Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>

Minchan Kim reports that when a system has many swap areas, and tmpfs
swaps out to the ninth or more, shmem_getpage_gfp()'s attempts to read
back the page cannot locate it, and the read fails with -ENOMEM.

Whoops.  Yes, I blindly followed read_swap_header()'s pte_to_swp_entry(
swp_entry_to_pte()) technique for determining maximum usable swap
offset, without stopping to realize that that actually depends upon the
pte swap encoding shifting swap offset to the higher bits and truncating
it there.  Whereas our radix_tree swap encoding leaves offset in the
lower bits: it's swap "type" (that is, index of swap area) that was
truncated.

Fix it by reducing the SWP_TYPE_SHIFT() in swapops.h, and removing the
broken radix_to_swp_entry(swp_to_radix_entry()) from read_swap_header().

This does not reduce the usable size of a swap area any further, it
leaves it as claimed when making the original commit: no change from 3.0
on x86_64, nor on i386 without PAE; but 3.0's 512GB is reduced to 128GB
per swapfile on i386 with PAE.  It's not a change I would have risked
five years ago, but with x86_64 supported for ten years, I believe it's
appropriate now.

Hmm, and what if some architecture implements its swap pte with offset
encoded below type? That would equally break the maximum usable swap
offset check.  Happily, they all follow the same tradition of encoding
offset above type, but I'll prepare a check on that for next.
Reported-and-Reviewed-and-Tested-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org [3.1, 3.2, 3.3, 3.4]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (as1558) fixes a problem affecting several ASUS computers:
The machine crashes or corrupts memory when going into suspend if the
ehci-hcd driver is bound to any controllers.  Users have been forced
to unbind or unload ehci-hcd before putting their systems to sleep.

After extensive testing, it was determined that the machines don't
like going into suspend when any EHCI controllers are in the PCI D3
power state.  Presumably this is a firmware bug, but there's nothing
we can do about it except to avoid putting the controllers in D3
during system sleep.

The patch adds a new flag to indicate whether the problem is present,
and avoids changing the controller's power state if the flag is set.
Runtime suspend is unaffected; this matters only for system suspend.
However as a side effect, the controller will not respond to remote
wakeup requests while the system is asleep.  Hence USB wakeup is not
functional -- but of course, this is already true in the current state
of affairs.

A similar patch has already been applied as commit
151b6128 (USB: EHCI: fix crash during
suspend on ASUS computers).  The patch supersedes that one and reverts
it.  There are two differences:

	The old patch added the flag at the USB level; this patch
	adds it at the PCI level.

	The old patch applied to all chipsets with the same vendor,
	subsystem vendor, and product IDs; this patch makes an
	exception for a known-good system (based on DMI information).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NDâniel Fraga <fragabr@gmail.com>
Tested-by: NAndrey Rahmatullin <wrar@wrar.name>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds an optional target_core_fabric_ops->put_session() caller
within the existing target_put_session() code path.

This is required by tcm_qla2xxx code in order to invoke it's own fabric
specific session shutdown handler using se_session->sess_kref.
Signed-off-by: NJoern Engel <joern@logfs.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Arun Easi <arun.easi@qlogic.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

In the transmit path of the bonding driver, skb->cb is used to
stash the skb->queue_mapping so that the bonding device can set its
own queue mapping.  This value becomes corrupted since the skb->cb is
also used in __dev_xmit_skb.

When transmitting through bonding driver, bond_select_queue is
called from dev_queue_xmit.  In bond_select_queue the original
skb->queue_mapping is copied into skb->cb (via bond_queue_mapping)
and skb->queue_mapping is overwritten with the bond driver queue.

Subsequently in dev_queue_xmit, __dev_xmit_skb is called which writes
the packet length into skb->cb, thereby overwriting the stashed
queue mappping.  In bond_dev_queue_xmit (called from hard_start_xmit),
the queue mapping for the skb is set to the stashed value which is now
the skb length and hence is an invalid queue for the slave device.

If we want to save skb->queue_mapping into skb->cb[], best place is to
add a field in struct qdisc_skb_cb, to make sure it wont conflict with
other layers (eg : Qdiscc, Infiniband...)

This patchs also makes sure (struct qdisc_skb_cb)->data is aligned on 8
bytes :

netem qdisc for example assumes it can store an u64 in it, without
misalignment penalty.

Note : we only have 20 bytes left in (struct qdisc_skb_cb)->data[].
The largest user is CHOKe and it fills it.

Based on a previous patch from Tom Herbert.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NTom Herbert <therbert@google.com>
Cc: John Fastabend <john.r.fastabend@intel.com>
Cc: Roland Dreier <roland@kernel.org>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before Kernel 3.5, no one was checking for the return value of
drm_connector_attach_property, so we never noticed that we were unable
to create some properties. Commit "drm: WARN() when
drm_connector_attach_property fails" added a WARN when we fail to
create a property, and the transition from "connector properties" to
"object properties" changed the warning message a little bit.

On i915 machines with many TV connectors we hit the maximum number of
properties (since each TV connector uses a lot of properties), so we
get a few backtraces in our logs. This commit increases the maximum
number of properties to 24 hoping we'll have enough room for
everybody.

Chris suggested that we convert this code to "lists", but I believe
this conversion can come after we make sure people's dmesgs are not
spammed by our driver.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reported-by: NDave Jones <davej@redhat.com>
Tested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

If I build with W=1, for every file that includes <net/route.h>, I get the warning

    include/net/route.h: In function 'ip_route_output':
    include/net/route.h:135:3: warning: initialized field overwritten [-Woverride-init]
    include/net/route.h:135:3: warning: (near initialization for 'fl4') [-Woverride-init]

(This is with "gcc (Debian 4.6.3-1) 4.6.3")

A fix seems pretty trivial: move the initialization of .flowi4_tos
earlier.  As far as I can tell, this has no effect on code generation.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

asm-generic/bug.h uses taint flags that are only defined in
linux/kernel.h, resulting in build failures on platforms that
don't include linux/kernel.h some other way:

        arch/sh/include/asm/thread_info.h:172:2: error: 'TAINT_WARN' undeclared (first use in this function)

Caused by commit edd63a27 ("set_restore_sigmask() is never called
without SIGPENDING (and never should be)").
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

I originally sent this patch to <trivial@kernel.org>, but Jiri Kosina did
not feel that this is fully appropriate for the trivial tree.

Using linux/tcp.h from C++ results in:

cat t.cc
#include <linux/tcp.h>
int main() { }

g++ -c t.cc

In file included from t.cc:1:
/usr/include/linux/tcp.h:72: error: '__u32 __fswab32(__u32)' cannot appear in a constant-expression
/usr/include/linux/tcp.h:72: error: a function call cannot appear in a constant-expression
...

Attached trivial patch fixes this problem.

Tested:
- the t.cc above compiles with g++ and
- the following program generates the same output before/after
  the patch:

#include <linux/tcp.h>
#include <stdio.h>

int main ()
{
#define P(a) printf("%s: %08x\n", #a, (int)a)
 P(TCP_FLAG_CWR);
 P(TCP_FLAG_ECE);
 P(TCP_FLAG_URG);
 P(TCP_FLAG_ACK);
 P(TCP_FLAG_PSH);
 P(TCP_FLAG_RST);
 P(TCP_FLAG_SYN);
 P(TCP_FLAG_FIN);
 P(TCP_RESERVED_BITS);
 P(TCP_DATA_OFFSET);
#undef P
 return 0;
}
Signed-off-by: NPaul Pluzhnikov <ppluzhnikov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix a typo that is built only when CONFIG_VGA_SWITCHEROO=n.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Add vga_switcheroo_get_client_state() to get the current state of the
client.  This is necessary to determine the proper initial state of
audio clients in HD-audio driver.
Acked-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Commit 026cee00 "params:
<level>_initcall-like kernel parameters" set old-style module
parameters to level 0.  And we call those level 0 calls where we used
to, early in start_kernel().

We also loop through the initcall levels and call the levelled
module_params before the corresponding initcall.  Unfortunately level
0 is early_init(), so we call the standard module_param calls twice.

(Turns out most things don't care, but at least ubi.mtd does).

Change the level to -1 for standard module_param calls.
Reported-by: NBenoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org

Zero is written at clear_tid_address when the process exits.  This
functionality is used by pthread_join().

We already have sys_set_tid_address() to change this address for the
current task but there is no way to obtain it from user space.

Without the ability to find this address and dump it we can't restore
pthread'ed apps which call pthread_join() once they have been restored.

This patch introduces the PR_GET_TID_ADDRESS prctl option which allows
the current process to obtain own clear_tid_address.

This feature is available iif CONFIG_CHECKPOINT_RESTORE is set.

[akpm@linux-foundation.org: fix prctl numbering]
Signed-off-by: NAndrew Vagin <avagin@openvz.org>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A fix for commit b32dfe37 ("c/r: prctl: add ability to set new
mm_struct::exe_file").

After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until
final mmput(), it never becomes NULL while task is alive.

We can check for other mapped files in mm instead of checking
mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in
order to forbid second changing of mm->exe_file.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Reviewed-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch addresses two issues:

a) Fix usage of u32 and __be32 that causes endianess warnings via sparse.
b) Ensure consistent hashing in a cluster that is composed of big and
   little endian systems. Thus, we obtain the same hash mark in an
   heterogeneous cluster.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NHans Schillstrom <hans@schillstrom.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

When a CPU is entering dyntick-idle mode, tick_nohz_stop_sched_tick()
calls rcu_needs_cpu() see if RCU needs that CPU, and, if not, computes the
next wakeup time based on the timer wheels.  Only later, when actually
entering the idle loop, rcu_prepare_for_idle() will be invoked.  In some
cases, rcu_prepare_for_idle() will post timers to wake the CPU back up.
But all for naught: The next wakeup time for the CPU has already been
computed, and posting a timer afterwards does not force that wakeup
time to be recomputed.  This means that rcu_prepare_for_idle()'s have
no effect.

This is not a problem on a busy system because something else will wake
up the CPU soon enough.  However, on lightly loaded systems, the CPU
might stay asleep for a considerable length of time.  If that CPU has
a callback that the rest of the system is waiting on, the system might
run very slowly or (in theory) even hang.

This commit avoids this problem by having rcu_needs_cpu() give
tick_nohz_stop_sched_tick() an estimate of when RCU will need the CPU
to wake back up, which tick_nohz_stop_sched_tick() takes into account
when programming the CPU's wakeup time.  An alternative approach is
for rcu_prepare_for_idle() to use hrtimers instead of normal timers,
but timers are much more efficient than are hrtimers for frequently
and repeatedly posting and cancelling a given timer, which is exactly
what RCU_FAST_NO_HZ does.
Reported-by: NPascal Chapperon <pascal.chapperon@wanadoo.fr>
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NPascal Chapperon <pascal.chapperon@wanadoo.fr>

In the current code, a short dyntick-idle interval (where there is
at least one non-lazy callback on the CPU) and a long dyntick-idle
interval (where there are only lazy callbacks on the CPU) are traced
identically, which can be less than helpful.  This commit therefore
emits different event traces in these two cases.
Signed-off-by: NPaul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NPascal Chapperon <pascal.chapperon@wanadoo.fr>

commit 5faa5df1 (inetpeer: Invalidate the inetpeer tree along with
the routing cache) added a race :

Before freeing an inetpeer, we must respect a RCU grace period, and make
sure no user will attempt to increase refcnt.

inetpeer_invalidate_tree() waits for a RCU grace period before inserting
inetpeer tree into gc_list and waking the worker. At that time, no
concurrent lookup can find a inetpeer in this tree.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Stack depth of 255 seems excessive, given that copy_from_user_nmi()
could be slow.
Signed-off-by: NArun Sharma <asharma@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1334961696-19580-3-git-send-email-asharma@fb.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Weird topologies can lead to asymmetric domain setups. This needs
further consideration since these setups are typically non-minimal
too.

For now, make it work by adding an extra mask selecting which CPUs
are allowed to iterate up.

The topology that triggered it is the one from David Rientjes:

	10 20 20 30
	20 10 20 20
	20 20 10 20
	30 20 20 10

resulting in boxes that wouldn't even boot.
Reported-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-3p86l9cuaqnxz7uxsojmz5rm@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

The new commit code fails to copy the verifier into the wb_verf field
of _all_ the nfs_page structures; it only copies it into the first entry.
The consequence is that most requests end up failing to match in
nfs_commit_release.

Fix is to copy the verifier into the req->wb_verf field in
nfs_write_completion.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Fred Isaman <iisaman@netapp.com>

This patch fixes bug in macro radix_tree_for_each_contig().

If radix_tree_next_slot() sees NULL in next slot it returns NULL, but following
radix_tree_next_chunk() switches iterating into next chunk. As result iterating
becomes non-contiguous and breaks vfs "splice" and all its users.
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Reported-and-bisected-by: NHans de Bruin <jmdebruin@xmsnet.nl>
Reported-and-bisected-by: NOndrej Zary <linux@rainbow-software.org>
Reported-bisected-and-tested-by: NToralf Förster <toralf.foerster@gmx.de>
Link: https://lkml.org/lkml/2012/6/5/64
Cc: stable <stable@vger.kernel.org> # 3.4.x
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

The open recovery code does not need to request a new value for the
mdsthreshold, and so does not allocate a struct nfs4_threshold.
The problem is that encode_getfattr_open() will still request an
mdsthreshold, and so we end up Oopsing in decode_attr_mdsthreshold.

This patch fixes encode_getfattr_open so that it doesn't request an
mdsthreshold when the caller isn't asking for one. It also fixes
decode_attr_mdsthreshold so that it errors if the server returns
an mdsthreshold that we didn't ask for (instead of Oopsing).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: Andy Adamson <andros@netapp.com>

size type of drm_exynos_gem_mmap struct is changed to uint64_t and
it adds pad for the struct to be aligned as 64bit.
Signed-off-by: NInki Dae <inki.dae@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

This is useful for SoCs whose I2C module's signals can be routed to
different sets of pins at run-time, using the pinctrl API.

                                 +-----+  +-----+
                                 | dev |  | dev |
    +------------------------+   +-----+  +-----+
    | SoC                    |      |        |
    |                   /----|------+--------+
    |   +---+   +------+     | child bus A, on first set of pins
    |   |I2C|---|Pinmux|     |
    |   +---+   +------+     | child bus B, on second set of pins
    |                   \----|------+--------+--------+
    |                        |      |        |        |
    +------------------------+  +-----+  +-----+  +-----+
                                | dev |  | dev |  | dev |
                                +-----+  +-----+  +-----+
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>

introduced in Linux-3.5-rc1 by
66886d6f
(ACPI: Add stubs for (un)register_acpi_bus_type)

Fix header file warnings when CONFIG_ACPI is not enabled:

include/acpi/acpi_bus.h:443:42: warning: 'struct acpi_bus_type' declared inside parameter list
include/acpi/acpi_bus.h:443:42: warning: its scope is only this definition or declaration, which is probably not
include/acpi/acpi_bus.h:444:44: warning: 'struct acpi_bus_type' declared inside parameter list
Signed-off-by: NLen Brown <len.brown@intel.com>

This reverts commit 5ceb9ce6.

That commit seems to be the cause of the mm compation list corruption
issues that Dave Jones reported.  The locking (or rather, absense
there-of) is dubious, as is the use of the 'page' variable once it has
been found to be outside the pageblock range.

So revert it for now, we can re-visit this for 3.6.  If we even need to:
as Minchan Kim says, "The patch wasn't a bug fix and even test workload
was very theoretical".
Reported-and-tested-by: NDave Jones <davej@redhat.com>
Acked-by: NHugh Dickins <hughd@google.com>
Acked-by: NKOSAKI Motohiro <kosaki.motohiro@gmail.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The comment above it says "Stat data, not accessed from path walking",
but in fact some of inode fields we use for the common stat data was way
down at the end of the inode, causing unnecessary cache misses for the
common stat operations.

The inode structure is pretty big, and this can change padding depending
on field width, but at least on the common 64-bit configurations this
doesn't change the size.  Some of our inode layout has historically been
to tro to avoid unnecessary padding fields, but cache locality is at
least as important for layout, if not more.

Noticed by looking at kernel profiles, and noticing that the "i_blkbits"
access stood out like a sore thumb.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d31 - tty: add lockdep annotations
  8f6576ad - tty: fix ldisc lock inversion trace
  d3ca8b64 - pty: Fix lock inversion
  b1d679af - tty: drop the pty lock during hangup
  abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef3 - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When NetLabel is not enabled, e.g. CONFIG_NETLABEL=n, and the system
receives a CIPSO tagged packet it is dropped (cipso_v4_validate()
returns non-zero).  In most cases this is the correct and desired
behavior, however, in the case where we are simply forwarding the
traffic, e.g. acting as a network bridge, this becomes a problem.

This patch fixes the forwarding problem by providing the basic CIPSO
validation code directly in ip_options_compile() without the need for
the NetLabel or CIPSO code.  The new validation code can not perform
any of the CIPSO option label/value verification that
cipso_v4_validate() does, but it can verify the basic CIPSO option
format.

The behavior when NetLabel is enabled is unchanged.
Signed-off-by: NPaul Moore <pmoore@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

replace boilerplate "should we use ->saved_sigmask or ->blocked?"
with calls of obvious inlined helper...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

first fruits of ..._restore_sigmask() helpers: now we can take
boilerplate "signal didn't have a handler, clear RESTORE_SIGMASK
and restore the blocked mask from ->saved_mask" into a common
helper.  Open-coded instances switched...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

helpers parallel to set_restore_sigmask(), used in the next commits
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>