Commit Graph

10653 Commits

Author SHA1 Message Date
john stultz
b5776c4a6d Fix rounding in clocks_calc_mult_shift()
Russell King reports:
| On the ARM dev boards, we have a 32-bit counter running at 24MHz.  Calling
| clocks_calc_mult_shift(&mult, &shift, 24MHz, NSEC_PER_SEC, 60) gives
| us a multiplier of 2796202666 and a shift of 26.
|
| Over a large counter delta, this produces an error - lets take a count
| from 362976315 to 4280663372:
|
| (4280663372-362976315) * 2796202666 / 2^26 - (4280663372-362976315) * (1000/24)
|  => -38.91872422891230269990
|
| Can we do better?
|
| (4280663372-362976315) * 2796202667 / 2^26 - (4280663372-362976315) * (1000/24)
| 19.45936211449532822051
|
| which is about twice as good as the 2796202666 multiplier.
|
| Looking at the equivalent divisions obtained, 2796202666 / 2^26 gives
| 41.66666665673255920410ns per tick, whereas 2796202667 / 2^26 gives
| 41.66666667163372039794ns.  The actual value wanted is 1000/24 =
| 41.66666666666666666666ns.

Fix this by ensuring we round to nearest when calculating the
multiplier.

Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Olof Johansson <olof@lixom.net>
Tested-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-12-22 22:44:43 +00:00
Linus Torvalds
33e0d57f5d Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"
This reverts commit 59365d136d.

It turns out that this can break certain existing user land setups.
Quoth Sarah Sharp:

 "On Wednesday, I updated my branch to commit 460781b from linus' tree,
  and my box would not boot.  klogd segfaulted, which stalled the whole
  system.

  At first I thought it actually hung the box, but it continued booting
  after 5 minutes, and I was able to log in.  It dropped back to the
  text console instead of the graphical bootup display for that period
  of time.  dmesg surprisingly still works.  I've bisected the problem
  down to this commit (commit 59365d136d)

  The box is running klogd 1.5.5ubuntu3 (from Jaunty).  Yes, I know
  that's old.  I read the bit in the commit about changing the
  permissions of kallsyms after boot, but if I can't boot that doesn't
  help."

So let's just keep the old default, and encourage distributions to do
the "chmod -r /proc/kallsyms" in their bootup scripts.  This is not
worth a kernel option to change default behavior, since it's so easily
done in user space.

Reported-and-bisected-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-19 11:54:40 -08:00
Linus Torvalds
2d42dc3feb Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb,ppc: Fix regression in evr register handling
  kgdb,x86: fix regression in detach handling
  kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
  kdb: fix memory leak in kdb_main.c
2010-11-18 08:24:58 -08:00
Jovi Zhang
5450d90405 kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the
kernel will fault.

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17 13:54:57 -06:00
Jovi Zhang
85e76ab50a kdb: fix memory leak in kdb_main.c
Call kfree in the error path as well as the success path in kdb_ll().

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17 13:54:57 -06:00
Arnd Bergmann
451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
Marcus Meissner
59365d136d kernel: make /proc/kallsyms mode 400 to reduce ease of attacking
Making /proc/kallsyms readable only for root by default makes it
slightly harder for attackers to write generic kernel exploits by
removing one source of knowledge where things are in the kernel.

This is the second submit, discussion happened on this on first submit
and mostly concerned that this is just one hole of the sieve ...  but
one of the bigger ones.

Changing the permissions of at least System.map and vmlinux is also
required to fix the same set, but a packaging issue.

Target of this starter patch and follow ups is removing any kind of
kernel space address information leak from the kernel.

[ Side note: the default of root-only reading is the "safe" value, and
  it's easy enough to then override at any time after boot.  The /proc
  filesystem allows root to change the permissions with a regular
  chmod, so you can "revert" this at run-time by simply doing

    chmod og+r /proc/kallsyms

  as root if you really want regular users to see the kernel symbols.
  It does help some tools like "perf" figure them out without any
  setup, so it may well make sense in some situations.  - Linus ]

Signed-off-by: Marcus Meissner <meissner@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16 19:06:01 -08:00
Linus Torvalds
d33fdee4d0 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Fix cross-sched-class wakeup preemption
  sched: Fix runnable condition for stoptask
  sched: Use group weight, idle cpu metrics to fix imbalances during idle
2010-11-16 15:20:05 -08:00
Linus Torvalds
1e8703b2e6 Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / PM QoS: Fix reversed min and max
  PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
  PM: Allow devices to be removed during late suspend and early resume
2010-11-16 15:18:17 -08:00
Linus Torvalds
45314915ed Merge branch 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  futex: Address compiler warnings in exit_robust_list
2010-11-16 14:31:03 -08:00
Linus Torvalds
2ebc8ec86f Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] kprobes: Fix the return address of multiple kretprobes
  [S390] kprobes: disable interrupts throughout
  [S390] ftrace: build without frame pointers on s390
  [S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking
  [S390] vmlogrdr: purge after recording is switched off
  [S390] cio: fix incorrect ccw_device_init_count
  [S390] tape: add medium state notifications
  [S390] fix get_user_pages_fast
2010-11-16 09:27:13 -08:00
Joe Perches
df6e61d4ca kernel/sysctl.c: Fix build failure with !CONFIG_PRINTK
Sigh...

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-16 07:56:09 -08:00
Eric Paris
12b3052c3e capabilities/syslog: open code cap_syslog logic to fix build failure
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n.  This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.

The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller.  All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15 15:40:01 -08:00
Colin Cross
00fafcda17 PM / PM QoS: Fix reversed min and max
pm_qos_get_value had min and max reversed, causing all pm_qos
requests to have no effect.

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: mark <markgross@thegnar.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@kernel.org
2010-11-15 22:45:22 +01:00
Linus Torvalds
8a9f772c14 Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (27 commits)
  block: remove unused copy_io_context()
  Documentation: remove anticipatory scheduler info
  block: remove REQ_HARDBARRIER
  ioprio: rcu_read_lock/unlock protect find_task_by_vpid call (V2)
  ioprio: fix RCU locking around task dereference
  block: ioctl: fix information leak to userland
  block: read i_size with i_size_read()
  cciss: fix proc warning on attempt to remove non-existant directory
  bio: take care not overflow page count when mapping/copying user data
  block: limit vec count in bio_kmalloc() and bio_alloc_map_data()
  block: take care not to overflow when calculating total iov length
  block: check for proper length of iov entries in blk_rq_map_user_iov()
  cciss: remove controllers supported by hpsa
  cciss: use usleep_range not msleep for small sleeps
  cciss: limit commands allocated on reset_devices
  cciss: Use kernel provided PCI state save and restore functions
  cciss: fix board status waiting code
  drbd: Removed checks for REQ_HARDBARRIER on incomming BIOs
  drbd: REQ_HARDBARRIER -> REQ_FUA transition for meta data accesses
  drbd: Removed the BIO_RW_BARRIER support form the receiver/epoch code
  ...
2010-11-12 08:52:47 -08:00
Linus Torvalds
28397babba Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf, amd: Use kmalloc_node(,__GFP_ZERO) for northbridge structure allocation
  perf_events: Fix time tracking in samples
  perf trace: update usage
  perf trace: update Documentation with new perf trace variants
  perf trace: live-mode command-line cleanup
  perf trace record: handle commands correctly
  perf record: make the record options available outside perf record
  perf trace scripting: remove system-wide param from shell scripts
  perf trace scripting: fix some small memory leaks and missing error checks
  perf: Fix usages of profile_cpu in builtin-top.c to use cpu_list
  perf, ui: Eliminate stack-smashing protection compiler complaint
2010-11-12 08:39:52 -08:00
Dan Rosenberg
eaf06b241b Restrict unprivileged access to kernel syslog
The kernel syslog contains debugging information that is often useful
during exploitation of other vulnerabilities, such as kernel heap
addresses.  Rather than futilely attempt to sanitize hundreds (or
thousands) of printk statements and simultaneously cripple useful
debugging functionality, it is far simpler to create an option that
prevents unprivileged users from reading the syslog.

This patch, loosely based on grsecurity's GRKERNSEC_DMESG, creates the
dmesg_restrict sysctl.  When set to "0", the default, no restrictions are
enforced.  When set to "1", only users with CAP_SYS_ADMIN can read the
kernel syslog via dmesg(8) or other mechanisms.

[akpm@linux-foundation.org: explain the config option in kernel.txt]
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Eugene Teo <eugeneteo@kernel.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12 07:55:32 -08:00
Ken Chen
38715258aa latencytop: fix per task accumulator
Per task latencytop accumulator prematurely terminates due to erroneous
placement of latency_record_count.  It should be incremented whenever a
new record is allocated instead of increment on every latencytop event.

Also fix search iterator to only search known record events instead of
blindly searching all pre-allocated space.

Signed-off-by: Ken Chen <kenchen@google.com>
Reviewed-by: Arjan van de Ven <arjan@infradead.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12 07:55:31 -08:00
Alexey Khoroshilov
834b40380e kernel/range.c: fix clean_sort_range() for the case of full array
clean_sort_range() should return a number of nonempty elements of range
array, but if the array is full clean_sort_range() returns 0.

The problem is that the number of nonempty elements is evaluated by
finding the first empty element of the array.  If there is no such element
it returns an initial value of local variable nr_range that is zero.

The fix is trivial: it changes initial value of nr_range to size of the
array.

The bug can lead to loss of information regarding all ranges, since
typically returned value of clean_sort_range() is considered as an actual
number of ranges in the array after a series of add/subtract operations.

Found by Analytical Verification project of Linux Verification Center
(linuxtesting.org), thanks to Alexander Kolosov.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-12 07:55:31 -08:00
Peter Zijlstra
1e5a74059f sched: Fix cross-sched-class wakeup preemption
Instead of dealing with sched classes inside each check_preempt_curr()
implementation, pull out this logic into the generic wakeup preemption
path.

This fixes a hang in KVM (and others) where we are waiting for the
stop machine thread to run ...

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1288891946.2039.31.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-11 14:37:23 +01:00
Mark Brown
43e60861fe PM / OPP: Hide OPP configuration when SoCs do not provide an implementation
Since the OPP API is only useful with an appropraite SoC-specific
implementation there is no point in offering the ability to enable
the API on general systems. Provide an ARCH_HAS OPP Kconfig symbol
which masks out the option unless selected by an implementation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-11-11 01:51:26 +01:00
Peter Zijlstra
2d46709082 sched: Fix runnable condition for stoptask
Heiko reported that the TASK_RUNNING check is not sufficient for
CONFIG_PREEMPT=y since we can get preempted with !TASK_RUNNING.

He suggested adding a ->se.on_rq test to the existing TASK_RUNNING
one, however TASK_RUNNING will always have ->se.on_rq, so we might as
well reduce that to a single test.

[ stop tasks should never get preempted, but its good to handle
  this case correctly should this ever happen ]

Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 23:13:58 +01:00
Suresh Siddha
aae6d3ddd8 sched: Use group weight, idle cpu metrics to fix imbalances during idle
Currently we consider a sched domain to be well balanced when the imbalance
is less than the domain's imablance_pct. As the number of cores and threads
are increasing, current values of imbalance_pct (for example 25% for a
NUMA domain) are not enough to detect imbalances like:

a) On a WSM-EP system (two sockets, each having 6 cores and 12 logical threads),
24 cpu-hogging tasks get scheduled as 13 on one socket and 11 on another
socket. Leading to an idle HT cpu.

b) On a hypothetial 2 socket NHM-EX system (each socket having 8 cores and
16 logical threads), 16 cpu-hogging tasks can get scheduled as 9 on one
socket and 7 on another socket. Leaving one core in a socket idle
whereas in another socket we have a core having both its HT siblings busy.

While this issue can be fixed by decreasing the domain's imbalance_pct
(by making it a function of number of logical cpus in the domain), it
can potentially cause more task migrations across sched groups in an
overloaded case.

Fix this by using imbalance_pct only during newly_idle and busy
load balancing. And during idle load balancing, check if there
is an imbalance in number of idle cpu's across the busiest and this
sched_group or if the busiest group has more tasks than its weight that
the idle cpu in this_group can pull.

Reported-by: Nikhil Rao <ncrao@google.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284760952.2676.11.camel@sbsiddha-MOBL3.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 23:13:56 +01:00
Stephane Eranian
eed01528a4 perf_events: Fix time tracking in samples
This patch corrects time tracking in samples. Without this patch
both time_enabled and time_running are bogus when user asks for
PERF_SAMPLE_READ.

One uses PERF_SAMPLE_READ to sample the values of other counters
in each sample. Because of multiplexing, it is necessary to know
both time_enabled, time_running to be able to scale counts correctly.

In this second version of the patch, we maintain a shadow
copy of ctx->time which allows us to compute ctx->time without
calling update_context_time() from NMI context. We avoid the
issue that update_context_time() must always be called with
ctx->lock held.

We do not keep shadow copies of the other event timings
because if the lead event is overflowing then it is active
and thus it's been scheduled in via event_sched_in() in
which case neither tstamp_stopped, tstamp_running can be modified.

This timing logic only applies to samples when PERF_SAMPLE_READ
is used.

Note that this patch does not address timing issues related
to sampling inheritance between tasks. This will be addressed
in a future patch.

With this patch, the libpfm4 example task_smpl now reports
correct counts (shown on 2.4GHz Core 2):

$ task_smpl -p 2400000000 -e unhalted_core_cycles:u,instructions_retired:u,baclears  noploop 5
noploop for 5 seconds
IIP:0x000000004006d6 PID:5596 TID:5596 TIME:466,210,211,430 STREAM_ID:33 PERIOD:2,400,000,000 ENA=1,010,157,814 RUN=1,010,157,814 NR=3
	2,400,000,254 unhalted_core_cycles:u (33)
	2,399,273,744 instructions_retired:u (34)
	53,340 baclears (35)

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4cc6e14b.1e07e30a.256e.5190@mx.google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-10 22:58:39 +01:00
Christoph Hellwig
02e031cbc8 block: remove REQ_HARDBARRIER
REQ_HARDBARRIER is dead now, so remove the leftovers.  What's left
at this point is:

 - various checks inside the block layer.
 - sanity checks in bio based drivers.
 - now unused bio_empty_barrier helper.
 - Xen blockfront use of BLKIF_OP_WRITE_BARRIER - it's dead for a while,
   but Xen really needs to sort out it's barrier situaton.
 - setting of ordered tags in uas - dead code copied from old scsi
   drivers.
 - scsi different retry for barriers - it's dead and should have been
   removed when flushes were converted to FS requests.
 - blktrace handling of barriers - removed.  Someone who knows blktrace
   better should add support for REQ_FLUSH and REQ_FUA, though.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-10 14:54:09 +01:00
Darren Hart
4c115e951d futex: Address compiler warnings in exit_robust_list
Since commit 1dcc41bb (futex: Change 3rd arg of fetch_robust_entry()
to unsigned int*) some gcc versions decided to emit the following
warning:

kernel/futex.c: In function ‘exit_robust_list’:
kernel/futex.c:2492: warning: ‘next_pi’ may be used uninitialized in this function

The commit did not introduce the warning as gcc should have warned
before that commit as well. It's just gcc being silly.

The code path really can't result in next_pi being unitialized (or
should not), but let's keep the build clean. Annotate next_pi as an
uninitialized_var.

[ tglx: Addressed the same issue in futex_compat.c and massaged the
  	changelog ]

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Tested-by: Matt Fleming <matt@console-pimps.org>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <1288897200-13008-1-git-send-email-dvhart@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-11-10 13:27:50 +01:00
Heiko Carstens
becf91f187 [S390] ftrace: build without frame pointers on s390
s390 doesn't need FRAME_POINTERS in order to have a working function tracer.
We don't need frame pointers in order to get strack traces since we always
have valid backchains by using the -mkernel-backchain gcc option.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-11-10 10:05:54 +01:00
David Daney
433039e97f watchdog: Fix section mismatch and potential undefined behavior.
Commit d9ca07a05c ("watchdog: Avoid kernel crash when disabling
watchdog") introduces a section mismatch.

Now that we reference no_watchdog from non-__init code it can no longer
be __initdata.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 17:45:35 -07:00
Oleg Nesterov
e0a7021710 posix-cpu-timers: workaround to suppress the problems with mt exec
posix-cpu-timers.c correctly assumes that the dying process does
posix_cpu_timers_exit_group() and removes all !CPUCLOCK_PERTHREAD
timers from signal->cpu_timers list.

But, it also assumes that timer->it.cpu.task is always the group
leader, and thus the dead ->task means the dead thread group.

This is obviously not true after de_thread() changes the leader.
After that almost every posix_cpu_timer_ method has problems.

It is not simple to fix this bug correctly. First of all, I think
that timer->it.cpu should use struct pid instead of task_struct.
Also, the locking should be reworked completely. In particular,
tasklist_lock should not be used at all. This all needs a lot of
nontrivial and hard-to-test changes.

Change __exit_signal() to do posix_cpu_timers_exit_group() when
the old leader dies during exec. This is not the fix, just the
temporary hack to hide the problem for 2.6.37 and stable. IOW,
this is obviously wrong but this is what we currently have anyway:
cpu timers do not work after mt exec.

In theory this change adds another race. The exiting leader can
detach the timers which were attached to the new leader. However,
the window between de_thread() and release_task() is small, we
can pretend that sys_timer_create() was called before de_thread().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 14:16:03 -07:00
Jesper Juhl
408af87a39 Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset
We can optimize kernel/relay.c::relay_alloc_page_array() slightly by
using vzalloc.  The patch makes these changes:

 - use vzalloc instead of vmalloc+memset.
 - remove redundant local variable 'array'.
 - declare local 'pa_size' as const.

Cuts down nicely on both source and object-code size.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-05 08:21:34 -07:00
Linus Torvalds
82279e6bd7 Merge branches 'irq-core-for-linus' and 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Fix up irq_node() for irq_data changes.
  genirq: Add single IRQ reservation helper
  genirq: Warn if enable_irq is called before irq is set up

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  semaphore: Remove mutex emulation
  staging: Final semaphore cleanup
  jbd2: Convert jbd2_slab_create_sem to mutex
  hpfs: Convert sbi->hpfs_creation_de to mutex

Fix up trivial change/delete conflicts with deleted 'dream' drivers
(drivers/staging/dream/camera/{mt9d112.c,mt9p012_fox.c,mt9t013.c,s5k3e2fx.c})
2010-10-31 20:40:24 -04:00
Linus Torvalds
f02a38d86a Merge branches 'perf-fixes-for-linus' and 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  jump label: Add work around to i386 gcc asm goto bug
  x86, ftrace: Use safe noops, drop trap test
  jump_label: Fix unaligned traps on sparc.
  jump label: Make arch_jump_label_text_poke_early() optional
  jump label: Fix error with preempt disable holding mutex
  oprofile: Remove deprecated use of flush_scheduled_work()
  oprofile: Fix the hang while taking the cpu offline
  jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
  jump label: Fix module __init section race

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
2010-10-30 11:43:26 -07:00
Al Viro
120a795da0 audit mmap
Normal syscall audit doesn't catch 5th argument of syscall.  It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping.  For old one it also misses
flags.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:43 -04:00
Thomas Gleixner
ab263f47c9 audit: Use rcu for task lookup protection
Protect the task lookups in audit_receive_msg() with rcu_read_lock()
instead of tasklist_lock and use lock/unlock_sighand to protect
against the exit race.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:42 -04:00
Thomas Gleixner
207032051a audit: Do not send uninitialized data for AUDIT_TTY_GET
audit_receive_msg() sends uninitialized data for AUDIT_TTY_GET when
the task was not found.

Send reply only when task was found.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:42 -04:00
Thomas Gleixner
3c80fe4ac9 audit: Call tty_audit_push_task() outside preempt disabled
While auditing all tasklist_lock read_lock sites I stumbled over the
following call chain:

audit_prepare_user_tty()
  read_lock(&tasklist_lock);
  tty_audit_push_task();
     mutex_lock(&buf->mutex);

     --> buf->mutex is locked with preemption disabled.

Solve this by acquiring a reference to the task struct under
rcu_read_lock and call tty_audit_push_task outside of the preempt
disabled region.

Move all code which needs to be protected by sighand lock into
tty_audit_push_task() and use lock/unlock_sighand as we do not hold
tasklist_lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 08:45:25 -04:00
Al Viro
f7a998a949 in untag_chunk() we need to do alloc_chunk() a bit earlier
... while we are not holding spinlocks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 02:18:32 -04:00
Stephen Hemminger
b8800aa5d9 audit: make functions static
I was doing some namespace checks and found some simple stuff in
audit that could be cleaned up. Make some functions static, and
put const on make_reply payload arg.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 01:42:19 -04:00
Miloslav Trmac
d29be158a6 Audit: add support to match lsm labels on user audit messages
Add support for matching by security label (e.g. SELinux context) of
the sender of an user-space audit record.

The audit filter code already allows user space to configure such
filters, but they were ignored during evaluation.  This patch implements
evaluation of these filters.

For example, after application of this patch, PAM authentication logs
caused by cron can be disabled using
	auditctl -a user,never -F subj_type=crond_t

Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-30 01:41:57 -04:00
Linus Torvalds
1e431a9d64 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb,ppc: Individual register get/set for ppc
  kgdbts: prevent re-entry to kgdbts before it unregisters
  debug_core,x86,blackfin: Clean up hw debug disable API
  kdb: Fix early debugging crash regression
  kgdb,arm: fix register dump
  kdb: fix per_cpu command to remove supress mask
  kdb: Add kdb kernel module sample
2010-10-29 11:49:38 -07:00
Dongdong Deng
d7ba979d45 debug_core,x86,blackfin: Clean up hw debug disable API
The kgdb_disable_hw_debug() was an architecture specific function for
disabling all hardware breakpoints on a per cpu basis when entering
the debug core.

This patch will remove the weak function kdbg_disable_hw_debug() and
change it into a call back which lives with the rest of hw breakpoint
call backs in struct kgdb_arch.

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:41 -05:00
Jason Wessel
578bd4dfcd kdb: Fix early debugging crash regression
The kdb_current legally be equal to NULL in the early boot of the x86
arch.  The problem pcan be observed by booting with the kernel arguments:

    earlyprintk=vga ekgdboc=kbd kgdbwait

The kdb shell will oops on entry and recursively fault because it
cannot get past the final stage of shell initialization.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:41 -05:00
Jason Wessel
931ea24819 kdb: fix per_cpu command to remove supress mask
Rusty pointed out that the per_cpu command uses up lots of space on
the stack and the cpu supress mask is probably not needed.

This patch removes the need for the supress mask as well as fixing up
the following problems with the kdb per_cpu command:
  * The per_cpu command should allow an address as an argument
  * When you have more data than can be displayed on one screen allow
    the user to break out of the print loop.

Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:40 -05:00
Steven Rostedt
95bcd683fb jump label: Make arch_jump_label_text_poke_early() optional
Some archs do not need to do anything special for jump labels on
startup (like MIPS).  This patch adds a weak function stub for
arch_jump_label_text_poke_early();

Cc: Jason Baron <jbaron@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Daney <ddaney@caviumnetworks.com>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <1286218615-24011-2-git-send-email-ddaney@caviumnetworks.com>
LKML-Reference: <20101015201037.703989993@goodmis.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-29 12:56:13 -04:00
Steven Rostedt
de31c3ca81 jump label: Fix error with preempt disable holding mutex
Kprobes and jump label were having a race between mutexes that
was fixed by reordering the jump label. But this reordering
moved the jump label mutex into a preempt disable location.

This patch does a little fiddling to move the grabbing of
the jump label mutex from inside the preempt disable section
and still keep the order correct between the mutex and the
kprobes lock.

Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jason Baron <jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-29 12:55:55 -04:00
Linus Torvalds
53113b06e4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (29 commits)
  braino in internal.h
  convert simple cases of nfs-related ->get_sb() to ->mount()
  convert btrfs
  convert ceph
  convert gfs2
  convert afs
  convert ecryptfs
  convert sysfs
  convert cgroup and cpuset
  switch get_sb_ns() users
  switch procfs to ->mount()
  setting ->proc_mnt doesn't belong in proc_get_sb()
  convert cifs
  convert nilfs
  switch logfs to ->mount()
  logfs: fix a leak in get_sb
  logfs get_sb, part 3
  logfs get_sb, part 2
  logfs get_sb massage, part 1
  convert v9fs
  ...
2010-10-29 08:06:25 -07:00
Linus Torvalds
37542b6a7e Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched_stat: Update sched_info_queue/dequeue() code comments
  sched, cgroup: Fixup broken cgroup movement
2010-10-29 08:05:33 -07:00
Al Viro
f7e835710a convert cgroup and cpuset
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:17:06 -04:00
Linus Torvalds
e9f29c9a56 Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
  x86: allocate space within a region top-down
  x86: update iomem_resource end based on CPU physical address capabilities
  x86/PCI: allocate space from the end of a region, not the beginning
  PCI: allocate bus resources from the top down
  resources: support allocating space within a region from the top down
  resources: handle overflow when aligning start of available area
  resources: ensure callback doesn't allocate outside available space
  resources: factor out resource_clip() to simplify find_resource()
  resources: add a default alignf to simplify find_resource()
  x86/PCI: MMCONFIG: fix region end calculation
  PCI: Add support for polling PME state on suspended legacy PCI devices
  PCI: Export some PCI PM functionality
  PCI: fix message typo
  PCI: log vendor/device ID always
  PCI: update Intel chipset names and defines
  PCI: use new ccflags variable in Makefile
  PCI: add PCI_MSIX_TABLE/PBA defines
  PCI: add PCI vendor id for STmicroelectronics
  x86/PCI: irq and pci_ids patch for Intel Patsburg DeviceIDs
  PCI: OLPC: Only enable PCI configuration type override on XO-1
  ...
2010-10-28 11:59:52 -07:00
Jason Baron
91bad2f8d3 jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
register_kprobe() downs the 'text_mutex' and then calls
jump_label_text_reserved(), which downs the 'jump_label_mutex'.
However, the jump label code takes those mutexes in the reverse
order.

Fix by requiring the caller of jump_label_text_reserved() to do
the jump label locking via the newly added: jump_label_lock(),
jump_label_unlock(). Currently, kprobes is the only user
of jump_label_text_reserved().

Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <759032c48d5e30c27f0bba003d09bffa8e9f28bb.1285965957.git.jbaron@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-28 09:17:40 -04:00