linux-kernel - Re: [PATCH] Introduce ActivePid: in /proc/self/status (v2, was Vpid:)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1308238412.8230.95.camel@bahia.local>
Date:	Thu, 16 Jun 2011 17:33:32 +0200
From:	Greg Kurz <gkurz@...ibm.com>
To:	"Eric W. Biederman" <ebiederm@...ssion.com>
Cc:	Cedric Le Goater <clg@...t.ibm.com>,
	Oleg Nesterov <oleg@...hat.com>, linux-kernel@...r.kernel.org,
	containers@...ts.osdl.org, akpm@...ux-foundation.org,
	xemul@...nvz.org
Subject: Re: [PATCH] Introduce ActivePid: in /proc/self/status (v2, was
 Vpid:)

On Thu, 2011-06-16 at 08:07 -0700, Eric W. Biederman wrote:
> > Finally, we thought that the 'ActivePid' information was interesting 
> > enough to be exposed in /proc and was solving the case we're facing 
> > rather easily with some framework (cgroups) in user space.
> 
> The pid number by which a process knows itself doesn't seem
> unreasonable.  I'm not totally 
> 
> After having a second look at the code in proc we already have
> a reference to the struct pid we want to print.  So simply
> printing
> pid->numbers[pid->level].nr
> seems reasonable, and race free.
> 
> Alternatively that could be written.
> pid_nr_ns(pid, ns_of_pid(pid));
> 
> Eric

So we end up with the following, since pid is valid:

diff --git a/fs/proc/array.c b/fs/proc/array.c
index 5e4f776..b7316cc 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -183,12 +183,14 @@ static inline void task_state(struct seq_file *m,
struct pid_namespace *ns,
 		"Pid:\t%d\n"
 		"PPid:\t%d\n"
 		"TracerPid:\t%d\n"
+		"ActivePid:\t%d\n"
 		"Uid:\t%d\t%d\t%d\t%d\n"
 		"Gid:\t%d\t%d\t%d\t%d\n",
 		get_task_state(p),
 		task_tgid_nr_ns(p, ns),
 		pid_nr_ns(pid, ns),
 		ppid, tpid,
+		pid_nr_ns(pid, ns_of_pid(pid)),
 		cred->uid, cred->euid, cred->suid, cred->fsuid,
 		cred->gid, cred->egid, cred->sgid, cred->fsgid);

-- 
Gregory Kurz                                     gkurz@...ibm.com
Software Engineer @ IBM/Meiosys                  http://www.ibm.com
Tel +33 (0)534 638 479                           Fax +33 (0)561 400 420

"Anarchy is about taking complete responsibility for yourself."
        Alan Moore.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/