Re: [resend][PATCH v9 2/3] /proc/PID/status: show all sets of pid according to ns

Re: [resend][PATCH v9 2/3] /proc/PID/status: show all sets of pid according to ns

[Nathan Scott]

Hi Chen, Eric,

Eric W. Biederman <ebiederm@xmission.com> writes:
> Chen Hanxiao <chenhanxiao@cn.fujitsu.com> writes:
> > If some issues occurred inside a container guest, host user
> > could not know which process is in trouble just by guest pid:
> > [...]
> > Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
> > Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
> >
> > Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
> 
> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
> 
> At a quick review and read through this looks good.  Once I finish
> clearing the security bug fixes from my tree I will see about picking
> this up.

I recently came across a need for this patch so I just wanted to
say thanks and since I've used it a fair bit feel free to add:

Tested-by: Nathan Scott <nathans@redhat.com>

One small tweak you could make is to drop the extra whitespace
from those new seq_printf calls - "\t%d " has a trailing space
that isn't needed.

Also there's proc status docs below Documentation/ that should be
updated for these changes.  They are slightly out-of-date already
and there's a few typos in the vicinity - something like this may
do the trick though ... ?  (will need to be updated at merge time
with the correct kernel version)


docs: add missing and new /proc/PID/status file entries, fix typos

Signed-off-by: Nathan Scott <nathans@redhat.com>

diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index aae9dd1..457cebd 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -197,12 +197,12 @@ contains details information about the process itself.  Its fields are
 explained in Table 1-4.
 
 (for SMP CONFIG users)
-For making accounting scalable, RSS related information are handled in
-asynchronous manner and the vaule may not be very precise. To see a precise
+For making accounting scalable, RSS related information are handled in an
+asynchronous manner and the value may not be very precise. To see a precise
 snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
 It's slow but very precise.
 
-Table 1-2: Contents of the status files (as of 2.6.30-rc7)
+Table 1-2: Contents of the status files (as of 3.20.0)
 ..............................................................................
  Field                       Content
  Name                        filename of the executable
@@ -210,6 +210,7 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
                              in an uninterruptible wait, Z is zombie,
 			     T is traced or stopped)
  Tgid                        thread group ID
+ Ngid                        NUMA group ID (0 if none)
  Pid                         process id
  PPid                        process id of the parent process
  TracerPid                   PID of process tracing this process (0 if not)
@@ -217,6 +218,10 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
  Gid                         Real, effective, saved set, and  file system GIDs
  FDSize                      number of file descriptor slots currently allocated
  Groups                      supplementary group list
+ NStgid                      descendant namespace thread group ID hierarchy
+ NSpid                       descendant namespace process ID hierarchy
+ NSpgid                      descendant namespace process group ID hierarchy
+ NSsid                       descendant namespace session ID hierarchy
  VmPeak                      peak virtual memory size
  VmSize                      total program size
  VmLck                       locked memory size

Re: [resend][PATCH v9 2/3] /proc/PID/status: show all sets of pid according to ns

[Eric W. Biederman]

Chen Hanxiao <chenhanxiao@cn.fujitsu.com> writes:

> If some issues occurred inside a container guest, host user
> could not know which process is in trouble just by guest pid:
> the users of container guest only knew the pid inside containers.
> This will bring obstacle for trouble shooting.
>
> This patch adds four fields: NStgid, NSpid, NSpgid and NSsid:
> a) In init_pid_ns, nothing changed;
>
> b) In one pidns, will tell the pid inside containers:
>   NStgid: 21776   5       1
>   NSpid:  21776   5       1
>   NSpgid: 21776   5       1
>   NSsid:  21729   1       0
>   ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2.
>
> c) If pidns is nested, it depends on which pidns are you in.
>   NStgid: 5       1
>   NSpid:  5       1
>   NSpgid: 5       1
>   NSsid:  1       0
>   ** Views from level 1
>
> Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
> Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
>
> Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>

At a quick review and read through this looks good.  Once I finish
clearing the security bug fixes from my tree I will see about picking this
up.

Eric


> ---
> v9: rebased on 3.19-rc1
> No change from v4-v8
> v3: add another two fielsd: NSpgid and NSsid.
> v2: add two new fields: NStgid and NSpid.
>     keep fields of Tgid and Pid unchanged for back compatibility.
>
>  fs/proc/array.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>
> diff --git a/fs/proc/array.c b/fs/proc/array.c
> index bd117d0..35205d4 100644
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -208,6 +208,22 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
>  			   from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
>  	put_cred(cred);
>  
> +	seq_puts(m, "\nNStgid:");
> +	for (g = ns->level; g <= pid->level; g++)
> +		seq_printf(m, "\t%d ",
> +			task_tgid_nr_ns(p, pid->numbers[g].ns));
> +	seq_puts(m, "\nNSpid:");
> +	for (g = ns->level; g <= pid->level; g++)
> +		seq_printf(m, "\t%d ",
> +			task_pid_nr_ns(p, pid->numbers[g].ns));
> +	seq_puts(m, "\nNSpgid:");
> +	for (g = ns->level; g <= pid->level; g++)
> +		seq_printf(m, "\t%d ",
> +			task_pgrp_nr_ns(p, pid->numbers[g].ns));
> +	seq_puts(m, "\nNSsid:");
> +	for (g = ns->level; g <= pid->level; g++)
> +		seq_printf(m, "\t%d ",
> +			task_session_nr_ns(p, pid->numbers[g].ns));
>  	seq_putc(m, '\n');
>  }

[resend][PATCH v9 2/3] /proc/PID/status: show all sets of pid according to ns

[Chen Hanxiao]

If some issues occurred inside a container guest, host user
could not know which process is in trouble just by guest pid:
the users of container guest only knew the pid inside containers.
This will bring obstacle for trouble shooting.

This patch adds four fields: NStgid, NSpid, NSpgid and NSsid:
a) In init_pid_ns, nothing changed;

b) In one pidns, will tell the pid inside containers:
  NStgid: 21776   5       1
  NSpid:  21776   5       1
  NSpgid: 21776   5       1
  NSsid:  21729   1       0
  ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2.

c) If pidns is nested, it depends on which pidns are you in.
  NStgid: 5       1
  NSpid:  5       1
  NSpgid: 5       1
  NSsid:  1       0
  ** Views from level 1

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Tested-by: Serge Hallyn <serge.hallyn@canonical.com>

Signed-off-by: Chen Hanxiao <chenhanxiao@cn.fujitsu.com>
---
v9: rebased on 3.19-rc1
No change from v4-v8
v3: add another two fielsd: NSpgid and NSsid.
v2: add two new fields: NStgid and NSpid.
    keep fields of Tgid and Pid unchanged for back compatibility.

 fs/proc/array.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index bd117d0..35205d4 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -208,6 +208,22 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
 			   from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
 	put_cred(cred);
 
+	seq_puts(m, "\nNStgid:");
+	for (g = ns->level; g <= pid->level; g++)
+		seq_printf(m, "\t%d ",
+			task_tgid_nr_ns(p, pid->numbers[g].ns));
+	seq_puts(m, "\nNSpid:");
+	for (g = ns->level; g <= pid->level; g++)
+		seq_printf(m, "\t%d ",
+			task_pid_nr_ns(p, pid->numbers[g].ns));
+	seq_puts(m, "\nNSpgid:");
+	for (g = ns->level; g <= pid->level; g++)
+		seq_printf(m, "\t%d ",
+			task_pgrp_nr_ns(p, pid->numbers[g].ns));
+	seq_puts(m, "\nNSsid:");
+	for (g = ns->level; g <= pid->level; g++)
+		seq_printf(m, "\t%d ",
+			task_session_nr_ns(p, pid->numbers[g].ns));
 	seq_putc(m, '\n');
 }
 
-- 
1.9.3