Merge tag 'hwmon-for-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "A couple of hwmon bug fixes:

   - Update k8temp documentation URL

   - Register address fixes in nct6775 driver

   - Fix potential division by zero in occ driver"

* tag 'hwmon-for-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (k8temp) documentation: update URL of datasheet
  hwmon: (nct6775) Fix register address and added missed tolerance for nct6106
  hwmon: (occ) Fix division by zero issue

Pull power management fixes from Rafael Wysocki
 "These fix two issues related to the RAPL MMIO interface support added
  recently and one cpufreq driver issue.

  Specifics:

   - Initialize the power capping subsystem and the RAPL driver earlier
     in case the int340X thermal driver is built-in and attempts to
     register an MMIO interface for RAPL which must not happen before
     the requisite infrastructure is ready (Zhang Rui)

   - Fix the int340X thermal driver's RAPL MMIO interface registration
     error path (Rafael Wysocki)

   - Fix possible use-after-free in the pasemi cpufreq driver (Wen
     Yang)"

* tag 'pm-5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init()
  int340X/processor_thermal_device: Fix proc_thermal_rapl_remove()
  powercap: Invoke powercap_init() and rapl_init() earlier

Pull RISC-V updates from Paul Walmsley:
 "Four minor RISC-V-related changes:

   - Add support for the new clone3 syscall for RV64, relying on the
     generic support

   - Add DT data for the gigabit Ethernet controller on the SiFive FU540
     and the HiFive Unleashed board

   - Update MAINTAINERS to add me to the arch/riscv maintainers' list

   - Add support for PCIe message-signaled interrupts by reusing the
     generic header file"

* tag 'riscv/for-v5.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: dts: Add DT node for SiFive FU540 Ethernet controller driver
  riscv: include generic support for MSI irqdomains
  MAINTAINERS: Add Paul as a RISC-V maintainer
  riscv: enable sys_clone3 syscall for rv64

Pull ktest fixlets from Steven Rostedt:
 "This contains only simple spelling fixes"

* tag 'ktest-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
  ktest: Fix some typos in config-bisect.pl

The access() (and faccessat()) credentials change can cause an
unnecessary load on the RCU machinery because every access() call ends
up freeing the temporary access credential using RCU.

This isn't really noticeable on small machines, but if you have hundreds
of cores you can cause huge slowdowns due to RCU storms.

It's easy to avoid: the temporary access crededntials aren't actually
normally accessed using RCU at all, so we can avoid the whole issue by
just marking them as such.

* access-creds:
  access: avoid the RCU grace period for the temporary subjective credentials

* pm-cpufreq:
  cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init()

This patch fixes some spelling typos in config-bisect.pl

Link: http://lkml.kernel.org/r/20190723032445.14220-1-standby24x7@gmail.comAcked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.

The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.

Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.

But it turns out that all of this is entirely unnecessary.  Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all.  Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.

So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this).  We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.

Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards.  It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.

It is possible that we should just remove the whole RCU markings for
->cred entirely.  Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.

But this is a "minimal semantic changes" change for the immediate
problem.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Glauber <jglauber@marvell.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull powerpc fixes from Michael Ellerman:
 "An assortment of non-regression fixes that have accumulated since the
  start of the merge window.

   - A fix for a user triggerable oops on machines where transactional
     memory is disabled, eg. Power9 bare metal, Power8 with TM disabled
     on the command line, or all Power7 or earlier machines.

   - Three fixes for handling of PMU and power saving registers when
     running nested KVM on Power9.

   - Two fixes for bugs found while stress testing the XIVE interrupt
     controller code, also on Power9.

   - A fix to allow guests to boot under Qemu/KVM on Power9 using the
     the Hash MMU with >= 1TB of memory.

   - Two fixes for bugs in the recent DMA cleanup, one of which could
     lead to checkstops.

   - And finally three fixes for the PAPR SCM nvdimm driver.

  Thanks to: Alexey Kardashevskiy, Andrea Arcangeli, Cédric Le Goater,
  Christoph Hellwig, David Gibson, Gautham R. Shenoy, Michael Neuling,
  Oliver O'Halloran, Satheesh Rajendran, Shawn Anastasio, Suraj Jitindar
  Singh, Vaibhav Jain"

* tag 'powerpc-5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/papr_scm: Force a scm-unbind if initial scm-bind fails
  powerpc/papr_scm: Update drc_pmem_unbind() to use H_SCM_UNBIND_ALL
  powerpc/pseries: Update SCM hcall op-codes in hvcall.h
  powerpc/tm: Fix oops on sigreturn on systems without TM
  powerpc/dma: Fix invalid DMA mmap behavior
  KVM: PPC: Book3S HV: XIVE: fix rollback when kvmppc_xive_create fails
  powerpc/xive: Fix loop exit-condition in xive_find_target_in_mask()
  powerpc: fix off by one in max_zone_pfn initialization for ZONE_DMA
  KVM: PPC: Book3S HV: Save and restore guest visible PSSCR bits on pseries
  powerpc/pmu: Set pmcregs_in_use in paca when running as LPAR
  KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nesting
  powerpc/mm: Limit rma_size to 1TB when running without HV mode

Pull KVM fixes from Paolo Bonzini:
 "Bugfixes, a pvspinlock optimization, and documentation moving"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: X86: Boost queue head vCPU to mitigate lock waiter preemption
  Documentation: move Documentation/virtual to Documentation/virt
  KVM: nVMX: Set cached_vmcs12 and cached_shadow_vmcs12 NULL after free
  KVM: X86: Dynamically allocate user_fpu
  KVM: X86: Fix fpu state crash in kvm guest
  Revert "kvm: x86: Use task structs fpu field for user"
  KVM: nVMX: Clear pending KVM_REQ_GET_VMCS12_PAGES when leaving nested

Pull dma-mapping regression fix from Christoph Hellwig:
 "Ensure that dma_addressing_limited doesn't crash on devices without a
  dma mask (Eric Auger)"

* tag 'dma-mapping-5.3-2' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: use dma_get_mask in dma_addressing_limited

Commit 11752adb (locking/pvqspinlock: Implement hybrid PV queued/unfair locks)
introduces hybrid PV queued/unfair locks
 - queued mode (no starvation)
 - unfair mode (good performance on not heavily contended lock)
The lock waiter goes into the unfair mode especially in VMs with over-commit
vCPUs since increaing over-commitment increase the likehood that the queue
head vCPU may have been preempted and not actively spinning.

However, reschedule queue head vCPU timely to acquire the lock still can get
better performance than just depending on lock stealing in over-subscribe
scenario.

Testing on 80 HT 2 socket Xeon Skylake server, with 80 vCPUs VM 80GB RAM:
ebizzy -M
             vanilla     boosting    improved
 1VM          23520        25040         6%
 2VM           8000        13600        70%
 3VM           3100         5400        74%

The lock holder vCPU yields to the queue head vCPU when unlock, to boost queue
head vCPU which is involuntary preemption or the one which is voluntary halt
due to fail to acquire the lock after a short spin in the guest.

Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Renaming docs seems to be en vogue at the moment, so fix on of the
grossly misnamed directories.  We usually never use "virtual" as
a shortcut for virtualization in the kernel, but always virt,
as seen in the virt/ top-level directory.  Fix up the documentation
to match that.

Fixes: ed16648e ("Move kvm, uml, and lguest subdirectories under a common "virtual" directory, I.E:")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull parisc fixes from Helge Deller:

 - Fix build issues when kprobes are enabled

 - Speed up ITLB/DTLB cache flushes when running on machines with
   combined TLBs

* 'parisc-5.3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: Flush ITLB in flush_tlb_all_local() only on split TLB machines
  parisc: add kprobe_fault_handler()

We currently have cases where the dma_addressing_limited() gets
called with dma_mask unset. This causes a NULL pointer dereference.

Use dma_get_mask() accessor to prevent the crash.

Fixes: b8664554 ("dma-mapping: add a dma_addressing_limited helper")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The cpu variable is still being used in the of_get_property() call
after the of_node_put() call, which may result in use-after-free.

Fixes: a9acc26b ("cpufreq/pasemi: fix possible object reference leak")
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Passing 0 to cpuhp_remove_state() triggers the BUG_ON() in
__cpuhp_remove_state_cpuslocked() and the argument passed to
powercap_unregister_control_type() is expected to be a valid
pointer, so avoid calling these functions with incorrect
arguments from proc_thermal_rapl_remove().

Fixes: 555c45fe ("int340X/processor_thermal_device: add support for MMIO RAPL")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>

DT node for SiFive FU540-C000 GEMGXL Ethernet controller driver added
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Sagar Kadam <sagar.kadam@sifive.com>
Cc: Andrew Lunn <andrew@lunn.ch>
[paul.walmsley@sifive.com: changed "phy1" to "phy0" at Andrew Lunn's
 suggestion]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

Some RISC-V systems include PCIe host controllers that support PCIe
message-signaled interrupts.  For this to work on Linux, we need to
enable PCI_MSI_IRQ_DOMAIN and define struct msi_alloc_info.  Support
for the latter is enabled by including the architecture-generic msi.h
include.
Signed-off-by: Wesley Terpstra <wesley@sifive.com>
[paul.walmsley@sifive.com: split initial patch into one arch/riscv
 patch and one drivers/pci patch]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

The RISC-V port has grown significantly over the past year.  Paul's been
helping out for a while ago.  We agreed in person that he'd take over
collecting the patches and submitting the PRs, but it looks like I
forgot to make it official.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

Pull preemption Kconfig fix from Thomas Gleixner:
 "The PREEMPT_RT stub config renamed PREEMPT to PREEMPT_LL and defined
  PREEMPT outside of the menu and made it selectable by both PREEMPT_LL
  and PREEMPT_RT.

  Stupid me missed that 114 defconfigs select CONFIG_PREEMPT which
  obviously can't work anymore. oldconfig builds are affected as well,
  but it's more obvious as the user gets asked. [old]defconfig silently
  fixes it up and selects PREEMPT_NONE.

  Unbreak it by undoing the rename and adding a intermediate config
  symbol which is selected by both PREEMPT and PREEMPT_RT. That requires
  to chase down a few #ifdefs, but it's better than tweaking 114
  defconfigs and annoying users"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/rt, Kconfig: Unbreak def/oldconfig with CONFIG_PREEMPT=y

Pull pidfd polling fix from Christian Brauner:
 "A fix for pidfd polling. It ensures that the task's exit state is
  visible to all waiters"

* tag 'for-linus-20190722' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  pidfd: fix a poll race when setting exit_state

Pull btrfs fixes from David Sterba:

 - fixes for leaks caused by recently merged patches

 - one build fix

 - a fix to prevent mixing of incompatible features

* tag 'for-5.3-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: don't leak extent_map in btrfs_get_io_geometry()
  btrfs: free checksum hash on in close_ctree
  btrfs: Fix build error while LIBCRC32C is module
  btrfs: inode: Don't compress if NODATASUM or NODATACOW set

The merge of the CONFIG_PREEMPT_RT stub renamed CONFIG_PREEMPT to
CONFIG_PREEMPT_LL which causes all defconfigs which have CONFIG_PREEMPT=y
set to fall back to CONFIG_PREEMPT_NONE because CONFIG_PREEMPT depends on
the preemption mode choice wich defaults to NONE. This also affects
oldconfig builds.

So rather than changing 114 defconfig files and being an annoyance to
users, revert the rename and select a new config symbol PREEMPTION. That
keeps everything working smoothly and the revelant ifdef's are going to be
fixed up step by step.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: a50a3f4b ("sched/rt, Kconfig: Introduce CONFIG_PREEMPT_RT")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Pull media fixes from Mauro Carvalho Chehab:
 "For two regressions in media core:

   - v4l2-subdev: fix regression in check_pad()

   - videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already
     in use"

* tag 'media/v5.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: videodev2.h: change V4L2_PIX_FMT_BGRA444 define: fourcc was already in use
  media: v4l2-subdev: fix regression in check_pad()

Pull networking fixes from David Miller:

 1) Several netfilter fixes including a nfnetlink deadlock fix from
    Florian Westphal and fix for dropping VRF packets from Miaohe Lin.

 2) Flow offload fixes from Pablo Neira Ayuso including a fix to restore
    proper block sharing.

 3) Fix r8169 PHY init from Thomas Voegtle.

 4) Fix memory leak in mac80211, from Lorenzo Bianconi.

 5) Missing NULL check on object allocation in cxgb4, from Navid
    Emamdoost.

 6) Fix scaling of RX power in sfp phy driver, from Andrew Lunn.

 7) Check that there is actually an ip header to access in skb->data in
    VRF, from Peter Kosyh.

 8) Remove spurious rcu unlock in hv_netvsc, from Haiyang Zhang.

 9) One more tweak the the TCP fragmentation memory limit changes, to be
    less harmful to applications setting small SO_SNDBUF values. From
    Eric Dumazet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (40 commits)
  tcp: be more careful in tcp_fragment()
  hv_netvsc: Fix extra rcu_read_unlock in netvsc_recv_callback()
  vrf: make sure skb->data contains ip header to make routing
  connector: remove redundant input callback from cn_dev
  qed: Prefer pcie_capability_read_word()
  igc: Prefer pcie_capability_read_word()
  cxgb4: Prefer pcie_capability_read_word()
  be2net: Synchronize be_update_queues with dev_watchdog
  bnx2x: Prevent load reordering in tx completion processing
  net: phy: sfp: hwmon: Fix scaling of RX power
  net: sched: verify that q!=NULL before setting q->flags
  chelsio: Fix a typo in a function name
  allocate_flower_entry: should check for null deref
  net: hns3: typo in the name of a constant
  kbuild: add net/netfilter/nf_tables_offload.h to header-test blacklist.
  tipc: Fix a typo
  mac80211: don't warn about CW params when not using them
  mac80211: fix possible memory leak in ieee80211_assign_beacon
  nl80211: fix NL80211_HE_MAX_CAPABILITY_LEN
  nl80211: fix VENDOR_CMD_RAW_DATA
  ...

There is a race between reading task->exit_state in pidfd_poll and
writing it after do_notify_parent calls do_notify_pidfd. Expected
sequence of events is:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
  tsk->exit_state = EXIT_DEAD
                                  pidfd_poll
                                     if (tsk->exit_state)

However nothing prevents the following sequence:

CPU 0                            CPU 1
------------------------------------------------
exit_notify
  do_notify_parent
    do_notify_pidfd
                                   pidfd_poll
                                      if (tsk->exit_state)
  tsk->exit_state = EXIT_DEAD

This causes a polling task to wait forever, since poll blocks because
exit_state is 0 and the waiting task is not notified again. A stress
test continuously doing pidfd poll and process exits uncovered this bug.

To fix it, we make sure that the task's exit_state is always set before
calling do_notify_pidfd.

Fixes: b53b0b9d ("pidfd: add polling support")
Cc: kernel-team@android.com
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lore.kernel.org/r/20190717172100.261204-1-joel@joelfernandes.org
[christian@brauner.io: adapt commit message and drop unneeded changes from wait_task_zombie]
Signed-off-by: Christian Brauner <christian@brauner.io>

In some cases initial bind of scm memory for an lpar can fail if
previously it wasn't released using a scm-unbind hcall. This situation
can arise due to panic of the previous kernel or forced lpar
fadump. In such cases the H_SCM_BIND_MEM return a H_OVERLAP error.

To mitigate such cases the patch updates papr_scm_probe() to force a
call to drc_pmem_unbind() in case the initial bind of scm memory fails
with EBUSY error. In case scm-bind operation again fails after the
forced scm-unbind then we follow the existing error path. We also
update drc_pmem_bind() to handle the H_OVERLAP error returned by phyp
and indicate it as a EBUSY error back to the caller.
Suggested-by: "Oliver O'Halloran" <oohall@gmail.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-4-vaibhav@linux.ibm.com

The new hcall named H_SCM_UNBIND_ALL has been introduce that can
unbind all or specific scm memory assigned to an lpar. This is
more efficient than using H_SCM_UNBIND_MEM as currently we don't
support partial unbind of scm memory.

Hence this patch proposes following changes to drc_pmem_unbind():

    * Update drc_pmem_unbind() to replace hcall H_SCM_UNBIND_MEM to
      H_SCM_UNBIND_ALL.

    * Update drc_pmem_unbind() to handles cases when PHYP asks the guest
      kernel to wait for specific amount of time before retrying the
      hcall via the 'LONG_BUSY' return value.

    * Ensure appropriate error code is returned back from the function
      in case of an error.
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-3-vaibhav@linux.ibm.com

Update the hvcalls.h to include op-codes for new hcalls introduce to
manage SCM memory. Also update existing hcall definitions to reflect
current papr specification for SCM.

The removed hcall op-codes H_SCM_MEM_QUERY, H_SCM_BLOCK_CLEAR were
transient proposals and there support was never implemented by
Power-VM nor they were used anywhere in Linux kernel. Hence we don't
expect anyone to be impacted by this change.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190629160610.23402-2-vaibhav@linux.ibm.com

Shall help finding use-after-free bugs earlier.
Suggested-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

After reverting commit 240c35a3 (kvm: x86: Use task structs fpu field
for user), struct kvm_vcpu is 19456 bytes on my server, PAGE_ALLOC_COSTLY_ORDER(3)
is the order at which allocations are deemed costly to service. In serveless
scenario, one host can service hundreds/thoudands firecracker/kata-container
instances, howerver, new instance will fail to launch after memory is too
fragmented to allocate kvm_vcpu struct on host, this was observed in some
cloud provider product environments.

This patch dynamically allocates user_fpu, kvm_vcpu is 15168 bytes now on my
Skylake server.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The idea before commit 240c35a3 (which has just been reverted)
was that we have the following FPU states:

               userspace (QEMU)             guest
---------------------------------------------------------------------------
               processor                    vcpu->arch.guest_fpu
>>> KVM_RUN: kvm_load_guest_fpu
               vcpu->arch.user_fpu          processor
>>> preempt out
               vcpu->arch.user_fpu          current->thread.fpu
>>> preempt in
               vcpu->arch.user_fpu          processor
>>> back to userspace
>>> kvm_put_guest_fpu
               processor                    vcpu->arch.guest_fpu
---------------------------------------------------------------------------

With the new lazy model we want to get the state back to the processor
when schedule in from current->thread.fpu.
Reported-by: Thomas Lambertz <mail@thomaslambertz.de>
Reported-by: anthony <antdev66@gmail.com>
Tested-by: anthony <antdev66@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Lambertz <mail@thomaslambertz.de>
Cc: anthony <antdev66@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 5f409e20 (x86/fpu: Defer FPU state load until return to userspace)
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Add a comment in front of the warning. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

This reverts commit 240c35a3
("kvm: x86: Use task structs fpu field for user", 2018-11-06).
The commit is broken and causes QEMU's FPU state to be destroyed
when KVM_RUN is preempted.

Fixes: 240c35a3 ("kvm: x86: Use task structs fpu field for user")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Letting this pend may cause nested_get_vmcs12_pages to run against an
invalid state, corrupting the effective vmcs of L1.

This was triggerable in QEMU after a guest corruption in L2, followed by
a L1 reset.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 7f7f1ba3 ("KVM: x86: do not load vmcs12 pages while still in SMM")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

The MMIO RAPL interface driver depends on both powercap subsystem and
the intel_rapl_common code.

But when all of them are built-in, the MMIO RAPL interface driver can
be loaded before the other two and this breaks the system during boot.

Fix this by adjusting the init order of the powercap subsystem and the
intel_rapl_common code, so that it can be initialized first.

Fixes: 555c45fe ("int340X/processor_thermal_device: add support for MMIO RAPL")
Reported-by: Kenneth R. Crudup <kenny@panix.com>
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Some applications set tiny SO_SNDBUF values and expect
TCP to just work. Recent patches to address CVE-2019-11478
broke them in case of losses, since retransmits might
be prevented.

We should allow these flows to make progress.

This patch allows the first and last skb in retransmit queue
to be split even if memory limits are hit.

It also adds the some room due to the fact that tcp_sendmsg()
and tcp_sendpage() might overshoot sk_wmem_queued by about one full
TSO skb (64KB size). Note this allowance was already present
in stable backports for kernels < 4.15

Note for < 4.15 backports :
 tcp_rtx_queue_tail() will probably look like :

static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk)
{
	struct sk_buff *skb = tcp_send_head(sk);

	return skb ? tcp_write_queue_prev(sk, skb) : tcp_write_queue_tail(sk);
}

Fixes: f070ef2a ("tcp: tcp_fragment() should apply sane memory limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Andrew Prout <aprout@ll.mit.edu>
Tested-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Tested-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Christoph Paasch <cpaasch@apple.com>
Cc: Jonathan Looney <jtl@netflix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is an extra rcu_read_unlock left in netvsc_recv_callback(),
after a previous patch that removes RCU from this function.
This patch removes the extra RCU unlock.

Fixes: 345ac089 ("hv_netvsc: pass netvsc_device to receive callback")
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

On systems like P9 powernv where we have no TM (or P8 booted with
ppc_tm=off), userspace can construct a signal context which still has
the MSR TS bits set. The kernel tries to restore this context which
results in the following crash:

  Unexpected TM Bad Thing exception at c0000000000022fc (msr 0x8000000102a03031) tm_scratch=800000020280f033
  Oops: Unrecoverable exception, sig: 6 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 1636 Comm: sigfuz Not tainted 5.2.0-11043-g0a8ad0ff #69
  NIP:  c0000000000022fc LR: 00007fffb2d67e48 CTR: 0000000000000000
  REGS: c00000003fffbd70 TRAP: 0700   Not tainted  (5.2.0-11045-g7142b497d8)
  MSR:  8000000102a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[E]>  CR: 42004242  XER: 00000000
  CFAR: c0000000000022e0 IRQMASK: 0
  GPR00: 0000000000000072 00007fffb2b6e560 00007fffb2d87f00 0000000000000669
  GPR04: 00007fffb2b6e728 0000000000000000 0000000000000000 00007fffb2b6f2a8
  GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
  GPR12: 0000000000000000 00007fffb2b76900 0000000000000000 0000000000000000
  GPR16: 00007fffb2370000 00007fffb2d84390 00007fffea3a15ac 000001000a250420
  GPR20: 00007fffb2b6f260 0000000010001770 0000000000000000 0000000000000000
  GPR24: 00007fffb2d843a0 00007fffea3a14a0 0000000000010000 0000000000800000
  GPR28: 00007fffea3a14d8 00000000003d0f00 0000000000000000 00007fffb2b6e728
  NIP [c0000000000022fc] rfi_flush_fallback+0x7c/0x80
  LR [00007fffb2d67e48] 0x7fffb2d67e48
  Call Trace:
  Instruction dump:
  e96a0220 e96a02a8 e96a0330 e96a03b8 394a0400 4200ffdc 7d2903a6 e92d0c00
  e94d0c08 e96d0c10 e82d0c18 7db242a6 <4c000024> 7db243a6 7db142a6 f82d0c18

The problem is the signal code assumes TM is enabled when
CONFIG_PPC_TRANSACTIONAL_MEM is enabled. This may not be the case as
with P9 powernv or if `ppc_tm=off` is used on P8.

This means any local user can crash the system.

Fix the problem by returning a bad stack frame to the user if they try
to set the MSR TS bits with sigreturn() on systems where TM is not
supported.

Found with sigfuz kernel selftest on P9.

This fixes CVE-2019-13648.

Fixes: 2b0a576d ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9
Reported-by: Praveen Pandey <Praveen.Pandey@in.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190719050502.405-1-mikey@neuling.org

The old URL is dead.
Signed-off-by: Robert Karszniewicz <avoidr@firemail.cc>
Link: https://lore.kernel.org/r/7139bc7707c24bd4dd7eb323e2da90105a3de9c1.1563522498.git.avoidr@firemail.ccSigned-off-by: Guenter Roeck <linux@roeck-us.net>