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2008-04-30signals: fold complete_signal() into send_signal/do_send_sigqueuePavel Emelyanov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Emelyanov
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 Emelyanov
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 Emelyanov
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 Nesterov
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 Nesterov
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 Nesterov
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 Nesterov
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 Emelyanov
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 Emelyanov
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 Emelyanov
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 Torvalds
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 Torvalds
* '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 Lameter
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 Hiramatsu
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 Nakagawa
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 Emelyanov
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 Emelyanov
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>
2008-04-29sysctl: allow embedded targets to disable sysctl_check.cHolger Schurig
Disable sysctl_check.c for embedded targets. This saves about about 11 kB in .text and another 11 kB in .data on a PXA255 embedded platform. Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29kernel: use non-racy method for proc entries creationDenis V. Lunev
Use proc_create()/proc_create_data() to make sure that ->proc_fops and ->data be setup before gluing PDE to main tree. Signed-off-by: Denis V. Lunev <den@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29proc: remove proc_root from driversAlexey Dobriyan
Remove proc_root export. Creation and removal works well if parent PDE is supplied as NULL -- it worked always that way. So, one useless export removed and consistency added, some drivers created PDEs with &proc_root as parent but removed them as NULL and so on. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29procfs task exe symlinkMatt Helsley
The kernel implements readlink of /proc/pid/exe by getting the file from the first executable VMA. Then the path to the file is reconstructed and reported as the result. Because of the VMA walk the code is slightly different on nommu systems. This patch avoids separate /proc/pid/exe code on nommu systems. Instead of walking the VMAs to find the first executable file-backed VMA we store a reference to the exec'd file in the mm_struct. That reference would prevent the filesystem holding the executable file from being unmounted even after unmapping the VMAs. So we track the number of VM_EXECUTABLE VMAs and drop the new reference when the last one is unmapped. This avoids pinning the mounted filesystem. [akpm@linux-foundation.org: improve comments] [yamamoto@valinux.co.jp: fix dup_mmap] Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: David Howells <dhowells@redhat.com> Cc:"Eric W. Biederman" <ebiederm@xmission.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hugh@veritas.com> Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29keys: make the keyring quotas controllable through /proc/sysDavid Howells
Make the keyring quotas controllable through /proc/sys files: (*) /proc/sys/kernel/keys/root_maxkeys /proc/sys/kernel/keys/root_maxbytes Maximum number of keys that root may have and the maximum total number of bytes of data that root may have stored in those keys. (*) /proc/sys/kernel/keys/maxkeys /proc/sys/kernel/keys/maxbytes Maximum number of keys that each non-root user may have and the maximum total number of bytes of data that each of those users may have stored in their keys. Also increase the quotas as a number of people have been complaining that it's not big enough. I'm not sure that it's big enough now either, but on the other hand, it can now be set in /etc/sysctl.conf. Signed-off-by: David Howells <dhowells@redhat.com> Cc: <kwc@citi.umich.edu> Cc: <arunsr@cse.iitk.ac.in> Cc: <dwalsh@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29keys: don't generate user and user session keyrings unless they're accessedDavid Howells
Don't generate the per-UID user and user session keyrings unless they're explicitly accessed. This solves a problem during a login process whereby set*uid() is called before the SELinux PAM module, resulting in the per-UID keyrings having the wrong security labels. This also cures the problem of multiple per-UID keyrings sometimes appearing due to PAM modules (including pam_keyinit) setuiding and causing user_structs to come into and go out of existence whilst the session keyring pins the user keyring. This is achieved by first searching for extant per-UID keyrings before inventing new ones. The serial bound argument is also dropped from find_keyring_by_name() as it's not currently made use of (setting it to 0 disables the feature). Signed-off-by: David Howells <dhowells@redhat.com> Cc: <kwc@citi.umich.edu> Cc: <arunsr@cse.iitk.ac.in> Cc: <dwalsh@redhat.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29ipc: sysvsem: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC)Serge E. Hallyn
CLONE_NEWIPC|CLONE_SYSVSEM interaction isn't handled properly. This can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 3: refuse clone(CLONE_SYSVSEM|CLONE_NEWIPC). With unshare, specifying CLONE_SYSVSEM means unshare the sysvsem. So it seems reasonable that CLONE_NEWIPC without CLONE_SYSVSEM would just imply CLONE_SYSVSEM. However with clone, specifying CLONE_SYSVSEM means *share* the sysvsem. So calling clone(CLONE_SYSVSEM|CLONE_NEWIPC) is explicitly asking for something we can't allow. So return -EINVAL in that case. [akpm@linux-foundation.org: cleanups] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29ipc: sysvsem: force unshare(CLONE_SYSVSEM) when CLONE_NEWIPCManfred Spraul
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 2: perform an implicit CLONE_SYSVSEM in CLONE_NEWIPC. CLONE_NEWIPC creates a new IPC namespace, the task cannot access the existing semaphore arrays after the unshare syscall. Thus the task can/must detach from the existing undo list entries, too. This fixes the kernel corruption, because it makes it impossible that undo records from two different namespaces are in sysvsem.undo_list. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29ipc: sysvsem: implement sys_unshare(CLONE_SYSVSEM)Manfred Spraul
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM) The original reason to not support it was the potential (inevitable?) confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the inverse meaning of clone(CLONE_SYSVSEM). Our two most reasonable options then appear to be (1) fully support CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM, but always do it anyway on unshare(CLONE_SYSVSEM). This patch does (1). Changelog: Apr 16: SEH: switch to Manfred's alternative patch which removes the unshare_semundo() function which always refused CLONE_SYSVSEM. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Pierre Peiffer <peifferp@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29ipc: re-enable msgmni automatic recomputing msgmni if set to negativeNadia Derbey
The enhancement as asked for by Yasunori: if msgmni is set to a negative value, register it back into the ipcns notifier chain. A new interface has been added to the notification mechanism: notifier_chain_cond_register() registers a notifier block only if not already registered. With that new interface we avoid taking care of the states changes in procfs. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Mingming Cao <cmm@us.ibm.com> Cc: Pierre Peiffer <pierre.peiffer@bull.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29simplify cpu_hotplug_begin()/put_online_cpus()Oleg Nesterov
cpu_hotplug_begin() must be always called under cpu_add_remove_lock, this means that only one process can be cpu_hotplug.active_writer. So we don't need the cpu_hotplug.writer_queue, we can wake up the ->active_writer directly. Also, fix the comment. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Dipankar Sarma <dipankar@in.ibm.com> Acked-by: Gautham R Shenoy <ego@in.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29cleanup_workqueue_thread: remove the unneeded "cpu" parameterOleg Nesterov
cleanup_workqueue_thread() doesn't need the second argument, remove it. 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>
2008-04-29workqueues: shrink cpu_populated_map when CPU diesOleg Nesterov
When cpu_populated_map was introduced, it was supposed that cwq->thread can survive after CPU_DEAD, that is why we never shrink cpu_populated_map. This is not very nice, we can safely remove the already dead CPU from the map. The only required change is that destroy_workqueue() must hold the hotplug lock until it destroys all cwq->thread's, to protect the cpu_populated_map. We could make the local copy of cpu mask and drop the lock, but sizeof(cpumask_t) may be very large. Also, fix the comment near queue_work(). Unless _cpu_down() happens we do guarantee the cpu-affinity of the work_struct, and we have users which rely on this. [akpm@linux-foundation.org: repair comment] 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>
2008-04-29Cpuset hardwall flag: add a mem_hardwall flag to cpusetsPaul Menage
This flag provides the hardwalling properties of mem_exclusive, without enforcing the exclusivity. Either mem_hardwall or mem_exclusive is sufficient to prevent GFP_KERNEL allocations from passing outside the cpuset's assigned nodes. Signed-off-by: Paul Menage <menage@google.com> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29Cpuset hardwall flag: switch cpusets to use the bulk cgroup_add_files() APIPaul Menage
Currently the cpusets mem_exclusive flag is overloaded to mean both "no-overlapping" and "no GFP_KERNEL allocations outside this cpuset". These patches add a new mem_hardwall flag with just the allocation restriction part of the mem_exclusive semantics, without breaking backwards-compatibility for those who continue to use just mem_exclusive. Additionally, the cgroup control file registration for cpusets is cleaned up to reduce boilerplate. This patch: This change tidies up the cpusets control file definitions, and reduces the amount of boilerplate required to add/change control files in the future. Signed-off-by: Paul Menage <menage@google.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>