random: Mix cputime from each thread that exits to the pool

When a thread exits mix it's cputime (userspace + kernelspace) to the entropy pool.

We don't know how "random" this is, so we use add_device_randomness that doesn't mess
with entropy count.

Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
posix_timers: Kick full dynticks CPUs when a posix cpu timer is armed

Kick the full dynticks CPUs when a posix cpu timer is enqueued by
way of a standard call to posix_cpu_timer_set() or set_process_cpu_timer().
This also include rescheduled firing timers.

This way they can re-evaluate the state of (and possibly restart) their
tick against the new expiry modification.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
posix_timers: New API to prevent from stopping the tick when timers are running

Bring a new helper that the full dynticks infrastructure can
call in order to know if it can safely stop the tick from
the posix cpu timers subsystem point of view.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
posix_timers: Fix pre-condition to stop the tick on full dynticks

The test that checks if a CPU can stop its tick from posix CPU
timers angle was mistakenly inverted.

What we want is to prevent the tick from being stopped as long
as the current CPU's task runs a posix CPU timer.

Fix this.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
+ "slab: prevent warnings when allocating with __GFP_NOWARN" - https://git.linaro.org/gitweb?p=people/rmk/linux-arm.git;a=commitdiff;h=907985f48bc60818e291c631249f9bc84c83a06f
+ "drivers: net: bcmdhd: neuter net_os_rxfilter_add_remove" -> https://github.com/neobuddy89/NX-Kernel-exynos4/commit/0702eb493f553d668f582165f3cb9b7b504b387b
+ "drivers: net: bcmdhd: Increase retries on failure" -> https://github.com/neobuddy89/NX-Kernel-exynos4/commit/4ab72364e98070c7d60abfe231d736464cbbcee6
+ "drivers: net: bcmdhd: More optimization" -> https://github.com/neobuddy89/NX-Kernel-exynos4/commit/37542373c6354457baac772fe73f454000a59d38

thx @ neobuddy89 | need testing
+ "mach-u1: Decreased LCD PowerOn delay" - https://github.com/sakindia123/android_kernel_samsung_smdk4412/commit/978e946f334f5f3ba5f41001b728bc006e7a560b
+ "sw_sync: export sw_sync API" - https://github.com/sakindia123/android_kernel_samsung_smdk4412/commit/10dc6fa1bf7fc8c1ddaeeee32627bdcdf170708c
+ "sw_sync: Fix error paths" - https://github.com/sakindia123/android_kernel_samsung_smdk4412/commit/dc0b65a38b07b4c2a419fc3a793ffb741fa95559
posix-timers: Fix clock_adjtime to always return timex data on success

The clock_adj call returns the clock state on success, which may be a
non-zero value (e.g. TIME_INS), but the modified timex data is copied
back to the user only when zero value (TIME_OK) was returned. Fix the
condition to copy the data also with positive return values.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
posix-timers: convert to idr_alloc()

Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
posix timers: Allocate timer id per process (v2)

Currently kernel generates IDs for posix timers in a global manner --
there's a kernel-wide IDR tree from which IDs are created. This makes
it impossible to recreate a timer with a desired ID (in particular
this is done by the CRIU checkpoint-restore project) -- since these
IDs are global it may happen, that at the time we recreate a timer, the
ID we want for it is already busy by some other timer.

In order to address this, replace the IDR tree with a global hash
table for timers and makes timer IDs unique per signal_struct (to
which timers are linked anyway). With this, two timers belonging to
different processes may have equal IDs and we can recreate either of
them with the ID we want.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513D9FF5.9010004@parallels.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
posix-timers: Remove unused variable

Remove the unused variable *node introduced by commit 5ed67f05 (posix
timers: Allocate timer id per process)

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
net: Dont use ifindices in hash fns

Eric noticed, that when there will be devices with equal indices, some
hash functions that use them will become less effective as they could.
Fix this in advance by mixing the net_device address into the hash value
instead of the device index.

This is true for arp and ndisc hash fns. The netlabel, can and llc ones
are also ifindex-based, but that three are init_net-only, thus will not
be affected.

Many thanks to David and Eric for the hash32_ptr implementation!

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kprobes: Make hash_64() as always inlined

Because hash_64() is called from the get_kprobe() inside
int3 handler, kernel causes int3 recursion and crashes if
kprobes user puts a probe on it.

Usually hash_64() is inlined into caller function, but in
some cases, it has instances by gcc's interprocedural
constant propagation.

This patch uses __always_inline instead of inline to
prevent gcc from doing such things.

Reported-by: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: David S. Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20130314115230.19690.39387.stgit@mhiramat-M0-7522
Signed-off-by: Ingo Molnar <mingo@kernel.org>
init: Do not warn on non-zero initcall return

Commit f91eb62f71b3 ("init: scream bloody murder if interrupts are
enabled too early") added three new warnings.  The first two seemed
reasonable, but the third included a warning when an initcall returned
non-zero.  Although, the third WARN() does include an imbalanced preempt
disabled, or irqs disable, it shouldn't warn if it only had an initcall
that just returns non-zero.

In fact, according to Linus, it shouldn't print at all.  As it only
prints with initcall_debug set, and that already shows enough
information to fix things.

Link: http://lkml.kernel.org/r/CA+55aFzaBC5SFi7=F2mfm+KWY5qTsBmOqgbbs8E+LUS8JK-sBg@mail.gmail.com

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init, block: try to load default elevator module early during boot

This patch adds default module loading and uses it to load the default
block elevator.  During boot, it's called right after initramfs or
initrd is made available and right before control is passed to
userland.  This ensures that as long as the modules are available in
the usual places in initramfs, initrd or the root filesystem, the
default modules are loaded as soon as possible.

This will replace the on-demand elevator module loading from elevator
init path.

v2: Fixed build breakage when !CONFIG_BLOCK.  Reported by kbuild test
    robot.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alex Riesen <raa.lkml@gmail.com>
Cc: Fengguang We <fengguang.wu@intel.com>
make sure that we always have a return path from kernel_execve()

The only place where kernel_execve() is called without a way to
return to the caller of kernel_thread() callback is kernel_post().
Reorganize kernel_init()/kernel_post() - instead of the former
calling the latter in the end (and getting freed by it), have the
latter *begin* with calling the former (and turn the latter into
kernel_thread() callback, of course).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Ensure that kernel_init_freeable() is not inlined into non __init code

Commit d6b2123802d "make sure that we always have a return path from
kernel_execve()" reshuffled kernel_init()/init_post() to ensure that
kernel_execve() has a caller to return to.

It removed __init annotation for kernel_init() and introduced/calls a
new routine kernel_init_freeable(). Latter however is inlined by any
reasonable compiler (ARC gcc 4.4 in this case), causing slight code
bloat.

This patch forces kernel_init_freeable() as noinline reducing the .text

bloat-o-meter vmlinux vmlinux_new
add/remove: 1/0 grow/shrink: 0/1 up/down: 374/-334 (40)
function                        old     new   delta
kernel_init_freeable              -     374    +374 (.init.text)
kernel_init                     628     294    -334 (.text)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
FRV: gcc-4.1.2 also inlines weak functions

gcc-4.1.2 inlines weak functions, which causes FRV to fail when the dummy
thread_info_cache_init() gets inlined into start_kernel().

Signed-off-by: David Howells <dhowells@redhat.com>
Small Fix for init/main.c