resource: fix the case of null pointer access

Richard and Daniel reported that UML is broken due to changes to
resource traversal functions.  Problem is that iomem_resource.child can
be null and new code does not consider that possibility.  Old code used
a for loop and that loop will not even execute if p was null.

Revert back to for() loop logic and bail out if p is null.

I also moved sibling_only check out of resource_lock. There is no
reason to keep it inside the lock.

Following is backtrace of the UML crash.

RIP: 0033:[<0000000060039b9f>]
RSP: 0000000081459da0  EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000219b3fff RCX: 000000006010d1d9
RDX: 0000000000000001 RSI: 00000000602dfb94 RDI: 0000000081459df8
RBP: 0000000081459de0 R08: 00000000601b59f4 R09: ffffffff0000ff00
R10: ffffffff0000ff00 R11: 0000000081459e88 R12: 0000000081459df8
R13: 00000000219b3fff R14: 00000000602dfb94 R15: 0000000000000000
Kernel panic - not syncing: Segfault with no mm
CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-10454-g58d08e3 #13
Stack:
 00000000 000080d0 81459df0 219b3fff
 81459e70 6010d1d9 ffffffff 6033e010
 81459e50 6003a269 81459e30 00000000
Call Trace:
 [<6010d1d9>] ? kclist_add_private+0x0/0xe7
 [<6003a269>] walk_system_ram_range+0x61/0xb7
 [<6000e859>] ? proc_kcore_init+0x0/0xf1
 [<6010d574>] kcore_update_ram+0x4c/0x168
 [<6010d72e>] ? kclist_add+0x0/0x2e
 [<6000e943>] proc_kcore_init+0xea/0xf1
 [<6000e859>] ? proc_kcore_init+0x0/0xf1
 [<6000e859>] ? proc_kcore_init+0x0/0xf1
 [<600189f0>] do_one_initcall+0x13c/0x204
 [<6004ca46>] ? parse_args+0x1df/0x2e0
 [<6004c82d>] ? parameq+0x0/0x3a
 [<601b5990>] ? strcpy+0x0/0x18
 [<60001e1a>] kernel_init_freeable+0x240/0x31e
 [<6026f1c0>] kernel_init+0x12/0x148
 [<60019fad>] new_thread_handler+0x81/0xa3

Fixes 8c86e70acead629aacb4a ("resource: provide new functions to walk
through resources").

Reported-by: Daniel Walter <sahne@0x90.at>
Tested-by: Richard Weinberger <richard@nod.at>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Daniel Walter <sahne@0x90.at>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
memblock, memhotplug: fix wrong type in memblock_find_in_range_node().

In memblock_find_in_range_node(), we defined ret as int.  But it should
be phys_addr_t because it is used to store the return value from
__memblock_find_range_bottom_up().

The bug has not been triggered because when allocating low memory near
the kernel end, the "int ret" won't turn out to be negative.  When we
started to allocate memory on other nodes, and the "int ret" could be
minus.  Then the kernel will panic.

A simple way to reproduce this: comment out the following code in
numa_init(),

        memblock_set_bottom_up(false);

and the kernel won't boot.

Reported-by: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Tested-by: Xishi Qiu <qiuxishi@huawei.com>
Cc: <stable@vger.kernel.org>	[3.13+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: actually clear pmd_numa before invalidating

Commit 67f87463d3a3 ("mm: clear pmd_numa before invalidating") cleared
the NUMA bit in a copy of the PMD entry, but then wrote back the
original

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib: turn CONFIG_STACKTRACE into an actual option.

I was puzzled why /proc/$$/stack had disappeared, until I figured out I
had disabled the last debug option that did a 'select STACKTRACE'.  This
patch makes the option show up at config time, so it can be enabled
without enabling any of the more heavyweight debug options.

Signed-off-by: Dave Jones <davej@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zram: fix incorrect stat with failed_reads

Since we allocate a temporary buffer in zram_bvec_read to handle partial
page operations in commit 924bd88d703e ("Staging: zram: allow partial
page operations"), our ->failed_reads value may be incorrect as we do
not increase its value when failing to allocate the temporary buffer.

Let's fix this issue and correct the annotation of failed_reads.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/zpool: use prefixed module loading

To avoid potential format string expansion via module parameters, do not
use the zpool type directly in request_module() without a format string.
Additionally, to avoid arbitrary modules being loaded via zpool API
(e.g.  via the zswap_zpool_type module parameter) add a "zpool-" prefix
to the requested module, as well as module aliases for the existing
zpool types (zbud and zsmalloc).

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hugetlb_cgroup: use lockdep_assert_held rather than spin_is_locked

spin_lock may be an empty struct for !SMP configurations and so
arch_spin_is_locked may return unconditional 0 and trigger the VM_BUG_ON
even when the lock is held.

Replace spin_is_locked by lockdep_assert_held.  We will not BUG anymore
but it is questionable whether crashing makes a lot of sense in the
uncharge path.  Uncharge happens after the last page reference was
released so nobody should touch the page and the function doesn't update
any shared state except for res counter which uses synchronization of
its own.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86,mm: fix pte_special versus pte_numa

Sasha Levin has shown oopses on ffffea0003480048 and ffffea0003480008 at
mm/memory.c:1132, running Trinity on different 3.16-rc-next kernels:
where zap_pte_range() checks page->mapping to see if PageAnon(page).

Those addresses fit struct pages for pfns d2001 and d2000, and in each
dump a register or a stack slot showed d2001730 or d2000730: pte flags
0x730 are PCD ACCESSED PROTNONE SPECIAL IOMAP; and Sasha's e820 map has
a hole between cfffffff and 100000000, which would need special access.

Commit c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on
the PMD and PTE levels") has broken vm_normal_page(): a PROTNONE SPECIAL
pte no longer passes the pte_special() test, so zap_pte_range() goes on
to try to access a non-existent struct page.

Fix this by refining pte_special() (SPECIAL with PRESENT or PROTNONE) to
complement pte_numa() (SPECIAL with neither PRESENT nor PROTNONE).  A
hint that this was a problem was that c46a7c817e66 added pte_numa() test
to vm_normal_page(), and moved its is_zero_pfn() test from slow to fast
path: This was papering over a pte_special() snag when the zero page was
encountered during zap.  This patch reverts vm_normal_page() to how it
was before, relying on pte_special().

It still appears that this patch may be incomplete: aren't there other
places which need to be handling PROTNONE along with PRESENT?  For
example, pte_mknuma() clears _PAGE_PRESENT and sets _PAGE_NUMA, but on a
PROT_NONE area, that would make it pte_special().  This is side-stepped
by the fact that NUMA hinting faults skipped PROT_NONE VMAs and there
are no grounds where a NUMA hinting fault on a PROT_NONE VMA would be
interesting.

Fixes: c46a7c817e66 ("x86: define _PAGE_NUMA by reusing software bits on the PMD and PTE levels")
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: <stable@vger.kernel.org>	[3.16]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kexec: create a new config option CONFIG_KEXEC_FILE for new syscall

Currently new system call kexec_file_load() and all the associated code
compiles if CONFIG_KEXEC=y.  But new syscall also compiles purgatory
code which currently uses gcc option -mcmodel=large.  This option seems
to be available only gcc 4.4 onwards.

Hiding new functionality behind a new config option will not break
existing users of old gcc.  Those who wish to enable new functionality
will require new gcc.  Having said that, I am trying to figure out how
can I move away from using -mcmodel=large but that can take a while.

I think there are other advantages of introducing this new config
option.  As this option will be enabled only on x86_64, other arches
don't have to compile generic kexec code which will never be used.  This
new code selects CRYPTO=y and CRYPTO_SHA256=y.  And all other arches had
to do this for CONFIG_KEXEC.  Now with introduction of new config
option, we can remove crypto dependency from other arches.

Now CONFIG_KEXEC_FILE is available only on x86_64.  So whereever I had
CONFIG_X86_64 defined, I got rid of that.

For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to
"depends on CRYPTO=y".  This should be safer as "select" is not
recursive.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kexec: remove CONFIG_KEXEC dependency on crypto

New system call depends on crypto.  As it did not have a separate config
option, CONFIG_KEXEC was modified to select CRYPTO and CRYPTO_SHA256.

But now previous patch introduced a new config option for new syscall.
So CONFIG_KEXEC does not require crypto.  Remove that dependency.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
xattr: fix check for simultaneous glibc header inclusion

The guard was introduced in commit ea1a8217b06b ("xattr: guard against
simultaneous glibc header inclusion") but it is using #ifdef to check
for a define that is either set to 1 or 0.  Fix it to use #if instead.

* Without this patch:

  $ { echo "#include <sys/xattr.h>"; echo "#include <linux/xattr.h>"; } | gcc -E -Iinclude/uapi - >/dev/null
  include/uapi/linux/xattr.h:19:0: warning: "XATTR_CREATE" redefined [enabled by default]
   #define XATTR_CREATE 0x1 /* set value, fail if attr already exists */
   ^
  /usr/include/x86_64-linux-gnu/sys/xattr.h:32:0: note: this is the location of the previous definition
   #define XATTR_CREATE XATTR_CREATE
   ^

* With this patch:

  $ { echo "#include <sys/xattr.h>"; echo "#include <linux/xattr.h>"; } | gcc -E -Iinclude/uapi - >/dev/null
  (no warnings)

Signed-off-by: Filipe Brandenburger <filbranden@google.com>
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Cc: Allan McRae <allan@archlinux.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-s5m.c: re-add support for devices without irq specified

The rtc-s5m driver used to support devices without irq specified in the
past.  Re-add this support.

The patch fixes boot for Insignal's Exynos4412 based Origen board.

Error messages before the patch:

  ...
  Unable to handle kernel NULL pointer dereference at virtual address 00000094
  pgd = c0004000
  [00000094] *pgd=00000000
  Internal error: Oops: 5 [#1] PREEMPT SMP ARM
  Modules linked in:
  CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.16.0-next-20140804-00008-ga59480f-dirty #701
  task: ea80f000 ti: ea882000 task.ti: ea882000
  PC is at regmap_irq_get_virq+0x0/0x28
  LR is at s5m_rtc_probe+0xdc/0x310
  pc : [<c02574fc>]    lr : [<c02de75c>]    psr: 80000153
  sp : ea883e48  ip : 00000000  fp : 00000000
  r10: 0000000c  r9 : c05de7ac  r8 : eaabc600
  r7 : eaa6b4d0  r6 : c0439e8c  r5 : eaabc610  r4 : eab30e50
  r3 : 00000000  r2 : 00000000  r1 : 0000000c  r0 : 00000000
  Flags: Nzcv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
  Control: 10c5387d  Table: 4000404a  DAC: 00000015
  Process swapper/0 (pid: 1, stack limit = 0xea882240)
  Backtrace:
    regmap_irq_get_virq
    s5m_rtc_probe
    platform_drv_probe
    driver_probe_device
    __driver_attach
    bus_for_each_dev
    bus_add_driver
    driver_register
    do_one_initcall
    kernel_init_freeable
    kernel_init
  ---[ end trace a954d7f019122700 ]---
  Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
  ...

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86/purgatory: use approprate -m64/-32 build flag for arch/x86/purgatory

Thomas reported that build of x86_64 kernel was failing for him.  He is
using 32bit tool chain.

Problem is that while compiling purgatory, I have not specified -m64
flag.  And 32bit tool chain must be assuming -m32 by default.

Following is error message.

(mini) [~/work/linux-2.6] make
scripts/kconfig/conf --silentoldconfig Kconfig
  CHK     include/config/kernel.release
  UPD     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  UPD     include/generated/utsrelease.h
  CC      arch/x86/purgatory/purgatory.o
arch/x86/purgatory/purgatory.c:1:0: error: code model 'large' not supported in
the 32 bit mode

Fix it by explicitly passing appropriate -m64/-m32 build flag for
purgatory.

Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Tested-by: Thomas Glanzmann <thomas@glanzmann.de>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2: do not write error flag to user structure we cannot copy from/to

If we failed to copy from the structure, writing back the flags leaks 31
bits of kernel memory (the rest of the ir_flags field).

In any case, if we cannot copy from/to the structure, why should we
expect putting just the flags to work?

Also make sure ocfs2_info_handle_freeinode() returns the right error
code if the copy_to_user() fails.

Fixes: ddee5cdb70e6 ('Ocfs2: Add new OCFS2_IOC_INFO ioctl for ocfs2 v8.')
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Joel Becker <jlbec@evilplan.org>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2: o2net: don't shutdown connection when idle timeout

This patch series is to fix a possible message lost bug in ocfs2 when
network go bad.  This bug will cause ocfs2 hung forever even network
become good again.

The messages may lost in this case.  After the tcp connection is
established between two nodes, an idle timer will be set to check its
state periodically, if no messages are received during this time, idle
timer will timeout, it will shutdown the connection and try to
reconnect, so pending messages in tcp queues will be lost.  This
messages may be from dlm.  Dlm may get hung in this case.  This may
cause the whole ocfs2 cluster hung.

This is very possible to happen when network state goes bad.  Do the
reconnect is useless, it will fail if network state is still bad.  Just
waiting there for network recovering may be a good idea, it will not
lost messages and some node will be fenced until cluster goes into
split-brain state, for this case, Tcp user timeout is used to override
the tcp retransmit timeout.  It will timeout after 25 days, user should
have notice this through the provided log and fix the network, if they
don't, ocfs2 will fall back to original reconnect way.

This patch (of 3):

Some messages in the tcp queue maybe lost if we shutdown the connection
and reconnect when idle timeout.  If packets lost and reconnect success,
then the ocfs2 cluster maybe hung.

To fix this, we can leave the connection there and do the fence decision
when idle timeout, if network recover before fence dicision is made, the
connection survive without lost any messages.

This bug can be saw when network state go bad.  It may cause ocfs2 hung
forever if some packets lost.  With this fix, ocfs2 will recover from
hung if network becomes good again.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2: o2net: set tcp user timeout to max value

When tcp retransmit timeout(15mins), the connection will be closed.
Pending messages may be lost during this time.  So we set tcp user
timeout to override the retransmit timeout to the max value.  This is OK
for ocfs2 since we have disk heartbeat, if peer crash, the disk
heartbeat will timeout and it will be evicted, if disk heartbeat not
timeout and connection idle for a long time, then this means the cluster
enters split-brain state, since fence can't happen, we'd better keep the
connection and wait network recover.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ocfs2: quorum: add a log for node not fenced

For debug use, we can see from the log whether the fence decision is
made and why it is not fenced.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tools: selftests: fix build issue with make kselftests target

Fix the typo of ARCH when running 'make kselftests'.  Change the 'X86'
to 'x86'.  Test by compilation.

Signed-off-by: Phong Tran <tranmanphong@gmail.com>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
flush_icache_range: export symbol to fix build errors

Fix building errors occuring due to a missing export of
flush_icache_range() in

kisskb.ellerman.id.au/kisskb/buildresult/11677809/

ERROR: "flush_icache_range" [drivers/misc/lkdtm.ko] undefined!

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vineet Gupta <vgupta@synopsys.com>	[arc]
Acked-by: Richard Kuo <rkuo@codeaurora.org>	[hexagon]
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>	[xtensa]
Cc: Noam Camus <noamc@ezchip.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Zhigang Lu <zlu@tilera.com>		[tile]
Cc: Kirill Tkhai <tkhai@yandex.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/kdump/kdump.txt: add ARM description

Add arm specific parts to kdump kernel documentation.

Signed-off-by: Hu Keping <hukeping@huawei.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Haren Myneni <hbabu@us.ibm.com>
Cc: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>