random: remove warning
Turn off -Wmaybe-uninitialized when building with -Os

gcc-4.7 and higher add a lot of false positive warnings about
potential uses of uninitialized warnings, but only when optimizing
for size (-Os). This is the default when building allyesconfig,
which turns on CONFIG_CC_OPTIMIZE_FOR_SIZE.

In order to avoid getting a lot of patches that initialize such
variables and accidentally hide real errors along the way, let's
just turn off this warning on the respective gcc versions
when building with size optimizations. The -Wmaybe-uninitialized
option was introduced in the same gcc version (4.7) that is now
causing the false positives, so there is no effect on older compilers.

A side effect is that when building with CONFIG_CC_OPTIMIZE_FOR_SIZE,
we might now see /fewer/ warnings about possibly uninitialized
warnings than with -O2, but that is still much better than seeing
warnings known to be bogus.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Git-commit: e74fc973b6e531fef1fce8b101ffff05ecfb774c
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>
block: Reserve only one queue tag for sync IO if only 3 tags are available

In case a device has three tags available we still reserve two of them
for sync IO. That leaves only a single tag for async IO such as
writeback from flusher thread which results in poor performance.

Allow async IO to consume two tags in case queue has three tag availabe
to get a decent async write performance.

This patch improves streaming write performance on a machine with such disk
from ~21 MB/s to ~52 MB/s. Also postmark throughput in presence of
streaming writer improves from 8 to 12 transactions per second so sync
IO doesn't seem to be harmed in presence of heavy async writer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
mach-msm: avs: revert to old one
sched: set power savings to POWERSAVINGS_BALANCE_WAKEUP

save some power by default
cpufreq: interactive: fix compiling warnings

The gcc warns like:

  cpufreq_interactive.c:745:6: warning: operation on 'ret' may be
undefined [-Wsequence-point]

It was introduced by commit cf0fad49d17cb8273ce555dd5b7afab67d7923bf.

Since sprintf(...) just return 1 (one character) in this case, ret
should not changed.
Just discarding the result of sprintf(...) leads to the result that
the committer of cf0fad49d17cb8273ce555dd5b7afab67d7923bf wants.

Change-Id: Ifed1cef6d6a31c3ed23dad03a567b3b9eddf3a57
Signed-off-by: Chih-Wei Huang <cwhuang@android-x86.org>
Signed-off-by: Dave Daynard <nardholio@gmail.com>
cpufreq: interactive: Allow 1 ms error in above_hispeed_delay comparisons

Allow for an error of 1 ms while taking into account
above_hispeed_delay for a frequency

Change-Id: I744e44387152e4efb5978df4f2b9533bf79d4582
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Reset floor_validate_time if busy at max for 100ms

When the interactive governor selects to run at max frequency it doesn't
re-schedule the timer until it hits an idle. This change checks if the CPU
has been continuously busy for last 100ms on hitting an idle start. If yes,
then floor_validate_time is reset so that the CPU stays at max frequency
for at least another 100 ms before stepping down.
This is an important feature for detecting CPU intensive workloads which
require high frequencies for achieving better performance.

Change-Id: I7d48ffbc3d50a80af9be3bf94667ee3d0120b763
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Add a sampling_down_factor for max frequencies

Change min_sample_time to 100ms when running at max

Change-Id: Ia7e35b0625bedf20e7ef3a1f52e5828ffbfed93e
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
cpufreq: interactive: Remove trace event from idle_start handler

Removed the trace_cpufreq_interactive_idle_start.
Also fix a crash resulting from accessing NULL policy before taking
the pcpu->enable_sem lock. The policy can be NULL if the core is
hotplugged out before the enable_sem lock is taken.

Change-Id: I7e2809cc016b3b383a44cdf3c697013e2d2b5417
Signed-off-by: Rohit Gupta <rohgup@codeaurora.org>
(cherry picked from commit 3b7992b90216c74a9ae9ce0df90bc446687a2313)
cpuidle: make a single register function for all

The usual scheme to initialize a cpuidle driver on a SMP is:

	cpuidle_register_driver(drv);
	for_each_possible_cpu(cpu) {
		device = &per_cpu(cpuidle_dev, cpu);
		cpuidle_register_device(device);
	}

This code is duplicated in each cpuidle driver.

On UP systems, it is done this way:

	cpuidle_register_driver(drv);
	device = &per_cpu(cpuidle_dev, cpu);
	cpuidle_register_device(device);

On UP, the macro 'for_each_cpu' does one iteration:

        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)

Hence, the initialization loop is the same for UP than SMP.

Beside, we saw different bugs / mis-initialization / return code unchecked in
the different drivers, the code is duplicated including bugs. After fixing all
these ones, it appears the initialization pattern is the same for everyone.

Please note, some drivers are doing dev->state_count = drv->state_count. This is
not necessary because it is done by the cpuidle_enable_device function in the
cpuidle framework. This is true, until you have the same states for all your
devices. Otherwise, the 'low level' API should be used instead with the specific
initialization for the driver.

Let's add a wrapper function doing this initialization with a cpumask parameter
for the coupled idle states and use it for all the drivers.

That will save a lot of LOC, consolidate the code, and the modifications in the
future could be done in a single place. Another benefit is the consolidation of
the cpuidle_device variable which is now in the cpuidle framework and no longer
spread accross the different arch specific drivers.

Change-Id: I8f75188d5770871620f758c2973b74384ac570d5
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
ext4: speed up truncate/unlink by not using bforget() unless needed

Do not iterate over data blocks scanning for bh's to forget as they're
never exist. This improves time taken by unlink / truncate syscall.
Tested by continuously truncating file that is being written by dd.
Another test is rm -rf of linux tree while tar unpacks it. With
ordered data mode condition unlikely(!tbh) was always met in
ext4_free_blocks. With journal data mode tbh was found only few times,
so optimisation is also possible.

Unlinking fallocated 60G file after doing sync && echo 3 >
/proc/sys/vm/drop_caches && time rm --help

X86 before (linux 3.6-rc4):
real    0m2.710s
user    0m0.000s
sys     0m1.530s

X86 after:
real    0m0.644s
user    0m0.003s
sys     0m0.060s

MIPS before (linux 2.6.37):
real    0m 4.93s
user    0m 0.00s
sys     0m 4.61s

MIPS after:
real    0m 0.16s
user    0m 0.00s
sys     0m 0.06s

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrey Sidorov <qrxd43@motorola.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>

Change-Id: Ie78a945cb82b3892eaf88701f2dc3b7726104fb5
jbd2: optimize jbd2_journal_force_commit

Current implementation of jbd2_journal_force_commit() is suboptimal because
result in empty and useless commits. But callers just want to force and wait
any unfinished commits. We already have jbd2_journal_force_commit_nested()
which does exactly what we want, except we are guaranteed that we do not hold
journal transaction open.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Change-Id: I5c041a1898838e880714a913b5a915f105a8dfb9
debug-pagealloc: Panic on pagealloc corruption

Currently, we just print the pagealloc corruption warnings and
proceed. Sometimes, we are getting multiple errors printed down
the line. It will be good to get the device state as early as
possible when we get the first pagealloc error.

Change-Id: I79155ac8a039b30a3a98d5dd1384d3923082712f
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
mm: methods for teaching filesystems about PG_swapcache pages

In order to teach filesystems to handle swap cache pages, three new page
functions are introduced:

  pgoff_t page_file_index(struct page *);
  loff_t page_file_offset(struct page *);
  struct address_space *page_file_mapping(struct page *);

page_file_index() - gives the offset of this page in the file in
PAGE_CACHE_SIZE blocks.  Like page->index is for mapped pages, this
function also gives the correct index for PG_swapcache pages.

page_file_offset() - uses page_file_index(), so that it will give the
expected result, even for PG_swapcache pages.

page_file_mapping() - gives the mapping backing the actual page; that is
for swap cache pages it will give swap_file->f_mapping.

Change-Id: I13d18bb25be606760eac26cc842eb7c9fc9e4766
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: f981c5950fa85916ba49bea5d9a7a5078f47e569
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[ohaugan@codeaurora.org: Resolved merge issues]
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
msm: vidc: enable pic_order_cnt_type for H264 encoding

-current implementation will result in poc_type as 0 in SPS
params (even though the poc increment value is 2 in the
encoded stream).
-So changes done to return poc_type as 2 in SPS params

Change-Id: I5a22af422b0e1591a69a0b5b868342667ee60bbf
Signed-off-by: srikarri <sridur@codeaurora.org>
SELinux: Fix kernel BUG on empty security contexts.

Setting an empty security context (length=0) on a file will
lead to incorrectly dereferencing the type and other fields
of the security context structure, yielding a kernel BUG.
As a zero-length security context is never valid, just reject
all such security contexts whether coming from userspace
via setxattr or coming from the filesystem upon a getxattr
request by SELinux.

Setting a security context value (empty or otherwise) unknown to
SELinux in the first place is only possible for a root process
(CAP_MAC_ADMIN), and, if running SELinux in enforcing mode, only
if the corresponding SELinux mac_admin permission is also granted
to the domain by policy.  In Fedora policies, this is only allowed for
specific domains such as livecd for setting down security contexts
that are not defined in the build host policy.

[On Android, this can only be set by root/CAP_MAC_ADMIN processes,
and if running SELinux in enforcing mode, only if mac_admin permission
is granted in policy.  In Android 4.4, this would only be allowed for
root/CAP_MAC_ADMIN processes that are also in unconfined domains. In current
AOSP master, mac_admin is not allowed for any domains except the recovery
console which has a legitimate need for it.  The other potential vector
is mounting a maliciously crafted filesystem for which SELinux fetches
xattrs (e.g. an ext4 filesystem on a SDcard).  However, the end result is
only a local denial-of-service (DOS) due to kernel BUG.  This fix is
queued for 3.14.]

Reproducer:
su
setenforce 0
touch foo
setfattr -n security.selinux foo

Caveat:
Relabeling or removing foo after doing the above may not be possible
without booting with SELinux disabled.  Any subsequent access to foo
after doing the above will also trigger the BUG.

BUG output from Matthew Thode:
[  473.893141] ------------[ cut here ]------------
[  473.962110] kernel BUG at security/selinux/ss/services.c:654!
[  473.995314] invalid opcode: 0000 [#6] SMP
[  474.027196] Modules linked in:
[  474.058118] CPU: 0 PID: 8138 Comm: ls Tainted: G      D   I
3.13.0-grsec #1
[  474.116637] Hardware name: Supermicro X8ST3/X8ST3, BIOS 2.0
07/29/10
[  474.149768] task: ffff8805f50cd010 ti: ffff8805f50cd488 task.ti:
ffff8805f50cd488
[  474.183707] RIP: 0010:[<ffffffff814681c7>]  [<ffffffff814681c7>]
context_struct_compute_av+0xce/0x308
[  474.219954] RSP: 0018:ffff8805c0ac3c38  EFLAGS: 00010246
[  474.252253] RAX: 0000000000000000 RBX: ffff8805c0ac3d94 RCX:
0000000000000100
[  474.287018] RDX: ffff8805e8aac000 RSI: 00000000ffffffff RDI:
ffff8805e8aaa000
[  474.321199] RBP: ffff8805c0ac3cb8 R08: 0000000000000010 R09:
0000000000000006
[  474.357446] R10: 0000000000000000 R11: ffff8805c567a000 R12:
0000000000000006
[  474.419191] R13: ffff8805c2b74e88 R14: 00000000000001da R15:
0000000000000000
[  474.453816] FS:  00007f2e75220800(0000) GS:ffff88061fc00000(0000)
knlGS:0000000000000000
[  474.489254] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  474.522215] CR2: 00007f2e74716090 CR3: 00000005c085e000 CR4:
00000000000207f0
[  474.556058] Stack:
[  474.584325]  ffff8805c0ac3c98 ffffffff811b549b ffff8805c0ac3c98
ffff8805f1190a40
[  474.618913]  ffff8805a6202f08 ffff8805c2b74e88 00068800d0464990
ffff8805e8aac860
[  474.653955]  ffff8805c0ac3cb8 000700068113833a ffff880606c75060
ffff8805c0ac3d94
[  474.690461] Call Trace:
[  474.723779]  [<ffffffff811b549b>] ? lookup_fast+0x1cd/0x22a
[  474.778049]  [<ffffffff81468824>] security_compute_av+0xf4/0x20b
[  474.811398]  [<ffffffff8196f419>] avc_compute_av+0x2a/0x179
[  474.843813]  [<ffffffff8145727b>] avc_has_perm+0x45/0xf4
[  474.875694]  [<ffffffff81457d0e>] inode_has_perm+0x2a/0x31
[  474.907370]  [<ffffffff81457e76>] selinux_inode_getattr+0x3c/0x3e
[  474.938726]  [<ffffffff81455cf6>] security_inode_getattr+0x1b/0x22
[  474.970036]  [<ffffffff811b057d>] vfs_getattr+0x19/0x2d
[  475.000618]  [<ffffffff811b05e5>] vfs_fstatat+0x54/0x91
[  475.030402]  [<ffffffff811b063b>] vfs_lstat+0x19/0x1b
[  475.061097]  [<ffffffff811b077e>] SyS_newlstat+0x15/0x30
[  475.094595]  [<ffffffff8113c5c1>] ? __audit_syscall_entry+0xa1/0xc3
[  475.148405]  [<ffffffff8197791e>] system_call_fastpath+0x16/0x1b
[  475.179201] Code: 00 48 85 c0 48 89 45 b8 75 02 0f 0b 48 8b 45 a0 48
8b 3d 45 d0 b6 00 8b 40 08 89 c6 ff ce e8 d1 b0 06 00 48 85 c0 49 89 c7
75 02 <0f> 0b 48 8b 45 b8 4c 8b 28 eb 1e 49 8d 7d 08 be 80 01 00 00 e8
[  475.255884] RIP  [<ffffffff814681c7>]
context_struct_compute_av+0xce/0x308
[  475.296120]  RSP <ffff8805c0ac3c38>
[  475.328734] ---[ end trace f076482e9d754adc ]---

[sds:  commit message edited to note Android implications and
to generate a unique Change-Id for gerrit]

Change-Id: I4d5389f0cfa72b5f59dada45081fa47e03805413
Reported-by:  Matthew Thode <mthode@mthode.org>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
sync: Fix a race condition between release_obj and print_obj

Before this change, a timeline would only be removed from the timeline
list *after* the sync driver had its release_obj() called. However, the
driver's release_obj() may free resources needed by print_obj().

Although the timeline list is locked when print_obj() is called, it is
not locked when release_obj() is called. If one CPU was in print_obj()
when another was in release_obj(), the print_obj() may make unsafe
accesses.

It is not actually necessary to hold the timeline list lock when calling
release_obj() if the call is made after the timeline is unlinked from
the list, since there is no possibility another thread could be in --
or enter -- print_obj() for that timeline.

This change moves the release_obj() call to after the timeline is
unlinked, preventing the above race from occurring.

Signed-off-by: Alistair Strachan <alistair.strachan@imgtec.com>

Change-Id: I563347e163ac4ef19c2f5930c3ec10e61f5f5d44
uio: msm_shared: Add support for platform data

Update the driver to support backward compatibility for devices
relying on board files for platform data.

CRs-Fixed: 592586
Change-Id: I04d4195a7fd4b926e52b0cbb2bb33cfcc054689f
Signed-off-by: Pratibhasagar V <pratibha@codeaurora.org>
writeback: fix race that cause writeback hung

There is a race between mark inode dirty and writeback thread, see the
following scenario.  In this case, writeback thread will not run though
there is dirty_io.

__mark_inode_dirty()                                          bdi_writeback_workfn()
	...                                                       	...
	spin_lock(&inode->i_lock);
	...
	if (bdi_cap_writeback_dirty(bdi)) {
	    <<< assume wb has dirty_io, so wakeup_bdi is false.
	    <<< the following inode_dirty also have wakeup_bdi false.
	    if (!wb_has_dirty_io(&bdi->wb))
		    wakeup_bdi = true;
	}
	spin_unlock(&inode->i_lock);
	                                                            <<< assume last dirty_io is removed here.
	                                                            pages_written = wb_do_writeback(wb);
	                                                            ...
	                                                            <<< work_list empty and wb has no dirty_io,
	                                                            <<< delayed_work will not be queued.
	                                                            if (!list_empty(&bdi->work_list) ||
	                                                                (wb_has_dirty_io(wb) && dirty_writeback_interval))
	                                                                queue_delayed_work(bdi_wq, &wb->dwork,
	                                                                    msecs_to_jiffies(dirty_writeback_interval * 10));
	spin_lock(&bdi->wb.list_lock);
	inode->dirtied_when = jiffies;
	<<< new dirty_io is added.
	list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
	spin_unlock(&bdi->wb.list_lock);

	<<< though there is dirty_io, but wakeup_bdi is false,
	<<< so writeback thread will not be waked up and
	<<< the new dirty_io will not be flushed.
	if (wakeup_bdi)
	    bdi_wakeup_thread_delayed(bdi);

Writeback will run until there is a new flush work queued.  This may cause
a lot of dirty pages stay in memory for a long time.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>

Change-Id: I973fcba5381881a003a035ffff48f64348660079