There is some reason to believe that Documentation/memory-barriers.txt
could use some help, and a major purpose of this patch is to provide
that help in the form of a design-time tool that can produce all valid
executions of a small fragment of concurrent Linux-kernel code, which is
called a "litmus test".  This tool's functionality is roughly similar to
a full state-space search.  Please note that this is a design-time tool,
not useful for regression testing.  However, we hope that the underlying
Linux-kernel memory model will be incorporated into other tools capable
of analyzing large bodies of code for regression-testing purposes.

The main tool is herd7, together with the linux-kernel.bell,
linux-kernel.cat, linux-kernel.cfg, linux-kernel.def, and lock.cat files
added by this patch.  The herd7 executable takes the other files as input,
and all of these files collectively define the Linux-kernel memory memory
model.  A brief description of each of these other files is provided
in the README file.  Although this tool does have its limitations,
which are documented in the README file, it does improve on the version
reported on in the LWN series (https://lwn.net/Articles/718628/ and
https://lwn.net/Articles/720550/) by supporting locking and arithmetic,
including a much wider variety of read-modify-write atomic operations.
Please note that herd7 is not part of this submission, but is freely
available from http://diy.inria.fr/sources/index.html (and via "git"
at https://github.com/herd/herdtools7).

A second tool is klitmus7, which converts litmus tests to loadable
kernel modules for direct testing.  As with herd7, the klitmus7
code is freely available from http://diy.inria.fr/sources/index.html
(and via "git" at https://github.com/herd/herdtools7).

Of course, litmus tests are not always the best way to fully understand a
memory model, so this patch also includes Documentation/explanation.txt,
which describes the memory model in detail.  In addition,
Documentation/recipes.txt provides example known-good and known-bad use
cases for those who prefer working by example.

This patch also includes a few sample litmus tests, and a great many
more litmus tests are available at https://github.com/paulmckrcu/litmus.

This patch was the result of a most excellent collaboration founded
by Jade Alglave and also including Alan Stern, Andrea Parri, and Luc
Maranget.  For more details on the history of this collaboration, please
refer to the Linux-kernel memory model presentations at 2016 LinuxCon EU,
2016 Kernel Summit, 2016 Linux Plumbers Conference, 2017 linux.conf.au,
or 2017 Linux Plumbers Conference microconference.  However, one aspect
of the history does bear repeating due to weak copyright tracking earlier
in this project, which extends back to early 2015.  This weakness came
to light in late 2017 after an LKMM presentation by Paul in which an
audience member noted the similarity of some LKMM code to code in early
published papers.  This prompted a copyright review.

From Alan Stern:

	To say that the model was mine is not entirely accurate.
	Pieces of it (especially the Scpv and Atomic axioms) were taken
	directly from Jade's models.  And of course the Happens-before
	and Propagation relations and axioms were heavily based on
	Jade and Luc's work, even though they weren't identical to the
	earlier versions.  Only the RCU portion was completely original.

	. . .

	One can make a much better case that I wrote the bulk of lock.cat.
	However, it was inspired by Luc's earlier version (and still
	shares some elements in common), and of course it benefited from
	feedback and testing from all members of our group.

The model prior to Alan's was Luc Maranget's.  From Luc:

	 I totally agree on Alan Stern's account of the linux kernel model
	 genesis.  I thank him for his acknowledgments of my participation
	 to previous model drafts.  I'd like to complete Alan Stern's
	 statement: any bell cat code I have written has its roots in
	 discussions with Jade Alglave and Paul McKenney. Moreover I
	 have borrowed cat and bell code written by Jade Alglave freely.

This copyright review therefore resulted in late adds to the copyright
statements of several files.

Discussion of v1 has raised several issues, which we do not believe should
block acceptance given that this level of change will be ongoing, just
as it has been with memory-barriers.txt:

o	Under what conditions should ordering provided by pure locking
	be seen by CPUs not holding the relevant lock(s)?  In particular,
	should the message-passing pattern be forbidden?

o	Should examples involving C11 release sequences be forbidden?
	Note that this C11 is still a moving target for this issue:
	http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0735r0.html

o	Some details of the handling of internal dependencies for atomic
	read-modify-write atomic operations are still subject to debate.

o	Changes recently accepted into mainline greatly reduce the need
	to handle DEC Alpha as a special case.  These changes add an
	smp_read_barrier_depends() to READ_ONCE(), thus causing Alpha
	to respect ordering of dependent reads.  If these changes stick,
	the memory model can be simplified accordingly.

o	Will changes be required to accommodate RISC-V?

Differences from v1:
	(http://lkml.kernel.org/r/20171113184031.GA26302@linux.vnet.ibm.com)

o	Add SPDX notations to .bell and .cat files, replacing
	textual license statements.

o	Add reference to upcoming ASPLOS paper to .bell and .cat files.

o	Updated identifier names in .bell and .cat files to match those
	used in the ASPLOS paper.

o	Updates to READMEs and other documentation based on review
	feedback.

o	Added a memory-ordering cheatsheet.

o	Update sigs to new Co-Developed-by and add acks and
	reviewed-bys.

o	Simplify rules detecting nested RCU read-side critical sections.

o	Update copyright statements as noted above.
Co-Developed-by: Alan Stern <stern@rowland.harvard.edu>
Co-Developed-by: Andrea Parri <parri.andrea@gmail.com>
Co-Developed-by: Jade Alglave <j.alglave@ucl.ac.uk>
Co-Developed-by: Luc Maranget <luc.maranget@inria.fr>
Co-Developed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Jade Alglave <j.alglave@ucl.ac.uk>
Signed-off-by: Luc Maranget <luc.maranget@inria.fr>
Signed-off-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: "Reshetova, Elena" <elena.reshetova@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Akira Yokosawa <akiyks@gmail.com>
Cc: <linux-arch@vger.kernel.org>

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
  ...

The generated assembler for the C fill RSB inline asm operations has
several issues:

- The C code sets up the loop register, which is then immediately
  overwritten in __FILL_RETURN_BUFFER with the same value again.

- The C code also passes in the iteration count in another register, which
  is not used at all.

Remove these two unnecessary operations. Just rely on the single constant
passed to the macro for the iterations.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: dave.hansen@intel.com
Cc: gregkh@linuxfoundation.org
Cc: torvalds@linux-foundation.org
Cc: arjan@linux.intel.com
Link: https://lkml.kernel.org/r/20180117225328.15414-1-andi@firstfloor.org

In section <2. Runtime Cost>, fix wrong index.
Signed-off-by: zhenwei.pi <zhenwei.pi@youruncloud.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@linux.intel.com
Link: https://lkml.kernel.org/r/1516237492-27739-1-git-send-email-zhenwei.pi@youruncloud.com

Since indirect jump instructions will be replaced by jump
to __x86_indirect_thunk_*, those jmp instruction must be
treated as an indirect jump. Since optprobe prohibits to
optimize probes in the function which uses an indirect jump,
it also needs to find out the function which jump to
__x86_indirect_thunk_* and disable optimization.

Add a check that the jump target address is between the
__indirect_thunk_start/end when optimizing kprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/151629212062.10241.6991266100233002273.stgit@devbox

Mark __x86_indirect_thunk_* functions as blacklist for kprobes
because those functions can be called from anywhere in the kernel
including blacklist functions of kprobes.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/151629209111.10241.5444852823378068683.stgit@devbox

Introduce start/end markers of __x86_indirect_thunk_* functions.
To make it easy, consolidate .text.__x86.indirect_thunk.* sections
to one .text.__x86.indirect_thunk section and put it in the
end of kernel text section and adds __indirect_thunk_start/end
so that other subsystem (e.g. kprobes) can identify it.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/151629206178.10241.6828804696410044771.stgit@devbox

The machine check idtentry uses an indirect branch directly from the low
level code. This evades the speculation protection.

Replace it by a direct call into C code and issue the indirect call there
so the compiler can apply the proper speculation protection.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Niced-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801181626290.1847@nanos

Stefan Wahren reports a problem with a warning fix that was merged
for v4.15: we had lots of device nodes with a 'phys' property pointing
to a device node that is not compliant with the binding documented in
Documentation/devicetree/bindings/phy/phy-bindings.txt

This generally works because USB HCD drivers that support both the generic
phy subsystem and the older usb-phy subsystem ignore most errors from
phy_get() and related calls and then use the usb-phy driver instead.

However, it turns out that making the usb-nop-xceiv device compatible with
the generic-phy binding changes the phy_get() return code from -EINVAL to
-EPROBE_DEFER, and the dwc2 usb controller driver for bcm2835 now returns
-EPROBE_DEFER from its probe function rather than ignoring the failure,
breaking all USB support on raspberry-pi when CONFIG_GENERIC_PHY is
enabled. The same code is used in the dwc3 driver and the usb_add_hcd()
function, so a reasonable assumption would be that many other platforms
are affected as well.

I have reviewed all the related patches and concluded that "usb-nop-xceiv"
is the only USB phy that is affected by the change, and since it is by far
the most commonly referenced phy, all the other USB phy drivers appear
to be used in ways that are are either safe in DT (they don't use the
'phys' property), or in the driver (they already ignore -EPROBE_DEFER
from generic-phy when usb-phy is available).

To work around the problem, this adds a special case to _of_phy_get()
so we ignore any PHY node that is compatible with "usb-nop-xceiv",
as we know that this can never load no matter how much we defer. In the
future, we might implement a generic-phy driver for "usb-nop-xceiv"
and then remove this workaround.

Since we generally want older kernels to also want to work with the
fixed devicetree files, it would be good to backport the patch into
stable kernels as well (3.13+ are possibly affected), even though they
don't contain any of the patches that may have caused regressions.

Fixes: 014d6da6 ARM: dts: bcm283x: Fix DTC warnings about missing phy-cells
Fixes: c5bbf358 arm: dts: nspire: Add missing #phy-cells to usb-nop-xceiv
Fixes: 44e5dced arm: dts: marvell: Add missing #phy-cells to usb-nop-xceiv
Fixes: f568f6f5 ARM: dts: omap: Add missing #phy-cells to usb-nop-xceiv
Fixes: d745d5f2 ARM: dts: imx51-zii-rdu1: Add missing #phy-cells to usb-nop-xceiv
Fixes: 915fbe59 ARM: dts: imx: Add missing #phy-cells to usb-nop-xceiv
Link: https://marc.info/?l=linux-usb&m=151518314314753&w=2
Link: https://patchwork.kernel.org/patch/10158145/
Cc: stable@vger.kernel.org
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Rob Herring <robh@kernel.org>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The DRM driver most notably, but also out of tree drivers (for now) like
the VPU or GPU drivers, are quite big consumers of large, contiguous memory
buffers. However, the sunxi_defconfig doesn't enable CMA in order to
mitigate that, which makes them almost unusable.

Enable it to make sure it somewhat works.

Cc: <stable@vger.kernel.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>