily unique if there is more than one proc fs) to
> > > uniquely identify it per kernel boot.
> > >
> > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > > ---
> >
> > > +/**
> > > + * ns_serial - compute a serial number for the namespace
> > > + *
> > > + * Compute a serial number for the namespace to uniquely identify it in
> > > + * audit records.
> > > + */
> > > +unsigned long long ns_serial(void)
> > > +{
> > > + static DEFINE_SPINLOCK(serial_lock);
> > > + static unsigned long long serial = 4; /* reserved for IPC, UTS, user, PID */
> > > + unsigned long flags;
> > > +
> > > + spin_lock_irqsave(&serial_lock, flags);
> > > + ++serial;
> > > + spin_unlock_irqrestore(&serial_lock, flags);
> > > + BUG_ON(!serial);
> > > +
> > > + return serial;
> > > +}
> > > +
> > > static inline struct nsproxy *create_nsproxy(void)
> > > {
> > > struct nsproxy *nsproxy;
> >
> > atomic64_t instead of doing it yourself?
>
> I'm willing to switch to atomic64_*. Thanks for pointing out its
> existence.

Same would then go for using atomic_t in audit_serial().

> > and why _irqsave() ? Can we seriously create new namespaces in irq
> > context? If you use the atomic though, you don't have to worry about
> > it...
>
> Agreed. That is unlikely.
>
> - RGB
>
> --
> Richard Guy Briggs <rbriggs@redhat.com>
> Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
> Remote, Ottawa, Canada
> Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545

- RGB

--
Richard Guy Briggs <rbriggs@redhat.com>
Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat
Remote, Ottawa, Canada
Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545


\
 
 \ /
  Last update: 2014-05-14 03:41    [W:0.945 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site