Kernel threads should not have TIF_FREEZE set when user space processes are
being frozen, since otherwise some of them might be frozen prematurely.
To prevent this from happening we can (1) make exit_mm() unset TIF_FREEZE
unconditionally just after clearing tsk->mm and (2) make try_to_freeze_tasks()
check if p->mm is different from zero and PF_BORROWED_MM is unset in p->flags
when user space processes are to be frozen.
Namely, when user space processes are being frozen, we only should set
TIF_FREEZE for tasks that have p->mm different from NULL and don't have
PF_BORROWED_MM set in p->flags. For this reason task_lock() must be used to
prevent try_to_freeze_tasks() from racing with use_mm()/unuse_mm(), in which
p->mm and p->flags.PF_BORROWED_MM are changed under task_lock(p). Also, we
need to prevent the following scenario from happening:
* daemonize() is called by a task spawned from a user space code path
* freezer checks if the task has p->mm set and the result is positive
* task enters exit_mm() and clears its TIF_FREEZE
* freezer sets TIF_FREEZE for the task
* task calls try_to_freeze() and goes to the refrigerator, which is wrong at
that point
This requires us to acquire task_lock(p) before p->flags.PF_BORROWED_MM and
p->mm are examined and release it after TIF_FREEZE is set for p (or it turns
out that TIF_FREEZE should not be set).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
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>
During hibernation we call hibernation_ops->prepare() before creating the image,
but then, before saving it, we cancel the power transition by calling
hibernation_ops->finish(). Thus prior to calling hibernation_ops->enter() we
should let the platform firmware know that we're going to enter the low power
state after all.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
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>
Change the code ordering so that hibernation_ops->prepare() is called after
device_suspend(). This is needed so that we don't violate the ACPI
specification, which states that the _PTS and _GTS system-control methods,
executed from acpi_sleep_prepare(), ought to be called after devices have been
put in low power states.
The "Finish" label in hibernation_restore() is moved, because device_suspend()
resumes devices if the suspending of them fails and the restore code ordering
should reflect the hibernation code ordering.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At least on some machines it is necessary to prepare the ACPI firmware for the
restoration of the system memory state from the hibernation image if the
"platform" mode of hibernation has been used. Namely, in that cases we need
to disable the GPEs before replacing the "boot" kernel with the "frozen"
kernel (cf. http://bugzilla.kernel.org/show_bug.cgi?id=7887). After the
restore they will be re-enabled by hibernation_ops->finish(), but if the
restore fails, they have to be re-enabled by the restore code explicitly.
For this purpose we can introduce two additional hibernation operations,
called pre_restore() and restore_cleanup() and call them from the restore code
path. Still, they should be called if the "platform" mode of hibernation has
been used, so we need to pass the information about the hibernation mode from
the "frozen" kernel to the "boot" kernel in the image header.
Apparently, we can't drop the disabling of GPEs before the restore because of
Bug #7887 . We also can't do it unconditionally, because the GPEs wouldn't
have been enabled after a successful restore if the suspend had been done in
the 'shutdown' or 'reboot' mode.
In principle we could (and probably should) unconditionally disable the GPEs
before each snapshot creation *and* before the restore, but then we'd have to
unconditionally enable them after the snapshot creation as well as after the
restore (or restore failure) Still, for this purpose we'd need to modify
acpi_enter_sleep_state_prep() and acpi_leave_sleep_state() and we'd have to
introduce some mechanism synchronizing the disablind/enabling of the GPEs with
the device drivers' .suspend()/.resume() routines and with
disable_/enable_nonboot_cpus(). However, this would have affected the
suspend (ie. s2ram) code as well as the hibernation, which I'd like to avoid
in this patch series.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, much of the code in kernel/power/disk.c is duplicated in
kernel/power/user.c , mainly for historical reasons. By eliminating this code
duplication we can reduce the size of user.c quite substantially and remove
the maintenance difficulty resulting from it.
[bunk@stusta.de: kernel/power/disk.c: make code static]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the face of the recent change of suspend code ordering (cf.
http://marc.info/?l=linux-acpi&m=117938245931603&w=2) we should also modify
the code ordering in swsusp so that hibernation_ops->prepare() is executed
after device_suspend().
However, for this purpose it seems reasonable to eliminate the code
duplication between kernel/power/disk.c and kernel/power/user.c first. By
eliminating it we can reduce the size of user.c quite substantially and remove
the maintenance difficulty with making essentially the same changes in two
different places.
Moreover, we should also remove the calls to "platform" functions from the
restore code path, since it doesn't carry out any power transition of the
system, but we generally need to disable the GPEs before the restore if the
'platform' hibernation mode has been used. To do this, we can introduce two
new hibernation_ops to be used in the restore code.
This patch:
Make the code hibernation code in kernel/power/user.c be functionally
equivalent to the corresponding code in kernel/power/disk.c , as it should be.
The calls to the platform functions removed by this patch are incorrect. They
should be replaced with some other "platform" invocations that will be
introduced in one of the subsequent patches.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to enable things like PM_TRACE, you're required to enable
PM_DEBUG, which sends a large spew of messages on boot, and often times can
overflow dmesg buffer.
Create new PM_VERBOSE and shift that to be the option that enables
drivers/base/power's messages.
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To see which tasks are stuck where.
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer. This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).
[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rather than using a tri-state integer for the wait flag in
call_usermodehelper_exec, define a proper enum, and use that. I've
preserved the integer values so that any callers I've missed should
still work OK.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
Various pieces of code around the kernel want to be able to trigger an
orderly poweroff. This pulls them together into a single
implementation.
By default the poweroff command is /sbin/poweroff, but it can be set
via sysctl: kernel/poweroff_cmd. This is split at whitespace, so it
can include command-line arguments.
This patch replaces four other instances of invoking either "poweroff"
or "shutdown -h now": two sbus drivers, and acpi thermal
management.
sparc64 has its own "powerd"; still need to determine whether it should
be replaced by orderly_poweroff().
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>
Rather than having hundreds of variations of call_usermodehelper for
various pieces of usermode state which could be set up, split the
info allocation and initialization from the actual process execution.
This means the general pattern becomes:
info = call_usermodehelper_setup(path, argv, envp); /* basic state */
call_usermodehelper_<SET EXTRA STATE>(info, stuff...); /* extra state */
call_usermodehelper_exec(info, wait); /* run process and free info */
This patch introduces wrappers for all the existing calling styles for
call_usermodehelper_*, but folds their implementations into one.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Bj?rn Steinbrink <B.Steinbrink@gmx.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Kill this warning...
kernel/auditfilter.c: In function ‘audit_receive_filter’:
kernel/auditfilter.c:1213: warning: ‘ndw’ may be used uninitialized in this function
kernel/auditfilter.c:1213: warning: ‘ndp’ may be used uninitialized in this function
...with a simplification of the code. audit_put_nd() can accept NULL
arguments, just like kfree(). It is cleaner to init two existing vars
to NULL, remove the redundant test variable 'putnd_needed' branches, and call
audit_put_nd() directly.
As a desired side effect, the warning goes away.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Pointed out by Michal Schmidt <mschmidt@redhat.com>.
The bug was introduced in 2.6.22 by me.
cleanup_workqueue_thread() does flush_cpu_workqueue(cwq) in a loop until
->worklist becomes empty. This is live-lockable, a re-niced caller can get
CPU after wake_up() and insert a new barrier before the lower-priority
cwq->thread has a chance to clear ->current_work.
Change cleanup_workqueue_thread() to do flush_cpu_workqueue(cwq) only once.
We can rely on the fact that run_workqueue() won't return until it flushes
all works. So it is safe to call kthread_stop() after that, the "should
stop" request won't be noticed until run_workqueue() returns.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer. This is nonsense and error-prone. Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.
This patch increments KSYM_NAME_LEN by one and updates code accordingly.
* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
is fixed.
* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
MODULE_NAME_LEN was treated as if it didn't include space for the
trailing '\0'. Fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a proper prototype for proc_nr_files() in include/linux/fs.h
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.
AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the kernel OOPSed or BUGed then it probably should be considered as
tainted. Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel. This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves. This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.
It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.
The patch causes all kernel threads to be nonfreezable by default (ie. to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE. It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear. Additionally, it updates documentation to
describe the freezing of tasks more accurately.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing
variant in the past. But with __GFP_ZERO it is possible now to do zeroing
while allocating.
Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever
we can.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Huge pages are not movable so are not allocated from ZONE_MOVABLE. However,
as ZONE_MOVABLE will always have pages that can be migrated or reclaimed, it
can be used to satisfy hugepage allocations even when the system has been
running a long time. This allows an administrator to resize the hugepage pool
at runtime depending on the size of ZONE_MOVABLE.
This patch adds a new sysctl called hugepages_treat_as_movable. When a
non-zero value is written to it, future allocations for the huge page pool
will use ZONE_MOVABLE. Despite huge pages being non-movable, we do not
introduce additional external fragmentation of note as huge pages are always
the largest contiguous block we care about.
[akpm@linux-foundation.org: various fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All of the clockevent notifiers expect a pointer to
an "unsigned int" cpu argument, but hrtimer_cpu_notify()
passes in a pointer to a long.
[ Discussed with and ok by Thomas Gleixner ]
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap noticed that the recent comment clarifications from Andrew
had somehow gotten duplicated. Quoth Andrew: "hm, that could have been
some late-night reject-fixing."
Fix it up.
Cc: From: Andrew Morton <akpm@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/printk.c: document possible deadlock against scheduler
The printk's comment states that it can be called from every context,
which might lead to false illusion that it could be called from everywhere
without any restrictions.
This is however not true - a call to printk() could deadlock if called from
scheduler code (namely from schedule(), wake_up(), etc) on runqueue lock
when it tries to wake up klogd. Document this.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now we always use stop_machine for module insertion or deletion, we no
longer need the modlist_lock: merely disabling preemption is sufficient to
block against list manipulation. This avoids deadlock on OOPSen where we
can potentially grab the lock twice.
Bug: 8695
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tobias Oed <tobiasoed@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change cancel_work_sync() and cancel_delayed_work_sync() to return a boolean
indicating whether the work was actually cancelled. A zero return value means
that the work was not pending/queued.
Without that kind of change it is not possible to avoid flush_workqueue()
sometimes, see the next patch as an example.
Also, this patch unifies both functions and kills the (unlikely) busy-wait
loop.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Imho, the current naming of cancel_xxx workqueue functions is very confusing.
cancel_delayed_work()
cancel_rearming_delayed_work()
cancel_rearming_delayed_workqueue() // obsolete
cancel_work_sync()
This looks as if the first 2 functions differ in "type" of their argument
which is not true any longer, nowadays the difference is the behaviour.
The semantics of cancel_rearming_delayed_work(dwork) was changed
significantly, it doesn't require that dwork rearms itself, and cancels dwork
synchronously.
Rename it to cancel_delayed_work_sync(). This matches cancel_delayed_work()
and cancel_work_sync(). Re-create cancel_rearming_delayed_work() as a simple
inline obsolete wrapper, like cancel_rearming_delayed_workqueue().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This follows a suggestion from Chuck Ebbert on how to make seccomp
absolutely zerocost in schedule too. The only remaining footprint of
seccomp is in terms of the bzImage size that becomes a few bytes (perhaps
even a few kbytes) larger, measure it if you care in the embedded.
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reduces the memory footprint and it enforces that only the current
task can enable seccomp on itself (this is a requirement for a
strightforward [modulo preempt ;) ] TIF_NOTSC implementation).
Signed-off-by: Andrea Arcangeli <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hopefully this will help people to understand the new regime.
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>
The recent PRIVATE and REQUEUE_PI changes to the futex code made it hard to
read. Tidy it up.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Improve performance of sys_time(). sys_time() returns time in seconds, but
it does so by calling do_gettimeofday() and then returning the tv_sec
portion of the GTOD time. But the data structure "xtime", which is updated
by every timer/scheduler tick, already offers HZ granularity time.
The patch improves the sysbench OLTP macrobenchmark significantly:
2.6.22-rc6:
#threads
1: transactions: 3733 (373.21 per sec.)
2: transactions: 6676 (667.46 per sec.)
3: transactions: 6957 (695.50 per sec.)
4: transactions: 7055 (705.48 per sec.)
5: transactions: 6596 (659.33 per sec.)
2.6.22-rc6 + sys_time.patch:
1: transactions: 4005 (400.47 per sec.)
2: transactions: 7379 (737.77 per sec.)
3: transactions: 7347 (734.49 per sec.)
4: transactions: 7468 (746.65 per sec.)
5: transactions: 7428 (742.47 per sec.)
Mixed API uses of gettimeofday() and time() are guaranteed to be coherent
via the use of a at-most-once-per-second slowpath that updates xtime.
[akpm@linux-foundation.org: build fixes]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While working on unshare support for the network namespace I noticed we
were putting clone flags in an int. Which is weird because the syscall
uses unsigned long and we at least need an unsigned to properly hold all of
the unshare flags.
So to make the code consistent, this patch updates the code to use
unsigned long instead of int for the clone flags in those places
where we get it wrong today.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OpenVZ Linux kernel team has discovered the problem with 32bit quota tools
working on 64bit architectures. In 2.6.10 kernel sys32_quotactl() function
was replaced by sys_quotactl() with the comment "sys_quotactl seems to be
32/64bit clean, enable it for 32bit" However this isn't right. Look at
if_dqblk structure:
struct if_dqblk {
__u64 dqb_bhardlimit;
__u64 dqb_bsoftlimit;
__u64 dqb_curspace;
__u64 dqb_ihardlimit;
__u64 dqb_isoftlimit;
__u64 dqb_curinodes;
__u64 dqb_btime;
__u64 dqb_itime;
__u32 dqb_valid;
};
For 32 bit quota tools sizeof(if_dqblk) == 0x44.
But for 64 bit kernel its size is 0x48, 'cause of alignment!
Thus we got a problem. Attached patch reintroduce sys32_quotactl() function,
that handles this and related situations.
[michal.k.k.piotrowski@gmail.com: build fix]
[akpm@linux-foundation.org: Make it link with CONFIG_QUOTA=n]
Signed-off-by: Vasily Tarasov <vtaras@openvz.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix parameter name in audit_core_dumps for kerneldoc.
Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It should improve performance in some scenarii where a lot of
these nsproxy objects are created by unsharing namespaces. This is
a typical use of virtual servers that are being created or entered.
This is also a good tool to find leaks and gather statistics on
namespace usage.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
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>
dup_mnt_ns() and clone_uts_ns() return NULL on failure. This is wrong,
create_new_namespaces() uses ERR_PTR() to catch an error. This means that the
subsequent create_new_namespaces() will hit BUG_ON() in copy_mnt_ns() or
copy_utsname().
Modify create_new_namespaces() to also use the errors returned by the
copy_*_ns routines and not to systematically return ENOMEM.
[oleg@tv-sign.ru: better changelog]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.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>
This patch enables the unshare of user namespaces.
It adds a new clone flag CLONE_NEWUSER and implements copy_user_ns() which
resets the current user_struct and adds a new root user (uid == 0)
For now, unsharing the user namespace allows a process to reset its
user_struct accounting and uid 0 in the new user namespace should be contained
using appropriate means, for instance selinux
The plan, when the full support is complete (all uid checks covered), is to
keep the original user's rights in the original namespace, and let a process
become uid 0 in the new namespace, with full capabilities to the new
namespace.
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Basically, it will allow a process to unshare its user_struct table,
resetting at the same time its own user_struct and all the associated
accounting.
A new root user (uid == 0) is added to the user namespace upon creation.
Such root users have full privileges and it seems that theses privileges
should be controlled through some means (process capabilities ?)
The unshare is not included in this patch.
Changes since [try #4]:
- Updated get_user_ns and put_user_ns to accept NULL, and
get_user_ns to return the namespace.
Changes since [try #3]:
- moved struct user_namespace to files user_namespace.{c,h}
Changes since [try #2]:
- removed struct user_namespace* argument from find_user()
Changes since [try #1]:
- removed struct user_namespace* argument from find_user()
- added a root_user per user namespace
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Andrew Morgan <agm@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_UTS_NS and CONFIG_IPC_NS have very little value as they only
deactivate the unshare of the uts and ipc namespaces and do not improve
performance.
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Pavel Emelianov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we handle spurious IRQ activity based upon seeing a lot of
invalid interrupts, and we clear things back on the base of lots of valid
interrupts.
Unfortunately in some cases you get legitimate invalid interrupts caused by
timing asynchronicity between the PCI bus and the APIC bus when disabling
interrupts and pulling other tricks. In this case although the spurious
IRQs are not a problem our unhandled counters didn't clear and they act as
a slow running timebomb. (This is effectively what the serial port/tty
problem that was fixed by clearing counters when registering a handler
showed up)
It's easy enough to add a second parameter - time. This means that if we
see a regular stream of harmless spurious interrupts which are not harming
processing we don't go off and do something stupid like disable the IRQ
after a month of running. OTOH lockups and performance killers show up a
lot more than 10/second
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make available to the user the following task and process performance
statistics:
* Involuntary Context Switches (task_struct->nivcsw)
* Voluntary Context Switches (task_struct->nvcsw)
Statistics information is available from:
1. taskstats interface (Documentation/accounting/)
2. /proc/PID/status (task only).
This data is useful for detecting hyperactivity patterns between processes.
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Maxim Uvarov <muvarov@ru.mvista.com>
Cc: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Jonathan Lim <jlim@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I forgot to remove capability.h from mm.h while removing sched.h! This
patch remedies that, because the only inline function which was using
CAP_something was made out of line.
Cross-compile tested without regressions on:
all powerpc defconfigs
all mips defconfigs
all m68k defconfigs
all arm defconfigs
all ia64 defconfigs
alpha alpha-allnoconfig alpha-defconfig alpha-up
arm
i386 i386-allnoconfig i386-defconfig i386-up
ia64 ia64-allnoconfig ia64-defconfig ia64-up
m68k
mips
parisc parisc-allnoconfig parisc-defconfig parisc-up
powerpc powerpc-up
s390 s390-allnoconfig s390-defconfig s390-up
sparc sparc-allnoconfig sparc-defconfig sparc-up
sparc64 sparc64-allnoconfig sparc64-defconfig sparc64-up
um-x86_64
x86_64 x86_64-allnoconfig x86_64-defconfig x86_64-up
as well as my two usual configs.
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>
Add a flag in /proc/timer_stats to indicate deferrable timers. This will
let developers/users to differentiate between types of tiemrs in
/proc/timer_stats.
Deferrable timer and normal timer will appear in /proc/timer_stats as below.
10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
10, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
Also version of timer_stats changes from v0.1 to v0.2
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow printk_time to be enabled or disabled at boot time. Previously it
could be enabled only, but not disabled.
Change printk_time from an int to a bool since that's what it is. Make its
logical (exposed) name just be "time" (was "printk_time").
Note: Changes kernel boot option syntax from "time" to "printk.time=value".
Since printk_time is declared as a module_param, it can also be
changed at run-time by modifying
/sys/module/printk/parameters/time
to a value of 1/Y/y to enabled it or 0/N/n to disable it.
Since printk_time is declared as a module_param, its value can also
be set at boot-time by using
linux printk.time=<bool>
If the "time" boot option is used, print a message that it is deprecated
and will be removed.
Note its planned removal in feature-removal-schedule.txt.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rafael J. Wysocki