linux-toradex.git/kernel/taskstats.c, branch v2.6.32.52

Make TASKSTATS require root access

2011-12-21T21:04:53+00:00

commit 1a51410abe7d0ee4b1d112780f46df87d3621043 upstream.

Ok, this isn't optimal, since it means that 'iotop' needs admin
capabilities, and we may have to work on this some more.  But at the
same time it is very much not acceptable to let anybody just read
anybody elses IO statistics quite at this level.

Use of the GENL_ADMIN_PERM suggested by Johannes Berg as an alternative
to checking the capabilities by hand.

Reported-by: Vasiliy Kulikov 
Cc: Johannes Berg 
Acked-by: Balbir Singh 
Signed-off-by: Linus Torvalds 
Cc: Moritz Mühlenhoff 
Signed-off-by: Greg Kroah-Hartman

taskstats: don't allow duplicate entries in listener mode

2011-07-13T03:29:25+00:00

commit 26c4caea9d697043cc5a458b96411b86d7f6babd upstream.

Currently a single process may register exit handlers unlimited times.
It may lead to a bloated listeners chain and very slow process
terminations.

Eg after 10KK sent TASKSTATS_CMD_ATTR_REGISTER_CPUMASKs ~300 Mb of
kernel memory is stolen for the handlers chain and "time id" shows 2-7
seconds instead of normal 0.003.  It makes it possible to exhaust all
kernel memory and to eat much of CPU time by triggerring numerous exits
on a single CPU.

The patch limits the number of times a single process may register
itself on a single CPU to one.

One little issue is kept unfixed - as taskstats_exit() is called before
exit_files() in do_exit(), the orphaned listener entry (if it was not
explicitly deregistered) is kept until the next someone's exit() and
implicit deregistration in send_cpu_listeners().  So, if a process
registered itself as a listener exits and the next spawned process gets
the same pid, it would inherit taskstats attributes.

Signed-off-by: Vasiliy Kulikov 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

genetlink: make netns aware

2009-07-12T21:03:27+00:00

This makes generic netlink network namespace aware. No
generic netlink families except for the controller family
are made namespace aware, they need to be checked one by
one and then set the family->netnsok member to true.

A new function genlmsg_multicast_netns() is introduced to
allow sending a multicast message in a given namespace,
for example when it applies to an object that lives in
that namespace, a new function genlmsg_multicast_allns()
to send a message to all network namespaces (for objects
that do not have an associated netns).

The function genlmsg_multicast() is changed to multicast
the message in just init_net, which is currently correct
for all generic netlink families since they only work in
init_net right now. Some will later want to work in all
net namespaces because they do not care about the netns
at all -- those will have to be converted to use one of
the new functions genlmsg_multicast_allns() or
genlmsg_multicast_netns() whenever they are made netns
aware in some way.

After this patch families can easily decide whether or
not they should be available in all net namespaces. Many
genl families us it for objects not related to networking
and should therefore be available in all namespaces, but
that will have to be done on a per family basis.

Note that this doesn't touch on the checkpoint/restart
problem where network namespaces could be used, genl
families and multicast groups are numbered globally and
I see no easy way of changing that, especially since it
must be possible to multicast to all network namespaces
for those families that do not care about netns.

Signed-off-by: Johannes Berg 
Signed-off-by: David S. Miller

cpumask: convert rest of files in kernel/

2008-12-31T23:42:28+00:00

Impact: Reduce stack usage, use new cpumask API.

Mainly changing cpumask_t to 'struct cpumask' and similar simple API
conversion.  Two conversions worth mentioning:

1) we use cpumask_any_but to avoid a temporary in kernel/softlockup.c,
2) Use cpumask_var_t in taskstats_user_cmd().

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Cc: Balbir Singh 
Cc: Ingo Molnar

cpumask: change cpumask_scnprintf, cpumask_parse_user, cpulist_parse, and cpulist_scnprintf to take pointers.

2008-12-13T10:50:25+00:00

Impact: change calling convention of existing cpumask APIs

Most cpumask functions started with cpus_: these have been replaced by
cpumask_ ones which take struct cpumask pointers as expected.

These four functions don't have good replacement names; fortunately
they're rarely used, so we just change them over.

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Acked-by: Ingo Molnar 
Cc: paulus@samba.org
Cc: mingo@redhat.com
Cc: tony.luck@intel.com
Cc: ralf@linux-mips.org
Cc: Greg Kroah-Hartman 
Cc: cl@linux-foundation.org
Cc: srostedt@redhat.com

taskstats: remove initialization of static per-cpu variable

2008-07-25T17:53:47+00:00

Cc: Shailabh Nagar 
Signed-off-by: Vegard Nossum 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

core: use performance variant for_each_cpu_mask_nr

2008-05-23T16:35:12+00:00

Change references from for_each_cpu_mask to for_each_cpu_mask_nr
where appropriate

Reviewed-by: Paul Jackson 
Reviewed-by: Christoph Lameter 
Signed-off-by: Mike Travis 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

Use find_task_by_vpid in taskstats

2008-04-30T15:29:48+00:00

The pid to lookup a task by is passed inside taskstats code via genetlink
message.

Since netlink packets are now processed in the context of the sending task,
this is correct to lookup the task with find_task_by_vpid() here.

Besides, I fix the call to fill_pid() from taskstats_exit(), since the
tsk->pid is not required in fill_pid() in this case, and the pid field on
task_struct is going to be deprecated as well.

Signed-off-by: Pavel Emelyanov 
Cc: "Eric W. Biederman" 
Cc: Balbir Singh 
Cc: Jay Lan 
Cc: Jonathan Lim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kernel/taskstats.c: fix bogus nlmsg_free()

2007-11-15T02:45:44+00:00

We'd better not nlmsg_free on a pointer containing an undefined value
(and without having anything allocated).

Spotted by the Coverity checker.

Signed-off-by: Adrian Bunk 
Acked-by: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix misspellings of "system", "controller", "interrupt" and "necessary".

2007-10-19T21:10:43+00:00

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day 
Signed-off-by: Adrian Bunk