btrfs_balance_delayed_items is the sole caller of
btrfs_wq_run_delayed_node and already includes one of the checks whether
the delayed inodes should be run. On the other hand
btrfs_wq_run_delayed_node duplicates that check and performs an
additional one for wq congestion.

Let's remove the duplicate check and move the congestion one in
btrfs_balance_delayed_items, leaving btrfs_wq_run_delayed_node to only
care about setting up the wq run. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Currently btrfs_async_run_delayed_root's implementation uses 3 goto
labels to mimic the functionality of a simple do {} while loop. Refactor
the function to use a do {} while construct, making intention clear and
code easier to follow. No functional changes.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

The following callpath is always invoked with mirror_num set to 0, so
let's remove it as an argument and directly pass 0 to __do_redpage. No
functional change.

extent_readpages
  __extent_readpages
    __do_contiguous_readpages
      __do_readpage
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

It's sole callsite was removed in a previous patch so just nuke it for good.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

As per atomic_t.txt documentation :
 - RMW operations that have a return value are fully ordered;

atomic_xchg is one such operation so it already includes everything it
needs w.r.t memory ordering and add a comment to be more explicit about
that.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit addc3fa7 ("Btrfs: Fix the problem that the dirty flag of dev
stats is cleared") reworked the way device stats changes are tracked. A
new atomic dev_stats_ccnt counter was introduced which is incremented
every time any of the device stats counters are changed. This serves as
a flag whether there are any pending stats changes. However, this patch
only partially implemented the correct memory barriers necessary:

- It only ordered the stores to the counters but not the reads e.g.
  btrfs_run_dev_stats
- It completely omitted any comments documenting the intended design and
  how the memory barriers pair with each-other

This patch provides the necessary comments as well as adds a missing
smp_rmb in btrfs_run_dev_stats. Furthermore since dev_stats_cnt is only
a snapshot at best there was no point in reading the counter twice -
once in btrfs_dev_stats_dirty and then again when assigning stats_cnt.
Just collapse both reads into 1.

Fixes: addc3fa7 ("Btrfs: Fix the problem that the dirty flag of dev stats is cleared")
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

btrfs_end_bio() is using btrfs_dev_stat_inc() and then
btrfs_dev_stat_print_on_error() separately instead use
btrfs_dev_stat_inc_and_print() directly.

As of now there isn't any bio in btrfs which is - a non-empty write and
also the REQ_PREFLUSH flag is set. So in actual the condition

   if (bio->bi_opf & REQ_PREFLUSH)

is never true in btrfs_end_bio(), and so there won't be any redundant
error log by using btrfs_dev_stat_inc_and_print() separately one for
write and another for flush.

This consolidation will help to add the device critical error handles in
the function btrfs_dev_stat_inc_and_print() and which can be renamed as
needed.
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

It's pointless to defer it to a kthread helper as we're not under a
special context.

For reference, commit 1f78160c ("Btrfs: using rcu lock in the reader
side of devices list") introduced RCU freeing for device structures.

Originally the blkdev_put was called from free_device and rcu_barrier had
to be called. This is no longer required, bdev and our device structures
are now freed separately.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>

In functions like btrfs_create(), we run both
btrfs_balance_delayed_items() and btrfs_btree_balance_dirty() after
the operation, but btrfs_btree_balance_dirty() is surely going to run
btrfs_balance_delayed_items().

This keeps only btrfs_btree_balance_dirty().
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

Pull x86 pti fixes from Thomas Gleixner:
 "A small set of fixes for the meltdown/spectre mitigations:

   - Make kprobes aware of retpolines to prevent probes in the retpoline
     thunks.

   - Make the machine check exception speculation protected. MCE used to
     issue an indirect call directly from the ASM entry code. Convert
     that to a direct call into a C-function and issue the indirect call
     from there so the compiler can add the retpoline protection,

   - Make the vmexit_fill_RSB() assembly less stupid

   - Fix a typo in the PTI documentation"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/retpoline: Optimize inline assembler for vmexit_fill_RSB
  x86/pti: Document fix wrong index
  kprobes/x86: Disable optimizing on the function jumps to indirect thunk
  kprobes/x86: Blacklist indirect thunk functions for kprobes
  retpoline: Introduce start/end markers of indirect thunk
  x86/mce: Make machine check speculation protected

Pull x86 kexec fix from Thomas Gleixner:
 "A single fix for the WBINVD issue introduced by the SME support which
  causes kexec fails on non AMD/SME capable CPUs. Issue WBINVD only when
  the CPU has SME and avoid doing so in a loop"

[ Side note: this patch fixes the problem, but it isn't entirely clear
  why it is required. The wbinvd should just work regardless, but there
  seems to be some system - as opposed to CPU - issue, since the wbinvd
  causes more problems later in the shutdown sequence, but wbinvd
  instructions while the system is still active are not problematic.

  Possibly some SMI or pending machine check issue on the affected system ]

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Rework wbinvd, hlt operation in stop_this_cpu()

Pull irq fix from Thomas Gleixner:
 "A single fix for the new matrix allocator to prevent vector exhaustion
  by certain network drivers which allocate gazillions of unused vectors
  which cannot be put into reservation mode due to MSI and the lack of
  MSI entry masking.

  The fix/workaround is to spread the vectors across CPUs by searching
  the supplied target CPU mask for the CPU with the smallest number of
  allocated vectors"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irq/matrix: Spread interrupts on allocation

Pull alpha fixes from Matt Turner:
 "A build fix and a regression fix"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha:
  alpha/PCI: Fix noname IRQ level detection
  alpha: extend memset16 to EV6 optimised routines

Commit bacf6b49 ("x86/mm: Use a struct to reduce parameters for SME
PGD mapping") moved some parameters into a structure.

The structure was large enough to trigger the stack protection canary in
sme_encrypt_kernel which doesn't work this early, causing reboots.

Mark sme_encrypt_kernel appropriately to not use the canary.

Fixes: bacf6b49 ("x86/mm: Use a struct to reduce parameters for SME PGD mapping")
Signed-off-by: Laura Abbott <labbott@redhat.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The conversion of the alpha architecture PCI host bridge legacy IRQ
mapping/swizzling to the new PCI host bridge map/swizzle hooks carried
out through:

commit 0e4c2eeb ("alpha/PCI: Replace pci_fixup_irqs() call with
host bridge IRQ mapping hooks")

implies that IRQ for devices are now allocated through pci_assign_irq()
function in pci_device_probe() that is called when a driver matching a
device is found in order to probe the device through the device driver.

Alpha noname platforms required IRQ level programming to be executed
in sio_fixup_irq_levels(), that is called in noname_init_pci(), a
platform hook called within a subsys_initcall.

In noname_init_pci(), present IRQs are detected through
sio_collect_irq_levels() that check the struct pci_dev->irq number
to detect if an IRQ has been allocated for the device.

By the time sio_collect_irq_levels() is called, some devices may still
have not a matching driver loaded to match them (eg loadable module)
therefore their IRQ allocation is still pending - which means that
sio_collect_irq_levels() does not programme the correct IRQ level for
those devices, causing their IRQ handling to be broken when the device
driver is actually loaded and the device is probed.

Fix the issue by adding code in the noname map_irq() function
(noname_map_irq()) that, whilst mapping/swizzling the IRQ line, it also
ensures that the correct IRQ level programming is executed at platform
level, fixing the issue.

Fixes: 0e4c2eeb ("alpha/PCI: Replace pci_fixup_irqs() call with
host bridge IRQ mapping hooks")
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org # 4.14
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Meelis Roos <mroos@linux.ee>
Signed-off-by: Matt Turner <mattst88@gmail.com>

Pull KVM fixes from Radim Krčmář:
 "ARM:
   - fix incorrect huge page mappings on systems using the contiguous
     hint for hugetlbfs
   - support alternative GICv4 init sequence
   - correctly implement the ARM SMCC for HVC and SMC handling

  PPC:
   - add KVM IOCTL for reporting vulnerability and workaround status

  s390:
   - provide userspace interface for branch prediction changes in
     firmware

  x86:
   - use correct macros for bits"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: s390: wire up bpb feature
  KVM: PPC: Book3S: Provide information about hardware/firmware CVE workarounds
  KVM/x86: Fix wrong macro references of X86_CR0_PG_BIT and X86_CR4_PAE_BIT in kvm_valid_sregs()
  arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls
  KVM: arm64: Fix GICv4 init when called from vgic_its_create
  KVM: arm/arm64: Check pagesize when allocating a hugepage at Stage 2

Pull MIPS fixes from James Hogan:
 "Some final MIPS fixes for 4.15, including important build fixes and a
  MAINTAINERS update:

   - Add myself as MIPS co-maintainer.

   - Fix various all*config build failures (particularly as a result of
     switching the default MIPS platform to the "generic" platform).

   - Fix GCC7 build failures (duplicate const and questionable calls to
     missing __multi3 intrinsic on mips64r6).

   - Fix warnings when CPU Idle is enabled (4.14).

   - Fix AR7 serial output (since 3.17).

   - Fix ralink platform_get_irq error checking (since 3.12)"

* tag 'mips_fixes_4.15_2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips:
  MAINTAINERS: Add James as MIPS co-maintainer
  MIPS: Fix undefined reference to physical_memsize
  MIPS: Implement __multi3 for GCC7 MIPS64r6 builds
  MIPS: mm: Fix duplicate "const" on insn_table_MM
  MIPS: CM: Drop WARN_ON(vp != 0)
  MIPS: ralink: Fix platform_get_irq's error checking
  MIPS: Fix CPS SMP NS16550 UART defaults
  MIPS: BCM47XX Avoid compile error with MIPS allnoconfig
  MIPS: RB532: Avoid undefined mac_pton without GENERIC_NET_UTILS
  MIPS: RB532: Avoid undefined early_serial_setup() without SERIAL_8250_CONSOLE
  MIPS: ath25: Avoid undefined early_serial_setup() without SERIAL_8250_CONSOLE
  MIPS: AR7: ensure the port type's FCR value is used

The new firmware interfaces for branch prediction behaviour changes
are transparently available for the guest. Nevertheless, there is
new state attached that should be migrated and properly resetted.
Provide a mechanism for handling reset, migration and VSIE.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
[Changed capability number to 152. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>

Add PPC KVM ioctl to report vulnerability and workaround status to userspace.

Pull SCSI fix from James Bottomley:
 "One fix for SAS attached SATA CD-ROMs. It turns out that the libata
  handling of CD devices relies on the SCSI error handler, so disable
  async aborts (which don't start the error handler) for these devices"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: libsas: Disable asynchronous aborts for SATA devices

Merge tag 'for-4.15/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "All fixes marked for stable:

   - Fix DM thinp btree corruption seen when inserting a new key/value
     pair into a full root node.

   - Fix DM thinp btree removal deadlock due to artificially low number
     of allowed concurrent locks allowed.

   - Fix possible DM crypt corruption if kernel keyring service is used.
     Only affects ciphers using following IVs: essiv, lmk and tcw.

   - Two DM crypt device initialization error checking fixes.

   - Fix DM integrity to allow use of async ciphers that require DMA"

* tag 'for-4.15/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: fix error return code in crypt_ctr()
  dm crypt: wipe kernel key copy after IV initialization
  dm integrity: don't store cipher request on the stack
  dm crypt: fix crash by adding missing check for auth key size
  dm btree: fix serious bug in btree_split_beneath()
  dm thin metadata: THIN_MAX_CONCURRENT_LOCKS should be 6

Pull tracing fixes from Steven Rostedt:
 "Two more small fixes

   - The conversion of enums into their actual numbers to display in the
     event format file had an off-by-one bug, that could cause an enum
     not to be converted, and break user space parsing tools.

   - A fix to a previous fix to bring back the context recursion checks.
     The interrupt case checks for NMI, IRQ and softirq, but the softirq
     returned the same number regardless if it was set or not, although
     the logic would force it to be set if it were hit"

* tag 'trace-v4.15-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix converting enum's from the map in trace_event_eval_update()
  ring-buffer: Fix duplicate results in mapping context to bits in recursive lock

Pull input fixes from Dmitry Torokhov:

 - a fix for use-after-free in Synaptics RMI4 driver

 - correction to multitouch contact tracking on certain ALPS touchpads
   (which got broken when we tried to fix the 2-finger scrolling)

 - touchpad on Lenovo T640p is switched over to SMbus/RMI

 - a few device node refcount fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: synaptics-rmi4 - prevent UAF reported by KASAN
  Input: ALPS - fix multi-touch decoding on SS4 plus touchpads
  Input: synaptics - Lenovo Thinkpad T460p devices should use RMI
  Input: of_touchscreen - add MODULE_LICENSE
  Input: 88pm860x-ts - fix child-node lookup
  Input: twl6040-vibra - fix child-node lookup
  Input: twl4030-vibra - fix sibling-node lookup

Pull i2c fixes from Wolfram Sang:
 "Two bugfixes for the I2C core: Lixing Wang fixed a refcounting problem
  with DT nodes. Jeremy Compostella fixed a buffer overflow possibility
  when using a 'don't use' ioctl interface directly"

* 'i2c/for-current-fixed' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core-smbus: prevent stack corruption on read I2C_BLOCK_DATA
  i2c: core: decrease reference count of device node in i2c_unregister_device

Pull libata fixlet from Tejun Heo:
 "This just adds one more entry for liteon optical drives to the device
  blacklist for large IOs.

  The change is very low risk"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  libata: apply MAX_SEC_1024 to all LITEON EP1 series devices

Pull cgroup fix from Tejun Heo:
 "cgroup.threads should be delegatable (ie. a container should be able
  to write to it from inside) but was missing the flag.

  The change is very low risk"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: make cgroup.threads delegatable

Pull workqueue fixlet from Tejun Heo:
 "One patch to add touch_nmi_watchdog() while dumping workqueue debug
  messages to avoid triggering the lockup detector spuriously.

  The change is very low risk"

* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: avoid hard lockups in show_workqueue_state()

Pull ARM SoC fixes from Arnd Bergmann:
 "We have various small DT fixes, and one important regression fix:

  The recent device tree bugfixes that were intended to address issues
  that 'dtc' started warning about in 4.15 fixed various USB PHY device
  nodes, but it turns out that we had code that depended on those nodes
  being incorrect and the probe failing with a particular error code.
  With the workaround we can also deal with correct device nodes.

  The DT fixes include:

   - Allwinner A10 and A20 had the display pipeline set up incorrectly
     (introduced in v4.15)

   - The Altera PMU lacked an interrupt-parent (never worked)

   - Pin muxing on the Openblocks A7 (never worked)

   - Clocks might get set up wrong on Armada 7K/8K (4.15 regression)

  We now have additional device tree patches to address all the
  remaining warnings introduced in 4.15, but decided to queue them for
  4.16 instead, to avoid risking another regression like the USB PHY
  thing mentioned above.

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  phy: work around 'phys' references to usb-nop-xceiv devices
  ARM: sunxi_defconfig: Enable CMA
  arm64: dts: socfpga: add missing interrupt-parent
  ARM: dts: sun[47]i: Fix display backend 1 output to TCON0 remote endpoint
  ARM64: dts: marvell: armada-cp110: Fix clock resources for various node
  ARM: dts: da850-lcdk: Remove leading 0x and 0s from unit address
  ARM: dts: kirkwood: fix pin-muxing of MPP7 on OpenBlocks A7

Pull powerpc fixes from Michael Ellerman:
 "More than we'd like after rc8, but nothing very alarming either, just
  tying up loose ends before the release:

  Since we changed powernv to use cpufreq_get() from show_cpuinfo(), we
  see warnings with PREEMPT enabled. But the preempt_disable() in
  show_cpuinfo() doesn't actually prevent CPU hotplug as it suggests, so
  remove it.

  Two updates to the recently merged RFI flush code. Wire up the generic
  sysfs file to report the status, and add a debugfs file to allow
  enabling/disabling it at runtime.

  Two updates to xmon, one to add the RFI flush related fields to the
  paca dump, and another to not use hashed pointers in the paca dump.

  And one minor fix to add a missing include of linux/types.h in
  asm/hvcall.h, not seen to break the build in upstream, but correct
  anyway.

  Thanks to: Benjamin Herrenschmidt, Michal Suchanek, Nicholas Piggin"

* tag 'powerpc-4.15-8' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/pseries: include linux/types.h in asm/hvcall.h
  powerpc/64s: Allow control of RFI flush via debugfs
  powerpc/64s: Wire up cpu_show_meltdown()
  powerpc: Don't preempt_disable() in show_cpuinfo()
  powerpc/xmon: Don't print hashed pointers in paca dump
  powerpc/xmon: Add RFI flush related fields to paca dump

Pull drm fixes from Dave Airlie:
 "Nouveau, i915, vmwgfx and sun4i regression fixes.

  The i915 change fixes a display corruption problem introduced in 4.15,
  the nouveau changes are for regressions in 4.15, one of the vmwgfx
  fixes goes back a little further, the other is a 4.15 regression fix,
  the 3 sun4i changes fix blank HDMI output on those devices"

* tag 'drm-fixes-for-v4.15-rc9' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau/mmu/mcp77: fix regressions in stolen memory handling
  drm/nouveau/bar/gk20a: Avoid bar teardown during init
  drm/nouveau/drm/nouveau: Pass the proper arguments to nvif_object_map_handle()
  drm/vmwgfx: fix memory corruption with legacy/sou connectors
  drm/vmwgfx: Fix a boot time warning
  drm/i915: Fix deadlock in i830_disable_pipe()
  drm/i915: Redo plane sanitation during readout
  drm/i915: Add .get_hw_state() method for planes
  drm/sun4i: hdmi: Add missing rate halving check in sun4i_tmds_determine_rate
  drm/sun4i: hdmi: Fix incorrect assignment in sun4i_tmds_determine_rate
  drm/sun4i: hdmi: Check for unset best_parent in sun4i_tmds_determine_rate

Merge misc fixes from Andrew Morton:
 "6 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  sparse doesn't support struct randomization
  proc: fix coredump vs read /proc/*/stat race
  scripts/gdb/linux/tasks.py: fix get_thread_info
  scripts/decodecode: fix decoding for AArch64 (arm64) instructions
  mm/page_owner.c: remove drain_all_pages from init_early_allocated_pages
  mm/memory.c: release locked page in do_swap_page()

Force __builtin_constant_p to evaluate whether the argument to atomic_add
& atomic_sub is constant in the front-end before optimisations which
can lead GCC to output a call to __bad_increment_for_ia64_fetch_and_add().

See GCC bugzilla 83653.
Signed-off-by: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Without this patch, I drown in a sea of unknown attribute warnings

Link: http://lkml.kernel.org/r/20180117024539.27354-1-willy@infradead.orgSigned-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

do_task_stat() accesses IP and SP of a task without bumping reference
count of a stack (which became an entity with independent lifetime at
some point).

Steps to reproduce:

    #include <stdio.h>
    #include <sys/types.h>
    #include <sys/stat.h>
    #include <fcntl.h>
    #include <sys/time.h>
    #include <sys/resource.h>
    #include <unistd.h>
    #include <sys/wait.h>

    int main(void)
    {
    	setrlimit(RLIMIT_CORE, &(struct rlimit){});

    	while (1) {
    		char buf[64];
    		char buf2[4096];
    		pid_t pid;
    		int fd;

    		pid = fork();
    		if (pid == 0) {
    			*(volatile int *)0 = 0;
    		}

    		snprintf(buf, sizeof(buf), "/proc/%u/stat", pid);
    		fd = open(buf, O_RDONLY);
    		read(fd, buf2, sizeof(buf2));
    		close(fd);

    		waitpid(pid, NULL, 0);
    	}
    	return 0;
    }

    BUG: unable to handle kernel paging request at 0000000000003fd8
    IP: do_task_stat+0x8b4/0xaf0
    PGD 800000003d73e067 P4D 800000003d73e067 PUD 3d558067 PMD 0
    Oops: 0000 [#1] PREEMPT SMP PTI
    CPU: 0 PID: 1417 Comm: a.out Not tainted 4.15.0-rc8-dirty #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1.fc27 04/01/2014
    RIP: 0010:do_task_stat+0x8b4/0xaf0
    Call Trace:
     proc_single_show+0x43/0x70
     seq_read+0xe6/0x3b0
     __vfs_read+0x1e/0x120
     vfs_read+0x84/0x110
     SyS_read+0x3d/0xa0
     entry_SYSCALL_64_fastpath+0x13/0x6c
    RIP: 0033:0x7f4d7928cba0
    RSP: 002b:00007ffddb245158 EFLAGS: 00000246
    Code: 03 b7 a0 01 00 00 4c 8b 4c 24 70 4c 8b 44 24 78 4c 89 74 24 18 e9 91 f9 ff ff f6 45 4d 02 0f 84 fd f7 ff ff 48 8b 45 40 48 89 ef <48> 8b 80 d8 3f 00 00 48 89 44 24 20 e8 9b 97 eb ff 48 89 44 24
    RIP: do_task_stat+0x8b4/0xaf0 RSP: ffffc90000607cc8
    CR2: 0000000000003fd8

John Ogness said: for my tests I added an else case to verify that the
race is hit and correctly mitigated.

Link: http://lkml.kernel.org/r/20180116175054.GA11513@avx2Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: "Kohli, Gaurav" <gkohli@codeaurora.org>
Tested-by: John Ogness <john.ogness@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@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>

Since kernel 4.9, the thread_info has been moved into task_struct, no
longer locates at the bottom of kernel stack.

See commits c65eacbe ("sched/core: Allow putting thread_info into
task_struct") and 15f4eae7 ("x86: Move thread_info into
task_struct").

Before fix:
  (gdb) set $current = $lx_current()
  (gdb) p $lx_thread_info($current)
  $1 = {flags = 1470918301}
  (gdb) p $current.thread_info
  $2 = {flags = 2147483648}

After fix:
  (gdb) p $lx_thread_info($current)
  $1 = {flags = 2147483648}
  (gdb) p $current.thread_info
  $2 = {flags = 2147483648}

Link: http://lkml.kernel.org/r/20180118210159.17223-1-imxikangjie@gmail.com
Fixes: 15f4eae7 ("x86: Move thread_info into task_struct")
Signed-off-by: Xi Kangjie <imxikangjie@gmail.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Kieran Bingham <kbingham@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There are a couple of problems with the decodecode script and arm64:

1. AArch64 objdump refuses to disassemble .4byte directives as instructions,
   insisting that they are data values and displaying them as:

	a94153f3	.word	0xa94153f3		<-- trapping instruction

   This is resolved by using the .inst directive instead.

2. Disassembly of branch instructions attempts to provide the target as
   an offset from a symbol, e.g.:

   0:	34000082	cbz	w2, 10 <.text+0x10>

  however this falls foul of the grep -v, which matches lines containing
  ".text" and ends up removing all branch instructions from the dump.

This patch resolves both issues by using the .inst directive for 4-byte
quantities on arm64 and stripping the resulting binaries (as is done on
arm already) to remove the mapping symbols.

Link: http://lkml.kernel.org/r/1506596147-23630-1-git-send-email-will.deacon@arm.comSigned-off-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When setting page_owner = on, the following warning can be seen in the
boot log:

  WARNING: CPU: 0 PID: 0 at mm/page_alloc.c:2537 drain_all_pages+0x171/0x1a0
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc7-next-20180109-1-default+ #7
  Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.11.3 11/09/2016
  RIP: 0010:drain_all_pages+0x171/0x1a0
  Call Trace:
    init_page_owner+0x4e/0x260
    start_kernel+0x3e6/0x4a6
    ? set_init_arg+0x55/0x55
    secondary_startup_64+0xa5/0xb0
  Code: c5 ed ff 89 df 48 c7 c6 20 3b 71 82 e8 f9 4b 52 00 3b 05 d7 0b f8 00 89 c3 72 d5 5b 5d 41 5

This warning is shown because we are calling drain_all_pages() in
init_early_allocated_pages(), but mm_percpu_wq is not up yet, it is being
set up later on in kernel_init_freeable() -> init_mm_internals().

Link: http://lkml.kernel.org/r/20180109153921.GA13070@techadventures.netSigned-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ayush Mittal <ayush.m@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

James reported a bug in swap paging-in from his testing.  It is that
do_swap_page doesn't release locked page so system hang-up happens due
to a deadlock on PG_locked.

It was introduced by 0bcac06f ("mm, swap: skip swapcache for swapin
of synchronous device") because I missed swap cache hit places to update
swapcache variable to work well with other logics against swapcache in
do_swap_page.

This patch fixes it.

Debugged by James Bottomley.

Link: http://lkml.kernel.org/r/<1514407817.4169.4.camel@HansenPartnership.com>
Link: http://lkml.kernel.org/r/20180102235606.GA19438@bboxSigned-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking fixes from David Miller:

 1) Fix BPF divides by zero, from Eric Dumazet and Alexei Starovoitov.

 2) Reject stores into bpf context via st and xadd, from Daniel
    Borkmann.

 3) Fix a memory leak in TUN, from Cong Wang.

 4) Disable RX aggregation on a specific troublesome configuration of
    r8152 in a Dell TB16b dock.

 5) Fix sw_ctx leak in tls, from Sabrina Dubroca.

 6) Fix program replacement in cls_bpf, from Daniel Borkmann.

 7) Fix uninitialized station_info structures in cfg80211, from Johannes
    Berg.

 8) Fix miscalculation of transport header offset field in flow
    dissector, from Eric Dumazet.

 9) Fix LPM tree leak on failure in mlxsw driver, from Ido Schimmel.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (29 commits)
  ibmvnic: Fix IPv6 packet descriptors
  ibmvnic: Fix IP offload control buffer
  ipv6: don't let tb6_root node share routes with other node
  ip6_gre: init dev->mtu and dev->hard_header_len correctly
  mlxsw: spectrum_router: Free LPM tree upon failure
  flow_dissector: properly cap thoff field
  fm10k: mark PM functions as __maybe_unused
  cfg80211: fix station info handling bugs
  netlink: reset extack earlier in netlink_rcv_skb
  can: af_can: canfd_rcv(): replace WARN_ONCE by pr_warn_once
  can: af_can: can_rcv(): replace WARN_ONCE by pr_warn_once
  bpf: mark dst unknown on inconsistent {s, u}bounds adjustments
  bpf: fix cls_bpf on filter replace
  Net: ethernet: ti: netcp: Fix inbound ping crash if MTU size is greater than 1500
  tls: reset crypto_info when do_tls_setsockopt_tx fails
  tls: return -EBUSY if crypto_info is already set
  tls: fix sw_ctx leak
  net/tls: Only attach to sockets in ESTABLISHED state
  net: fs_enet: do not call phy_stop() in interrupts
  r8152: disable RX aggregation on Dell TB16 dock
  ...