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2008-04-30document de_thread() with exit_notify() connectionOleg Nesterov1-0/+1
Add a couple of small comments, it is not easy to see what this code does. 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>
2008-04-30reparent_thread: use same_thread_group()Oleg Nesterov1-1/+1
Trivial, use same_thread_group() in reparent_thread(). 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>
2008-04-30ptrace: introduce task_detached() helperOleg Nesterov1-20/+25
exit.c has numerous "->exit_signal == -1" comparisons, this check is subtle and deserves a helper. Imho makes the code more parseable for humans. At least it's surely more greppable. Also, a couple of whitespace cleanups. No functional changes. 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>
2008-04-30signals: add set_restore_sigmaskRoland McGrath2-3/+2
This adds the set_restore_sigmask() inline in <linux/thread_info.h> and replaces every set_thread_flag(TIF_RESTORE_SIGMASK) with a call to it. No change, but abstracts the details of the flag protocol from all the calls. Signed-off-by: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: allow the kernel to actually kill /sbin/initOleg Nesterov1-1/+4
Currently the buggy /sbin/init hangs if SIGSEGV/etc happens. The kernel sends the signal, init dequeues it and ignores, returns from the exception, repeats the faulting instruction, and so on forever. Imho, such a behaviour is not good. I think that the explicit loud death of the buggy /sbin/init is better than the silent hang. Change force_sig_info() to clear SIGNAL_UNKILLABLE when the task should be really killed. 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>
2008-04-30signals: fix /sbin/init protection from unwanted signalsOleg Nesterov1-3/+6
The global init has a lot of long standing problems with the unhandled fatal signals. - The "is_global_init(current)" check in get_signal_to_deliver() protects only the main thread. Sub-thread can dequee the fatal signal and shutdown the whole thread group except the main thread. If it dequeues SIGSTOP /sbin/init will be stopped, this is not right too. Note that we can't use is_global_init(->group_leader), this breaks exec and this can't solve other problems we have. - Even if afterwards ignored, the fatal signals sets SIGNAL_GROUP_EXIT on delivery. This breaks exec, has other bad implications, and this is just wrong. Introduce the new SIGNAL_UNKILLABLE flag to fix these problems. It also helps to solve some other problems addressed by the subsequent patches. Currently we use this flag for the global init only, but it could also be used by kthreads and (perhaps) by the sub-namespace inits. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: "Eric W. Biederman" <ebiederm@xmission.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>
2008-04-30signals: check_kill_permission: remove tasklist_lockOleg Nesterov1-2/+0
Now that task_session() can't return a false NULL, check_kill_permission() 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>
2008-04-30signals: check_kill_permission: check session under tasklist_lockOleg Nesterov1-5/+19
This wasn't documented, but as Atsushi Tsuji pointed out check_kill_permission() needs tasklist_lock for task_session_nr(). I missed this fact when removed tasklist from the callers. Change check_kill_permission() to take tasklist_lock for the SIGCONT case. Re-order security checks so that we take tasklist_lock only if/when it is actually needed. This is a minimal fix for now, tasklist will be removed later. Also change the code to use task_session() instead of task_session_nr(). Also, remove the SIGCONT check from cap_task_kill(), it is bogus (and the whole function is bogus. Serge, Eric, why it is still alive?). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Atsushi Tsuji <a-tsuji@bk.jp.nec.com> Cc: Roland McGrath <roland@redhat.com> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: send_signal: be paranoid about signalfd_notify()Oleg Nesterov1-7/+1
send_signal() shouldn't call signalfd_notify() if it then fails with -EAGAIN. Harmless, just a paranoid cleanup. Also remove the comment. It is obsolete, signalfd_notify() was simplified and does a simple wakeup. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Davide Libenzi <davidel@xmailserver.org> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30signals: document CLD_CONTINUED notification mechanicsOleg Nesterov1-1/+10
A couple of small comments about how CLD_CONTINUED notification works. 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>
2008-04-30signals: fold sig_ignored() into handle_stop_signal()Oleg Nesterov1-15/+17
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>
2008-04-30signals: cleanup the usage of print_fatal_signal()Oleg Nesterov1-2/+3
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>
2008-04-30signals: handle_stop_signal: don't worry about SIGKILLOleg Nesterov1-6/+0
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>
2008-04-30signals: join send_sigqueue() with send_group_sigqueue()Oleg Nesterov2-18/+3
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>
2008-04-30signals: unify send_sigqueue/send_group_sigqueue completelyOleg Nesterov1-37/+21
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>
2008-04-30signals: fold complete_signal() into send_signal/do_send_sigqueuePavel Emelyanov1-35/+11
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>
2008-04-30signals: use __group_complete_signal() for the specific signals tooOleg Nesterov1-9/+6
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>
2008-04-30signals: change send_signal/do_send_sigqueue to take "boolean group" parameterOleg Nesterov1-9/+16
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>
2008-04-30signals: move the definition of __group_complete_signal() upOleg Nesterov1-96/+96
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>
2008-04-30signals: microoptimize the usage of ->curr_targetOleg Nesterov2-5/+1
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>
2008-04-30signals: send_sig_info: don't take tasklist_lockOleg Nesterov1-10/+1
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>
2008-04-30signals: do_tkill: don't use tasklist_lockOleg Nesterov1-5/+9
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>
2008-04-30signals: move handle_stop_signal() into send_signal()Oleg Nesterov1-8/+3
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>
2008-04-30signals: send_group_sigqueue: don't take tasklist_lockOleg Nesterov1-2/+1
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>
2008-04-30signals: __group_complete_signal: cache the value of p->signalOleg Nesterov1-8/+9
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>
2008-04-30signals: send_sigqueue: don't forget about handle_stop_signal()Oleg Nesterov1-2/+3
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>
2008-04-30signals: send_sigqueue: don't take rcu lockOleg Nesterov1-4/+0
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>
2008-04-30get_signal_to_deliver: use the cached ->signal/sighand valuesOleg Nesterov1-15/+15
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>
2008-04-30handle_stop_signal: use the cached p->signal valueOleg Nesterov1-15/+13
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>
2008-04-30handle_stop_signal: unify partial/full stop handlingOleg Nesterov1-26/+19
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>
2008-04-30kill_pid_info: don't take now unneeded tasklist_lockOleg Nesterov1-6/+1
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>
2008-04-30signals: re-assign CLD_CONTINUED notification from the sender to recieverOleg Nesterov1-10/+19
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>
2008-04-30signals: cleanup security_task_kill() usage/implementationOleg Nesterov1-13/+14
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>
2008-04-30signals: consolidate send_sigqueue and send_group_sigqueuePavel Emelyanov1-57/+29
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>
2008-04-30signals: clean dequeue_signal from excess checks and assignmentsPavel Emelyanov1-5/+7
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>
2008-04-30signals: consolidate checks for whether or not to ignore a signalPavel Emelyanov1-10/+14
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>
2008-04-30k_getrusage: don't take rcu_read_lock()Oleg Nesterov1-6/+1
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>
2008-04-30lock_task_sighand: add rcu lock/unlockOleg Nesterov1-3/+2
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>
2008-04-30signals: do_group_exit(): use signal_group_exit() more consistentlyOleg Nesterov1-3/+4
do_group_exit() checks SIGNAL_GROUP_EXIT to avoid taking sighand->siglock. Since ed5d2cac114202fe2978a9cbcab8f5032796d538 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>
2008-04-30signals: do_signal_stop(): use signal_group_exit()Oleg Nesterov1-1/+1
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>
2008-04-30signals: consolidate checking for ignored/legacy signalsPavel Emelyanov1-25/+17
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>
2008-04-30signals: turn LEGACY_QUEUE macro into static inline functionPavel Emelyanov1-5/+7
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>
2008-04-30signals: remove unused variable from send_signal()Pavel Emelyanov1-2/+1
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>
2008-04-29Merge branch 'audit.b50' of ↵Linus Torvalds4-112/+235
git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current * 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: [PATCH] new predicate - AUDIT_FILETYPE [patch 2/2] Use find_task_by_vpid in audit code [patch 1/2] audit: let userspace fully control TTY input auditing [PATCH 2/2] audit: fix sparse shadowed variable warnings [PATCH 1/2] audit: move extern declarations to audit.h Audit: MAINTAINERS update Audit: increase the maximum length of the key field Audit: standardize string audit interfaces Audit: stop deadlock from signals under load Audit: save audit_backlog_limit audit messages in case auditd comes back Audit: collect sessionid in netlink messages Audit: end printk with newline
2008-04-29Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds1-1/+1
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: Skip I/O merges when disabled block: add large command support block: replace sizeof(rq->cmd) with BLK_MAX_CDB ide: use blk_rq_init() to initialize the request block: use blk_rq_init() to initialize the request block: rename and export rq_init() block: no need to initialize rq->cmd with blk_get_request block: no need to initialize rq->cmd in prepare_flush_fn hook block/blk-barrier.c:blk_ordered_cur_seq() mustn't be inline block/elevator.c:elv_rq_merge_ok() mustn't be inline block: make queue flags non-atomic block: add dma alignment and padding support to blk_rq_map_kern unexport blk_max_pfn ps3disk: Remove superfluous cast block: make rq_init() do a full memset() relay: fix splice problem
2008-04-29Add kbuild.h that contains common definitions for kbuild usersChristoph Lameter1-5/+1
The same definitions are used for the bounds logic and the asm-offsets.h generation by kbuild. Put them into include/linux/kbuild.h file. Also add a new feature COMMENT("text") which can be used to insert lines of ocmments into asm-offsets.h and bounds.h. Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jay Estabrook <jay.estabrook@hp.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Chris Zankel <chris@zankel.net> Cc: David S. Miller <davem@davemloft.net> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Bryan Wu <bryan.wu@analog.com> Cc: Mike Frysinger <vapier.adi@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Greg Ungerer <gerg@uclinux.org> Cc: David Howells <dhowells@redhat.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Grant Grundler <grundler@parisc-linux.org> Cc: Matthew Wilcox <matthew@wil.cx> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Miles Bader <miles@gnu.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29relayfs: support larger relay bufferMasami Hiramatsu1-3/+32
Use vmalloc() and memset() instead of kcalloc() to allocate a page* array when the array size is bigger than one page. This enables relayfs to support bigger relay buffers than 64MB on 4k-page system, 512MB on 16k-page system. [akpm@linux-foundation.org: cleanup] Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: David Wilder <dwilder@us.ibm.com> Reviewed-by: Tom Zanussi <zanussi@comcast.net> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29Remove duplicated unlikely() in IS_ERR()Hirofumi Nakagawa1-5/+5
Some drivers have duplicated unlikely() macros. IS_ERR() already has unlikely() in itself. This patch cleans up such pointless code. Signed-off-by: Hirofumi Nakagawa <hnakagawa@miraclelinux.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Jeff Garzik <jeff@garzik.org> Cc: Paul Clements <paul.clements@steeleye.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Carsten Otte <cotte@de.ibm.com> Cc: Patrick McHardy <kaber@trash.net> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.de> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29sysctl: add the ->permissions callback on the ctl_table_rootPavel Emelyanov1-7/+18
When reading from/writing to some table, a root, which this table came from, may affect this table's permissions, depending on who is working with the table. The core hunk is at the bottom of this patch. All the rest is just pushing the ctl_table_root argument up to the sysctl_perm() function. This will be mostly (only?) used in the net sysctls. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29sysctl: clean from unneeded extern and forward declarationsPavel Emelyanov1-76/+68
The do_sysctl_strategy isn't used outside kernel/sysctl.c, so this can be static and without a prototype in header. Besides, move this one and parse_table() above their callers and drop the forward declarations of the latter call. One more "besides" - fix two checkpatch warnings: space before a ( and an extra space at the end of a line. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>