Now kbuild core scripts create empty built-in.o where necessary.
Remove "obj- := dummy.o" tricks.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Commit a7be6e5a ("mm: drop useless local parameters of
__register_one_node()") removed the last user of parent_node().

The parent_node() macro in tile platform is unnecessary.

Remove it for cleanup.

Link: http://lkml.kernel.org/r/1504234599-29533-7-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NChris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit a7be6e5a ("mm: drop useless local parameters of
__register_one_node()") removed the last user of parent_node().

The parent_node() macro in SPARC64 platform is unnecessary.

Remove it for cleanup.

Link: http://lkml.kernel.org/r/1504234599-29533-6-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit a7be6e5a ("mm: drop useless local parameters of
__register_one_node()") removed the last user of parent_node().

The parent_node() macro in SUPERH platform is unnecessary.

Remove it for cleanup.

Link: http://lkml.kernel.org/r/1504234599-29533-5-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit a7be6e5a ("mm: drop useless local parameters of
__register_one_node()") removed the last user of parent_node().

The parent_node() macro in IA64(Itanium) platform is unnecessary.

Remove it for cleanup.

Link: http://lkml.kernel.org/r/1504234599-29533-2-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Reported-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

pidhash is no longer required as all the information can be looked up
from idr tree.  nr_hashed represented the number of pids that had been
hashed.  Since, nr_hashed and PIDNS_HASH_ADDING are no longer relevant,
it has been renamed to pid_allocated and PIDNS_ADDING respectively.

[gs051095@gmail.com: v6]
  Link: http://lkml.kernel.org/r/1507760379-21662-3-git-send-email-gs051095@gmail.com
Link: http://lkml.kernel.org/r/1507583624-22146-3-git-send-email-gs051095@gmail.comSigned-off-by: NGargi Sharma <gs051095@gmail.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>	[ia64]
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "Replacing PID bitmap implementation with IDR API", v4.

This series replaces kernel bitmap implementation of PID allocation with
IDR API.  These patches are written to simplify the kernel by replacing
custom code with calls to generic code.

The following are the stats for pid and pid_namespace object files
before and after the replacement.  There is a noteworthy change between
the IDR and bitmap implementation.

Before
   text       data        bss        dec        hex    filename
   8447       3894         64      12405       3075    kernel/pid.o
After
   text       data        bss        dec        hex    filename
   3397        304          0       3701        e75    kernel/pid.o

Before
   text       data        bss        dec        hex    filename
   5692       1842        192       7726       1e2e    kernel/pid_namespace.o
After
   text       data        bss        dec        hex    filename
   2854        216         16       3086        c0e    kernel/pid_namespace.o

The following are the stats for ps, pstree and calling readdir on /proc
for 10,000 processes.

ps:
        With IDR API    With bitmap
real    0m1.479s        0m2.319s
user    0m0.070s        0m0.060s
sys     0m0.289s        0m0.516s

pstree:
        With IDR API    With bitmap
real    0m1.024s        0m1.794s
user    0m0.348s        0m0.612s
sys     0m0.184s        0m0.264s

proc:
        With IDR API    With bitmap
real    0m0.059s        0m0.074s
user    0m0.000s        0m0.004s
sys     0m0.016s        0m0.016s

This patch (of 2):

Replace the current bitmap implementation for Process ID allocation.
Functions that are no longer required, for example, free_pidmap(),
alloc_pidmap(), etc.  are removed.  The rest of the functions are
modified to use the IDR API.  The change was made to make the PID
allocation less complex by replacing custom code with calls to generic
API.

[gs051095@gmail.com: v6]
  Link: http://lkml.kernel.org/r/1507760379-21662-2-git-send-email-gs051095@gmail.com
[avagin@openvz.org: restore the old behaviour of the ns_last_pid sysctl]
  Link: http://lkml.kernel.org/r/20171106183144.16368-1-avagin@openvz.org
Link: http://lkml.kernel.org/r/1507583624-22146-2-git-send-email-gs051095@gmail.comSigned-off-by: NGargi Sharma <gs051095@gmail.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "cut here" string is used in a few paths.  Define it in a single
place.

Link: http://lkml.kernel.org/r/1510100869-73751-3-git-send-email-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The sh decompressor code triggers stack-protector code generation when
using CONFIG_CC_STACKPROTECTOR_STRONG.  As done for arm and mips, add a
simple static stack-protector canary.  As this wasn't protected before,
the risk of using a weak canary is minimized.  Once the kernel is
actually up, a better canary is chosen.

Link: http://lkml.kernel.org/r/1506972007-80614-2-git-send-email-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <mmarek@suse.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix duplicates for sparc and parisc. This was due these following commits.

1. commit 4c97a0c8 ("arch: define CPU_BIG_ENDIAN for all fixed big
   endian archs")
2. commit 97d9f969 ("arch/sparc: Define config parameter
   CPU_BIG_ENDIAN")
3. commit 74ad3d28 ("parisc: Define CONFIG_CPU_BIG_ENDIAN")

Remove duplicates.
Signed-off-by: NBabu Moger <babu.moger@oracle.com>
Signed-off-by: NHelge Deller <deller@gmx.de>

While working on a qemu and SeaBIOS-port to parisc, those PDC structures are
useful to have accessible from userspace.
Signed-off-by: NHelge Deller <deller@gmx.de>

parisc is big-endian only but sparse assumes the same endianness as the
building machine.
This is problematic for code which expect __BYTE_ORDER__ being correctly
predefined by the compiler which sparse can then pre-process differently
from what gcc would.

Fix this by letting sparse know about the architecture endianness.

To: James Bottomley <jejb@parisc-linux.org>
To: Helge Deller <deller@gmx.de>
CC: linux-parisc@vger.kernel.org
Signed-off-by: NLuc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: NHelge Deller <deller@gmx.de>

Add topology support, including multi-core scheduler support on
PA8800/PA8900 CPUs and enhanced output in /proc/cpuinfo, e.g.
lscpu now reports on a single-socket, dual-core machine:

Architecture:          parisc64
CPU(s):                2
On-line CPU(s) list:   0,1
Thread(s) per core:    1
Core(s) per socket:    2
Socket(s):             1
CPU family:            PA-RISC 2.0
Model name:            PA8800 (Mako)
Signed-off-by: NHelge Deller <deller@gmx.de>

As noted by Christoph Biedl, passing a pointer size of 4 in the new CAS
implementation causes a kernel crash.  The attached patch corrects the
off by one error in the argument validity check.

In reviewing the code, I noticed that we only perform word operations
with the pointer size argument.  The subi instruction intentionally uses
a word condition on 64-bit kernels.  Nullification was used instead of a
cmpib instruction as the branch should never be taken.  The shlw
pseudo-operation generates a depw,z instruction and it clears the target
before doing a shift left word deposit.  Thus, we don't need to clip the
upper 32 bits of this argument on 64-bit kernels.

Tested with a gcc testsuite run with a 64-bit kernel.  The gcc atomic
code in libgcc is the only direct user of the new CAS implementation
that I am aware of.
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 3.13+
Signed-off-by: NHelge Deller <deller@gmx.de>

Commit 429f203e ("arm64: dts: uniphier: route on-board device IRQ
to GPIO controller") missed to update this DTS.  It becames a real
problem when arm and arm64 trees are merged together.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

These files are copied from arch/sh/lib, so should be ignored by git.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>

Remove unused parameter from the call function,
which I accidentally added.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The hardware sampler creates samples that are processed at a later
point in time.  The PID and TID values of the perf samples that are
created for hardware samples are initialized with values from the
current task.  Hence, the PID and TID values are not correct and
perf samples are associated with wrong processes.

The PID and TID values are obtained from the Host Program Parameter
(HPP) field in the basic-sampling data entries.  These PIDs are
valid in the init PID namespace.  Ensure that the PIDs in the perf
samples are resolved considering the PID namespace in which the
perf event was created.

To correct the PID and TID values in the created perf samples,
a special overflow handler is installed.  It replaces the default
overflow handler and does not become effective if any other
overflow handler is used.  With the special overflow handler most
of the perf samples are associated with the right processes.
For processes, that are no longer exist, the association might
still be wrong.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The lpp instruction is used to place the PID of the current
task in the program-parameter (PP) register.  The register
contents is then included in the sampling data entries.

The lpp instruction loads the PP register only when at least
one sampling function is enabled.  Otherwise it is executed
as a no-op.

Linux calls lpp at context switch.  If the context switch
happens before the sampler is enabled, the PP register is
empty.  That means, the PID of the task that is sampled is
not stored in sampling data until the next context switch.

Hence, always call lpp when enabling the sampler.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Extend the perf register support to also export floating-point register
contents for user space tasks.  Floating-point registers might be used
in leaf functions to contain the return address.  Hence, they are required
for proper DWARF unwinding.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add s390 support to dump user stack to user space for DWARF
stack unwinding.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-and-tested-by: NThomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Previously, the cpum_sf PMU was registered even if there is no
sampling mode authorized.  Add a check and register cpum_sf only
at least one sampling mode is authorized.
Signed-off-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Raw sample was implemented to export the diagnostic samples.
With having this achieved with AUX buffers, there is no requirement
for basic samples to export raw data.  In particular, most basic
sampling information are consumed for creating the perf event sample.
Signed-off-by: NPu Hou <bjhoupu@linux.vnet.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Modify PMU callback to use AUX buffer for diagnostic mode sampling.
Basic-mode sampling still use orignal way.
Signed-off-by: NPu Hou <bjhoupu@linux.vnet.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Current implementation uses a private buffer for cpumf to dump samples.
Samples first go to this buffer. Then copy to ring buffer allocated
by perf core. With AUX buffer, this copy is not needed. AUX buffer is
shared and zero-copy mapped to user space. The trailer information at
the end of each SDB(sample data block) is also exported to user space.
AUX buffer is used when diagnostic sampling mode is enabled.

This patch contains functions to setup/free AUX buffer or to begin/end
sampling per-cpu. Also include function called in interrupt to
collect samples.
Signed-off-by: NPu Hou <bjhoupu@linux.vnet.ibm.com>
Reviewed-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Current buffer size of 64 is too small. objdump shows that there are
instructions which would require up to 75 bytes buffer (with current
formating). 128 bytes "ought to be enough for anybody".

Also replaces 8 spaces with a single tab to reduce the memory footprint.

Fixes the following KASAN finding:

BUG: KASAN: stack-out-of-bounds in number+0x3fe/0x538
Write of size 1 at addr 000000005a4a75a0 by task bash/1282

CPU: 1 PID: 1282 Comm: bash Not tainted 4.14.0+ #215
Hardware name: IBM 2964 N96 702 (z/VM 6.4.0)
Call Trace:
([<000000000011eeb6>] show_stack+0x56/0x88)
 [<0000000000e1ce1a>] dump_stack+0x15a/0x1b0
 [<00000000004e2994>] print_address_description+0xf4/0x288
 [<00000000004e2cf2>] kasan_report+0x13a/0x230
 [<0000000000e38ae6>] number+0x3fe/0x538
 [<0000000000e3dfe4>] vsnprintf+0x194/0x948
 [<0000000000e3ea42>] sprintf+0xa2/0xb8
 [<00000000001198dc>] print_insn+0x374/0x500
 [<0000000000119346>] show_code+0x4ee/0x538
 [<000000000011f234>] show_registers+0x34c/0x388
 [<000000000011f2ae>] show_regs+0x3e/0xa8
 [<000000000011f502>] die+0x1ea/0x2e8
 [<0000000000138f0e>] do_no_context+0x106/0x168
 [<0000000000139a1a>] do_protection_exception+0x4da/0x7d0
 [<0000000000e55914>] pgm_check_handler+0x16c/0x1c0
 [<000000000090639e>] sysrq_handle_crash+0x46/0x58
([<0000000000000007>] 0x7)
 [<00000000009073fa>] __handle_sysrq+0x102/0x218
 [<0000000000907c06>] write_sysrq_trigger+0xd6/0x100
 [<000000000061d67a>] proc_reg_write+0xb2/0x128
 [<0000000000520be6>] __vfs_write+0xee/0x368
 [<0000000000521222>] vfs_write+0x21a/0x278
 [<000000000052156a>] SyS_write+0xda/0x178
 [<0000000000e555cc>] system_call+0xc4/0x270

The buggy address belongs to the page:
page:000003d1016929c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x0()
raw: 0000000000000000 0000000000000000 0000000000000000 ffffffff00000000
raw: 0000000000000100 0000000000000200 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 000000005a4a7480: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 000000005a4a7500: 00 00 00 00 00 00 00 00 f2 f2 f2 f2 00 00 00 00
>000000005a4a7580: 00 00 00 00 f3 f3 f3 f3 00 00 00 00 00 00 00 00
                               ^
 000000005a4a7600: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 f8 f8
 000000005a4a7680: f2 f2 f2 f2 f2 f2 f8 f8 f2 f2 f3 f3 f3 f3 00 00
==================================================================

Cc: <stable@vger.kernel.org>
Signed-off-by: NVasily Gorbik <gor@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When running the crash tool on a s390 live system we get a kernel panic
for reading memory within the kernel image:

 # uname -a
   Linux r3545011 4.14.0-rc8-00066-g1c9dbd46 #45 SMP PREEMPT Fri Nov 10 16:16:22 CET 2017 s390x s390x s390x GNU/Linux
 # crash /boot/vmlinux-devel /dev/mem
 # crash> rd 0x100000

 usercopy: kernel memory exposure attempt detected from 0000000000100000 (<kernel text>) (8 bytes)
 ------------[ cut here ]------------
 kernel BUG at mm/usercopy.c:72!
 illegal operation: 0001 ilc:1 [#1] PREEMPT SMP.
 Modules linked in:
 CPU: 0 PID: 1461 Comm: crash Not tainted 4.14.0-rc8-00066-g1c9dbd46-dirty #46
 Hardware name: IBM 2827 H66 706 (z/VM 6.3.0)
 task: 000000001ad10100 task.stack: 000000001df78000
 Krnl PSW : 0704d00180000000 000000000038165c (__check_object_size+0x164/0x1d0)
            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3
 Krnl GPRS: 0000000012440e1d 0000000080000000 0000000000000061 00000000001cabc0
            00000000001cc6d6 0000000000000000 0000000000cc4ed2 0000000000001000
            000003ffc22fdd20 0000000000000008 0000000000100008 0000000000000001
            0000000000000008 0000000000100000 0000000000381658 000000001df7bc90
 Krnl Code: 000000000038164c: c020004a1c4a        larl    %r2,cc4ee0
            0000000000381652: c0e5fff2581b        brasl   %r14,1cc688
           #0000000000381658: a7f40001            brc     15,38165a
           >000000000038165c: eb42000c000c        srlg    %r4,%r2,12
            0000000000381662: eb32001c000c        srlg    %r3,%r2,28
            0000000000381668: c0110003ffff        lgfi    %r1,262143
            000000000038166e: ec31ff752065        clgrj   %r3,%r1,2,381558
            0000000000381674: a7f4ff67            brc     15,381542
 Call Trace:
 ([<0000000000381658>] __check_object_size+0x160/0x1d0)
  [<000000000082263a>] read_mem+0xaa/0x130.
  [<0000000000386182>] __vfs_read+0x42/0x168.
  [<000000000038632e>] vfs_read+0x86/0x140.
  [<0000000000386a26>] SyS_read+0x66/0xc0.
  [<0000000000ace6a4>] system_call+0xc4/0x2b0.
 INFO: lockdep is turned off.
 Last Breaking-Event-Address:
  [<0000000000381658>] __check_object_size+0x160/0x1d0

 Kernel panic - not syncing: Fatal exception: panic_on_oops

With CONFIG_HARDENED_USERCOPY copy_to_user() checks in __check_object_size()
if the source address is within the kernel image. When the crash tool reads
from 0x100000, this check leads to the kernel BUG().

So disable the kernel config option until this bug is fixed.

Corresponding bug report on LKML: https://lkml.org/lkml/2017/11/10/341Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

While doing memory hotplug tests under heavy memory pressure we have
noticed too many page allocation failures when allocating vmemmap memmap
backed by huge page

  kworker/u3072:1: page allocation failure: order:9, mode:0x24084c0(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO)
  [...]
  Call Trace:
    dump_trace+0x59/0x310
    show_stack_log_lvl+0xea/0x170
    show_stack+0x21/0x40
    dump_stack+0x5c/0x7c
    warn_alloc_failed+0xe2/0x150
    __alloc_pages_nodemask+0x3ed/0xb20
    alloc_pages_current+0x7f/0x100
    vmemmap_alloc_block+0x79/0xb6
    __vmemmap_alloc_block_buf+0x136/0x145
    vmemmap_populate+0xd2/0x2b9
    sparse_mem_map_populate+0x23/0x30
    sparse_add_one_section+0x68/0x18e
    __add_pages+0x10a/0x1d0
    arch_add_memory+0x4a/0xc0
    add_memory_resource+0x89/0x160
    add_memory+0x6d/0xd0
    acpi_memory_device_add+0x181/0x251
    acpi_bus_attach+0xfd/0x19b
    acpi_bus_scan+0x59/0x69
    acpi_device_hotplug+0xd2/0x41f
    acpi_hotplug_work_fn+0x1a/0x23
    process_one_work+0x14e/0x410
    worker_thread+0x116/0x490
    kthread+0xbd/0xe0
    ret_from_fork+0x3f/0x70

and we do see many of those because essentially every allocation fails
for each memory section.  This is an excessive way to tell the user that
there is nothing to really worry about because we do have a fallback
mechanism to use base pages.  The only downside might be a performance
degradation due to TLB pressure.

This patch changes vmemmap_alloc_block() to use __GFP_NOWARN and warn
explicitly once on the first allocation failure.  This will reduce the
noise in the kernel log considerably, while we still have an indication
that a performance might be impacted.

[mhocko@kernel.org: forgot to git add the follow up fix]
  Link: http://lkml.kernel.org/r/20171107090635.c27thtse2lchjgvb@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20171106092228.31098-1-mhocko@kernel.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Most callers users of free_hot_cold_page claim the pages being released
are cache hot.  The exception is the page reclaim paths where it is
likely that enough pages will be freed in the near future that the
per-cpu lists are going to be recycled and the cache hotness information
is lost.  As no one really cares about the hotness of pages being
released to the allocator, just ditch the parameter.

The APIs are renamed to indicate that it's no longer about hot/cold
pages.  It should also be less confusing as there are subtle differences
between them.  __free_pages drops a reference and frees a page when the
refcount reaches zero.  free_hot_cold_page handled pages whose refcount
was already zero which is non-obvious from the name.  free_unref_page
should be more obvious.

No performance impact is expected as the overhead is marginal.  The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.

[mgorman@techsingularity.net: add pages to head, not tail]
  Link: http://lkml.kernel.org/r/20171019154321.qtpzaeftoyyw4iey@techsingularity.net
Link: http://lkml.kernel.org/r/20171018075952.10627-8-mgorman@techsingularity.netSigned-off-by: NMel Gorman <mgorman@techsingularity.net>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an optimized mm_zero_struct_page(), so struct page's are zeroed
without calling memset().  We do eight to ten regular stores based on
the size of struct page.  Compiler optimizes out the conditions of
switch() statement.

SPARC-M6 with 15T of memory, single thread performance:

                               BASE            FIX  OPTIMIZED_FIX
        bootmem_init   28.440467985s   2.305674818s   2.305161615s
free_area_init_nodes  202.845901673s 225.343084508s 172.556506560s
                      --------------------------------------------
Total                 231.286369658s 227.648759326s 174.861668175s

BASE:  current linux
FIX:   This patch series without "optimized struct page zeroing"
OPTIMIZED_FIX: This patch series including the current patch.

bootmem_init() is where memory for struct pages is zeroed during
allocation.  Note, about two seconds in this function is a fixed time:
it does not increase as memory is increased.

Link: http://lkml.kernel.org/r/20171013173214.27300-11-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: NSteven Sistare <steven.sistare@oracle.com>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: NBob Picco <bob.picco@oracle.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kasan shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt.  However,
since that no longer zeroes the mapped pages, it is not suitable for
kasan, which requires zeroed shadow memory.

Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate().  Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.

Link: http://lkml.kernel.org/r/20171103185147.2688-3-pasha.tatashin@oracle.comSigned-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The kasan shadow is currently mapped using vmemmap_populate() since that
provides a semi-convenient way to map pages into init_top_pgt.  However,
since that no longer zeroes the mapped pages, it is not suitable for
kasan, which requires zeroed shadow memory.

Add kasan_populate_shadow() interface and use it instead of
vmemmap_populate().  Besides, this allows us to take advantage of
gigantic pages and use them to populate the shadow, which should save us
some memory wasted on page tables and reduce TLB pressure.

Link: http://lkml.kernel.org/r/20171103185147.2688-2-pasha.tatashin@oracle.comSigned-off-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Picco <bob.picco@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove duplicating code by using common functions vmemmap_pud_populate
and vmemmap_pgd_populate.

Link: http://lkml.kernel.org/r/20171013173214.27300-5-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: NSteven Sistare <steven.sistare@oracle.com>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: NBob Picco <bob.picco@oracle.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().

With deferred struct page feature enabled there is a case where we set
some fields prior to initializing:

mem_init() {
     register_page_bootmem_info();
     free_all_bootmem();
     ...
}

When register_page_bootmem_info() is called only non-deferred struct
pages are initialized.  But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.

mem_init
register_page_bootmem_info
register_page_bootmem_info_node
 get_page_bootmem
  .. setting fields here ..
  such as: page->freelist = (void *)type;

free_all_bootmem()
free_low_memory_core_early()
 for_each_reserved_mem_region()
  reserve_bootmem_region()
   init_reserved_page() <- Only if this is deferred reserved page
    __init_single_pfn()
     __init_single_page()
      memset(0) <-- Loose the set fields here

We end up with similar issue as in the previous patch, where currently
we do not observe problem as memory is zeroed.  But, if flag asserts are
changed we can start hitting issues.

Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.

The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.

Link: http://lkml.kernel.org/r/20171013173214.27300-4-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: NSteven Sistare <steven.sistare@oracle.com>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: NBob Picco <bob.picco@oracle.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().

With deferred struct page feature enabled, however, we set fields in
register_page_bootmem_info that are subsequently clobbered right after
in free_all_bootmem:

        mem_init() {
                register_page_bootmem_info();
                free_all_bootmem();
                ...
        }

When register_page_bootmem_info() is called only non-deferred struct
pages are initialized.  But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.

  mem_init
   register_page_bootmem_info
    register_page_bootmem_info_node
     get_page_bootmem
      .. setting fields here ..
      such as: page->freelist = (void *)type;

  free_all_bootmem()
   free_low_memory_core_early()
    for_each_reserved_mem_region()
     reserve_bootmem_region()
      init_reserved_page() <- Only if this is deferred reserved page
       __init_single_pfn()
        __init_single_page()
            memset(0) <-- Loose the set fields here

We end up with issue where, currently we do not observe problem as
memory is explicitly zeroed.  But, if flag asserts are changed we can
start hitting issues.

Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.

The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.

Link: http://lkml.kernel.org/r/20171013173214.27300-3-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: NSteven Sistare <steven.sistare@oracle.com>
Reviewed-by: NDaniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: NBob Picco <bob.picco@oracle.com>
Tested-by: NBob Picco <bob.picco@oracle.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix up makefiles, remove references, and git rm kmemcheck.

Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now that kmemcheck is gone, we don't need the NOTRACK flags.

Link: http://lkml.kernel.org/r/20171007030159.22241-5-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Convert all allocations that used a NOTRACK flag to stop using it.

Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "kmemcheck: kill kmemcheck", v2.

As discussed at LSF/MM, kill kmemcheck.

KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow).  KASan is already upstream.

We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).

The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.

Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.

This patch (of 4):

Remove kmemcheck annotations, and calls to kmemcheck from the kernel.

[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
  Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.comSigned-off-by: NSasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>