Commit c937ca03 ("[media] MAINTAINERS: Add maintainer entry for
si4713 FM transmitter driver") typoed the pattern, fix it.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NEduardo Valentin <edubezval@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 786baecf ("[media] dvb-usb: move it to
drivers/media/usb/dvb-usb") moved the files, update the pattern.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 77c5f5d2 ("ghes_edac: Register at EDAC core the BIOS report")
typoed the file pattern.  Fix it.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 09ec1d7e ("ARM: S3C24XX: Remove plat-s3c24xx directory in
arch/arm/") moved the files, remove the pattern.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 694e33a7 ("ARM: plat-nomadik: move MTU, kill plat-nomadik")
moved the files, update the patterns.
Signed-off-by: NJoe Perches <joe@perches.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit a7ed099f ("ARM: spear: move all files to mach-spear") moved
all the files into a single directory, delete the now unnecessary
duplicate sections and update the pattern.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 85fd6d63 ("ARM: S3C2410: move mach-s3c2410/* into
mach-s3c24xx/") moved the files, update the patterns.
Signed-off-by: NJoe Perches <joe@perches.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 49815399 ("ARM: OMAP2+: powerdomain/PRM: move the low-level
powerdomain") renamed the files, update the patterns.

Identical to a patch earlier sent by Cesar Eduardo Barros.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Cesar Eduardo Barros <cesarb@cesarb.eti.br>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 4bd5259e ("ARM: OMAP2/3: clockdomain/PRM/CM: move the
low-level clockdomain functions into PRM/CM") deleted the files, update
the pattern.

Identical to a patch earlier sent by Cesar Eduardo Barros.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Cesar Eduardo Barros <cesarb@cesarb.eti.br>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit ca914350 ("ARM: EXYNOS: Remove unused board files") removed
the files, remove the patterns too.
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No functional changes, just comments.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Trivial.  Remove the unnecessary "work = NULL" initialization and turn
read_barrier_depends() into smp_read_barrier_depends() in
task_work_cancel().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As in commit f21afc25 ("smp.h: Use local_irq_{save,restore}() in
!SMP version of on_each_cpu()"), we don't want to enable irqs if they
are not already enabled.

I don't know of any bugs currently caused by this unconditional
local_irq_enable(), but I want to use this function in MIPS/OCTEON early
boot (when we have early_boot_irqs_disabled).  This also makes this
function have similar semantics to on_each_cpu() which is good in
itself.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Unclutter -Wmissing-prototypes warning types (enabled at make W=1)

    linux/include/linux/syscalls.h:190:18: warning: no previous prototype for 'SyS_semctl' [-Wmissing-prototypes]
      asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
                      ^
    linux/include/linux/syscalls.h:183:2: note: in expansion of macro '__SYSCALL_DEFINEx'
      __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
      ^
by adding forward declarations right before definitions.
Signed-off-by: NSergei Trofimovich <slyfox@gentoo.org>
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>

At least on ARM no-MMU the extable is empty and so there is nothing to
sort. So add a check for the table to be empty which effectively only
changes that the misleading pr_notice is suppressed.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David Daney <david.daney@cavium.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All of the other non-trivial !SMP versions of functions in smp.h are
out-of-line in up.c.  Move on_each_cpu() there as well.

This allows us to get rid of the #include <linux/irqflags.h>.  The
drawback is that this makes both the x86_64 and i386 defconfig !SMP
kernels about 200 bytes larger each.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The SMP version of this function doesn't unconditionally enable irqs, so
neither should this !SMP version.  There are no know problems caused by
this, but we make the change for consistency's sake.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As in commit f21afc25 ("smp.h: Use local_irq_{save,restore}() in
!SMP version of on_each_cpu()"), we don't want to enable irqs if they
are not already enabled.  There are currently no known problematical
callers of these functions, but since it is a known failure pattern, we
preemptively fix them.

Since they are not trivial functions, make them non-inline by moving
them to up.c.  This also makes it so we don't have to fix #include
dependancies for preempt_{disable,enable}.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When running with GENERIC_LOCKBREAK=y, the locking implementations emit
calls to arch_{read,write,spin}_relax when spinning on a contended lock
in order to allow architectures to favour the CPU owning the lock if
possible.

In reality, everybody apart from PowerPC and S390 just does cpu_relax()
here, so make that the default behaviour and allow it to be overridden
if required.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When failure occurs in hotplug_cfd(), need release related resources, or
will cause memory leak.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Acked-by: NWang YanQing <udknight@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Free the bio_integrity_pool in the fail path of biovec_create_pool in
function bioset_integrity_create().
Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We cannot assume that the inline assembler code always ends up in the same
file as the original C file.  So make any assembler labels that are called
with "extern" by C global
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

const has to use __initconst, not __initdata
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I found the following pattern that leads in to interesting findings:

  grep -r "ret.*|=.*__put_user" *
  grep -r "ret.*|=.*__get_user" *
  grep -r "ret.*|=.*__copy" *

The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat,
since those appear in compat code, we could probably expect the kernel
addresses not to be reachable in the lower 32-bit range, so I think they
might not be exploitable.

For the "__get_user" cases, I don't think those are exploitable: the worse
that can happen is that the kernel will copy kernel memory into in-kernel
buffers, and will fail immediately afterward.

The alpha csum_partial_copy_from_user() seems to be missing the
access_ok() check entirely.  The fix is inspired from x86.  This could
lead to information leak on alpha.  I also noticed that many architectures
map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I
wonder if the latter is performing the access checks on every
architectures.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The use of strict_strtoul() is not preferred, because strict_strtoul() is
obsolete.  Thus, kstrtoul() should be used.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Tom Gundersen <teg@jklm.no>
Cc: Mike Waychison <mikew@google.com>
Acked-by: NMike Waychison <mikew@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert drivers/platform/x86/apple-gmux to use dev_pm_ops instead of
legacy pm_ops.  This patch depends on pnp driver bus ops change to invoke
pnp_driver dev_pm_ops.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Ashley Lai <ashley@ashleylai.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Peter Hüwe <PeterHuewe@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert drivers/char/tpm/tpm_tis.c to use dev_pm_ops instead of legacy
pm_ops.  This patch depends on pnp driver bus ops change to invoke
pnp_driver dev_pm_ops.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Ashley Lai <ashley@ashleylai.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Peter Hüwe <PeterHuewe@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert drivers/rtc/rtc-cmos to use dev_pm_ops instead of legacy pm_ops.
This patch depends on pnp driver bus ops change to invoke pnp_driver
dev_pm_ops.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Ashley Lai <ashley@ashleylai.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Peter Hüwe <PeterHuewe@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pnp_bus_suspend() and pnp_bus_resume() invoke legacy pm_ops from
pnp_driver.  Changed pnp_bus_suspend() and pnp_bus_resume() to check if
pnp driver has dev_pm_ops and call.  If dev_pm_ops don't exist, then call
use legacy pm_ops.  Without this change, pnp_driver dev_pm_ops will not
get called.

In addition to the pnp driver bus pm_ops change to invoke driver
dev_pm_ops, this patch set contains changes to rtc-cmos, tpm_tis, and
apple-gmux pnp drivers to convert from legacy pm_ops to dev_pm_ops.

This patch (of 4):

pnp_bus_suspend() and pnp_bus_resume() invoke legacy pm_ops from
pnp_driver.  Changed pnp_bus_suspend() and pnp_bus_resume() to check if
pnp driver has dev_pm_ops and call.  If dev_pm_ops don't exist, then call
use legacy pm_ops.  Without this change, pnp_driver dev_pm_ops will not
get called.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Ashley Lai <ashley@ashleylai.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Peter Hüwe <PeterHuewe@gmx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A memory cgroup with (1) multiple threshold notifications and (2) at least
one threshold >=2G was not reliable.  Specifically the notifications would
either not fire or would not fire in the proper order.

The __mem_cgroup_threshold() signaling logic depends on keeping 64 bit
thresholds in sorted order.  mem_cgroup_usage_register_event() sorts them
with compare_thresholds(), which returns the difference of two 64 bit
thresholds as an int.  If the difference is positive but has bit[31] set,
then sort() treats the difference as negative and breaks sort order.

This fix compares the two arbitrary 64 bit thresholds returning the
classic -1, 0, 1 result.

The test below sets two notifications (at 0x1000 and 0x81001000):
  cd /sys/fs/cgroup/memory
  mkdir x
  for x in 4096 2164264960; do
    cgroup_event_listener x/memory.usage_in_bytes $x | sed "s/^/$x listener:/" &
  done
  echo $$ > x/cgroup.procs
  anon_leaker 500M

v3.11-rc7 fails to signal the 4096 event listener:
  Leaking...
  Done leaking pages.

Patched v3.11-rc7 properly notifies:
  Leaking...
  4096 listener:2013:8:31:14:13:36
  Done leaking pages.

The fixed bug is old.  It appears to date back to the introduction of
memcg threshold notifications in v2.6.34-rc1-116-g2e72b634 "memcg:
implement memory thresholds"
Signed-off-by: NGreg Thelen <gthelen@google.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the helper function instead of __GFP_ZERO.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the helper function instead of __GFP_ZERO.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pgoff is not used after the statement "pgoff = vma->vm_pgoff;", so the
assignment is redundant.
Signed-off-by: NYanchuan Nian <ycnian@gmail.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NJunxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

madvise_hwpoison() has two locals called "ret".  Fix it all up.

Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The return value outside for loop is always zero which means
madvise_hwpoison return success, however, this is not truth for
soft_offline_page w/ failure return value.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  Injecting memory failure for page 0x19d0 at 0xb77d2000
  MCE 0x19d0: non LRU page recovery: Ignored
  MCE: Software-unpoisoned page 0x19d0
  BUG: Bad page state in process bash  pfn:019d0
  page:f3461a00 count:0 mapcount:0 mapping:  (null) index:0x0
  page flags: 0x40000404(referenced|reserved)
  Modules linked in: nfsd auth_rpcgss i915 nfs_acl nfs lockd video drm_kms_helper drm bnep rfcomm sunrpc bluetooth psmouse parport_pc ppdev lp serio_raw fscache parport gpio_ich lpc_ich mac_hid i2c_algo_bit tpm_tis wmi usb_storage hid_generic usbhid hid e1000e firewire_ohci firewire_core ahci ptp libahci pps_core crc_itu_t
  CPU: 3 PID: 2123 Comm: bash Not tainted 3.11.0-rc6+ #12
  Hardware name: LENOVO 7034DD7/        , BIOS 9HKT47AUS 01//2012
   00000000 00000000 e9625ea0 c15ec49b f3461a00 e9625eb8 c15ea119 c17cbf18
   ef084314 000019d0 f3461a00 e9625ed8 c110dc8a f3461a00 00000001 00000000
   f3461a00 40000404 00000000 e9625ef8 c110dcc1 f3461a00 f3461a00 000019d0
  Call Trace:
    dump_stack+0x41/0x52
    bad_page+0xcf/0xeb
    free_pages_prepare+0x12a/0x140
    free_hot_cold_page+0x21/0x110
    __put_single_page+0x21/0x30
    put_page+0x25/0x40
    unpoison_memory+0x107/0x200
    hwpoison_unpoison+0x20/0x30
    simple_attr_write+0xb6/0xd0
    vfs_write+0xa0/0x1b0
    SyS_write+0x4f/0x90
    sysenter_do_call+0x12/0x22
  Disabling lock debugging due to kernel taint

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 1
#define PAGE_SIZE	4096

int main(void)
{
	char *mem;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

There is one page reference count for default empty zero page,
madvise_hwpoison add another one by get_user_pages_fast.  memory_hwpoison
reduce one page reference count since it's a non LRU page.
unpoison_memory release the last page reference count and free empty zero
page to buddy system which is not correct since empty zero page has
PG_reserved flag.  This patch fix it by don't reduce the page reference
count under 1 against empty zero page.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Hwpoison injection doesn't implement read method for
corrupt-pfn/unpoison-pfn attributes:

# cat /sys/kernel/debug/hwpoison/corrupt-pfn
cat: /sys/kernel/debug/hwpoison/corrupt-pfn: Permission denied
# cat /sys/kernel/debug/hwpoison/unpoison-pfn
cat: /sys/kernel/debug/hwpoison/unpoison-pfn: Permission denied

This patch changes the permission of corrupt-pfn/unpoison-pfn to 0200.
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

madvise hwpoison inject will poison the read-only empty zero page if there
is no write access before poison.  Empty zero page reference count will be
increased for hwpoison, subsequent poison zero page will return directly
since page has already been set PG_hwpoison, however, page reference count
is still increased by get_user_pages_fast.  The unpoison process will
unpoison the empty zero page and decrease the reference count successfully
for the fist time, however, subsequent unpoison empty zero page will
return directly since page has already been unpoisoned and without
decrease the page reference count of empty zero page.

This patch fixes it by make madvise_hwpoison() put a page and return
immediately (without calling memory_failure() or soft_offline_page()) when
the page is already hwpoisoned.

Testcase:

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <errno.h>

#define PAGES_TO_TEST 3
#define PAGE_SIZE	4096

int main(void)
{
	char *mem;
	int i;

	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);

	if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1)
		return -1;

	munmap(mem, PAGES_TO_TEST * PAGE_SIZE);

	return 0;
}

Add printk to dump page reference count:

[   93.075959] Injecting memory failure for page 0x19d0 at 0xb77d8000
[   93.076207] MCE 0x19d0: non LRU page recovery: Ignored
[   93.076209] pfn 0x19d0, page count = 1 after memory failure
[   93.076220] Injecting memory failure for page 0x19d0 at 0xb77d9000
[   93.076221] MCE 0x19d0: already hardware poisoned
[   93.076222] pfn 0x19d0, page count = 2 after memory failure
[   93.076224] Injecting memory failure for page 0x19d0 at 0xb77da000
[   93.076224] MCE 0x19d0: already hardware poisoned
[   93.076225] pfn 0x19d0, page count = 3 after memory failure
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Suggested-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add '#' to madvise_hwpoison.

Before patch:

[   95.892866] Injecting memory failure for page 19d0 at b7786000
[   95.893151] MCE 0x19d0: non LRU page recovery: Ignored

After patch:

[   95.892866] Injecting memory failure for page 0x19d0 at 0xb7786000
[   95.893151] MCE 0x19d0: non LRU page recovery: Ignored
Signed-off-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>