linux.git/fs/proc/base.c, branch v2.6.33

Switch proc/self to nd_set_link()

2010-02-19T15:25:41+00:00

Signed-off-by: Al Viro

fix autofs/afs/etc. magic mountpoint breakage

2010-01-14T14:05:25+00:00

We end up trying to kfree() nd.last.name on open("/mnt/tmp", O_CREAT)
if /mnt/tmp is an autofs direct mount.  The reason is that nd.last_type
is bogus here; we want LAST_BIND for everything of that kind and we
get LAST_NORM left over from finding parent directory.

So make sure that it *is* set properly; set to LAST_BIND before
doing ->follow_link() - for normal symlinks it will be changed
by __vfs_follow_link() and everything else needs it set that way.

Signed-off-by: Al Viro

elf: kill USE_ELF_CORE_DUMP

2009-12-16T15:20:12+00:00

Currently all architectures but microblaze unconditionally define
USE_ELF_CORE_DUMP.  The microblaze omission seems like an error to me, so
let's kill this ifdef and make sure we are the same everywhere.

Signed-off-by: Christoph Hellwig 
Acked-by: Hugh Dickins 
Cc: 
Cc: Michal Simek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

procfs: allow threads to rename siblings via /proc/pid/tasks/tid/comm

2009-12-15T16:53:24+00:00

Setting a thread's comm to be something unique is a very useful ability
and is helpful for debugging complicated threaded applications.  However
currently the only way to set a thread name is for the thread to name
itself via the PR_SET_NAME prctl.

However, there may be situations where it would be advantageous for a
thread dispatcher to be naming the threads its managing, rather then
having the threads self-describe themselves.  This sort of behavior is
available on other systems via the pthread_setname_np() interface.

This patch exports a task's comm via proc/pid/comm and
proc/pid/task/tid/comm interfaces, and allows thread siblings to write to
these values.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: John Stultz 
Cc: Andi Kleen 
Cc: Arjan van de Ven 
Cc: Mike Fulton 
Cc: Sean Foley 
Cc: Darren Hart 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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