Commit Graph

4894 Commits

Author SHA1 Message Date
Borislav Petkov
f8b64d08dd x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present
Move smp_num_siblings and cpu_llc_id to cpu/common.c so that they're
always present as symbols and not only in the CONFIG_SMP case. Then,
other code using them doesn't need ugly ifdeffery anymore. Get rid of
some ifdeffery.

Signed-off-by: Borislav Petkov <bpetkov@suse.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524864877-111962-2-git-send-email-suravee.suthikulpanit@amd.com
2018-05-06 12:49:14 +02:00
Luck, Tony
985c78d3ff x86/MCE: Fix stack out-of-bounds write in mce-inject.c: Flags_read()
Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE]
in flags_read() is two characters long. But the sprintf() adds
a trailing newline and will add a terminating NUL byte. So
MAX_FLAG_OPT_SIZE needs to be 4.

sprintf() calls vsnprintf() and *that* does return:

" * The return value is the number of characters which would
 * be generated for the given input, excluding the trailing
 * '\0', as per ISO C99."

Note the "excluding".

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180427163707.ktaiysvbk3yhk4wm@agluck-desk
2018-05-06 12:46:39 +02:00
David Wang
13e8582245 x86/MCE: Enable MCE broadcasting on new Centaur CPUs
Newer Centaur multi-core CPUs also support MCE broadcasting to all
cores. Add a Centaur-specific init function setting that up.

 [ bp:
   - make mce_centaur_feature_init() static
   - flip check to do the f/m/s first for better readability
   - touch up text
  ]

Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: Greg KH <greg@kroah.com>
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: Tony Luck <tony.luck@intel.com>
Cc: benjaminpan@viatech.com
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1524652420-17330-2-git-send-email-davidwang@zhaoxin.com
2018-05-06 12:46:25 +02:00
Kees Cook
f21b53b20c x86/speculation: Make "seccomp" the default mode for Speculative Store Bypass
Unless explicitly opted out of, anything running under seccomp will have
SSB mitigations enabled. Choosing the "prctl" mode will disable this.

[ tglx: Adjusted it to the new arch_seccomp_spec_mitigate() mechanism ]

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-05 00:51:45 +02:00
Thomas Gleixner
8bf37d8c06 seccomp: Move speculation migitation control to arch code
The migitation control is simpler to implement in architecture code as it
avoids the extra function call to check the mode. Aside of that having an
explicit seccomp enabled mode in the architecture mitigations would require
even more workarounds.

Move it into architecture code and provide a weak function in the seccomp
code. Remove the 'which' argument as this allows the architecture to decide
which mitigations are relevant for seccomp.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-05 00:51:44 +02:00
Thomas Gleixner
356e4bfff2 prctl: Add force disable speculation
For certain use cases it is desired to enforce mitigations so they cannot
be undone afterwards. That's important for loader stubs which want to
prevent a child from disabling the mitigation again. Will also be used for
seccomp(). The extra state preserving of the prctl state for SSB is a
preparatory step for EBPF dymanic speculation control.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-05 00:51:43 +02:00
Kees Cook
f9544b2b07 x86/bugs: Make boot modes __ro_after_init
There's no reason for these to be changed after boot.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-05 00:51:43 +02:00
Kees Cook
7bbf1373e2 nospec: Allow getting/setting on non-current task
Adjust arch_prctl_get/set_spec_ctrl() to operate on tasks other than
current.

This is needed both for /proc/$pid/status queries and for seccomp (since
thread-syncing can trigger seccomp in non-current threads).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-05-03 13:55:51 +02:00
Thomas Gleixner
a73ec77ee1 x86/speculation: Add prctl for Speculative Store Bypass mitigation
Add prctl based control for Speculative Store Bypass mitigation and make it
the default mitigation for Intel and AMD.

Andi Kleen provided the following rationale (slightly redacted):

 There are multiple levels of impact of Speculative Store Bypass:

 1) JITed sandbox.
    It cannot invoke system calls, but can do PRIME+PROBE and may have call
    interfaces to other code

 2) Native code process.
    No protection inside the process at this level.

 3) Kernel.

 4) Between processes. 

 The prctl tries to protect against case (1) doing attacks.

 If the untrusted code can do random system calls then control is already
 lost in a much worse way. So there needs to be system call protection in
 some way (using a JIT not allowing them or seccomp). Or rather if the
 process can subvert its environment somehow to do the prctl it can already
 execute arbitrary code, which is much worse than SSB.

 To put it differently, the point of the prctl is to not allow JITed code
 to read data it shouldn't read from its JITed sandbox. If it already has
 escaped its sandbox then it can already read everything it wants in its
 address space, and do much worse.

 The ability to control Speculative Store Bypass allows to enable the
 protection selectively without affecting overall system performance.

Based on an initial patch from Tim Chen. Completely rewritten.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-05-03 13:55:51 +02:00
Thomas Gleixner
885f82bfbc x86/process: Allow runtime control of Speculative Store Bypass
The Speculative Store Bypass vulnerability can be mitigated with the
Reduced Data Speculation (RDS) feature. To allow finer grained control of
this eventually expensive mitigation a per task mitigation control is
required.

Add a new TIF_RDS flag and put it into the group of TIF flags which are
evaluated for mismatch in switch_to(). If these bits differ in the previous
and the next task, then the slow path function __switch_to_xtra() is
invoked. Implement the TIF_RDS dependent mitigation control in the slow
path.

If the prctl for controlling Speculative Store Bypass is disabled or no
task uses the prctl then there is no overhead in the switch_to() fast
path.

Update the KVM related speculation control functions to take TID_RDS into
account as well.

Based on a patch from Tim Chen. Completely rewritten.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2018-05-03 13:55:50 +02:00
Thomas Gleixner
28a2775217 x86/speculation: Create spec-ctrl.h to avoid include hell
Having everything in nospec-branch.h creates a hell of dependencies when
adding the prctl based switching mechanism. Move everything which is not
required in nospec-branch.h to spec-ctrl.h and fix up the includes in the
relevant files.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:50 +02:00
Konrad Rzeszutek Wilk
764f3c2158 x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requested
AMD does not need the Speculative Store Bypass mitigation to be enabled.

The parameters for this are already available and can be done via MSR
C001_1020. Each family uses a different bit in that MSR for this.

[ tglx: Expose the bit mask via a variable and move the actual MSR fiddling
  	into the bugs code as that's the right thing to do and also required
	to prepare for dynamic enable/disable ]

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:49 +02:00
Konrad Rzeszutek Wilk
1115a859f3 x86/bugs: Whitelist allowed SPEC_CTRL MSR values
Intel and AMD SPEC_CTRL (0x48) MSR semantics may differ in the
future (or in fact use different MSRs for the same functionality).

As such a run-time mechanism is required to whitelist the appropriate MSR
values.

[ tglx: Made the variable __ro_after_init ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:49 +02:00
Konrad Rzeszutek Wilk
772439717d x86/bugs/intel: Set proper CPU features and setup RDS
Intel CPUs expose methods to:

 - Detect whether RDS capability is available via CPUID.7.0.EDX[31],

 - The SPEC_CTRL MSR(0x48), bit 2 set to enable RDS.

 - MSR_IA32_ARCH_CAPABILITIES, Bit(4) no need to enable RRS.

With that in mind if spec_store_bypass_disable=[auto,on] is selected set at
boot-time the SPEC_CTRL MSR to enable RDS if the platform requires it.

Note that this does not fix the KVM case where the SPEC_CTRL is exposed to
guests which can muck with it, see patch titled :
 KVM/SVM/VMX/x86/spectre_v2: Support the combination of guest and host IBRS.

And for the firmware (IBRS to be set), see patch titled:
 x86/spectre_v2: Read SPEC_CTRL MSR during boot and re-use reserved bits

[ tglx: Distangled it from the intel implementation and kept the call order ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:48 +02:00
Konrad Rzeszutek Wilk
24f7fc83b9 x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation
Contemporary high performance processors use a common industry-wide
optimization known as "Speculative Store Bypass" in which loads from
addresses to which a recent store has occurred may (speculatively) see an
older value. Intel refers to this feature as "Memory Disambiguation" which
is part of their "Smart Memory Access" capability.

Memory Disambiguation can expose a cache side-channel attack against such
speculatively read values. An attacker can create exploit code that allows
them to read memory outside of a sandbox environment (for example,
malicious JavaScript in a web page), or to perform more complex attacks
against code running within the same privilege level, e.g. via the stack.

As a first step to mitigate against such attacks, provide two boot command
line control knobs:

 nospec_store_bypass_disable
 spec_store_bypass_disable=[off,auto,on]

By default affected x86 processors will power on with Speculative
Store Bypass enabled. Hence the provided kernel parameters are written
from the point of view of whether to enable a mitigation or not.
The parameters are as follows:

 - auto - Kernel detects whether your CPU model contains an implementation
	  of Speculative Store Bypass and picks the most appropriate
	  mitigation.

 - on   - disable Speculative Store Bypass
 - off  - enable Speculative Store Bypass

[ tglx: Reordered the checks so that the whole evaluation is not done
  	when the CPU does not support RDS ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:48 +02:00
Konrad Rzeszutek Wilk
c456442cd3 x86/bugs: Expose /sys/../spec_store_bypass
Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.

Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.

It assumes that older Cyrix, Centaur, etc. cores are immune.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:47 +02:00
Konrad Rzeszutek Wilk
5cf6875487 x86/bugs, KVM: Support the combination of guest and host IBRS
A guest may modify the SPEC_CTRL MSR from the value used by the
kernel. Since the kernel doesn't use IBRS, this means a value of zero is
what is needed in the host.

But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to
the other bits as reserved so the kernel should respect the boot time
SPEC_CTRL value and use that.

This allows to deal with future extensions to the SPEC_CTRL interface if
any at all.

Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any
difference as paravirt will over-write the callq *0xfff.. with the wrmsrl
assembler code.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:47 +02:00
Konrad Rzeszutek Wilk
1b86883ccb x86/bugs: Read SPEC_CTRL MSR during boot and re-use reserved bits
The 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to all
the other bits as reserved. The Intel SDM glossary defines reserved as
implementation specific - aka unknown.

As such at bootup this must be taken it into account and proper masking for
the bits in use applied.

A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199511

[ tglx: Made x86_spec_ctrl_base __ro_after_init ]

Suggested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:47 +02:00
Konrad Rzeszutek Wilk
d1059518b4 x86/bugs: Concentrate bug reporting into a separate function
Those SysFS functions have a similar preamble, as such make common
code to handle them.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:46 +02:00
Konrad Rzeszutek Wilk
4a28bfe326 x86/bugs: Concentrate bug detection into a separate function
Combine the various logic which goes through all those
x86_cpu_id matching structures in one function.

Suggested-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-05-03 13:55:46 +02:00
Thomas Gleixner
c65732e4f7 x86/cpu: Restore CPUID_8000_0008_EBX reload
The recent commt which addresses the x86_phys_bits corruption with
encrypted memory on CPUID reload after a microcode update lost the reload
of CPUID_8000_0008_EBX as well.

As a consequence IBRS and IBRS_FW are not longer detected

Restore the behaviour by bringing the reload of CPUID_8000_0008_EBX
back. This restore has a twist due to the convoluted way the cpuid analysis
works:

CPUID_8000_0008_EBX is used by AMD to enumerate IBRB, IBRS, STIBP. On Intel
EBX is not used. But the speculation control code sets the AMD bits when
running on Intel depending on the Intel specific speculation control
bits. This was done to use the same bits for alternatives.

The change which moved the 8000_0008 evaluation out of get_cpu_cap() broke
this nasty scheme due to ordering. So that on Intel the store to
CPUID_8000_0008_EBX clears the IBRB, IBRS, STIBP bits which had been set
before by software.

So the actual CPUID_8000_0008_EBX needs to go back to the place where it
was and the phys/virt address space calculation cannot touch it.

In hindsight this should have used completely synthetic bits for IBRB,
IBRS, STIBP instead of reusing the AMD bits, but that's for 4.18.

/me needs to find time to cleanup that steaming pile of ...

Fixes: d94a155c59 ("x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption")
Reported-by: Jörg Otte <jrg.otte@gmail.com>
Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: kirill.shutemov@linux.intel.com
Cc: Borislav Petkov <bp@alien8.de
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1805021043510.1668@nanos.tec.linutronix.de
2018-05-02 16:44:38 +02:00
jacek.tomaka@poczta.fm
b837913fc2 x86/cpu/intel: Add missing TLB cpuid values
Make kernel print the correct number of TLB entries on Intel Xeon Phi 7210
(and others)

Before:
[ 0.320005] Last level dTLB entries: 4KB 0, 2MB 0, 4MB 0, 1GB 0
After:
[ 0.320005] Last level dTLB entries: 4KB 256, 2MB 128, 4MB 128, 1GB 16

The entries do exist in the official Intel SMD but the type column there is
incorrect (states "Cache" where it should read "TLB"), but the entries for
the values 0x6B, 0x6C and 0x6D are correctly described as 'Data TLB'.

Signed-off-by: Jacek Tomaka <jacek.tomaka@poczta.fm>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20180423161425.24366-1-jacekt@dugeo.com
2018-04-26 21:42:44 +02:00
Borislav Petkov
09e182d17e x86/microcode: Do not exit early from __reload_late()
Vitezslav reported a case where the

  "Timeout during microcode update!"

panic would hit. After a deeper look, it turned out that his .config had
CONFIG_HOTPLUG_CPU disabled which practically made save_mc_for_early() a
no-op.

When that happened, the discovered microcode patch wasn't saved into the
cache and the late loading path wouldn't find any.

This, then, lead to early exit from __reload_late() and thus CPUs waiting
until the timeout is reached, leading to the panic.

In hindsight, that function should have been written so it does not return
before the post-synchronization. Oh well, I know better now...

Fixes: bb8c13d61a ("x86/microcode: Fix CPU synchronization routine")
Reported-by: Vitezslav Samel <vitezslav@samel.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vitezslav Samel <vitezslav@samel.cz>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-2-bp@alien8.de
2018-04-24 09:48:22 +02:00
Borislav Petkov
84749d8375 x86/microcode/intel: Save microcode patch unconditionally
save_mc_for_early() was a no-op on !CONFIG_HOTPLUG_CPU but the
generic_load_microcode() path saves the microcode patches it has found into
the cache of patches which is used for late loading too. Regardless of
whether CPU hotplug is used or not.

Make the saving unconditional so that late loading can find the proper
patch.

Reported-by: Vitezslav Samel <vitezslav@samel.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vitezslav Samel <vitezslav@samel.cz>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-1-bp@alien8.de
2018-04-24 09:48:22 +02:00
David Wang
60882cc159 x86/Centaur: Initialize supported CPU features properly
Centaur CPUs have some Intel compatible capabilities,including Permformance
Monitoring Counters and CPU virtualization capabilities. Initialize them in
the Centaur specific init code.

Signed-off-by: David Wang <davidwang@zhaoxin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: lukelin@viacpu.com
Cc: qiyuanwang@zhaoxin.com
Cc: gregkh@linuxfoundation.org
Cc: brucechang@via-alliance.com
Cc: timguo@zhaoxin.com
Cc: cooperyan@zhaoxin.com
Cc: hpa@zytor.com
Cc: benjaminpan@viatech.com
Link: https://lkml.kernel.org/r/1524212968-28998-1-git-send-email-davidwang@zhaoxin.com
2018-04-20 12:08:17 +02:00
Linus Torvalds
9fb71c2f23 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "A set of fixes and updates for x86:

   - Address a swiotlb regression which was caused by the recent DMA
     rework and made driver fail because dma_direct_supported() returned
     false

   - Fix a signedness bug in the APIC ID validation which caused invalid
     APIC IDs to be detected as valid thereby bloating the CPU possible
     space.

   - Fix inconsisten config dependcy/select magic for the MFD_CS5535
     driver.

   - Fix a corruption of the physical address space bits when encryption
     has reduced the address space and late cpuinfo updates overwrite
     the reduced bit information with the original value.

   - Dominiks syscall rework which consolidates the architecture
     specific syscall functions so all syscalls can be wrapped with the
     same macros. This allows to switch x86/64 to struct pt_regs based
     syscalls. Extend the clearing of user space controlled registers in
     the entry patch to the lower registers"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic: Fix signedness bug in APIC ID validity checks
  x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption
  x86/olpc: Fix inconsistent MFD_CS5535 configuration
  swiotlb: Use dma_direct_supported() for swiotlb_ops
  syscalls/x86: Adapt syscall_wrapper.h to the new syscall stub naming convention
  syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()
  syscalls/core, syscalls/x86: Clean up compat syscall stub naming convention
  syscalls/core, syscalls/x86: Clean up syscall stub naming convention
  syscalls/x86: Extend register clearing on syscall entry to lower registers
  syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64
  syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32
  syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls
  syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls
  syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y
  x86/syscalls: Don't pointlessly reload the system call number
  x86/mm: Fix documentation of module mapping range with 4-level paging
  x86/cpuid: Switch to 'static const' specifier
2018-04-15 16:12:35 -07:00
Ingo Molnar
ef389b7346 Merge branch 'WIP.x86/asm' into x86/urgent, because the topic is ready
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-12 09:42:34 +02:00
Kirill A. Shutemov
d94a155c59 x86/cpu: Prevent cpuinfo_x86::x86_phys_bits adjustment corruption
Some features (Intel MKTME, AMD SME) reduce the number of effectively
available physical address bits. cpuinfo_x86::x86_phys_bits is adjusted
accordingly during the early cpu feature detection.

Though if get_cpu_cap() is called later again then this adjustement is
overwritten. That happens in setup_pku(), which is called after
detect_tme().

To address this, extract the address sizes enumeration into a separate
function, which is only called only from early_identify_cpu() and from
generic_identify().

This makes get_cpu_cap() safe to be called later during boot proccess
without overwriting cpuinfo_x86::x86_phys_bits.

[ tglx: Massaged changelog ]

Fixes: cb06d8e3d0 ("x86/tme: Detect if TME and MKTME is activated by BIOS")
Reported-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: linux-mm@kvack.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180410092704.41106-1-kirill.shutemov@linux.intel.com
2018-04-10 16:33:21 +02:00
Linus Torvalds
d8312a3f61 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "ARM:
   - VHE optimizations

   - EL2 address space randomization

   - speculative execution mitigations ("variant 3a", aka execution past
     invalid privilege register access)

   - bugfixes and cleanups

  PPC:
   - improvements for the radix page fault handler for HV KVM on POWER9

  s390:
   - more kvm stat counters

   - virtio gpu plumbing

   - documentation

   - facilities improvements

  x86:
   - support for VMware magic I/O port and pseudo-PMCs

   - AMD pause loop exiting

   - support for AMD core performance extensions

   - support for synchronous register access

   - expose nVMX capabilities to userspace

   - support for Hyper-V signaling via eventfd

   - use Enlightened VMCS when running on Hyper-V

   - allow userspace to disable MWAIT/HLT/PAUSE vmexits

   - usual roundup of optimizations and nested virtualization bugfixes

  Generic:
   - API selftest infrastructure (though the only tests are for x86 as
     of now)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits)
  kvm: x86: fix a prototype warning
  kvm: selftests: add sync_regs_test
  kvm: selftests: add API testing infrastructure
  kvm: x86: fix a compile warning
  KVM: X86: Add Force Emulation Prefix for "emulate the next instruction"
  KVM: X86: Introduce handle_ud()
  KVM: vmx: unify adjacent #ifdefs
  x86: kvm: hide the unused 'cpu' variable
  KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig
  Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown"
  kvm: Add emulation for movups/movupd
  KVM: VMX: raise internal error for exception during invalid protected mode state
  KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending
  KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending
  KVM: x86: Fix misleading comments on handling pending exceptions
  KVM: x86: Rename interrupt.pending to interrupt.injected
  KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt
  x86/kvm: use Enlightened VMCS when running on Hyper-V
  x86/hyper-v: detect nested features
  x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits
  ...
2018-04-09 11:42:31 -07:00
Linus Torvalds
672a9c1069 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  kfifo: fix inaccurate comment
  tools/thermal: tmon: fix for segfault
  net: Spelling s/stucture/structure/
  edd: don't spam log if no EDD information is present
  Documentation: Fix early-microcode.txt references after file rename
  tracing: Block comments should align the * on each line
  treewide: Fix typos in printk
  GenWQE: Fix a typo in two comments
  treewide: Align function definition open/close braces
2018-04-05 11:56:35 -07:00
Linus Torvalds
06dd3dfeea Merge tag 'char-misc-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc updates from Greg KH:
 "Here is the big set of char/misc driver patches for 4.17-rc1.

  There are a lot of little things in here, nothing huge, but all
  important to the different hardware types involved:

   -  thunderbolt driver updates

   -  parport updates (people still care...)

   -  nvmem driver updates

   -  mei updates (as always)

   -  hwtracing driver updates

   -  hyperv driver updates

   -  extcon driver updates

   -  ... and a handful of even smaller driver subsystem and individual
      driver updates

  All of these have been in linux-next with no reported issues"

* tag 'char-misc-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (149 commits)
  hwtracing: Add HW tracing support menu
  intel_th: Add ACPI glue layer
  intel_th: Allow forcing host mode through drvdata
  intel_th: Pick up irq number from resources
  intel_th: Don't touch switch routing in host mode
  intel_th: Use correct method of finding hub
  intel_th: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate
  stm class: Make dummy's master/channel ranges configurable
  stm class: Add SPDX GPL-2.0 header to replace GPLv2 boilerplate
  MAINTAINERS: Bestow upon myself the care for drivers/hwtracing
  hv: add SPDX license id to Kconfig
  hv: add SPDX license to trace
  Drivers: hv: vmbus: do not mark HV_PCIE as perf_device
  Drivers: hv: vmbus: respect what we get from hv_get_synint_state()
  /dev/mem: Avoid overwriting "err" in read_mem()
  eeprom: at24: use SPDX identifier instead of GPL boiler-plate
  eeprom: at24: simplify the i2c functionality checking
  eeprom: at24: fix a line break
  eeprom: at24: tweak newlines
  eeprom: at24: refactor at24_probe()
  ...
2018-04-04 20:07:20 -07:00
Linus Torvalds
a5532439eb Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 timer updates from Ingo Molnar:
 "Two changes: add the new convert_art_ns_to_tsc() API for upcoming
  Intel Goldmont+ drivers, and remove the obsolete rdtscll() API"

* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsc: Get rid of rdtscll()
  x86/tsc: Convert ART in nanoseconds to TSC
2018-04-02 16:18:31 -07:00
Linus Torvalds
cea061e455 Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 platform updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Add "Jailhouse" hypervisor support (Jan Kiszka)

   - Update DeviceTree support (Ivan Gorinov)

   - Improve DMI date handling (Andy Shevchenko)"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/PCI: Fix a potential regression when using dmi_get_bios_year()
  firmware/dmi_scan: Uninline dmi_get_bios_year() helper
  x86/devicetree: Use CPU description from Device Tree
  of/Documentation: Specify local APIC ID in "reg"
  MAINTAINERS: Add entry for Jailhouse
  x86/jailhouse: Allow to use PCI_MMCONFIG without ACPI
  x86: Consolidate PCI_MMCONFIG configs
  x86: Align x86_64 PCI_MMCONFIG with 32-bit variant
  x86/jailhouse: Enable PCI mmconfig access in inmates
  PCI: Scan all functions when running over Jailhouse
  jailhouse: Provide detection for non-x86 systems
  x86/devicetree: Fix device IRQ settings in DT
  x86/devicetree: Initialize device tree before using it
  pci: Simplify code by using the new dmi_get_bios_year() helper
  ACPI/sleep: Simplify code by using the new dmi_get_bios_year() helper
  x86/pci: Simplify code by using the new dmi_get_bios_year() helper
  dmi: Introduce the dmi_get_bios_year() helper function
  x86/platform/quark: Re-use DEFINE_SHOW_ATTRIBUTE() macro
  x86/platform/atom: Re-use DEFINE_SHOW_ATTRIBUTE() macro
2018-04-02 16:15:32 -07:00
Linus Torvalds
d22fff8141 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:

 - Extend the memmap= boot parameter syntax to allow the redeclaration
   and dropping of existing ranges, and to support all e820 range types
   (Jan H. Schönherr)

 - Improve the W+X boot time security checks to remove false positive
   warnings on Xen (Jan Beulich)

 - Support booting as Xen PVH guest (Juergen Gross)

 - Improved 5-level paging (LA57) support, in particular it's possible
   now to have a single kernel image for both 4-level and 5-level
   hardware (Kirill A. Shutemov)

 - AMD hardware RAM encryption support (SME/SEV) fixes (Tom Lendacky)

 - Preparatory commits for hardware-encrypted RAM support on Intel CPUs.
   (Kirill A. Shutemov)

 - Improved Intel-MID support (Andy Shevchenko)

 - Show EFI page tables in page_tables debug files (Andy Lutomirski)

 - ... plus misc fixes and smaller cleanups

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits)
  x86/cpu/tme: Fix spelling: "configuation" -> "configuration"
  x86/boot: Fix SEV boot failure from change to __PHYSICAL_MASK_SHIFT
  x86/mm: Update comment in detect_tme() regarding x86_phys_bits
  x86/mm/32: Remove unused node_memmap_size_bytes() & CONFIG_NEED_NODE_MEMMAP_SIZE logic
  x86/mm: Remove pointless checks in vmalloc_fault
  x86/platform/intel-mid: Add special handling for ACPI HW reduced platforms
  ACPI, x86/boot: Introduce the ->reduced_hw_early_init() ACPI callback
  ACPI, x86/boot: Split out acpi_generic_reduce_hw_init() and export
  x86/pconfig: Provide defines and helper to run MKTME_KEY_PROG leaf
  x86/pconfig: Detect PCONFIG targets
  x86/tme: Detect if TME and MKTME is activated by BIOS
  x86/boot/compressed/64: Handle 5-level paging boot if kernel is above 4G
  x86/boot/compressed/64: Use page table in trampoline memory
  x86/boot/compressed/64: Use stack from trampoline memory
  x86/boot/compressed/64: Make sure we have a 32-bit code segment
  x86/mm: Do not use paravirtualized calls in native_set_p4d()
  kdump, vmcoreinfo: Export pgtable_l5_enabled value
  x86/boot/compressed/64: Prepare new top-level page table for trampoline
  x86/boot/compressed/64: Set up trampoline memory
  x86/boot/compressed/64: Save and restore trampoline memory
  ...
2018-04-02 15:45:30 -07:00
Linus Torvalds
86bbbebac1 Merge branch 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 RAS updates from Ingo Molnar:
 "The main changes in this cycle were:

   - AMD MCE support/decoding improvements (Yazen Ghannam)

   - general MCE header cleanups and reorganization (Borislav Petkov)"

* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "x86/mce/AMD: Collect error info even if valid bits are not set"
  x86/MCE: Cleanup and complete struct mce fields definitions
  x86/mce/AMD: Carve out SMCA get_block_address() code
  x86/mce/AMD: Get address from already initialized block
  x86/mce/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type
  x86/mce/AMD: Pass the bank number to smca_get_bank_type()
  x86/mce/AMD: Collect error info even if valid bits are not set
  x86/mce: Issue the 'mcelog --ascii' message only on !AMD
  x86/mce: Convert 'struct mca_config' bools to a bitfield
  x86/mce: Put private structures and definitions into the internal header
2018-04-02 11:47:07 -07:00
Colin Ian King
eaeb8e76cd x86/cpu/tme: Fix spelling: "configuation" -> "configuration"
Trivial fix to spelling mistake in the pr_err_once() error message text.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20180313154709.1015-1-colin.king@canonical.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-31 10:46:40 +02:00
Vitaly Kuznetsov
5431390b30 x86/hyper-v: detect nested features
TLFS 5.0 says: "Support for an enlightened VMCS interface is reported with
CPUID leaf 0x40000004. If an enlightened VMCS interface is supported,
 additional nested enlightenments may be discovered by reading the CPUID
leaf 0x4000000A (see 2.4.11)."

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-28 22:47:06 +02:00
Vitaly Kuznetsov
415bd1cd3a x86/hyper-v: move definitions from TLFS to hyperv-tlfs.h
mshyperv.h now only contains fucntions/variables we define in kernel, all
definitions from TLFS should go to hyperv-tlfs.h.

'enum hv_cpuid_function' is removed as we already have this info in
hyperv-tlfs.h, code in mshyperv.c is adjusted accordingly.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-28 22:47:06 +02:00
Vitaly Kuznetsov
5a48580322 x86/hyper-v: move hyperv.h out of uapi
hyperv.h is not part of uapi, there are no (known) users outside of kernel.
We are making changes to this file to match current Hyper-V Hypervisor
Top-Level Functional Specification (TLFS, see:
https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs)
and we don't want to maintain backwards compatibility.

Move the file renaming to hyperv-tlfs.h to avoid confusing it with
mshyperv.h. In future, all definitions from TLFS should go to it and
all kernel objects should go to mshyperv.h or include/linux/hyperv.h.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2018-03-28 22:47:06 +02:00
Yazen Ghannam
e2efacb6a5 Revert "x86/mce/AMD: Collect error info even if valid bits are not set"
This reverts commit 4b1e84276a.

Software uses the valid bits to decide if the values can be used for
further processing or other actions. So setting the valid bits will have
software act on values that it shouldn't be acting on.

The recommendation to save all the register values does not mean that
the values are always valid.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: tony.luck@intel.com
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Cc: bp@suse.de
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/20180326191526.64314-1-Yazen.Ghannam@amd.com
2018-03-28 20:34:59 +02:00
Greg Kroah-Hartman
b24d0d5b12 Merge 4.16-rc7 into char-misc-next
We want the hyperv fix in here for merging and testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28 12:27:35 +02:00
Kirill A. Shutemov
547edaca24 x86/mm: Update comment in detect_tme() regarding x86_phys_bits
As Kai pointed out, the primary reason for adjusting x86_phys_bits is to
reflect that the the address space is reduced and not the ability to
communicate the available physical address space to virtual machines.

Suggested-by: Kai Huang <kai.huang@linux.intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: linux-mm@kvack.org
Link: https://lkml.kernel.org/r/20180315134907.9311-2-kirill.shutemov@linux.intel.com
2018-03-27 11:49:58 +02:00
Jaak Ristioja
1897a9691e Documentation: Fix early-microcode.txt references after file rename
The file Documentation/x86/early-microcode.txt was renamed to
Documentation/x86/microcode.txt in 0e3258753f, but it was still
referenced by its old name in a three places:

* Documentation/x86/00-INDEX
* arch/x86/Kconfig
* arch/x86/kernel/cpu/microcode/amd.c

This commit updates these references accordingly.

Fixes: 0e3258753f ("x86/microcode: Document the three loading methods")
Signed-off-by: Jaak Ristioja <jaak@ristioja.ee>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-03-27 09:51:23 +02:00
Ingo Molnar
0bc91d4ba7 Merge tag 'v4.16-rc7' into x86/mm, to fix up conflict
Conflicts:
	arch/x86/mm/init_64.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-27 08:43:39 +02:00
Thomas Gleixner
ea89c06548 x86/tsc: Get rid of rdtscll()
Commit 99770737ca ("x86/asm/tsc: Add rdtscll() merge helper") added
rdtscll() in August 2015 along with the comment:

 /* Deprecated, keep it for a cycle for easier merging: */

12 cycles later it's really overdue for removal.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2018-03-23 20:07:54 +01:00
Linus Torvalds
9e1909b9da Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86/pti updates from Thomas Gleixner:
 "Another set of melted spectrum updates:

   - Iron out the last late microcode loading issues by actually
     checking whether new microcode is present and preventing the CPU
     synchronization to run into a timeout induced hang.

   - Remove Skylake C2 from the microcode blacklist according to the
     latest Intel documentation

   - Fix the VM86 POPF emulation which traps if VIP is set, but VIF is
     not. Enhance the selftests to catch that kind of issue

   - Annotate indirect calls/jumps for objtool on 32bit. This is not a
     functional issue, but for consistency sake its the right thing to
     do.

   - Fix a jump label build warning observed on SPARC64 which uses 32bit
     storage for the code location which is casted to 64 bit pointer w/o
     extending it to 64bit first.

   - Add two new cpufeature bits. Not really an urgent issue, but
     provides them for both x86 and x86/kvm work. No impact on the
     current kernel"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode: Fix CPU synchronization routine
  x86/microcode: Attempt late loading only when new microcode is present
  x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
  jump_label: Fix sparc64 warning
  x86/speculation, objtool: Annotate indirect calls/jumps for objtool on 32-bit kernels
  x86/vm86/32: Fix POPF emulation
  selftests/x86/entry_from_vm86: Add test cases for POPF
  selftests/x86/entry_from_vm86: Exit with 1 if we fail
  x86/cpufeatures: Add Intel PCONFIG cpufeature
  x86/cpufeatures: Add Intel Total Memory Encryption cpufeature
2018-03-18 12:03:15 -07:00
Vitaly Kuznetsov
35060ed6a1 x86/kvm/vmx: avoid expensive rdmsr for MSR_GS_BASE
vmx_save_host_state() is only called from kvm_arch_vcpu_ioctl_run() so
the context is pretty well defined and as we're past 'swapgs' MSR_GS_BASE
should contain kernel's GS base which we point to irq_stack_union.

Add new kernelmode_gs_base() API, irq_stack_union needs to be exported
as KVM can be build as module.

Acked-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-03-16 22:03:54 +01:00
Borislav Petkov
bb8c13d61a x86/microcode: Fix CPU synchronization routine
Emanuel reported an issue with a hang during microcode update because my
dumb idea to use one atomic synchronization variable for both rendezvous
- before and after update - was simply bollocks:

  microcode: microcode_reload_late: late_cpus: 4
  microcode: __reload_late: cpu 2 entered
  microcode: __reload_late: cpu 1 entered
  microcode: __reload_late: cpu 3 entered
  microcode: __reload_late: cpu 0 entered
  microcode: __reload_late: cpu 1 left
  microcode: Timeout while waiting for CPUs rendezvous, remaining: 1

CPU1 above would finish, leave and the others will still spin waiting for
it to join.

So do two synchronization atomics instead, which makes the code a lot more
straightforward.

Also, since the update is serialized and it also takes quite some time per
microcode engine, increase the exit timeout by the number of CPUs on the
system.

That's ok because the moment all CPUs are done, that timeout will be cut
short.

Furthermore, panic when some of the CPUs timeout when returning from a
microcode update: we can't allow a system with not all cores updated.

Also, as an optimization, do not do the exit sync if microcode wasn't
updated.

Reported-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20180314183615.17629-2-bp@alien8.de
2018-03-16 20:55:51 +01:00
Borislav Petkov
2613f36ed9 x86/microcode: Attempt late loading only when new microcode is present
Return UCODE_NEW from the scanning functions to denote that new microcode
was found and only then attempt the expensive synchronization dance.

Reported-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Emanuel Czirai <xftroxgpx@protonmail.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20180314183615.17629-1-bp@alien8.de
2018-03-16 20:55:51 +01:00
Alexander Sergeyev
e3b3121fa8 x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
In accordance with Intel's microcode revision guidance from March 6 MCU
rev 0xc2 is cleared on both Skylake H/S and Skylake Xeon E3 processors
that share CPUID 506E3.

Signed-off-by: Alexander Sergeyev <sergeev917@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jia Zhang <qianyue.zj@alibaba-inc.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kyle Huey <me@kylehuey.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180313193856.GA8580@localhost.localdomain
2018-03-16 12:33:11 +01:00