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Commit Graph

95607 Commits

Author SHA1 Message Date
Oleg Nesterov
7e695a5ef5 signals: fold sig_ignored() into handle_stop_signal()
Rename handle_stop_signal() to prepare_signal(), make it return a boolean, and
move the callsites of sig_ignored() into it.

No functional changes for now.  But it would be nice to factor out the "should
we drop this signal" checks as much as possible, before we try to fix the bugs
with the sub-namespace init's signals (actually the global /sbin/init has some
problems with signals too).

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
2dce81bff2 signals: cleanup the usage of print_fatal_signal()
Move the callsite of print_fatal_signal() down, under "if
(sig_kernel_coredump(signr))", so we don't need to check signr != SIGKILL.

We are only interested in the sig_kernel_coredump() signals anyway, and due to
the previous changes we almost never can see other fatal signals here except
SIGKILL.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
34c8f07b9a signals: handle_stop_signal: don't worry about SIGKILL
handle_stop_signal() clears SIGNAL_STOP_DEQUEUED when sig == SIGKILL.  Remove
this nasty special case.  It was needed to prevent the race with group stop
and exit caused by thread-specific SIGKILL.  Now that we use complete_signal()
for private signals too this is not needed, complete_signal() will notice
SIGKILL and abort the soon-to-begin group stop.

Except: the target thread is dead (has PF_EXITING).  But in that case we
should not just clear SIGNAL_STOP_DEQUEUED and nothing more.  We should either
kill the whole thread group, or silently ignore the signal.

I suspect we are not right wrt zombie leaders, but this is another issue which
and should be fixed separately.  Note that this check can't abort the group
stop if it was already started/finished, this check only adds a subtle side
effect if we race with the thread which has already dequeued sig_kernel_stop()
signal and temporary released ->siglock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
ac5c215383 signals: join send_sigqueue() with send_group_sigqueue()
We export send_sigqueue() and send_group_sigqueue() for the only user,
posix_timer_event().  This is a bit silly, because both are just trivial
helpers on top of do_send_sigqueue() and because the we pass the unused
.si_signo parameter.

Kill them both, rename do_send_sigqueue() to send_sigqueue(), and export it.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
e62e6650e9 signals: unify send_sigqueue/send_group_sigqueue completely
Suggested by Pavel Emelyanov.

send_sigqueue/send_group_sigqueue are only differ in how they lock ->siglock.
Unify them.  send_group_sigqueue() uses spin_lock() because it knows the task
can't exit, but in that case lock_task_sighand() can't fail and doesn't hurt.

Note that the "sig" argument is ignored, it is always equal to ->si_signo.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Pavel Emelyanov
4cd4b6d4e0 signals: fold complete_signal() into send_signal/do_send_sigqueue
Factor out complete_signal() callsites.  This change completely unifies the
helpers sending the specific/group signals.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
5fcd835bf8 signals: use __group_complete_signal() for the specific signals too
Based on Pavel Emelyanov's suggestion.

Rename __group_complete_signal() to complete_signal() and use it to process
the specific signals too.  To do this we simply add the "int group" argument.

This allows us to greatly simply the signal-sending code and adds a useful
behaviour change.  We can avoid the unneeded wakeups for the private signals
because wants_signal() is more clever than sigismember(blocked), but more
importantly we now take into account the fatal specific signals too.

The latter allows us to kill some subtle checks in handle_stop_signal() and
makes the specific/group signal's behaviour more consistent.  For example,
currently sigtimedwait(FATAL_SIGNAL) behaves differently depending on was the
signal sent by kill() or tkill() if the signal was not blocked.

And.  This allows us to tweak/fix the behaviour when the specific signal is
sent to the dying/dead ->group_leader.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:36 -07:00
Oleg Nesterov
2ca3515aa5 signals: change send_signal/do_send_sigqueue to take "boolean group" parameter
send_signal() is used either with ->pending or with ->signal->shared_pending.
Change it to take "int group" instead, this argument will be re-used later.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
71f11dc025 signals: move the definition of __group_complete_signal() up
Move the unchanged definition of __group_complete_signal() so that send_signal
can see it.  To simplify the reading of the next patches.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
db51aeccd7 signals: microoptimize the usage of ->curr_target
Suggested by Roland McGrath.

Initialize signal->curr_target in copy_signal().  This way ->curr_target is
never == NULL, we can kill the check in __group_complete_signal's hot path.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
08d2c30ce9 signals: send_sig_info: don't take tasklist_lock
The comment in send_sig_info() is wrong, tasklist_lock can't help.

The caller must ensure the task can't go away, otherwise ->sighand can be NULL
even before we take the lock.

p->sighand could be changed by exec(), but I can't imagine how it is possible
to prevent exit(), but not exec().

Since the things seem to work, I assume all callers are correct.  However,
drm_vbl_send_signals() looks broken.  block_all_signals() which is solely used
by drm is definitely broken.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
3547ff3aef signals: do_tkill: don't use tasklist_lock
Convert do_tkill() to use rcu_read_lock() + lock_task_sighand() to avoid
taking tasklist lock.

Note that we don't return an error if lock_task_sighand() fails, we pretend
the task dies after receiving the signal.  Otherwise, we should fight with the
nasty races with mt-exec without having any advantage.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
6e65acba7c signals: move handle_stop_signal() into send_signal()
Move handle_stop_signal() into send_signal().  This factors out a couple of
callsites and allows us to do further unifications.

Also, with this change specific_send_sig_info() does handle_stop_signal().
Not that this is really important, we never send STOP/CONT via send_sig() and
friends, but still this looks more consistent.

The only (afaics) special case is get_signal_to_deliver().  If the traced task
dequeues SIGCONT, it can re-send it to itself after ptrace_stop() if the
signal was blocked by debugger.  In that case handle_stop_signal() is
unnecessary, but hopefully not a problem.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
c99fcf28b8 signals: send_group_sigqueue: don't take tasklist_lock
handle_stop_signal() was changed, now send_group_sigqueue() doesn't need
tasklist_lock.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
f8c5b5c06f signals: __group_complete_signal: cache the value of p->signal
Cosmetic, cache p->signal to make the code a bit more readable.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
5fc894bb4f signals: send_sigqueue: don't forget about handle_stop_signal()
send_group_sigqueue() calls handle_stop_signal(), send_sigqueue() doesn't.
This is not consistent and in fact I'd say this is (minor) bug.

Move handle_stop_signal() from send_group_sigqueue() to do_send_sigqueue(),
the latter is called by send_sigqueue() too.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
5c193e8871 signals: send_sigqueue: don't take rcu lock
lock_task_sighand() was changed, send_sigqueue() doesn't need rcu_read_lock()
any longer.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
f6b76d4fb0 get_signal_to_deliver: use the cached ->signal/sighand values
Cache the values of current->signal/sighand.  Shrinks .text a bit and makes
the code more readable.  Also, remove "sigset_t *mask", it is pointless
because in fact we save the constant offset.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:35 -07:00
Oleg Nesterov
ad16a46069 handle_stop_signal: use the cached p->signal value
Cache the value of p->signal, and change the code to use while_each_thread()
helper.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
fc321d2e60 handle_stop_signal: unify partial/full stop handling
Now that handle_stop_signal() doesn't drop ->siglock, we can't see both
->group_stop_count && SIGNAL_STOP_STOPPED.  Merge two "if" branches.

As Roland pointed out, we never actually needed 2 do_notify_parent_cldstop()
calls.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
6ca25b5513 kill_pid_info: don't take now unneeded tasklist_lock
Previously handle_stop_signal(SIGCONT) could drop ->siglock.  That is why
kill_pid_info(SIGCONT) takes tasklist_lock to make sure the target task can't
go away after unlock.  Not needed now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
e442055193 signals: re-assign CLD_CONTINUED notification from the sender to reciever
Based on discussion with Jiri and Roland.

In short: currently handle_stop_signal(SIGCONT, p) sends the notification to
p->parent, with this patch p itself notifies its parent when it becomes
running.

handle_stop_signal(SIGCONT) has to drop ->siglock temporary in order to notify
the parent with do_notify_parent_cldstop().  This leads to multiple problems:

	- as Jiri Kosina pointed out, the stopped task can resume without
	  actually seeing SIGCONT which may have a handler.

	- we race with another sig_kernel_stop() signal which may come in
	  that window.

	- we race with sig_fatal() signals which may set SIGNAL_GROUP_EXIT
	  in that window.

	- we can't avoid taking tasklist_lock() while sending SIGCONT.

With this patch handle_stop_signal() just sets the new SIGNAL_CLD_CONTINUED
flag in p->signal->flags and returns.  The notification is sent by the first
task which returns from finish_stop() (there should be at least one) or any
other signalled thread from get_signal_to_deliver().

This is a user-visible change.  Say, currently kill(SIGCONT, stopped_child)
can't return without seeing SIGCHLD, with this patch SIGCHLD can be delayed
unpredictably.  Another difference is that if the child is ptraced by another
process, CLD_CONTINUED may be delivered to ->real_parent after ptrace_detach()
while currently it always goes to the tracer which doesn't actually need this
notification.  Hopefully not a problem.

The patch asks for the futher obvious cleanups, I'll send them separately.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
3b5e9e53c6 signals: cleanup security_task_kill() usage/implementation
Every implementation of ->task_kill() does nothing when the signal comes from
the kernel.  This is correct, but means that check_kill_permission() should
call security_task_kill() only for SI_FROMUSER() case, and we can remove the
same check from ->task_kill() implementations.

(sadly, check_kill_permission() is the last user of signal->session/__session
 but we can't s/task_session_nr/task_session/ here).

NOTE: Eric W.  Biederman pointed out cap_task_kill() should die, and I think
he is very right.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: David Quigley <dpquigl@tycho.nsa.gov>
Cc: Eric Paris <eparis@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
9e3bd6c3fb signals: consolidate send_sigqueue and send_group_sigqueue
Both functions do the same thing after proper locking, but with
different sigpending structs, so move the common code into a helper.

After this we have 4 places that look very similar: send_sigqueue: calls
do_send_sigqueue and signal_wakeup send_group_sigqueue: calls
do_send_sigqueue and __group_complete_signal __group_send_sig_info:
calls send_signal and __group_complete_signal specific_send_sig_info:
calls send_signal and signal_wakeup

Besides, send_signal performs actions similar to do_send_sigqueue's
and __group_complete_signal - to signal_wakeup.

It looks like they can be consolidated gracefully.

Oleg said:

  Personally, I think this change is very good.  But send_sigqueue() and
  send_group_sigqueue() have a very subtle difference which I was never able
  to understand.

  Let's suppose that sigqueue is already queued, and the signal is ignored
  (the latter means we should re-schedule cpu timer or handle overrruns).  In
  that case send_sigqueue() returns 0, but send_group_sigqueue() returns 1.

  I think this is not the problem (in fact, I think this patch makes the
  behaviour more correct), but I hope Thomas can take a look and confirm.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
c5363d0363 signals: clean dequeue_signal from excess checks and assignments
The signr variable may be declared without initialization - it is set ro the
return value from __dequeue_signal() right at the function beginning.

Besides, after recalc_sigpending() two checks for signr to be not 0 may be
merged into one.  Both if-s become easier to read.

Thanks to Oleg for pointing out mistakes in the first version of this patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Pavel Emelyanov
93585eeaf3 signals: consolidate checks for whether or not to ignore a signal
Both sig_ignored() and do_sigaction() check for signr to be explicitly or
implicitly ignored.  Introduce a helper for them.

This patch is aimed to help handling signals by pid namespace's init, and was
derived from one of Oleg's patches
https://lists.linux-foundation.org/pipermail/containers/2007-December/009308.html
so, if he doesn't mind, he should be considered as an author.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
06fffb1267 do_task_stat: don't take rcu_read_lock()
lock_task_sighand() was changed, and do_task_stat() doesn't need
rcu_read_lock any longer.  sighand->siglock protects all "interesting"
fields.

Except: it doesn't protect ->tty->pgrp, but neither does rcu_read_lock(), this
should be fixed.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Pavel Emelyanov <xemul@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
d6cf723a14 k_getrusage: don't take rcu_read_lock()
Just a trivial example, more to come.

k_getrusage() holds rcu_read_lock() because it was previously required by
lock_task_sighand().  Unneeded now.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
Oleg Nesterov
1406f2d321 lock_task_sighand: add rcu lock/unlock
Most of the callers of lock_task_sighand() doesn't actually need rcu_lock().
lock_task_sighand() needs it only to safely play with tsk->sighand, it can
take the lock itself.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Oleg Nesterov
bfc4b0890a signals: do_group_exit(): use signal_group_exit() more consistently
do_group_exit() checks SIGNAL_GROUP_EXIT to avoid taking sighand->siglock.
Since ed5d2cac11 exec() doesn't set this
flag, we should use signal_group_exit().

This is not needed for correctness, but can speedup the multithreaded exec
and makes the code more consistent.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Oleg Nesterov
573cf9ad72 signals: do_signal_stop(): use signal_group_exit()
do_signal_stop() needs signal_group_exit() but checks sig->group_exit_task.
 This (optimization) is correct, SIGNAL_STOP_DEQUEUED and SIGNAL_GROUP_EXIT
are mutually exclusive, but looks confusing.  Use signal_group_exit(), this
is not fastpath, the code clarity is more important.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
2acb024d55 signals: consolidate checking for ignored/legacy signals
Two callers for send_signal() - the specific_send_sig_info and the
__group_send_sig_info - both check for sig to be ignored or already queued.

Move these checks into send_signal() and make it return 1 to indicate that the
signal is dropped, but there's no error in this.

Besides, merge comments and spell-check them.

[oleg@tv-sign.ru: simplifications]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
af7fff9c13 signals: turn LEGACY_QUEUE macro into static inline function
This makes the code more readable, due to less brackets and small letters in
name.

I also move it above the send_signal() as a preparation for the 3rd patch.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Pavel Emelyanov
e1401c6bbb signals: remove unused variable from send_signal()
This function doesn't change the ret's value and thus always returns 0, with a
single exception of returning -EAGAIN explicitly.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Jan Kara
2deb1acc65 isofs: fix access to unallocated memory when reading corrupted filesystem
When a directory on isofs is corrupted, we did not check whether length of the
name in a directory entry and the length of the directory entry itself are
consistent.  This could lead to possible access beyond the end of buffer when
the length of the name was too big.  Add this sanity check to directory
reading code.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Dan Williams
6bfe0b4990 md: support blocking writes to an array on device failure
Allows a userspace metadata handler to take action upon detecting a device
failure.

Based on an original patch by Neil Brown.

Changes:
-added blocked_wait waitqueue to rdev
-don't qualify Blocked with Faulty always let userspace block writes
-added md_wait_for_blocked_rdev to wait for the block device to be clear, if
 userspace misses the notification another one is sent every 5 seconds
-set MD_RECOVERY_NEEDED after clearing "blocked"
-kill DoBlock flag, just test mddev->external

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Dan Williams
11e2ede022 md: prevent duplicates in bind_rdev_to_array
Found when trying to reassemble an active externally managed array.  Without
this check we hit the more noisy "sysfs duplicate" warning in the later call
to kobject_add.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
Dan Williams
242b363e22 md: remove a stray command from a copy and paste error in resync_start_store
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:33 -07:00
NeilBrown
648b629ed4 md: fix up switching md arrays between read-only and read-write
When setting an array to 'readonly' or to 'active' via sysfs, we must make the
appropriate set_disk_ro call too.

Also when switching to "read_auto" (which is like readonly, but blocks on the
first write so that metadata can be marked 'dirty') we need to be more careful
about what state we are changing from.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
NeilBrown
31a59e3425 md: fix 'safemode' handling for external metadata.
'safemode' relates to marking an array as 'clean' if there has been no write
traffic for a while (a couple of seconds), to reduce the chance of the array
being found dirty on reboot.

->safemode is set to '1' when there have been no write for a while, and it
gets set to '0' when the superblock is updates with the 'clean' flag set.

This requires a few fixes for 'external' metadata:
 - When an array is set to 'clean' via sysfs, 'safemode' must be cleared.
 - when we write to an array that has 'safemode' set (there must have been
        some delay in updating the metadata), we need to clear safemode.
 - Don't try to update external metadata in md_check_recovery for safemode
        transitions - it won't work.

Also, don't try to support "immediate safe mode" (safemode==2) for external
metadata, it cannot really work (the safemode timeout can be set very low if
this is really needed).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
NeilBrown
d897dbf914 md: reinitialise more mddev fields in do_md_stop.
I keep finding problems where an mddev gets reused and some fields has a value
from a previous usage that confuses the new usage.  So clear all fields that
could possible need clearing when calling do_md_stop.

Also initialise the 'level' of a new array to LEVEL_NONE (which isn't 0).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
NeilBrown
8377bc8080 md: skip all metadata update processing when using external metadata.
All the metadata update processing for external metadata is on in user-space
or through the sysfs interfaces, so make "md_update_sb" a no-op in that case.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Dan Williams
6a51830e14 md: fix use after free when removing rdev via sysfs
rdev->mddev is no longer valid upon return from entry->store() when the
'remove' command is given.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Eric Miao
7f1133cbf2 pxafb: preliminary smart panel interface support (update)
FB_PXA_SMARTPANEL defaults to "n" and removed the cast to void *.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Eric Miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Eric Miao
3c42a44910 pxafb: preliminary smart panel interface support
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Eric Miao
90eabbf0ec pxafb: move parallel LCD timing setup into dedicate function
the new_regs stuff has been removed, and all the setup (modification to those
fbi->reg_*) is protected with IRQ disabled

   * disable IRQ is too heavy here, provided that no IRQ context will
     touch the fbi->reg_* and the only possible contending place is
     in the CPUFREQ_POSTCHANGE (task context), a mutex will be better,
     leave this for future improvement

Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Eric Miao
2ba162b933 pxafb: use completion for LCD disable wait code
Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
Eric Miao
a7535ba730 pxafb: introduce lcd_{read,write}l() to wrap the __raw_{read,write}l()
using __raw_{read,write}l() everywhere looks messy, introduce
lcd_{read,write}l() to get this cleaned up a bit

Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:32 -07:00
eric miao
0454bd09de pxafb: make lubbock/mainstone/zylonite/littleton to use new LCD connection type
Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:31 -07:00
eric miao
84f43c308b pxafb: introduce register independent LCD connection type for pxafb
Reasons:

  1. straight forward: the name "LCD_COLOR_DSTN_16BPP" is much better
     than "LCCR0_Pas | LCCR0_Color | LCCR0_Dual"

  2. by defining LCD connection types as constants, it allows only
     valid possibilities

  3. by removing the dependency of register bits definitions, those
     can be later moved into the body of pxafb.c, instead of having
     a regs-lcd.h around

Currently, only lubbock, mainstone, zylonite and littleton have been
modified to support these types (see coming patches after this).
Other platforms are encouraged to change their way describing the
LCD controller connections.

Signed-off-by: eric miao <eric.miao@marvell.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:31 -07:00