Staging: android: fixed white spaces coding style issue in
 logger.c

This patch fixes some space-before-tabs warnings found by checkpatch tool on the staging android driver file logger.c

Change-Id: I20226ed7b76070d4fd2de3fca1f78b029db6351d
Signed-off-by: Marco Navarra <fromenglish@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
random: run random_int_secret_init() run after all late_initcalls

commit 47d06e532e95b71c0db3839ebdef3fe8812fca2c upstream.

The some platforms (e.g., ARM) initializes their clocks as
late_initcalls for some unknown reason.  So make sure
random_int_secret_init() is run after all of the late_initcalls are
run.

Change-Id: Ifc7ed1c9fafcadea67396606042b07b97b01071d
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
random: fix accounting race condition with lockless irq entropy_count update

commit 10b3a32d292c21ea5b3ad5ca5975e88bb20b8d68 upstream.

Commit 902c098a3663 ("random: use lockless techniques in the interrupt
path") turned IRQ path from being spinlock protected into lockless
cmpxchg-retry update.

That commit removed r->lock serialization between crediting entropy bits
from IRQ context and accounting when extracting entropy on userspace
read path, but didn't turn the r->entropy_count reads/updates in
account() to use cmpxchg as well.

It has been observed, that under certain circumstances this leads to
read() on /dev/urandom to return 0 (EOF), as r->entropy_count gets
corrupted and becomes negative, which in turn results in propagating 0
all the way from account() to the actual read() call.

Convert the accounting code to be the proper lockless counterpart of
what has been partially done by 902c098a3663.

Change-Id: I1c057050633441e64d43c97897e77117510cdaeb
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
random32: fix off-by-one in seeding requirement

[ Upstream commit 51c37a70aaa3f95773af560e6db3073520513912 ]

For properly initialising the Tausworthe generator [1], we have
a strict seeding requirement, that is, s1 > 1, s2 > 7, s3 > 15.

Commit 697f8d0348 ("random32: seeding improvement") introduced
a __seed() function that imposes boundary checks proposed by the
errata paper [2] to properly ensure above conditions.

However, we're off by one, as the function is implemented as:
"return (x < m) ? x + m : x;", and called with __seed(X, 1),
__seed(X, 7), __seed(X, 15). Thus, an unwanted seed of 1, 7, 15
would be possible, whereas the lower boundary should actually
be of at least 2, 8, 16, just as GSL does. Fix this, as otherwise
an initialization with an unwanted seed could have the effect
that Tausworthe's PRNG properties cannot not be ensured.

Note that this PRNG is *not* used for cryptography in the kernel.

 [1] http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
 [2] http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps

Joint work with Hannes Frederic Sowa.

Change-Id: I53ee85d2fd2f8503b09fa2cce623e6e24fbda2c2
Fixes: 697f8d0348a6 ("random32: seeding improvement")
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ashmem: fix deadlock when system is low on memory

When system is low on memory, allocating memory while holding the
ashmem_mutex may try to directly reclaim memory. Then ashmem_shrink()
is called in same thread. It will deadlock at acquiring ashmem_mutex.
This change lets ashmem_shrink() return failure if ashmem_mutex is not
available. Memory will be reclaimed from others.

Change-Id: Ic6439ac9877b53c006b42d007e94062b87d9bac6
lzo: properly check for overruns

commit 206a81c18401c0cde6e579164f752c4b147324ce upstream.

The lzo decompressor can, if given some really crazy data, possibly
overrun some variable types.  Modify the checking logic to properly
detect overruns before they happen.

Change-Id: I69c6604cab9687b1f0d5f8a6b47804289ae76b99
Reported-by: "Don A. Bailey" <donb@securitymouse.com>
Tested-by: "Don A. Bailey" <donb@securitymouse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
printk: fix buffer overflow when calling log_prefix function from call_console_drivers

This patch corrects a buffer overflow in kernels from 3.0 to 3.4 when calling
log_prefix() function from call_console_drivers().

This bug existed in previous releases but has been revealed with commit
162a7e7500f9664636e649ba59defe541b7c2c60 (2.6.39 => 3.0) that made changes
about how to allocate memory for early printk buffer (use of memblock_alloc).
It disappears with commit 7ff9554bb578ba02166071d2d487b7fc7d860d62 (3.4 => 3.5)
that does a refactoring of printk buffer management.

In log_prefix(), the access to "p[0]", "p[1]", "p[2]" or
"simple_strtoul(&p[1], &endp, 10)" may cause a buffer overflow as this
function is called from call_console_drivers by passing "&LOG_BUF(cur_index)"
where the index must be masked to do not exceed the buffer's boundary.

The trick is to prepare in call_console_drivers() a buffer with the necessary
data (PRI field of syslog message) to be safely evaluated in log_prefix().

This patch can be applied to stable kernel branches 3.0.y, 3.2.y and 3.4.y.

Without this patch, one can freeze a server running this loop from shell :
  $ export DUMMY=`cat /dev/urandom | tr -dc '12345AZERTYUIOPQSDFGHJKLMWXCVBNazertyuiopqsdfghjklmwxcvbn' | head -c255`
  $ while true do ; echo $DUMMY > /dev/kmsg ; done

The "server freeze" depends on where memblock_alloc does allocate printk buffer :
if the buffer overflow is inside another kernel allocation the problem may not
be revealed, else the server may hangs up.

Change-Id: If36e3c92fcb286d6ab8711e484b5807325178104
Signed-off-by: Alexandre SIMON <Alexandre.Simon@univ-lorraine.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
slub: fix a possible memory leak

Memory allocated by kstrdup should be freed,
when kmalloc(kmem_size, GFP_KERNEL) is failed.

Change-Id: I4d07288da8e094b6e2898303d9b8af690d2ca877
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
slub: tid must be retrieved from the percpu area of the current processor

As Steven Rostedt has pointer out: rescheduling could occur on a
different processor after the determination of the per cpu pointer and
before the tid is retrieved. This could result in allocation from the
wrong node in slab_alloc().

The effect is much more severe in slab_free() where we could free to the
freelist of the wrong page.

The window for something like that occurring is pretty small but it is
possible.

Change-Id: Ie558aaf74d2219bae0f3b4b5fe87d1346f10ea55
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
slub: add taint flag outputting to debug paths

When we get corruption reports, it's useful to see if the kernel was
tainted, to rule out problems we can't do anything about.

Change-Id: Ic9de8598061883545c1feb2a72a412ff4dd4add7
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
lib/int_sqrt.c: optimize square root algorithm

Optimize the current version of the shift-and-subtract (hardware)
algorithm, described by John von Newmann[1] and Guy L Steele.

Iterating 1,000,000 times, perf shows for the current version:

 Performance counter stats for './sqrt-curr' (10 runs):

         27.170996 task-clock                #    0.979 CPUs utilized            ( +-  3.19% )
                 3 context-switches          #    0.103 K/sec                    ( +-  4.76% )
                 0 cpu-migrations            #    0.004 K/sec                    ( +-100.00% )
               104 page-faults               #    0.004 M/sec                    ( +-  0.16% )
        64,921,199 cycles                    #    2.389 GHz                      ( +-  0.03% )
        28,967,789 stalled-cycles-frontend   #   44.62% frontend cycles idle     ( +-  0.18% )
   <not supported> stalled-cycles-backend
       104,502,623 instructions              #    1.61  insns per cycle
                                             #    0.28  stalled cycles per insn  ( +-  0.00% )
        34,088,368 branches                  # 1254.587 M/sec                    ( +-  0.00% )
             4,901 branch-misses             #    0.01% of all branches          ( +-  1.32% )

       0.027763015 seconds time elapsed                                          ( +-  3.22% )

And for the new version:

Performance counter stats for './sqrt-new' (10 runs):

          0.496869 task-clock                #    0.519 CPUs utilized            ( +-  2.38% )
                 0 context-switches          #    0.000 K/sec
                 0 cpu-migrations            #    0.403 K/sec                    ( +-100.00% )
               104 page-faults               #    0.209 M/sec                    ( +-  0.15% )
           590,760 cycles                    #    1.189 GHz                      ( +-  2.35% )
           395,053 stalled-cycles-frontend   #   66.87% frontend cycles idle     ( +-  3.67% )
   <not supported> stalled-cycles-backend
           398,963 instructions              #    0.68  insns per cycle
                                             #    0.99  stalled cycles per insn  ( +-  0.39% )
            70,228 branches                  #  141.341 M/sec                    ( +-  0.36% )
             3,364 branch-misses             #    4.79% of all branches          ( +-  5.45% )

       0.000957440 seconds time elapsed                                          ( +-  2.42% )

Furthermore, this saves space in instruction text:

   text    data     bss     dec     hex filename
    111       0       0     111      6f lib/int_sqrt-baseline.o
     89       0       0      89      59 lib/int_sqrt.o

[1] http://en.wikipedia.org/wiki/First_Draft_of_a_Report_on_the_EDVAC

Change-Id: I149138da0c69f25520d52d94bcbb6817aa9eb75d
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Reviewed-by: Jonathan Gonzalez <jgonzlez@linets.cl>
Tested-by: Jonathan Gonzalez <jgonzlez@linets.cl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
old bug in htree_dirblock_to_tree()

Both ext3 and ext4 htree_dirblock_to_tree() is just filling
the in-core rbtree for use by call_filldir().  All updates of
->f_pos are done by the latter; bumping it here (on error) is obviously
wrong - we might very well have it nowhere near the block we'd found
an error in.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Paul Reioux <reioux@gmail.com>
block/deadline: tweak for better android performance