Thomas Gleixner
6a9e529272
x86/speculation/mds: Add mds_clear_cpu_buffers() ...
The Microarchitectural Data Sampling (MDS) vulernabilities are mitigated by
clearing the affected CPU buffers. The mechanism for clearing the buffers
uses the unused and obsolete VERW instruction in combination with a
microcode update which triggers a CPU buffer clear when VERW is executed.
Provide a inline function with the assembly magic. The argument of the VERW
instruction must be a memory operand as documented:
"MD_CLEAR enumerates that the memory-operand variant of VERW (for
example, VERW m16) has been extended to also overwrite buffers affected
by MDS. This buffer overwriting functionality is not guaranteed for the
register operand variant of VERW."
Documentation also recommends to use a writable data segment selector:
"The buffer overwriting occurs regardless of the result of the VERW
permission check, as well as when the selector is null or causes a
descriptor load segment violation. However, for lowest latency we
recommend using a selector that indicates a valid writable data
segment."
Add x86 specific documentation about MDS and the internal workings of the
mitigation.
Signed-off-by: Thomas Gleixner <[email protected] >
Reviewed-by: Borislav Petkov <[email protected] >
Reviewed-by: Greg Kroah-Hartman <[email protected] >
Reviewed-by: Frederic Weisbecker <[email protected] >
Reviewed-by: Jon Masters <[email protected] >
Tested-by: Jon Masters <[email protected] >
2019-03-06 21:52:12 +01:00
Documentation/ABI: Correct mlxreg-io KernelVersion for 5.0
2019-01-26 11:30:26 -08:00
psi: cgroup support
2018-10-26 16:26:32 -07:00
A single patch from Arnd bringing some top-level docs into the 5.0 era.
2019-02-20 14:14:31 -08:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
arm64 festive updates for 4.21
2018-12-25 17:41:56 -08:00
block: doc: add slice_idle_us to bfq documentation
2019-01-09 07:38:48 -07:00
zram: idle writeback fixes and cleanup
2019-01-08 17:15:10 -08:00
bpf, doc: update design qa to reflect kern_version requirement
2019-01-07 15:52:00 -08:00
Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2018-10-25 17:15:46 -07:00
XArray: Honour reserved entries in xa_insert
2019-01-06 22:12:58 -05:00
Documentation: cpu-freq: Frequencies aren't always sorted
2018-11-07 13:29:04 +01:00
Documentation: admin-guide: PM: Add cpuidle document
2018-12-03 10:03:36 +01:00
crypto: skcipher - remove remnants of internal IV generators
2018-12-23 11:52:45 +08:00
A fairly normal cycle for documentation stuff. We have a new
2018-12-29 11:21:49 -08:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
A single fix for building DT bindings in-tree.
2019-02-02 10:34:32 -08:00
doc:process: add links where missing
2018-12-06 10:21:19 -07:00
pci-v4.21-changes
2019-01-05 17:57:34 -08:00
Documentation: driver core: remove use of BUS_ATTR
2019-01-08 15:17:45 +01:00
Correct gen_init_cpio tool's documentation
2018-11-25 12:25:53 -07:00
Docs/EDID: Calculate CRC while building the code
2018-11-06 07:36:22 -07:00
fbdev: fbmem: convert CONFIG_FB_LOGO_CENTER into a cmd line option
2019-01-16 17:42:35 +01:00
Documentation/features: Add csky kernel features
2019-01-07 22:22:16 +08:00
Documentation: driver core: remove use of BUS_ATTR
2019-01-08 15:17:45 +01:00
A fairly normal cycle for documentation stuff. We have a new
2018-12-29 11:21:49 -08:00
HID: doc: fix wrong data structure reference for UHID_OUTPUT
2018-12-18 14:55:22 +01:00
hwmon: Introduce SENSOR_DEVICE_ATTR_{RO, RW, WO} and variants
2018-12-16 15:13:22 -08:00
i2c: add i2c bus driver for NVIDIA GPU
2018-11-09 17:46:43 +01:00
Input: add REL_WHEEL_HI_RES and REL_HWHEEL_HI_RES
2018-12-07 16:27:11 +01:00
seccomp: add a return code to trap to userspace
2018-12-11 16:28:41 -08:00
kbuild: generate asm-generic wrappers if mandatory headers are missing
2019-01-06 09:46:51 +09:00
platform-drivers-x86 for v4.20-1
2018-11-01 08:42:21 -07:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
This is a fairly typical cycle for documentation. There's some welcome
2018-10-24 18:01:11 +01:00
A fairly normal cycle for documentation stuff. We have a new
2018-12-29 11:21:49 -08:00
net: dsa: Remove documentation for port_fdb_prepare
2019-02-23 18:38:00 -08:00
libnvdimm/security: Add documentation for nvdimm security support
2018-12-21 12:44:41 -08:00
Documentation: nvmem: document cell tables and lookup entries
2018-09-28 15:14:54 +02:00
pci-v4.20-changes
2018-10-25 06:50:48 -07:00
Documentation: perf: Add documentation for ThunderX2 PMU uncore driver
2018-12-06 12:29:47 +00:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
powerpc/fadump: Reservationless firmware assisted dump
2018-12-21 11:32:49 +11:00
Documentation: change linux-4.x references to 5.x
2019-02-17 15:41:05 -07:00
doc: Fix "struction" typo in RCU memory-ordering documentation
2018-11-12 08:56:25 -08:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
This is a fairly typical cycle for documentation. There's some welcome
2018-10-24 18:01:11 +01:00
SCSI misc on 20181224
2018-12-28 14:48:06 -08:00
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-01-02 09:43:14 -08:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
sh: remove board_time_init() callback
2018-12-18 16:13:04 +01:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
docs: improve readability for people with poorer eyesight
2018-10-07 09:16:50 -06:00
Documentation: Fix grammatical error in sysctl/fs.txt & clarify negative dentry
2019-02-11 09:10:22 -08:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'
2019-01-11 10:09:51 +01:00
Documentation: change linux-4.x references to 5.x
2019-02-17 15:41:05 -07:00
Documentation/usb: Fix typo
2018-11-26 16:56:34 +01:00
Merge branch 'next-seccomp' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-01-02 09:48:13 -08:00
Documentation/virtual/kvm: Update URL for AMD SEV API specification
2019-01-11 18:38:07 +01:00
A fairly normal cycle for documentation stuff. We have a new
2018-12-29 11:21:49 -08:00
watchdog: docs: kernel-api: don't reference removed functions
2018-12-24 13:15:06 +01:00
x86/speculation/mds: Add mds_clear_cpu_buffers()
2019-03-06 21:52:12 +01:00
Documentation: xilinx: Add documentation for eemi APIs
2018-10-09 13:26:05 +02:00
This is a fairly typical cycle for documentation. There's some welcome
2018-10-24 18:01:11 +01:00
dma-mapping: deprecate dma_zalloc_coherent
2018-12-20 08:14:09 +01:00
x86/speculation/mds: Add mds_clear_cpu_buffers()
2019-03-06 21:52:12 +01:00
kref/kobject: Improve documentation
2018-12-06 13:57:03 +01:00
kbuild: Add support for DT binding schema checks
2018-12-13 09:41:32 -06:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
Documentation: preempt-locking: Use better example
2018-10-12 11:35:47 -06:00
Documentation: Use "while" instead of "whilst"
2018-11-20 09:30:43 -07:00
NTB: switchtec_ntb: Update switchtec documentation with prerequisites for NTB
2018-10-11 11:28:53 -05:00
6a9e529272
