This driver solves three problems:
 1). Parse and upload ACPI0007 (or PROCESSOR_TYPE) information to the
     hypervisor - aka P-states (cpufreq data).
 2). Upload the the Cx state information (cpuidle data).
 3). Inhibit CPU frequency scaling drivers from loading.

The reason for wanting to solve 1) and 2) is such that the Xen hypervisor
is the only one that knows the CPU usage of different guests and can
make the proper decision of when to put CPUs and packages in proper states.
Unfortunately the hypervisor has no support to parse ACPI DSDT tables, hence it
needs help from the initial domain to provide this information. The reason
for 3) is that we do not want the initial domain to change P-states while the
hypervisor is doing it as well - it causes rather some funny cases of P-states
transitions.

For this to work, the driver parses the Power Management data and uploads said
information to the Xen hypervisor. It also calls acpi_processor_notify_smm()
to inhibit the other CPU frequency scaling drivers from being loaded.

Everything revolves around the 'struct acpi_processor' structure which
gets updated during the bootup cycle in different stages. At the startup, when
the ACPI parser starts, the C-state information is processed (processor_idle)
and saved in said structure as 'power' element. Later on, the CPU frequency
scaling driver (powernow-k8 or acpi_cpufreq), would call the the
acpi_processor_* (processor_perflib functions) to parse P-states information
and populate in the said structure the 'performance' element.

Since we do not want the CPU frequency scaling drivers from loading
we have to call the acpi_processor_* functions to parse the P-states and
call "acpi_processor_notify_smm" to stop them from loading.

There is also one oddity in this driver which is that under Xen, the
physical online CPU count can be different from the virtual online CPU count.
Meaning that the macros 'for_[online|possible]_cpu' would process only
up to virtual online CPU count. We on the other hand want to process
the full amount of physical CPUs. For that, the driver checks if the ACPI IDs
count is different from the APIC ID count - which can happen if the user
choose to use dom0_max_vcpu argument. In such a case a backup of the PM
structure is used and uploaded to the hypervisor.

[v1-v2: Initial RFC implementations that were posted]
[v3: Changed the name to passthru suggested by Pasi Kärkkäinen <pasik@iki.fi>]
[v4: Added vCPU != pCPU support - aka dom0_max_vcpus support]
[v5: Cleaned up the driver, fix bug under Athlon XP]
[v6: Changed the driver to a CPU frequency governor]
[v7: Jan Beulich <jbeulich@suse.com> suggestion to make it a cpufreq scaling driver
     made me rework it as driver that inhibits cpufreq scaling driver]
[v8: Per Jan's review comments, fixed up the driver]
[v9: Allow to continue even if acpi_processor_preregister_perf.. fails]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The functions these get passed to have been taking pointers to const
since at least 2.6.16.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Unfortunately xend creates a bogus console/0 frotend/backend entry pair
on xenstore that console backends cannot properly cope with.
Any guest behavior that is not completely ignoring console/0 is going
to either cause problems with xenconsoled or qemu.
Returning 0 or -ENODEV from xencons_probe is not enough because it is
going to cause the frontend state to become 4 or 6 respectively.
The best possible thing we can do here is just ignore the entry from
xenbus_probe_frontend.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Introduce a new config option HVC_XEN_FRONTEND to enable/disable the
xenbus based pv console frontend.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

This patch implements support for multiple consoles:
consoles other than the first one are setup using the traditional xenbus
and grant-table based mechanism.
We use a list to keep track of the allocated consoles, we don't
expect too many of them anyway.

Changes in v3:

- call hvc_remove before removing the console from xenconsoles;
- do not lock xencons_lock twice in the destruction path;
- use the DEFINE_XENBUS_DRIVER macro.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The individual drivers' remove functions could legitimately attempt to
access this information (for logging messages if nothing else). Note
that I did not in fact observe a problem anywhere, but I came across
this while looking into the reasons for what turned out to need the
fix at https://lkml.org/lkml/2012/3/5/336 to vsprintf().
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

For the hypervisor to take advantage of the MWAIT support it needs
to extract from the ACPI _CST the register address. But the
hypervisor does not have the support to parse DSDT so it relies on
the initial domain (dom0) to parse the ACPI Power Management information
and push it up to the hypervisor. The pushing of the data is done
by the processor_harveset_xen module which parses the information that
the ACPI parser has graciously exposed in 'struct acpi_processor'.

For the ACPI parser to also expose the Cx states for MWAIT, we need
to expose the MWAIT capability (leaf 1). Furthermore we also need to
expose the MWAIT_LEAF capability (leaf 5) for cstate.c to properly
function.

The hypervisor could expose these flags when it traps the XEN_EMULATE_PREFIX
operations, but it can't do it since it needs to be backwards compatible.
Instead we choose to use the native CPUID to figure out if the MWAIT
capability exists and use the XEN_SET_PDC query hypercall to figure out
if the hypervisor wants us to expose the MWAIT_LEAF capability or not.

Note: The XEN_SET_PDC query was implemented in c/s 23783:
"ACPI: add _PDC input override mechanism".

With this in place, instead of
 C3 ACPI IOPORT 415
we get now
 C3:ACPI FFH INTEL MWAIT 0x20

Note: The cpu_idle which would be calling the mwait variants for idling
never gets set b/c we set the default pm_idle to be the hypercall variant.
Acked-by: NJan Beulich <JBeulich@suse.com>
[v2: Fix missing header file include and #ifdef]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We needed that call in the past to force the kernel to use
default_idle (which called safe_halt, which called xen_safe_halt).

But set_pm_idle_to_default() does now that, so there is no need
to use this boot option operand.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

- casting pointers to integer types of different size is being warned on
- an uninitialized variable warning occurred on certain gcc versions
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

percpu_xxx funcs are duplicated with this_cpu_xxx funcs, so replace them
for further code clean up.

I don't know much of xen code. But, since the code is in x86 architecture,
the percpu_xxx is exactly same as this_cpu_xxx serials functions. So, the
change is safe.
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Acked-by: NChristoph Lameter <cl@gentwo.org>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

We use the __pci_reset_function_locked to perform the action.
Also on attaching ("bind") and detaching ("unbind") we save and
restore the configuration states. When the device is disconnected
from a guest we use the "pci_reset_function" to also reset the
device before being passed to another guest.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The use case of this is when a driver wants to call FLR when a device
is attached to it using the SysFS "bind" or "unbind" functionality.

The call chain when a user does "bind" looks as so:

 echo "0000:01.07.0" > /sys/bus/pci/drivers/XXXX/bind

and ends up calling:
  driver_bind:
    device_lock(dev);  <=== TAKES LOCK
    XXXX_probe:
         .. pci_enable_device()
         ...__pci_reset_function(), which calls
                 pci_dev_reset(dev, 0):
                        if (!0) {
                                device_lock(dev) <==== DEADLOCK

The __pci_reset_function_locked function allows the the drivers
'probe' function to call the "pci_reset_function" while still holding
the driver mutex lock.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

to make a hypercall to restore the vectors in the MSI/MSI-X
configuration space.
Signed-off-by: NTang Liang <liang.tang@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci: (80 commits)
  x86/PCI: Expand the x86_msi_ops to have a restore MSIs.
  PCI: Increase resource array mask bit size in pcim_iomap_regions()
  PCI: DEVICE_COUNT_RESOURCE should be equal to PCI_NUM_RESOURCES
  PCI: pci_ids: add device ids for STA2X11 device (aka ConneXT)
  PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB
  x86/PCI: amd: factor out MMCONFIG discovery
  PCI: Enable ATS at the device state restore
  PCI: msi: fix imbalanced refcount of msi irq sysfs objects
  PCI: kconfig: English typo in pci/pcie/Kconfig
  PCI/PM/Runtime: make PCI traces quieter
  PCI: remove pci_create_bus()
  xtensa/PCI: convert to pci_scan_root_bus() for correct root bus resources
  x86/PCI: convert to pci_create_root_bus() and pci_scan_root_bus()
  x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
  x86/PCI: read Broadcom CNB20LE host bridge info before PCI scan
  sparc32, leon/PCI: convert to pci_scan_root_bus() for correct root bus resources
  sparc/PCI: convert to pci_create_root_bus()
  sh/PCI: convert to pci_scan_root_bus() for correct root bus resources
  powerpc/PCI: convert to pci_create_root_bus()
  powerpc/PCI: split PHB part out of pcibios_map_io_space()
  ...

Fix up conflicts in drivers/pci/msi.c and include/linux/pci_regs.h due
to the same patches being applied in other branches.

frv, h8300, m68k, microblaze, openrisc, score, um and xtensa currently
do not register a CPU device.  Add the config option GENERIC_CPU_DEVICES
which causes a generic CPU device to be registered for each present CPU,
and make all these architectures select it.

Richard Weinberger <richard@nod.at> covered UML and suggested using
per_cpu.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

cpu_dev_init() is only called from driver_init(), which does not check
its return value.  Therefore make cpu_dev_init() return void.

We must register the CPU subsystem, so panic if this fails.

If sched_create_sysfs_power_savings_entries() fails, the damage is
contained, so ignore this (as before).
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (54 commits)
  crypto: gf128mul - remove leftover "(EXPERIMENTAL)" in Kconfig
  crypto: serpent-sse2 - remove unneeded LRW/XTS #ifdefs
  crypto: serpent-sse2 - select LRW and XTS
  crypto: twofish-x86_64-3way - remove unneeded LRW/XTS #ifdefs
  crypto: twofish-x86_64-3way - select LRW and XTS
  crypto: xts - remove dependency on EXPERIMENTAL
  crypto: lrw - remove dependency on EXPERIMENTAL
  crypto: picoxcell - fix boolean and / or confusion
  crypto: caam - remove DECO access initialization code
  crypto: caam - fix polarity of "propagate error" logic
  crypto: caam - more desc.h cleanups
  crypto: caam - desc.h - convert spaces to tabs
  crypto: talitos - convert talitos_error to struct device
  crypto: talitos - remove NO_IRQ references
  crypto: talitos - fix bad kfree
  crypto: convert drivers/crypto/* to use module_platform_driver()
  char: hw_random: convert drivers/char/hw_random/* to use module_platform_driver()
  crypto: serpent-sse2 - should select CRYPTO_CRYPTD
  crypto: serpent - rename serpent.c to serpent_generic.c
  crypto: serpent - cleanup checkpatch errors and warnings
  ...

* 'for-linus' of git://selinuxproject.org/~jmorris/linux-security: (32 commits)
  ima: fix invalid memory reference
  ima: free duplicate measurement memory
  security: update security_file_mmap() docs
  selinux: Casting (void *) value returned by kmalloc is useless
  apparmor: fix module parameter handling
  Security: tomoyo: add .gitignore file
  tomoyo: add missing rcu_dereference()
  apparmor: add missing rcu_dereference()
  evm: prevent racing during tfm allocation
  evm: key must be set once during initialization
  mpi/mpi-mpow: NULL dereference on allocation failure
  digsig: build dependency fix
  KEYS: Give key types their own lockdep class for key->sem
  TPM: fix transmit_cmd error logic
  TPM: NSC and TIS drivers X86 dependency fix
  TPM: Export wait_for_stat for other vendor specific drivers
  TPM: Use vendor specific function for status probe
  tpm_tis: add delay after aborting command
  tpm_tis: Check return code from getting timeouts/durations
  tpm: Introduce function to poll for result of self test
  ...

Fix up trivial conflict in lib/Makefile due to addition of CONFIG_MPI
and SIGSIG next to CONFIG_DQL addition.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  autofs4: deal with autofs4_write/autofs4_write races
  autofs4: catatonic_mode vs. notify_daemon race
  autofs4: autofs4_wait() vs. autofs4_catatonic_mode() race
  hfsplus: creation of hidden dir on mount can fail
  block_dev: Suppress bdev_cache_init() kmemleak warninig
  fix shrink_dcache_parent() livelock
  coda: switch coda_cnode_make() to sane API as well, clean coda_lookup()
  coda: deal correctly with allocation failure from coda_cnode_makectl()
  securityfs: fix object creation races

Just serialize the actual writing of packets into pipe on
a new mutex, independent from everything else in the locking
hierarchy.  As soon as something has started feeding a piece
of packet into the pipe to daemon, we *want* everything else
about to try the same to wait until we are done.
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

we need to hold ->wq_mutex while we are forming the packet to send,
lest we have autofs4_catatonic_mode() setting wq->name.name to NULL
just as autofs4_notify_daemon() decides to memcpy() from it...

We do have check for catatonic mode immediately after that (under
->wq_mutex, as it ought to be) and packet won't be actually sent,
but it'll be too late for us if we oops on that memcpy() from NULL...

Fix is obvious - just extend the area covered by ->wq_mutex over
that switch and check whether it's catatonic *before* doing anything
else.
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We need to recheck ->catatonic after autofs4_wait() got ->wq_mutex
for good, or we might end up with wq inserted into queue after
autofs4_catatonic_mode() had done its thing.  It will stick there
forever, since there won't be anything to clear its ->name.name.

A bit of a complication: validate_request() drops and regains ->wq_mutex.
It actually ends up the most convenient place to stick the check into...
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

lib: use generic pci_iomap on all architectures

Many architectures don't want to pull in iomap.c,
so they ended up duplicating pci_iomap from that file.
That function isn't trivial, and we are going to modify it
https://lkml.org/lkml/2011/11/14/183
so the duplication hurts.

This reduces the scope of the problem significantly,
by moving pci_iomap to a separate file and
referencing that from all architectures.

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  alpha: drop pci_iomap/pci_iounmap from pci-noop.c
  mn10300: switch to GENERIC_PCI_IOMAP
  mn10300: add missing __iomap markers
  frv: switch to GENERIC_PCI_IOMAP
  tile: switch to GENERIC_PCI_IOMAP
  tile: don't panic on iomap
  sparc: switch to GENERIC_PCI_IOMAP
  sh: switch to GENERIC_PCI_IOMAP
  powerpc: switch to GENERIC_PCI_IOMAP
  parisc: switch to GENERIC_PCI_IOMAP
  mips: switch to GENERIC_PCI_IOMAP
  microblaze: switch to GENERIC_PCI_IOMAP
  arm: switch to GENERIC_PCI_IOMAP
  alpha: switch to GENERIC_PCI_IOMAP
  lib: add GENERIC_PCI_IOMAP
  lib: move GENERIC_IOMAP to lib/Kconfig

Fix up trivial conflicts due to changes nearby in arch/{m68k,score}/Kconfig

* tag 'for-linux-3.3-merge-window' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming: (29 commits)
  C6X: replace tick_nohz_stop/restart_sched_tick calls
  C6X: add register_cpu call
  C6X: deal with memblock API changes
  C6X: fix timer64 initialization
  C6X: fix layout of EMIFA registers
  C6X: MAINTAINERS
  C6X: DSCR - Device State Configuration Registers
  C6X: EMIF - External Memory Interface
  C6X: general SoC support
  C6X: library code
  C6X: headers
  C6X: ptrace support
  C6X: loadable module support
  C6X: cache control
  C6X: clocks
  C6X: build infrastructure
  C6X: syscalls
  C6X: interrupt handling
  C6X: time management
  C6X: signal management
  ...

* 'next' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Wire-up new system calls
  microblaze: Remove NO_IRQ from architecture
  input: xilinx_ps2: Don't use NO_IRQ
  block: xsysace: Don't use NO_IRQ
  microblaze: Trivial asm fix
  microblaze: Fix debug message in module
  microblaze: Remove eprintk macro
  microblaze: Send CR before LF for early console
  microblaze: Change NO_IRQ to 0
  microblaze: Use irq_of_parse_and_map for timer
  microblaze: intc: Change variable name
  microblaze: Use of_find_compatible_node for timer and intc
  microblaze: Add __cmpdi2
  microblaze: Synchronize __pa __va macros

* 'unicore32' of git://github.com/gxt/linux:
  rtc-puv3: solve section mismatch in rtc-puv3.c
  rtc-puv3: using module_platform_driver()
  i2c-puv3: using module_platform_driver()
  rtc-puv3: irq: remove IRQF_DISABLED
  unicore32: Remove IRQF_DISABLED
  unicore32: Use set_current_blocked()
  unicore32: add ioremap_nocache definition
  unicore32: delete specified xlate_dev_mem_ptr
  of: add include asm/setup.h in drivers/of/fdt.c
  unicore32: standardize /proc/iomem "Kernel code" name

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lliubbo/blackfin:
  blackfin: bf561: add adv7183 capture support
  blackfin: bf537: add capture support
  blackfin: bf548: add capture support
  blackfin: time-ts: rm unused func broadcast_timer_setup()
  blackfin: i2c-lcd: change default clock rate
  blackfin: mac: dsa: add vlan mask in board file
  blackfin: bf537: change num_chipselect for spi-sport
  blackfin: serial: bfin-uart: remove unused field
  bf54x: get mem size: missing break in switch
  blackfin: smp: fix msg queue overflow issue
  blackfin: config: update macro SPI_BFIN in board file
  blackfin: config: update def config for all boards
  blackfin: smp: cleanup smp code
  blackfin: smp: add suspend and wakeup irq flags
  blackfin: bf533-stamp: add missed patches for new asoc driver
  blackfin: bf533-stamp: fix ad1836 name

* 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c
  writeback: balanced_rate cannot exceed write bandwidth
  writeback: do strict bdi dirty_exceeded
  writeback: avoid tiny dirty poll intervals
  writeback: max, min and target dirty pause time
  writeback: dirty ratelimit - think time compensation
  btrfs: fix dirtied pages accounting on sub-page writes
  writeback: fix dirtied pages accounting on redirty
  writeback: fix dirtied pages accounting on sub-page writes
  writeback: charge leaked page dirties to active tasks
  writeback: Include all dirty inodes in background writeback

Andrew elucidates:
 - First installmeant of MM.  We have a HUGE number of MM patches this
   time.  It's crazy.
 - MAINTAINERS updates
 - backlight updates
 - leds
 - checkpatch updates
 - misc ELF stuff
 - rtc updates
 - reiserfs
 - procfs
 - some misc other bits

* akpm: (124 commits)
  user namespace: make signal.c respect user namespaces
  workqueue: make alloc_workqueue() take printf fmt and args for name
  procfs: add hidepid= and gid= mount options
  procfs: parse mount options
  procfs: introduce the /proc/<pid>/map_files/ directory
  procfs: make proc_get_link to use dentry instead of inode
  signal: add block_sigmask() for adding sigmask to current->blocked
  sparc: make SA_NOMASK a synonym of SA_NODEFER
  reiserfs: don't lock root inode searching
  reiserfs: don't lock journal_init()
  reiserfs: delay reiserfs lock until journal initialization
  reiserfs: delete comments referring to the BKL
  drivers/rtc/interface.c: fix alarm rollover when day or month is out-of-range
  drivers/rtc/rtc-twl.c: add DT support for RTC inside twl4030/twl6030
  drivers/rtc/: remove redundant spi driver bus initialization
  drivers/rtc/rtc-jz4740.c: make jz4740_rtc_driver static
  drivers/rtc/rtc-mc13xxx.c: make mc13xxx_rtc_idtable static
  rtc: convert drivers/rtc/* to use module_platform_driver()
  drivers/rtc/rtc-wm831x.c: convert to devm_kzalloc()
  drivers/rtc/rtc-wm831x.c: remove unused period IRQ handler
  ...

ipc/mqueue.c: for __SI_MESQ, convert the uid being sent to recipient's
user namespace. (new, thanks Oleg)

__send_signal: convert current's uid to the recipient's user namespace
for any siginfo which is not SI_FROMKERNEL (patch from Oleg, thanks
again :)

do_notify_parent and do_notify_parent_cldstop: map task's uid to parent's
user namespace

ptrace_signal maps parent's uid into current's user namespace before
including in signal to current.  IIUC Oleg has argued that this shouldn't
matter as the debugger will play with it, but it seems like not converting
the value currently being set is misleading.

Changelog:
Sep 20: Inspired by Oleg's suggestion, define map_cred_ns() helper to
	simplify callers and help make clear what we are translating
        (which uid into which namespace).  Passing the target task would
	make callers even easier to read, but we pass in user_ns because
	current_user_ns() != task_cred_xxx(current, user_ns).
Sep 20: As recommended by Oleg, also put task_pid_vnr() under rcu_read_lock
	in ptrace_signal().
Sep 23: In send_signal(), detect when (user) signal is coming from an
	ancestor or unrelated user namespace.  Pass that on to __send_signal,
	which sets si_uid to 0 or overflowuid if needed.
Oct 12: Base on Oleg's fixup_uid() patch.  On top of that, handle all
	SI_FROMKERNEL cases at callers, because we can't assume sender is
	current in those cases.
Nov 10: (mhelsley) rename fixup_uid to more meaningful usern_fixup_signal_uid
Nov 10: (akpm) make the !CONFIG_USER_NS case clearer
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
From: Serge Hallyn <serge.hallyn@canonical.com>
Subject: __send_signal: pass q->info, not info, to userns_fixup_signal_uid (v2)

Eric Biederman pointed out that passing info is a bug and could lead to a
NULL pointer deref to boot.

A collection of signal, securebits, filecaps, cap_bounds, and a few other
ltp tests passed with this kernel.

Changelog:
    Nov 18: previous patch missed a leading '&'
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
From: Dan Carpenter <dan.carpenter@oracle.com>
Subject: ipc/mqueue: lock() => unlock() typo

There was a double lock typo introduced in b085f4bd6b21 "user namespace:
make signal.c respect user namespaces"
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

alloc_workqueue() currently expects the passed in @name pointer to remain
accessible.  This is inconvenient and a bit silly given that the whole wq
is being dynamically allocated.  This patch updates alloc_workqueue() and
friends to take printf format string instead of opaque string and matching
varargs at the end.  The name is allocated together with the wq and
formatted.

alloc_ordered_workqueue() is converted to a macro to unify varargs
handling with alloc_workqueue(), and, while at it, add comment to
alloc_workqueue().

None of the current in-kernel users pass in string with '%' as constant
name and this change shouldn't cause any problem.

[akpm@linux-foundation.org: use __printf]
Signed-off-by: NTejun Heo <tj@kernel.org>
Suggested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for mount options to restrict access to /proc/PID/
directories.  The default backward-compatible "relaxed" behaviour is left
untouched.

The first mount option is called "hidepid" and its value defines how much
info about processes we want to be available for non-owners:

hidepid=0 (default) means the old behavior - anybody may read all
world-readable /proc/PID/* files.

hidepid=1 means users may not access any /proc/<pid>/ directories, but
their own.  Sensitive files like cmdline, sched*, status are now protected
against other users.  As permission checking done in proc_pid_permission()
and files' permissions are left untouched, programs expecting specific
files' modes are not confused.

hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other
users.  It doesn't mean that it hides whether a process exists (it can be
learned by other means, e.g.  by kill -0 $PID), but it hides process' euid
and egid.  It compicates intruder's task of gathering info about running
processes, whether some daemon runs with elevated privileges, whether
another user runs some sensitive program, whether other users run any
program at all, etc.

gid=XXX defines a group that will be able to gather all processes' info
(as in hidepid=0 mode).  This group should be used instead of putting
nonroot user in sudoers file or something.  However, untrusted users (like
daemons, etc.) which are not supposed to monitor the tasks in the whole
system should not be added to the group.

hidepid=1 or higher is designed to restrict access to procfs files, which
might reveal some sensitive private information like precise keystrokes
timings:

http://www.openwall.com/lists/oss-security/2011/11/05/3

hidepid=1/2 doesn't break monitoring userspace tools.  ps, top, pgrep, and
conky gracefully handle EPERM/ENOENT and behave as if the current user is
the only user running processes.  pstree shows the process subtree which
contains "pstree" process.

Note: the patch doesn't deal with setuid/setgid issues of keeping
preopened descriptors of procfs files (like
https://lkml.org/lkml/2011/2/7/368).  We rely on that the leaked
information like the scheduling counters of setuid apps doesn't threaten
anybody's privacy - only the user started the setuid program may read the
counters.
Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Theodore Tso <tytso@MIT.EDU>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: James Morris <jmorris@namei.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for procfs mount options.  Actual mount options are coming in
the next patches.
Signed-off-by: NVasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Theodore Tso <tytso@MIT.EDU>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: James Morris <jmorris@namei.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This one behaves similarly to the /proc/<pid>/fd/ one - it contains
symlinks one for each mapping with file, the name of a symlink is
"vma->vm_start-vma->vm_end", the target is the file.  Opening a symlink
results in a file that point exactly to the same inode as them vma's one.

For example the ls -l of some arbitrary /proc/<pid>/map_files/

 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so
 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1
 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0
 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so
 | lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so

This *helps* checkpointing process in three ways:

1. When dumping a task mappings we do know exact file that is mapped
   by particular region.  We do this by opening
   /proc/$pid/map_files/$address symlink the way we do with file
   descriptors.

2. This also helps in determining which anonymous shared mappings are
   shared with each other by comparing the inodes of them.

3. When restoring a set of processes in case two of them has a mapping
   shared, we map the memory by the 1st one and then open its
   /proc/$pid/map_files/$address file and map it by the 2nd task.

Using /proc/$pid/maps for this is quite inconvenient since it brings
repeatable re-reading and reparsing for this text file which slows down
restore procedure significantly.  Also as being pointed in (3) it is a way
easier to use top level shared mapping in children as
/proc/$pid/map_files/$address when needed.

[akpm@linux-foundation.org: coding-style fixes]
[gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE]
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: NVasiliy Kulikov <segoon@openwall.com>
Reviewed-by: N"Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prepare the ground for the next "map_files" patch which needs a name of a
link file to analyse.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Abstract the code sequence for adding a signal handler's sa_mask to
current->blocked because the sequence is identical for all architectures.
Furthermore, in the past some architectures actually got this code wrong,
so introduce a wrapper that all architectures can use.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Unlike other architectures, sparc currently has no SA_NODEFER definition
but only the older SA_NOMASK.  Since SA_NOMASK is the historical name for
SA_NODEFER, add SA_NODEFER and copy what other architectures do by making
SA_NOMASK a synonym for SA_NODEFER.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nothing requires that we lock the filesystem until the root inode is
provided.

Also iget5_locked() triggers a warning because we are holding the
filesystem lock while allocating the inode, which result in a lockdep
suspicion that we have a lock inversion against the reclaim path:

[ 1986.896979] =================================
[ 1986.896990] [ INFO: inconsistent lock state ]
[ 1986.896997] 3.1.1-main #8
[ 1986.897001] ---------------------------------
[ 1986.897007] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 1986.897016] kswapd0/16 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 1986.897023]  (&REISERFS_SB(s)->lock){+.+.?.}, at: [<c01f8bd4>] reiserfs_write_lock+0x20/0x2a
[ 1986.897044] {RECLAIM_FS-ON-W} state was registered at:
[ 1986.897050]   [<c014a5b9>] mark_held_locks+0xae/0xd0
[ 1986.897060]   [<c014aab3>] lockdep_trace_alloc+0x7d/0x91
[ 1986.897068]   [<c0190ee0>] kmem_cache_alloc+0x1a/0x93
[ 1986.897078]   [<c01e7728>] reiserfs_alloc_inode+0x13/0x3d
[ 1986.897088]   [<c01a5b06>] alloc_inode+0x14/0x5f
[ 1986.897097]   [<c01a5cb9>] iget5_locked+0x62/0x13a
[ 1986.897106]   [<c01e99e0>] reiserfs_fill_super+0x410/0x8b9
[ 1986.897114]   [<c01953da>] mount_bdev+0x10b/0x159
[ 1986.897123]   [<c01e764d>] get_super_block+0x10/0x12
[ 1986.897131]   [<c0195b38>] mount_fs+0x59/0x12d
[ 1986.897138]   [<c01a80d1>] vfs_kern_mount+0x45/0x7a
[ 1986.897147]   [<c01a83e3>] do_kern_mount+0x2f/0xb0
[ 1986.897155]   [<c01a987a>] do_mount+0x5c2/0x612
[ 1986.897163]   [<c01a9a72>] sys_mount+0x61/0x8f
[ 1986.897170]   [<c044060c>] sysenter_do_call+0x12/0x32
[ 1986.897181] irq event stamp: 7509691
[ 1986.897186] hardirqs last  enabled at (7509691): [<c0190f34>] kmem_cache_alloc+0x6e/0x93
[ 1986.897197] hardirqs last disabled at (7509690): [<c0190eea>] kmem_cache_alloc+0x24/0x93
[ 1986.897209] softirqs last  enabled at (7508896): [<c01294bd>] __do_softirq+0xee/0xfd
[ 1986.897222] softirqs last disabled at (7508859): [<c01030ed>] do_softirq+0x50/0x9d
[ 1986.897234]
[ 1986.897235] other info that might help us debug this:
[ 1986.897242]  Possible unsafe locking scenario:
[ 1986.897244]
[ 1986.897250]        CPU0
[ 1986.897254]        ----
[ 1986.897257]   lock(&REISERFS_SB(s)->lock);
[ 1986.897265] <Interrupt>
[ 1986.897269]     lock(&REISERFS_SB(s)->lock);
[ 1986.897276]
[ 1986.897277]  *** DEADLOCK ***
[ 1986.897278]
[ 1986.897286] no locks held by kswapd0/16.
[ 1986.897291]
[ 1986.897292] stack backtrace:
[ 1986.897299] Pid: 16, comm: kswapd0 Not tainted 3.1.1-main #8
[ 1986.897306] Call Trace:
[ 1986.897314]  [<c0439e76>] ? printk+0xf/0x11
[ 1986.897324]  [<c01482d1>] print_usage_bug+0x20e/0x21a
[ 1986.897332]  [<c01479b8>] ? print_irq_inversion_bug+0x172/0x172
[ 1986.897341]  [<c014855c>] mark_lock+0x27f/0x483
[ 1986.897349]  [<c0148d88>] __lock_acquire+0x628/0x1472
[ 1986.897358]  [<c0149fae>] lock_acquire+0x47/0x5e
[ 1986.897366]  [<c01f8bd4>] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897384]  [<c01f8bd4>] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897397]  [<c043b5ef>] mutex_lock_nested+0x35/0x26f
[ 1986.897409]  [<c01f8bd4>] ? reiserfs_write_lock+0x20/0x2a
[ 1986.897421]  [<c01f8bd4>] reiserfs_write_lock+0x20/0x2a
[ 1986.897433]  [<c01e2edd>] map_block_for_writepage+0xc9/0x590
[ 1986.897448]  [<c01b1706>] ? create_empty_buffers+0x33/0x8f
[ 1986.897461]  [<c0121124>] ? get_parent_ip+0xb/0x31
[ 1986.897472]  [<c043ef7f>] ? sub_preempt_count+0x81/0x8e
[ 1986.897485]  [<c043cae0>] ? _raw_spin_unlock+0x27/0x3d
[ 1986.897496]  [<c0121124>] ? get_parent_ip+0xb/0x31
[ 1986.897508]  [<c01e355d>] reiserfs_writepage+0x1b9/0x3e7
[ 1986.897521]  [<c0173b40>] ? clear_page_dirty_for_io+0xcb/0xde
[ 1986.897533]  [<c014a6e3>] ? trace_hardirqs_on_caller+0x108/0x138
[ 1986.897546]  [<c014a71e>] ? trace_hardirqs_on+0xb/0xd
[ 1986.897559]  [<c0177b38>] shrink_page_list+0x34f/0x5e2
[ 1986.897572]  [<c01780a7>] shrink_inactive_list+0x172/0x22c
[ 1986.897585]  [<c0178464>] shrink_zone+0x303/0x3b1
[ 1986.897597]  [<c043cae0>] ? _raw_spin_unlock+0x27/0x3d
[ 1986.897611]  [<c01788c9>] kswapd+0x3b7/0x5f2

The deadlock shouldn't happen since we are doing that allocation in the
mount path, the filesystem is not available for any reclaim.  Still the
warning is annoying.

To solve this, acquire the lock later only where we need it, right before
calling reiserfs_read_locked_inode() that wants to lock to walk the tree.
Reported-by: NKnut Petersen <Knut_Petersen@t-online.de>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

journal_init() doesn't need the lock since no operation on the filesystem
is involved there.  journal_read() and get_list_bitmap() have yet to be
reviewed carefully though before removing the lock there.  Just keep the
it around these two calls for safety.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>