Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y
CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false,
and so triggers some BUGs in Transparent HugePage codepaths.

asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x);
but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE,
VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In current code, pltfm->als_vmin is set to LM3530_ALS_WINDOW_mV and
pltfm->als_vmax is 0.  This does not make sense.  I think what we want
here is setting pltfm->als_vmax to LM3530_ALS_WINDOW_mV.

Both als_vmin and als_vmax local variables will be set to
pltfm->als_vmin and pltfm->als_vmax by a few lines latter.  Thus also
remove a redundant assignment for als_vmin and als_vmax in this patch.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Acked-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Tested-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When isolating pages for migration, migration starts at the start of a
zone while the free scanner starts at the end of the zone.  Migration
avoids entering a new zone by never going beyond the free scanned.

Unfortunately, in very rare cases nodes can overlap.  When this happens,
migration isolates pages without the LRU lock held, corrupting lists
which will trigger errors in reclaim or during page free such as in the
following oops

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  IP: [<ffffffff810f795c>] free_pcppages_bulk+0xcc/0x450
  PGD 1dda554067 PUD 1e1cb58067 PMD 0
  Oops: 0000 [#1] SMP
  CPU 37
  Pid: 17088, comm: memcg_process_s Tainted: G            X
  RIP: free_pcppages_bulk+0xcc/0x450
  Process memcg_process_s (pid: 17088, threadinfo ffff881c2926e000, task ffff881c2926c0c0)
  Call Trace:
    free_hot_cold_page+0x17e/0x1f0
    __pagevec_free+0x90/0xb0
    release_pages+0x22a/0x260
    pagevec_lru_move_fn+0xf3/0x110
    putback_lru_page+0x66/0xe0
    unmap_and_move+0x156/0x180
    migrate_pages+0x9e/0x1b0
    compact_zone+0x1f3/0x2f0
    compact_zone_order+0xa2/0xe0
    try_to_compact_pages+0xdf/0x110
    __alloc_pages_direct_compact+0xee/0x1c0
    __alloc_pages_slowpath+0x370/0x830
    __alloc_pages_nodemask+0x1b1/0x1c0
    alloc_pages_vma+0x9b/0x160
    do_huge_pmd_anonymous_page+0x160/0x270
    do_page_fault+0x207/0x4c0
    page_fault+0x25/0x30

The "X" in the taint flag means that external modules were loaded but but
is unrelated to the bug triggering.  The real problem was because the PFN
layout looks like this

  Zone PFN ranges:
    DMA      0x00000010 -> 0x00001000
    DMA32    0x00001000 -> 0x00100000
    Normal   0x00100000 -> 0x01e80000
  Movable zone start PFN for each node
  early_node_map[14] active PFN ranges
      0: 0x00000010 -> 0x0000009b
      0: 0x00000100 -> 0x0007a1ec
      0: 0x0007a354 -> 0x0007a379
      0: 0x0007f7ff -> 0x0007f800
      0: 0x00100000 -> 0x00680000
      1: 0x00680000 -> 0x00e80000
      0: 0x00e80000 -> 0x01080000
      1: 0x01080000 -> 0x01280000
      0: 0x01280000 -> 0x01480000
      1: 0x01480000 -> 0x01680000
      0: 0x01680000 -> 0x01880000
      1: 0x01880000 -> 0x01a80000
      0: 0x01a80000 -> 0x01c80000
      1: 0x01c80000 -> 0x01e80000

The fix is straight-forward.  isolate_migratepages() has to make a
similar check to isolate_freepage to ensure that it never isolates pages
from a zone it does not hold the LRU lock for.

This was discovered in a 3.0-based kernel but it affects 3.1.x, 3.2.x
and current mainline.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

nsegs is read from userspace.  Limit its value and avoid overflowing nsegs
* sizeof(__u64) in the subsequent call to memdup_user().

This patch complements 481fe17e ("nilfs2: potential integer overflow
in nilfs_ioctl_clean_segments()").
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Haogang Chen <haogangchen@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fbdev fixes for 3.3

It includes:
 - compile fix for fsl-diu-fb
 - fix for a suspend/resume issue in atmel_lcdfb
 - fix for a suspend/resume issue in OMAP
 - workaround for a hardware bug to avoid physical damage in OMAP
 - really trivial dead code removal in intelfb

* tag 'fbdev-fixes-for-3.3-1' of git://github.com/schandinat/linux-2.6:
  atmel_lcdfb: fix usage of CONTRAST_CTR in suspend/resume
  intelfb: remove some dead code
  drivers/video: compile fixes for fsl-diu-fb.c
  OMAPDSS: HDMI: PHY burnout fix
  OMAP: 4430SDP/Panda: add HDMI HPD gpio
  OMAP: 4430SDP/Panda: setup HDMI GPIO muxes
  OMAPDSS: remove wrong HDMI HPD muxing
  OMAP: 4430SDP/Panda: rename HPD GPIO to CT_CP_HPD
  OMAP: 4430SDP/Panda: use gpio_free_array to free HDMI gpios
  OMAPDSS: use sync versions of pm_runtime_put

Overly indented code should be refactored.

Suggest refactoring excessive indentation of of
if/else/for/do/while/switch statements.

For example:

$ cat t.c
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv)
{

	if (1)
		if (2)
			if (3)
				if (4)
					if (5)
						if (6)
							if (7)
								if (8)
									;
	return 0;
}

$ ./scripts/checkpatch.pl -f t.c
WARNING: Too many leading tabs - consider code refactoring
#12: FILE: t.c:12:
+						if (6)

WARNING: Too many leading tabs - consider code refactoring
#13: FILE: t.c:13:
+							if (7)

WARNING: Too many leading tabs - consider code refactoring
#14: FILE: t.c:14:
+								if (8)

total: 0 errors, 3 warnings, 17 lines checked

t.c has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Cleanups and error path fixes for the new SRP (SCSI RDMA protocol) target.

* tag 'ib-srpt-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
  IB/srpt: Don't return freed pointer from srpt_alloc_ioctx_ring()
  IB/srpt: Fix ERR_PTR() vs. NULL checking confusion
  IB/srpt: Remove unneeded <linux/version.h> include
  IB/srpt: Use ARRAY_SIZE() instead of open-coding
  IB/srpt: Use DEFINE_SPINLOCK()/LIST_HEAD()

arch: fix ioport mapping on mips,sh

Kevin Cernekee reported that recent cleanup that replaced pci_iomap with
a generic function failed to take into account the differences in io
port handling on mips and sh architectures.

Rather than revert the changes reintroducing the code duplication, this
patchset fixes this by adding ability for architectures to override
ioport mapping for pci devices.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  sh: use the the PCI channels's io_map_base
  mips: use the the PCI controller's io_map_base
  lib: add NO_GENERIC_PCI_IOPORT_MAP

Those lines have two copies.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Thomas Renninger <trenn@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.samba.org/sfrench/cifs-2.6:
  cifs: Fix oops in session setup code for null user mounts
  [CIFS] Update cifs Kconfig title to match removal of experimental dependency
  cifs: fix printk format warnings
  cifs: check offset in decode_ntlmssp_challenge()
  cifs: NULL dereference on allocation failure

* 'upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: wiimote: fix invalid power_supply_powers call
  HID: wacom: Fix invalid power_supply_powers calls
  HID: hyperv: Properly disconnect the input device
  HID: usbhid: fix dead lock between open and disconect

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-2.6:
  mfd: Avoid twl6040-codec PLL reconfiguration when not needed
  mfd: Store twl6040-codec mclk configuration

Analogically to d7cb3dbd1 ("HID: wacom: Fix invalid power_supply_powers
calls"), fix also the same occurence in wiimote driver.

Reported-by: przemo@firszt.eu
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Update quilt tree location for Documentation/ patches.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Two of the bits in the tainted flag are not documented.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fixing a regression with the PMU MSRs when PMU virtualization is
disabled, a guest-internal DoS with the SYSCALL instruction, and a dirty
memory logging race that may cause live migration to fail.

* 'kvm-updates/3.3' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: do not #GP on perf MSR writes when vPMU is disabled
  KVM: x86: fix missing checks in syscall emulation
  KVM: x86: extend "struct x86_emulate_ops" with "get_cpuid"
  KVM: Fix __set_bit() race in mark_page_dirty() during dirty logging

GPIO fixes for v3.3-rc2

Straight forward bug fixes in this branch.  A couple of x86 gpio drivers
missing spinlock initialization, an API change fixup for the samsung driver
and a name typo fix.

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  gpio: Add missing spin_lock_init in gpio-ml-ioh driver
  gpio: Add missing spin_lock_init in gpio-pch driver
  gpio: samsung: adapt to changes in gpio specifier translator function declaration
  Correct bad gpio naming

Merge tag 'hwmon-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

One patch to fix fan detection on NCT6776F.

* tag 'hwmon-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (w83627ehf) Fix number of fans for NCT6776F

Setting the task name is done within setup_new_exec() by accessing
bprm->filename. However this happens after flush_old_exec().
This may result in a use after free bug, flush_old_exec() may
"complete" vfork_done, which will wake up the parent which in turn
may free the passed in filename.
To fix this add a new tcomm field in struct linux_binprm which
contains the now early generated task name until it is used.

Fixes this bug on s390:

  Unable to handle kernel pointer dereference at virtual kernel address 0000000039768000
  Process kworker/u:3 (pid: 245, task: 000000003a3dc840, ksp: 0000000039453818)
  Krnl PSW : 0704000180000000 0000000000282e94 (setup_new_exec+0xa0/0x374)
  Call Trace:
  ([<0000000000282e2c>] setup_new_exec+0x38/0x374)
   [<00000000002dd12e>] load_elf_binary+0x402/0x1bf4
   [<0000000000280a42>] search_binary_handler+0x38e/0x5bc
   [<0000000000282b6c>] do_execve_common+0x410/0x514
   [<0000000000282cb6>] do_execve+0x46/0x58
   [<00000000005bce58>] kernel_execve+0x28/0x70
   [<000000000014ba2e>] ____call_usermodehelper+0x102/0x140
   [<00000000005bc8da>] kernel_thread_starter+0x6/0xc
   [<00000000005bc8d4>] kernel_thread_starter+0x0/0xc
  Last Breaking-Event-Address:
   [<00000000002830f0>] setup_new_exec+0x2fc/0x374

  Kernel panic - not syncing: Fatal exception: panic_on_oops
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Roland Dreier <roland@purestorage.com>

power_supply_powers calls added in 35b4c01e ("power_supply: add "powers" links
to self-powered HID devices") have to be called after power device is created.
This patch also fixes the second call - it has to be "ac" instead of "battery"
Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into upstream-fixes

Sync with Linus' tree. This is necessary to have a base for
patch that fixes commit 35b4c01e ("power_supply: add "powers"
links to self-powered HID devices") which went in through Anton's
tree.

NCT6776F can select fan input pins for fans 3 to 5 with a secondary set of
chip register bits. Check that second set of bits in addition to the first set
to detect if fans 3..5 are monitored.
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: stable@vger.kernel.org # 3.0+
Acked-by: Jean Delvare <khali@linux-fr.org>

Power management fixes for 3.3-rc3

Three power management regression fixes, one for a recent regression introcuded
by the freezer changes during the 3.3 merge window and two for regressions
in cpuidle (resulting from PM QoS changes) and in the hibernate user space
interface, both introduced during the 3.2 development cycle.

They include:

* Two hibernate (s2disk) regression fixes from Srivatsa S. Bhat (for
 regressions introduced during the 3.3 merge window and during the 3.2
 development cycle).

* A cpuidle fix from Venki Pallipadi for a regression resulting from PM QoS
 changes during the 3.2 development cycle causing cpuidle to work incorrectly
 for CONFIG_PM unset.

* tag 'pm-fixes-for-3.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / QoS: CPU C-state breakage with PM Qos change
  PM / Freezer: Thaw only kernel threads if freezing of kernel threads fails
  PM / Hibernate: Thaw kernel threads in SNAPSHOT_CREATE_IMAGE ioctl path

Looks like change "PM QoS: Move and rename the implementation files"
merged during the 3.2 development cycle made PM QoS depend on
CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME).

That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs
to spend time in Polling loop idle instead of going into deep C-states,
consuming way way more power. This is with either acpi idle or intel idle
enabled.

Either CONFIG_PM should be enabled with any pm_qos users or
the !CONFIG_PM pm_qos_request() should return sane defaults not to break
the existing users. Here's is the patch for the latter option.

[rjw: Modified the changelog slightly.]
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@vger.kernel.org

If freezing of kernel threads fails, we are expected to automatically
thaw tasks in the error recovery path. However, at times, we encounter
situations in which we would like the automatic error recovery path
to thaw only the kernel threads, because we want to be able to do
some more cleanup before we thaw userspace. Something like:

error = freeze_kernel_threads();
if (error) {
	/* Do some cleanup */

	/* Only then thaw userspace tasks*/
	thaw_processes();
}

An example of such a situation is where we freeze/thaw filesystems
during suspend/hibernation. There, if freezing of kernel threads
fails, we would like to thaw the frozen filesystems before thawing
the userspace tasks.

So, modify freeze_kernel_threads() to thaw only kernel threads in
case of freezing failure. And change suspend_freeze_processes()
accordingly. (At the same time, let us also get rid of the rather
cryptic usage of the conditional operator (:?) in that function.)

[rjw: In fact, this patch fixes a regression introduced during the
 3.3 merge window, because without it thaw_processes() may be called
 before swsusp_free() in some situations and that may lead to massive
 memory allocation failures.]
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

arm-soc fixes for 3.3-rc

* A series of OMAP regression fixes for merge window fallout
* Two patches for Davinci, one removes some misdefined clocks, the other
  is a regression fix for merge window fallout
* Two patches that makes Broadcom bcmring build again (and removes a
  bunch of unused code in the process)

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: bcmring: fix build failure in mach-bcmring/arch.c
  ARM: bcmring: remove unused DMA map code
  ARM: davinci: update mdio bus name
  ARM: OMAP2+: arch/arm/mach-omap2/smartreflex.c: add missing iounmap
  ARM: OMAP2+: arch/arm/mach-omap2/devices.c: introduce missing kfree
  ARM: OMAP: fix MMC2 loopback clock handling
  ARM: OMAP: fix erroneous mmc2 clock change on mmc3 setup
  ARM: OMAP2+: GPMC: fix device size setup
  ARM: OMAP2+: timer: Fix crash due to wrong arg to __omap_dm_timer_read_counter
  ARM: OMAP3: hwmod data: register dss hwmods after dss_core
  ARM: OMAP2/3: PRM: fix missing plat/irqs.h build breakage
  ARM: OMAP2+: io: fix compilation breakage on 2420-only configs
  ARM: OMAP4: hwmod data: Add names for DMIC memory address space
  ARM: OMAP3: hwmod data: add SYSC_HAS_ENAWAKEUP for dispc
  ARM: OMAP2+: hwmod data: split omap2/3 dispc hwmod class
  ARM: davinci: DA850: remove non-existing pll1_sysclk4-7 clocks
  ARM: OMAP2: fix regulator warnings
  ARM: OMAP2: fix omap3 touchbook kconfig warning
  i2c: OMAP: Fix OMAP1 build error

Upstream commit d1fce9c1

   "ARM: restart: bcmring: use new restart hook"

breaks building of this platform, since what used to be the
last field of the MACHINE_START/END block didn't have a
trailing comma.  Once another field was added below, we get:

arch/arm/mach-bcmring/arch.c:198: error: request for member 'restart' in something not a structure or union
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

Remove BCMRING DMA map code which is no longer used.

This also fixes a build error with dma.c introduced by
bfcd2ea6.
Signed-off-by: Jiandong Zheng <jdzheng@broadcom.com>
Signed-off-by: Olof Johansson <olof@lixom.net>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: i8042 - add Lenovo Ideapad U455 to 'reset' blacklist
  Input: serio_raw - return proper result when serio_raw_read fails
  Input: document device properties
  Input: twl4030_keypad - fix comment (trivial)
  Input: gpio_keys - fix struct device declared inside parameter list
  Input: evdev - fix variable initialisation

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  i.MX SDMA: Fix burstsize settings
  ARM: mach-shmobile: both USB DMAC instances on sh7372 are slave-only
  dma: sh_dma: not all SH DMAC implementations support MEMCPY
  at_hdmac: bugfix for enabling channel irq
  dmaengine: fix missing 'cnt' in ?: in dmatest

* akpm:
  mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during isolation for migration
  readahead: fix pipeline break caused by block plug
  kprobes: fix a memory leak in function pre_handler_kretprobe()
  drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer
  lkdtm: avoid calling lkdtm_do_action() with spinlock held
  mm/filemap_xip.c: fix race condition in xip_file_fault()
  mm/memcontrol.c: fix warning with CONFIG_NUMA=n
  avr32: select generic atomic64_t support
  mm: postpone migrated page mapping reset
  xtensa: fix memscan()
  MAINTAINERS: update lguest F: patterns
  MAINTAINERS: remove staging sections
  MAINTAINERS: remove iMX5 section
  MAINTAINERS: update partitions block F: patterns

 - Fix a regression in 16-bit Atmel NAND flash which was introduced in 3.1
 - Fix breakage with MTD suspend caused by the API rework
 - Fix a problem with resetting the MX28 BCH module
 - A couple of other trivial fixes

* tag 'for-linus-3.3-20120204' of git://git.infradead.org/~dwmw2/mtd-3.3:
  Revert "mtd: atmel_nand: optimize read/write buffer functions"
  mtd: fix MTD suspend
  jffs2: do not initialize variable unnecessarily
  mtd: gpmi-nand bugfix: reset the BCH module when it is not MX23
  mtd: nand: fix typo in comment

This reverts commit fb542750.

The reason is that it breaks 16 bits NAND flash as it was reported by
Nikolaus Voss and confirmed by Eric Bénard.

Nicolas Ferre <nicolas.ferre@atmel.com> alco confirmed:
"After double checking with designers, I must admit that I misunderstood
the way of optimizing accesses to SMC. 16 bit nand is not so common
those days..."
Reported-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.1+]

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7314/1: kuser: consistently use usr_ret for returning from helpers
  ARM: 7302/1: Add TLB flushing for both entries in a PMD
  ARM: 7303/1: perf: add empty NODE event definitions for Cortex-A5 and Cortex-A15
  ARM: 7308/1: vfp: flush thread hwstate before copying ptrace registers
  ARM: 7307/1: vfp: fix ptrace regset modification race
  ARM: 7306/1: vfp: flush thread hwstate before restoring context from sigframe
  Revert "ARM: 7304/1: ioremap: fix boundary check when reusing static mapping"

mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during isolation for migration

When isolating for migration, migration starts at the start of a zone
which is not necessarily pageblock aligned.  Further, it stops isolating
when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally
not aligned.  This allows isolate_migratepages() to call pfn_to_page() on
an invalid PFN which can result in a crash.  This was originally reported
against a 3.0-based kernel with the following trace in a crash dump.

PID: 9902   TASK: d47aecd0  CPU: 0   COMMAND: "memcg_process_s"
 #0 [d72d3ad0] crash_kexec at c028cfdb
 #1 [d72d3b24] oops_end at c05c5322
 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60
 #3 [d72d3bec] bad_area at c0227fb6
 #4 [d72d3c00] do_page_fault at c05c72ec
 #5 [d72d3c80] error_code (via page_fault) at c05c47a4
    EAX: 00000000  EBX: 000c0000  ECX: 00000001  EDX: 00000807  EBP: 000c0000
    DS:  007b      ESI: 00000001  ES:  007b      EDI: f3000a80  GS:  6f50
    CS:  0060      EIP: c030b15a  ERR: ffffffff  EFLAGS: 00010002
 #6 [d72d3cb4] isolate_migratepages at c030b15a
 #7 [d72d3d14] zone_watermark_ok at c02d26cb
 #8 [d72d3d2c] compact_zone at c030b8de
 #9 [d72d3d68] compact_zone_order at c030bba1
#10 [d72d3db4] try_to_compact_pages at c030bc84
#11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7
#12 [d72d3e08] __alloc_pages_slowpath at c02d66c7
#13 [d72d3e78] __alloc_pages_nodemask at c02d6a97
#14 [d72d3eb8] alloc_pages_vma at c030a845
#15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb
#16 [d72d3f00] handle_mm_fault at c02f36c6
#17 [d72d3f30] do_page_fault at c05c70ed
#18 [d72d3fb0] error_code (via page_fault) at c05c47a4
    EAX: b71ff000  EBX: 00000001  ECX: 00001600  EDX: 00000431
    DS:  007b      ESI: 08048950  ES:  007b      EDI: bfaa3788
    SS:  007b      ESP: bfaa36e0  EBP: bfaa3828  GS:  6f50
    CS:  0073      EIP: 080487c8  ERR: ffffffff  EFLAGS: 00010202

It was also reported by Herbert van den Bergh against 3.1-based kernel
with the following snippet from the console log.

BUG: unable to handle kernel paging request at 01c00008
IP: [<c0522399>] isolate_migratepages+0x119/0x390
*pdpt = 000000002f7ce001 *pde = 0000000000000000

It is expected that it also affects 3.2.x and current mainline.

The problem is that pfn_valid is only called on the first PFN being
checked and that PFN is not necessarily aligned.  Lets say we have a case
like this

H = MAX_ORDER_NR_PAGES boundary
| = pageblock boundary
m = cc->migrate_pfn
f = cc->free_pfn
o = memory hole

H------|------H------|----m-Hoooooo|ooooooH-f----|------H

The migrate_pfn is just below a memory hole and the free scanner is beyond
the hole.  When isolate_migratepages started, it scans from migrate_pfn to
migrate_pfn+pageblock_nr_pages which is now in a memory hole.  It checks
pfn_valid() on the first PFN but then scans into the hole where there are
not necessarily valid struct pages.

This patch ensures that isolate_migratepages calls pfn_valid when
necessary.
Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Herbert Poetzl reported a performance regression since 2.6.39.  The test
is a simple dd read, but with big block size.  The reason is:

T1: ra (A, A+128k), (A+128k, A+256k)
T2: lock_page for page A, submit the 256k
T3: hit page A+128K, ra (A+256k, A+384). the range isn't submitted
because of plug and there isn't any lock_page till we hit page A+256k
because all pages from A to A+256k is in memory
T4: hit page A+256k, ra (A+384, A+ 512). Because of plug, the range isn't
submitted again.
T5: lock_page A+256k, so (A+256k, A+512k) will be submitted. The task is
waitting for (A+256k, A+512k) finish.

There is no request to disk in T3 and T4, so readahead pipeline breaks.

We really don't need block plug for generic_file_aio_read() for buffered
I/O.  The readahead already has plug and has fine grained control when I/O
should be submitted.  Deleting plug for buffered I/O fixes the regression.

One side effect is plug makes the request size 256k, the size is 128k
without it.  This is because default ra size is 128k and not a reason we
need plug here.

Vivek said:

: We submit some readahead IO to device request queue but because of nested
: plug, queue never gets unplugged.  When read logic reaches a page which is
: not in page cache, it waits for page to be read from the disk
: (lock_page_killable()) and that time we flush the plug list.
:
: So effectively read ahead logic is kind of broken in parts because of
: nested plugging.  Removing top level plug (generic_file_aio_read()) for
: buffered reads, will allow unplugging queue earlier for readahead.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Reported-by: Herbert Poetzl <herbert@13thfloor.at>
Tested-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In function pre_handler_kretprobe(), the allocated kretprobe_instance
object will get leaked if the entry_handler callback returns non-zero.
This may cause all the preallocated kretprobe_instance objects exhausted.

This issue can be reproduced by changing
samples/kprobes/kretprobe_example.c to probe "mutex_unlock".  And the fix
is straightforward: just put the allocated kretprobe_instance object back
onto the free_instances list.

[akpm@linux-foundation.org: use raw_spin_lock/unlock]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland
with a 64bit kernel if the font width is not 8.

This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes
con_font_get return EIO in such case.

This flag should *not* be set for KDFONTOP, since it's actually the whole
point of this flag (see comment in con_font_set for instance).
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arthur Taylor <art@ified.ca>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lkdtm_do_action() may call sleeping functions like kmalloc(), so do not
call it with spin lock held.
Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>