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linux/arch/x86/kernel
Andi Kleen ed5194c273 x86/speculation/mds: Add basic bug infrastructure for MDS
Microarchitectural Data Sampling (MDS), is a class of side channel attacks
on internal buffers in Intel CPUs. The variants are:

 - Microarchitectural Store Buffer Data Sampling (MSBDS) (CVE-2018-12126)
 - Microarchitectural Fill Buffer Data Sampling (MFBDS) (CVE-2018-12130)
 - Microarchitectural Load Port Data Sampling (MLPDS) (CVE-2018-12127)

MSBDS leaks Store Buffer Entries which can be speculatively forwarded to a
dependent load (store-to-load forwarding) as an optimization. The forward
can also happen to a faulting or assisting load operation for a different
memory address, which can be exploited under certain conditions. Store
buffers are partitioned between Hyper-Threads so cross thread forwarding is
not possible. But if a thread enters or exits a sleep state the store
buffer is repartitioned which can expose data from one thread to the other.

MFBDS leaks Fill Buffer Entries. Fill buffers are used internally to manage
L1 miss situations and to hold data which is returned or sent in response
to a memory or I/O operation. Fill buffers can forward data to a load
operation and also write data to the cache. When the fill buffer is
deallocated it can retain the stale data of the preceding operations which
can then be forwarded to a faulting or assisting load operation, which can
be exploited under certain conditions. Fill buffers are shared between
Hyper-Threads so cross thread leakage is possible.

MLDPS leaks Load Port Data. Load ports are used to perform load operations
from memory or I/O. The received data is then forwarded to the register
file or a subsequent operation. In some implementations the Load Port can
contain stale data from a previous operation which can be forwarded to
faulting or assisting loads under certain conditions, which again can be
exploited eventually. Load ports are shared between Hyper-Threads so cross
thread leakage is possible.

All variants have the same mitigation for single CPU thread case (SMT off),
so the kernel can treat them as one MDS issue.

Add the basic infrastructure to detect if the current CPU is affected by
MDS.

[ tglx: Rewrote changelog ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
2019-03-06 21:52:11 +01:00
..
acpi x86: Fix various typos in comments 2018-12-03 10:49:13 +01:00
apic x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
cpu x86/speculation/mds: Add basic bug infrastructure for MDS 2019-03-06 21:52:11 +01:00
fpu Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
kprobes Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 17:03:51 -08:00
.gitignore
alternative.c Merge branch 'x86-paravirt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 17:54:58 +01:00
amd_gart_64.c x86/amd_gart: fix unmapping of non-GART mappings 2019-01-05 08:27:32 +01:00
amd_nb.c x86/amd_nb: Add PCI device IDs for family 17h, model 30h 2018-11-07 21:36:09 +01:00
apb_timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
aperture_64.c x86/gart: Rewrite early_gart_iommu_check() comment 2018-11-05 21:18:31 +01:00
apm_32.c x86/APM: Fix build warning when PROC_FS is not enabled 2018-09-15 10:16:25 +02:00
asm-offsets.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
asm-offsets_32.c x86/entry/32: Load task stack from x86_tss.sp1 in SYSENTER handler 2018-07-20 01:11:36 +02:00
asm-offsets_64.c x86/paravirt: Move the pv_irq_ops under the PARAVIRT_XXL umbrella 2018-09-03 16:50:36 +02:00
audit_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bootflag.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
check.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
cpuid.c x86/cpuid: Allow cpuid_read() to schedule 2018-03-27 12:01:48 +02:00
crash.c x86/kexec: Fix a kexec_file_load() failure 2019-01-15 12:12:50 +01:00
crash_dump_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crash_dump_64.c x86: Fix various typos in comments 2018-12-03 10:49:13 +01:00
devicetree.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
doublefault.c x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss 2017-12-17 13:59:55 +01:00
dumpstack.c x86/process: Don't mix user/kernel regs in 64bit __show_regs() 2018-09-06 14:33:12 +02:00
dumpstack_32.c x86/dumpstack: Unify show_regs() 2018-03-08 12:04:59 +01:00
dumpstack_64.c x86/dumpstack: Unify show_regs() 2018-03-08 12:04:59 +01:00
e820.c memblock: stop using implicit alignment to SMP_CACHE_BYTES 2018-10-31 08:54:16 -07:00
early-quirks.c On GEM side: 2018-07-20 12:29:24 +10:00
early_printk.c x86/earlyprintk: Add a force option for pciserial device 2018-10-02 21:02:47 +02:00
ebda.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eisa.c x86/EISA: Don't probe EISA bus for Xen PV guests 2018-09-11 23:36:50 +02:00
espfix_64.c x86/espfix: Document use of _PAGE_GLOBAL 2018-04-09 18:27:33 +02:00
ftrace.c x86/ftrace: Do not call function graph from dynamic trampolines 2018-12-19 22:43:37 -05:00
ftrace_32.S x86/retpoline/ftrace: Convert ftrace assembler indirect jumps 2018-01-12 00:14:30 +01:00
ftrace_64.S x86/ftrace: Do not call function graph from dynamic trampolines 2018-12-19 22:43:37 -05:00
head32.c x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
head64.c x86/boot: Mostly revert commit ae7e1238e6 ("Add ACPI RSDP address to setup_header") 2018-11-20 09:43:10 +01:00
head_32.S x86/pgtable/32: Allocate 8k page-tables when PTI is enabled 2018-07-20 01:11:41 +02:00
head_64.S xen/pvh: Split CONFIG_XEN_PVH into CONFIG_PVH and CONFIG_XEN_PVH 2018-12-13 13:41:49 -05:00
hpet.c x86/hpet: Remove unused FSEC_PER_NSEC define 2018-12-04 12:17:21 +01:00
hw_breakpoint.c perf/arch/x86: Implement hw_breakpoint_arch_parse() 2018-06-26 09:07:55 +02:00
i8237.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
i8253.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
i8259.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
idt.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
ima_arch.c x86/ima: retry detecting secure boot mode 2018-12-11 07:19:45 -05:00
io_delay.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ioport.c x86/ioport: add ksys_ioperm() helper; remove in-kernel calls to sys_ioperm() 2018-04-02 20:16:12 +02:00
irq.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irq_32.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irq_64.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
irq_work.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irqflags.S x86/paravirt: Make native_save_fl() extern inline 2018-07-03 10:56:27 +02:00
irqinit.c x86: Don't include linux/irq.h from asm/hardirq.h 2018-08-05 09:53:13 +02:00
itmt.c x86/headers: Remove duplicate #includes 2017-12-12 11:32:24 +01:00
jailhouse.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
kdebugfs.c x86, mpparse, x86/acpi, x86/PCI, x86/dmi, SFI: Use memremap() for RAM mappings 2017-07-18 11:37:58 +02:00
kexec-bzimage64.c x86/kexec: Don't setup EFI info if EFI runtime is not enabled 2019-02-01 18:18:54 +01:00
kgdb.c kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops 2018-12-30 08:33:06 +00:00
ksysfs.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
kvm.c KVM: x86: WARN_ONCE if sending a PV IPI returns a fatal error 2019-01-25 19:11:33 +01:00
kvmclock.c x86/kvmclock: convert to SPDX identifiers 2018-12-21 11:28:25 +01:00
ldt.c x86/ldt: Remove unused variable in map_ldt_struct() 2018-11-06 21:35:11 +01:00
livepatch.c livepatch/x86: apply alternatives and paravirt patches after relocations 2016-08-18 23:41:55 +02:00
machine_kexec_32.c x86/kexec: Allocate 8k PGDs for PTI 2018-07-30 13:53:48 +02:00
machine_kexec_64.c x86/mm: Stop pretending pgtable_l5_enabled is a variable 2018-05-19 11:56:57 +02:00
Makefile jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
mmconf-fam10h_64.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
module.c x86: Add support for 64-bit place relative relocations 2018-09-27 17:56:47 +02:00
mpparse.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
msr.c x86: Clean up 'sizeof x' => 'sizeof(x)' 2018-10-29 07:13:28 +01:00
nmi.c locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() 2017-10-25 11:01:08 +02:00
nmi_selftest.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
paravirt-spinlocks.c x86/paravirt: Use a single ops structure 2018-09-03 16:50:35 +02:00
paravirt.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt_patch_32.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
paravirt_patch_64.c x86/paravirt: Remove unused _paravirt_ident_32 2018-10-30 09:55:31 +01:00
pci-calgary_64.c x86/calgary: remove the mapping_error dma_map_ops method 2018-12-06 06:56:46 -08:00
pci-dma.c dma-mapping: bypass indirect calls for dma-direct 2018-12-13 21:06:18 +01:00
pci-iommu_table.c x86/iommu: Use NULL instead of 0 2018-08-02 14:33:19 +02:00
pci-swiotlb.c dma-direct: merge swiotlb_dma_ops into the dma_direct code 2018-12-13 21:06:17 +01:00
pcspeaker.c x86/platform/pcspeaker: Use PTR_ERR_OR_ZERO() to fix ptr_ret.cocci warning 2018-07-24 09:46:42 +02:00
perf_regs.c perf/x86: Store user space frame-pointer value on a sample 2018-05-25 08:11:12 +02:00
platform-quirks.c x86/i8237: Register device based on FADT legacy boot flag 2018-04-27 16:44:29 +02:00
pmem.c resource: Provide resource struct in resource walk callback 2017-11-07 15:35:57 +01:00
probe_roms.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
process.c Linux 4.20-rc5 2018-12-03 10:47:53 +01:00
process.h x86/speculation: Change misspelled STIPB to STIBP 2018-12-06 11:49:15 +01:00
process_32.c Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 17:37:51 -08:00
process_64.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 18:08:18 -08:00
ptrace.c x86/fsgsbase/64: Fix the base write helper functions 2018-12-18 14:26:09 +01:00
pvclock.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
quirks.c x86/headers: Fix -Wmissing-prototypes warning 2018-11-23 07:59:59 +01:00
reboot.c x86/apic: Fix restoring boot IRQ mode in reboot and kexec/kdump 2018-02-17 11:47:45 +01:00
reboot_fixups_32.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
relocate_kernel_32.S
relocate_kernel_64.S x86/kexec: Make kexec (mostly) work in 5-level paging mode 2018-01-31 08:39:40 +01:00
resource.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
rtc.c x86: Convert x86_platform_ops to timespec64 2018-05-19 14:03:14 +02:00
setup.c Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-01-05 13:25:58 -08:00
setup_percpu.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
signal.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
signal_compat.c signal: Add TRAP_UNK si_code for undiagnosted trap exceptions 2018-04-25 10:40:56 -05:00
smp.c x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d 2018-08-05 09:53:13 +02:00
smpboot.c x86/topology: Use total_cpus for max logical packages calculation 2018-12-18 13:38:37 +01:00
stacktrace.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
step.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sys_x86_64.c x86/compat: Adjust in_compat_syscall() to generic code under !COMPAT 2018-11-01 12:59:25 +01:00
sysfb.c
sysfb_efi.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
sysfb_simplefb.c x86/sysfb: Fix lfb_size calculation 2016-11-16 09:38:23 +01:00
tboot.c iommu/vtd: Cleanup dma_remapping.h header 2018-11-12 14:22:56 +01:00
tce_64.c mm: remove include/linux/bootmem.h 2018-10-31 08:54:16 -07:00
time.c Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 19:07:25 +01:00
tls.c x86/ldt: Make the LDT mapping RO 2017-12-23 21:13:01 +01:00
tls.h
topology.c x86/xen: Disable CPU0 hotplug for Xen PV 2018-09-12 21:15:02 +02:00
trace_clock.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tracepoint.c x86/kernel: Fix more -Wmissing-prototypes warnings 2018-12-08 12:24:35 +01:00
traps.c x86/traps: Use format string with panic() call 2018-10-29 07:19:26 +01:00
tsc.c x86/tsc: Make calibration refinement more robust 2018-11-06 21:53:15 +01:00
tsc_msr.c x86/cpu: Sanitize FAM6_ATOM naming 2018-10-02 10:14:32 +02:00
tsc_sync.c Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 19:07:38 -08:00
umip.c signal/x86: Use force_sig_fault where appropriate 2018-09-21 15:30:54 +02:00
unwind_frame.c x86/unwind: Disable unwinder warnings on 32-bit 2017-10-10 12:49:49 +02:00
unwind_guess.c x86/unwind: Add the ORC unwinder 2017-07-26 13:18:20 +02:00
unwind_orc.c x86/unwind/orc: Detect the end of the stack 2018-06-21 16:34:56 +02:00
uprobes.c signal: Properly deliver SIGSEGV from x86 uprobes 2018-09-11 21:18:53 +02:00
verify_cpu.S x86/boot: Annotate verify_cpu() as a callable function 2017-09-28 09:39:03 +02:00
vm86_32.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
vmlinux.lds.S Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 18:43:04 +01:00
vsmp_64.c x86/vsmp: Remove dependency on pv_irq_ops 2018-11-06 21:35:11 +01:00
x86_init.c x86/acpi, x86/boot: Take RSDP address for boot params if available 2018-10-10 10:44:22 +02:00