linux-toradex.git/fs/proc/base.c, branch v2.6.32.31

procfs: fix tid fdinfo

2010-05-12T21:57:03+00:00

commit 3835541dd481091c4dbf5ef83c08aed12e50fd61 upstream.

Correct the file_operations struct in fdinfo entry of tid_base_stuff[].

Presently /proc/*/task/*/fdinfo contains symlinks to opened files like
/proc/*/fd/.

Signed-off-by: Jerome Marchand 
Cc: Alexander Viro 
Cc: Miklos Szeredi 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

oom: fix the unsafe usage of badness() in proc_oom_score()

2010-04-26T14:41:13+00:00

commit b95c35e76b29ba812e5dabdd91592e25ec640e93 upstream.

proc_oom_score(task) has a reference to task_struct, but that is all.
If this task was already released before we take tasklist_lock

	- we can't use task->group_leader, it points to nowhere

	- it is not safe to call badness() even if this task is
	  ->group_leader, has_intersects_mems_allowed() assumes
	  it is safe to iterate over ->thread_group list.

	- even worse, badness() can hit ->signal == NULL

Add the pid_alive() check to ensure __unhash_process() was not called.

Also, use "task" instead of task->group_leader. badness() should return
the same result for any sub-thread. Currently this is not true, but
this should be changed anyway.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Switch proc/self to nd_set_link()

2010-03-15T15:49:37+00:00

commit 7fee4868be91e71a3ee8e57289ebf5e10a12297e upstream.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

pidns: fix a leak in /proc dentries and inodes with pid namespaces.

2009-11-12T15:25:57+00:00

Daniel Lezcano reported a leak in 'struct pid' and 'struct pid_namespace'
that is discussed in:

	http://lkml.org/lkml/2009/10/2/159.

To summarize the thread, when container-init is terminated, it sets the
PF_EXITING flag, zaps other processes in the container and waits to reap
them.  As a part of reaping, the container-init should flush any /proc
dentries associated with the processes.  But because the container-init is
itself exiting and the following PF_EXITING check, the dentries are not
flushed, resulting in leak in /proc inodes and dentries.

This fix reverts the commit 7766755a2f249e7e0 ("Fix /proc dcache deadlock
in do_exit") which introduced the check for PF_EXITING.  At the time of
the commit, shrink_dcache_parent() flushed dentries from other filesystems
also and could have caused a deadlock which the commit fixed.  But as
pointed out by Eric Biederman, after commit 0feae5c47aabdde59,
shrink_dcache_parent() no longer affects other filesystems.  So reverting
the commit is now safe.

As pointed out by Jan Kara, the leak is not as critical since the
unclaimed space will be reclaimed under memory pressure or by:

	echo 3 > /proc/sys/vm/drop_caches

But since this check is no longer required, its best to remove it.

Signed-off-by: Sukadev Bhattiprolu 
Reported-by: Daniel Lezcano 
Acked-by: Eric W. Biederman 
Acked-by: Jan Kara 
Cc: Andrea Arcangeli 
Cc: Serge Hallyn 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/proc/base.c: fix proc_fault_inject_write() input sanity check

2009-09-23T14:39:40+00:00

Remove obfuscated zero-length input check and return -EINVAL instead of
-EIO error to make the error message clear to user.  Add whitespace
stripping.  No functionality changes.

The old code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Input/output error)

The new code:

echo  1  > /proc/pid/make-it-fail (ok)
echo 1foo > /proc/pid/make-it-fail (-bash: echo: write error: Invalid argument)

This patch is conservative in changes to not breaking existing
scripts/applications.

Signed-off-by: Vincent Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc_flush_task: flush /proc/tid/task/pid when a sub-thread exits

2009-09-23T14:39:40+00:00

The exiting sub-thread flushes /proc/pid only, but this doesn't buy too
much: ps and friends mostly use /proc/tid/task/pid.

Remove "if (thread_group_leader())" checks from proc_flush_task() path,
this means we always remove /proc/tid/task/pid dentry on exit, and this
actually matches the comment above proc_flush_task().

The test-case:

	static void* tfunc(void *arg)
	{
		char name[256];

		sprintf(name, "/proc/%d/task/%ld/status", getpid(), gettid());
		close(open(name, O_RDONLY));

		return NULL;
	}

	int main(void)
	{
		pthread_t t;

		for (;;) {
			if (!pthread_create(&t, NULL, &tfunc, NULL))
				pthread_join(t, NULL);
		}
	}

slabtop shows that pid/proc_inode_cache/etc grow quickly and
"indefinitely" until the task is killed or shrink_slab() is called, not
good.  And the main thread needs a lot of time to exit.

The same can happen if something like "ps -efL" runs continuously, while
some application spawns short-living threads.

Reported-by: "James M. Leddy" 
Signed-off-by: Oleg Nesterov 
Cc: Alexey Dobriyan 
Cc: "Eric W. Biederman" 
Cc: Dominic Duval 
Cc: Frank Hirtz 
Cc: "Fuller, Johnray" 
Cc: Larry Woodman 
Cc: Paul Batkowski 
Cc: Roland McGrath 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: fix reported unit for RLIMIT_CPU

2009-09-23T14:39:40+00:00

/proc/$pid/limits should show RLIMIT_CPU as seconds, which is the unit
used in kernel/posix-cpu-timers.c:

        unsigned long psecs = cputime_to_secs(ptime);
        ...
        if (psecs >= sig->rlim[RLIMIT_CPU].rlim_max) {
                ...
                __group_send_sig_info(SIGKILL, SEND_SIG_PRIV, tsk);

Signed-off-by: Kees Cook 
Acked-by: WANG Cong 
Acked-by: Neil Horman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: fix oom_adjust_write() input sanity check

2009-09-22T14:17:39+00:00

Andrew Morton pointed out oom_adjust_write() has very strange EIO
and new line handling. this patch fixes it.

Signed-off-by: KOSAKI Motohiro 
Cc: Paul Menage 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: make oom_score to per-process value

2009-09-22T14:17:39+00:00

oom-killer kills a process, not task.  Then oom_score should be calculated
as per-process too.  it makes consistency more and makes speed up
select_bad_process().

Signed-off-by: KOSAKI Motohiro 
Cc: Paul Menage 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: move oom_adj value from task_struct to signal_struct

2009-09-22T14:17:39+00:00

Currently, OOM logic callflow is here.

    __out_of_memory()
        select_bad_process()            for each task
            badness()                   calculate badness of one task
                oom_kill_process()      search child
                    oom_kill_task()     kill target task and mm shared tasks with it

example, process-A have two thread, thread-A and thread-B and it have very
fat memory and each thread have following oom_adj and oom_score.

     thread-A: oom_adj = OOM_DISABLE, oom_score = 0
     thread-B: oom_adj = 0,           oom_score = very-high

Then, select_bad_process() select thread-B, but oom_kill_task() refuse
kill the task because thread-A have OOM_DISABLE.  Thus __out_of_memory()
call select_bad_process() again.  but select_bad_process() select the same
task.  It mean kernel fall in livelock.

The fact is, select_bad_process() must select killable task.  otherwise
OOM logic go into livelock.

And root cause is, oom_adj shouldn't be per-thread value.  it should be
per-process value because OOM-killer kill a process, not thread.  Thus
This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct signal_struct.  it naturally prevent
select_bad_process() choose wrong task.

Signed-off-by: KOSAKI Motohiro 
Cc: Paul Menage 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: Rik van Riel 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds