* [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
[not found] ` <cover.1390495874.git.rgb@redhat.com>
@ 2014-01-23 19:32 ` Richard Guy Briggs
2014-02-20 19:01 ` Oleg Nesterov
2014-03-17 20:14 ` Tony Luck
0 siblings, 2 replies; 6+ messages in thread
From: Richard Guy Briggs @ 2014-01-23 19:32 UTC (permalink / raw)
To: linux-audit, linux-kernel
Cc: Richard Guy Briggs, eparis, sgrubb, akpm, peterz, oleg, stable,
Eric W. Biederman
Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
arbitrary and init_pid_ns.
This provides an alternative to sys_getppid(), which is relative to the child
process' pid namespace.
(informed by ebiederman's 6c621b7e)
Cc: stable@vger.kernel.org
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
include/linux/sched.h | 18 ++++++++++++++++++
1 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2016d92..cba2486 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1561,6 +1561,24 @@ static inline pid_t task_tgid_vnr(const struct task_struct *tsk)
}
+static int pid_alive(const struct task_struct *p);
+static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
+{
+ pid_t pid = 0;
+
+ rcu_read_lock();
+ if (pid_alive(tsk))
+ pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
+ rcu_read_unlock();
+
+ return pid;
+}
+
+static inline pid_t task_ppid_nr(const struct task_struct *tsk)
+{
+ return task_ppid_nr_ns(tsk, &init_pid_ns);
+}
+
static inline pid_t task_pgrp_nr_ns(const struct task_struct *tsk,
struct pid_namespace *ns)
{
--
1.7.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
2014-01-23 19:32 ` [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns Richard Guy Briggs
@ 2014-02-20 19:01 ` Oleg Nesterov
2014-02-21 18:10 ` Richard Guy Briggs
2014-03-17 20:14 ` Tony Luck
1 sibling, 1 reply; 6+ messages in thread
From: Oleg Nesterov @ 2014-02-20 19:01 UTC (permalink / raw)
To: Richard Guy Briggs
Cc: linux-audit, linux-kernel, eparis, sgrubb, akpm, peterz, stable,
Eric W. Biederman
On 01/23, Richard Guy Briggs wrote:
>
> Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
> of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
> arbitrary and init_pid_ns.
> This provides an alternative to sys_getppid(), which is relative to the child
> process' pid namespace.
I agree, this makes sense.
imho it would be better to send this patch along with sys_getppid()
conversions, but I won't argue.
> +static int pid_alive(const struct task_struct *p);
> +static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
> +{
> + pid_t pid = 0;
> +
> + rcu_read_lock();
> + if (pid_alive(tsk))
> + pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
> + rcu_read_unlock();
> +
> + return pid;
> +}
Perhaps it should be named task_ptgid_nr_ns() or even parent_tgid_nr_ns().
Since it returns tgid, not pid (== tid).
But this is cosmetic, I won't insist.
Oleg.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
2014-02-20 19:01 ` Oleg Nesterov
@ 2014-02-21 18:10 ` Richard Guy Briggs
2014-02-24 18:32 ` Oleg Nesterov
0 siblings, 1 reply; 6+ messages in thread
From: Richard Guy Briggs @ 2014-02-21 18:10 UTC (permalink / raw)
To: Oleg Nesterov
Cc: peterz, linux-kernel, linux-audit, stable, akpm,
Eric W. Biederman
On 14/02/20, Oleg Nesterov wrote:
> On 01/23, Richard Guy Briggs wrote:
> >
> > Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
> > of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
> > arbitrary and init_pid_ns.
> > This provides an alternative to sys_getppid(), which is relative to the child
> > process' pid namespace.
>
> I agree, this makes sense.
>
>
> imho it would be better to send this patch along with sys_getppid()
> conversions, but I won't argue.
I don't think sys_getppid() should be changed since it is a syscall
whose userspace user would assume the working namespace. Many of the
kernel internal uses of it are likely wrong though, so fixing that
should probably fall under another patch. I fixed audit in another
patch.
> > +static int pid_alive(const struct task_struct *p);
> > +static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
> > +{
> > + pid_t pid = 0;
> > +
> > + rcu_read_lock();
> > + if (pid_alive(tsk))
> > + pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
> > + rcu_read_unlock();
> > +
> > + return pid;
> > +}
>
> Perhaps it should be named task_ptgid_nr_ns() or even parent_tgid_nr_ns().
> Since it returns tgid, not pid (== tid).
I like task_ptgid_nr_ns() (or maybe even task_parent_tgid_nr_ns() but
that gets a bit long.
> But this is cosmetic, I won't insist.
>
> Oleg.
- 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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
2014-02-21 18:10 ` Richard Guy Briggs
@ 2014-02-24 18:32 ` Oleg Nesterov
0 siblings, 0 replies; 6+ messages in thread
From: Oleg Nesterov @ 2014-02-24 18:32 UTC (permalink / raw)
To: Richard Guy Briggs
Cc: peterz, linux-kernel, linux-audit, stable, akpm,
Eric W. Biederman
On 02/21, Richard Guy Briggs wrote:
>
> On 14/02/20, Oleg Nesterov wrote:
> >
> > imho it would be better to send this patch along with sys_getppid()
> > conversions, but I won't argue.
>
> I don't think sys_getppid() should be changed since it is a syscall
> whose userspace user would assume the working namespace.
Sorry for confusion, I didn't mean we need to change sys_getppid(),
> Many of the
> kernel internal uses of it are likely wrong though, so fixing that
> should probably fall under another patch. I fixed audit in another
> patch.
Yes, this is what I meant. And this patch should probably go into
that series which fixes the in-kernel users of sys_getppid().
And in fact you already did this? I see another series which resends
this patch as 1/5.
Oleg.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
2014-01-23 19:32 ` [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns Richard Guy Briggs
2014-02-20 19:01 ` Oleg Nesterov
@ 2014-03-17 20:14 ` Tony Luck
2014-03-17 20:15 ` Eric Paris
1 sibling, 1 reply; 6+ messages in thread
From: Tony Luck @ 2014-03-17 20:14 UTC (permalink / raw)
To: Richard Guy Briggs
Cc: linux-audit, Linux Kernel Mailing List, Eric Paris, sgrubb,
Andrew Morton, Peter Zijlstra, Oleg Nesterov, stable,
Eric W. Biederman
On Thu, Jan 23, 2014 at 11:32 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
> of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
> arbitrary and init_pid_ns.
> This provides an alternative to sys_getppid(), which is relative to the child
> process' pid namespace.
...
> +static int pid_alive(const struct task_struct *p);
This patch (or some successor version of it) showed up
in next-20140317 and the above declaration caused a
bunch of warnings on ia64:
include/linux/sched.h:1718: warning: 'pid_alive' declared inline after
being called
[repeated 1675 times across files that include this]
The ia64 complier is a lot happier if "inline" is added like this:
static inline int pid_alive(const struct task_struct *p);
-Tony
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns
2014-03-17 20:14 ` Tony Luck
@ 2014-03-17 20:15 ` Eric Paris
0 siblings, 0 replies; 6+ messages in thread
From: Eric Paris @ 2014-03-17 20:15 UTC (permalink / raw)
To: Tony Luck
Cc: Richard Guy Briggs, linux-audit, Linux Kernel Mailing List,
sgrubb, Andrew Morton, Peter Zijlstra, Oleg Nesterov, stable,
Eric W. Biederman
On Mon, 2014-03-17 at 13:14 -0700, Tony Luck wrote:
> On Thu, Jan 23, 2014 at 11:32 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
> > Added the functions task_ppid_nr_ns() and task_ppid_nr() to abstract the lookup
> > of the PPID (real_parent's pid_t) of a process, including rcu locking, in the
> > arbitrary and init_pid_ns.
> > This provides an alternative to sys_getppid(), which is relative to the child
> > process' pid namespace.
> ...
> > +static int pid_alive(const struct task_struct *p);
>
> This patch (or some successor version of it) showed up
> in next-20140317 and the above declaration caused a
> bunch of warnings on ia64:
>
> include/linux/sched.h:1718: warning: 'pid_alive' declared inline after
> being called
>
> [repeated 1675 times across files that include this]
>
> The ia64 complier is a lot happier if "inline" is added like this:
>
> static inline int pid_alive(const struct task_struct *p);
Fixed for tomorrow.
^ permalink raw reply [flat|nested] 6+ messages in thread
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[not found] ` <cover.1390495874.git.rgb@redhat.com>
2014-01-23 19:32 ` [PATCH 7/7] pid: get pid_t ppid of task in init_pid_ns Richard Guy Briggs
2014-02-20 19:01 ` Oleg Nesterov
2014-02-21 18:10 ` Richard Guy Briggs
2014-02-24 18:32 ` Oleg Nesterov
2014-03-17 20:14 ` Tony Luck
2014-03-17 20:15 ` Eric Paris
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