Merge tag 'v4.19.90' of http://git.kernel.org/pub/scm/linux/kernel/gi…

…t/stable/linux-stable into ti-linux-4.19.y

This is the 4.19.90 stable release

* tag 'v4.19.90' of http://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (1925 commits)
  Linux 4.19.90
  of: unittest: fix memory leak in attach_node_and_children
  scsi: zorro_esp: Limit DMA transfers to 65536 bytes (except on Fastlane)
  idr: Fix idr_get_next_ul race with idr_remove
  iio: imu: mpu6050: add missing available scan masks
  scsi: qla2xxx: Change discovery state before PLOGI
  raid5: need to set STRIPE_HANDLE for batch head
  gpiolib: acpi: Add Terra Pad 1061 to the run_edge_events_on_boot_blacklist
  cifs: Fix potential softlockups while refreshing DFS cache
  kernel/module.c: wakeup processes in module_wq on module unload
  of: overlay: add_changeset_property() memory leak
  gfs2: fix glock reference problem in gfs2_trans_remove_revoke
  PCI: rcar: Fix missing MACCTLR register setting in initialization sequence
  leds: trigger: netdev: fix handling on interface rename
  net/mlx5e: Fix SFF 8472 eeprom length
  sunrpc: fix crash when cache_head become valid before update
  firmware: arm_scmi: Avoid double free in error flow
  gre: refetch erspan header from skb->data after pskb_may_pull()
  perf callchain: Fix segfault in thread__resolve_callchain_sample()
  workqueue: Fix missing kfree(rescuer) in destroy_workqueue()
  ...

Signed-off-by: Dan Murphy <[email protected]>

# Conflicts:
#	arch/arm64/boot/dts/ti/k3-am65-main.dtsi
#	arch/arm64/boot/dts/ti/k3-am65.dtsi
#	drivers/ata/ahci_platform.c
#	drivers/mtd/spi-nor/cadence-quadspi.c
#	drivers/net/phy/dp83867.c
#	drivers/pci/controller/dwc/pci-keystone.c
#	drivers/remoteproc/da8xx_remoteproc.c
#	drivers/remoteproc/remoteproc_sysfs.c

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -478,6 +478,8 @@ What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
 		/sys/devices/system/cpu/vulnerabilities/l1tf
 		/sys/devices/system/cpu/vulnerabilities/mds
+		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
 Date:		January 2018
 Contact:	Linux kernel mailing list <[email protected]>
 Description:	Information about CPU vulnerabilities

Documentation/admin-guide/hw-vuln/index.rst

@@ -12,3 +12,5 @@ are configurable at compile, boot or run time.
    spectre
    l1tf
    mds
+   tsx_async_abort
+   multihit.rst

Documentation/admin-guide/hw-vuln/mds.rst

@@ -265,8 +265,11 @@ time with the option "mds=". The valid arguments for this option are:
 
   ============  =============================================================
 
-Not specifying this option is equivalent to "mds=full".
-
+Not specifying this option is equivalent to "mds=full". For processors
+that are affected by both TAA (TSX Asynchronous Abort) and MDS,
+specifying just "mds=off" without an accompanying "tsx_async_abort=off"
+will have no effect as the same mitigation is used for both
+vulnerabilities.
 
 Mitigation selection guide
 --------------------------

Documentation/admin-guide/hw-vuln/multihit.rst

@@ -0,0 +1,163 @@
+iTLB multihit
+=============
+
+iTLB multihit is an erratum where some processors may incur a machine check
+error, possibly resulting in an unrecoverable CPU lockup, when an
+instruction fetch hits multiple entries in the instruction TLB. This can
+occur when the page size is changed along with either the physical address
+or cache type. A malicious guest running on a virtualized system can
+exploit this erratum to perform a denial of service attack.
+
+
+Affected processors
+-------------------
+
+Variations of this erratum are present on most Intel Core and Xeon processor
+models. The erratum is not present on:
+
+   - non-Intel processors
+
+   - Some Atoms (Airmont, Bonnell, Goldmont, GoldmontPlus, Saltwell, Silvermont)
+
+   - Intel processors that have the PSCHANGE_MC_NO bit set in the
+     IA32_ARCH_CAPABILITIES MSR.
+
+
+Related CVEs
+------------
+
+The following CVE entry is related to this issue:
+
+   ==============  =================================================
+   CVE-2018-12207  Machine Check Error Avoidance on Page Size Change
+   ==============  =================================================
+
+
+Problem
+-------
+
+Privileged software, including OS and virtual machine managers (VMM), are in
+charge of memory management. A key component in memory management is the control
+of the page tables. Modern processors use virtual memory, a technique that creates
+the illusion of a very large memory for processors. This virtual space is split
+into pages of a given size. Page tables translate virtual addresses to physical
+addresses.
+
+To reduce latency when performing a virtual to physical address translation,
+processors include a structure, called TLB, that caches recent translations.
+There are separate TLBs for instruction (iTLB) and data (dTLB).
+
+Under this errata, instructions are fetched from a linear address translated
+using a 4 KB translation cached in the iTLB. Privileged software modifies the
+paging structure so that the same linear address using large page size (2 MB, 4
+MB, 1 GB) with a different physical address or memory type.  After the page
+structure modification but before the software invalidates any iTLB entries for
+the linear address, a code fetch that happens on the same linear address may
+cause a machine-check error which can result in a system hang or shutdown.
+
+
+Attack scenarios
+----------------
+
+Attacks against the iTLB multihit erratum can be mounted from malicious
+guests in a virtualized system.
+
+
+iTLB multihit system information
+--------------------------------
+
+The Linux kernel provides a sysfs interface to enumerate the current iTLB
+multihit status of the system:whether the system is vulnerable and which
+mitigations are active. The relevant sysfs file is:
+
+/sys/devices/system/cpu/vulnerabilities/itlb_multihit
+
+The possible values in this file are:
+
+.. list-table::
+
+     * - Not affected
+       - The processor is not vulnerable.
+     * - KVM: Mitigation: Split huge pages
+       - Software changes mitigate this issue.
+     * - KVM: Vulnerable
+       - The processor is vulnerable, but no mitigation enabled
+
+
+Enumeration of the erratum
+--------------------------------
+
+A new bit has been allocated in the IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) msr
+and will be set on CPU's which are mitigated against this issue.
+
+   =======================================   ===========   ===============================
+   IA32_ARCH_CAPABILITIES MSR                Not present   Possibly vulnerable,check model
+   IA32_ARCH_CAPABILITIES[PSCHANGE_MC_NO]    '0'           Likely vulnerable,check model
+   IA32_ARCH_CAPABILITIES[PSCHANGE_MC_NO]    '1'           Not vulnerable
+   =======================================   ===========   ===============================
+
+
+Mitigation mechanism
+-------------------------
+
+This erratum can be mitigated by restricting the use of large page sizes to
+non-executable pages.  This forces all iTLB entries to be 4K, and removes
+the possibility of multiple hits.
+
+In order to mitigate the vulnerability, KVM initially marks all huge pages
+as non-executable. If the guest attempts to execute in one of those pages,
+the page is broken down into 4K pages, which are then marked executable.
+
+If EPT is disabled or not available on the host, KVM is in control of TLB
+flushes and the problematic situation cannot happen.  However, the shadow
+EPT paging mechanism used by nested virtualization is vulnerable, because
+the nested guest can trigger multiple iTLB hits by modifying its own
+(non-nested) page tables.  For simplicity, KVM will make large pages
+non-executable in all shadow paging modes.
+
+Mitigation control on the kernel command line and KVM - module parameter
+------------------------------------------------------------------------
+
+The KVM hypervisor mitigation mechanism for marking huge pages as
+non-executable can be controlled with a module parameter "nx_huge_pages=".
+The kernel command line allows to control the iTLB multihit mitigations at
+boot time with the option "kvm.nx_huge_pages=".
+
+The valid arguments for these options are:
+
+  ==========  ================================================================
+  force       Mitigation is enabled. In this case, the mitigation implements
+              non-executable huge pages in Linux kernel KVM module. All huge
+              pages in the EPT are marked as non-executable.
+              If a guest attempts to execute in one of those pages, the page is
+              broken down into 4K pages, which are then marked executable.
+
+  off	      Mitigation is disabled.
+
+  auto        Enable mitigation only if the platform is affected and the kernel
+              was not booted with the "mitigations=off" command line parameter.
+	      This is the default option.
+  ==========  ================================================================
+
+
+Mitigation selection guide
+--------------------------
+
+1. No virtualization in use
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+   The system is protected by the kernel unconditionally and no further
+   action is required.
+
+2. Virtualization with trusted guests
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+   If the guest comes from a trusted source, you may assume that the guest will
+   not attempt to maliciously exploit these errata and no further action is
+   required.
+
+3. Virtualization with untrusted guests
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   If the guest comes from an untrusted source, the guest host kernel will need
+   to apply iTLB multihit mitigation via the kernel command line or kvm
+   module parameter.