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The current handling of MSR_IA32_ENERGY_PERF_BIAS in the kernel is
problematic, because it may cause changes made by user space to that
MSR (with the help of the x86_energy_perf_policy tool, for example)
to be lost every time a CPU goes offline and then back online as well
as during system-wide power management transitions into sleep states
and back into the working state.
The first problem is that if the current EPB value for a CPU going
online is 0 ('performance'), the kernel will change it to 6 ('normal')
regardless of whether or not this is the first bring-up of that CPU.
That also happens during system-wide resume from sleep states
(including, but not limited to, hibernation). However, the EPB may
have been adjusted by user space this way and the kernel should not
blindly override that setting.
The second problem is that if the platform firmware resets the EPB
values for any CPUs during system-wide resume from a sleep state,
the kernel will not restore their previous EPB values that may
have been set by user space before the preceding system-wide
suspend transition. Again, that behavior may at least be confusing
from the user space perspective.
In order to address these issues, rework the handling of
MSR_IA32_ENERGY_PERF_BIAS so that the EPB value is saved on CPU
offline and restored on CPU online as well as (for the boot CPU)
during the syscore stages of system-wide suspend and resume
transitions, respectively.
However, retain the policy by which the EPB is set to 6 ('normal')
on the first bring-up of each CPU if its initial value is 0, based
on the observation that 0 may mean 'not initialized' just as well as
'performance' in that case.
While at it, move the MSR_IA32_ENERGY_PERF_BIAS handling code into
a separate file and document it in Documentation/admin-guide.
Fixes: abe48b108247 (x86, intel, power: Initialize MSR_IA32_ENERGY_PERF_BIAS)
Fixes: b51ef52df71c (x86/cpu: Restore MSR_IA32_ENERGY_PERF_BIAS after resume)
Reported-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
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The check for Spectre microcodes does not check for family 6, only the
model numbers.
Add a family 6 check to avoid ambiguity with other families.
Fixes: a5b296636453 ("x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180824170351.34874-2-andi@firstfloor.org
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Merge L1 Terminal Fault fixes from Thomas Gleixner:
"L1TF, aka L1 Terminal Fault, is yet another speculative hardware
engineering trainwreck. It's a hardware vulnerability which allows
unprivileged speculative access to data which is available in the
Level 1 Data Cache when the page table entry controlling the virtual
address, which is used for the access, has the Present bit cleared or
other reserved bits set.
If an instruction accesses a virtual address for which the relevant
page table entry (PTE) has the Present bit cleared or other reserved
bits set, then speculative execution ignores the invalid PTE and loads
the referenced data if it is present in the Level 1 Data Cache, as if
the page referenced by the address bits in the PTE was still present
and accessible.
While this is a purely speculative mechanism and the instruction will
raise a page fault when it is retired eventually, the pure act of
loading the data and making it available to other speculative
instructions opens up the opportunity for side channel attacks to
unprivileged malicious code, similar to the Meltdown attack.
While Meltdown breaks the user space to kernel space protection, L1TF
allows to attack any physical memory address in the system and the
attack works across all protection domains. It allows an attack of SGX
and also works from inside virtual machines because the speculation
bypasses the extended page table (EPT) protection mechanism.
The assoicated CVEs are: CVE-2018-3615, CVE-2018-3620, CVE-2018-3646
The mitigations provided by this pull request include:
- Host side protection by inverting the upper address bits of a non
present page table entry so the entry points to uncacheable memory.
- Hypervisor protection by flushing L1 Data Cache on VMENTER.
- SMT (HyperThreading) control knobs, which allow to 'turn off' SMT
by offlining the sibling CPU threads. The knobs are available on
the kernel command line and at runtime via sysfs
- Control knobs for the hypervisor mitigation, related to L1D flush
and SMT control. The knobs are available on the kernel command line
and at runtime via sysfs
- Extensive documentation about L1TF including various degrees of
mitigations.
Thanks to all people who have contributed to this in various ways -
patches, review, testing, backporting - and the fruitful, sometimes
heated, but at the end constructive discussions.
There is work in progress to provide other forms of mitigations, which
might be less horrible performance wise for a particular kind of
workloads, but this is not yet ready for consumption due to their
complexity and limitations"
* 'l1tf-final' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits)
x86/microcode: Allow late microcode loading with SMT disabled
tools headers: Synchronise x86 cpufeatures.h for L1TF additions
x86/mm/kmmio: Make the tracer robust against L1TF
x86/mm/pat: Make set_memory_np() L1TF safe
x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert
x86/speculation/l1tf: Invert all not present mappings
cpu/hotplug: Fix SMT supported evaluation
KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry
x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry
x86/speculation: Simplify sysfs report of VMX L1TF vulnerability
Documentation/l1tf: Remove Yonah processors from not vulnerable list
x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr()
x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d
x86: Don't include linux/irq.h from asm/hardirq.h
x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d
x86/irq: Demote irq_cpustat_t::__softirq_pending to u16
x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush()
x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond'
x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush()
cpu/hotplug: detect SMT disabled by BIOS
...
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Some Intel processors have an EPT feature whereby the accessed & dirty bits
in EPT entries can be updated by HW. MSR IA32_VMX_EPT_VPID_CAP exposes the
presence of this capability.
There is no point in trying to use that new feature bit in the VMX code as
VMX needs to read the MSR anyway to access other bits, but having the
feature bit for EPT_AD in place helps virtualization management as it
exposes "ept_ad" in /proc/cpuinfo/$proc/flags if the feature is present.
[ tglx: Amended changelog ]
Signed-off-by: Peter Feiner <pfeiner@google.com>
Signed-off-by: Peter Shier <pshier@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180801180657.138051-1-pshier@google.com
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Make use of the new early detection function to initialize smp_num_siblings
on the boot cpu before the MP-Table or ACPI/MADT scan happens. That's
required for force disabling SMT.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
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Pull x86 boot updates from Ingo Molnar:
- Centaur CPU updates (David Wang)
- AMD and other CPU topology enumeration improvements and fixes
(Borislav Petkov, Thomas Gleixner, Suravee Suthikulpanit)
- Continued 5-level paging work (Kirill A. Shutemov)
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Mark __pgtable_l5_enabled __initdata
x86/mm: Mark p4d_offset() __always_inline
x86/mm: Introduce the 'no5lvl' kernel parameter
x86/mm: Stop pretending pgtable_l5_enabled is a variable
x86/mm: Unify pgtable_l5_enabled usage in early boot code
x86/boot/compressed/64: Fix trampoline page table address calculation
x86/CPU: Move x86_cpuinfo::x86_max_cores assignment to detect_num_cpu_cores()
x86/Centaur: Report correct CPU/cache topology
x86/CPU: Move cpu_detect_cache_sizes() into init_intel_cacheinfo()
x86/CPU: Make intel_num_cpu_cores() generic
x86/CPU: Move cpu local function declarations to local header
x86/CPU/AMD: Derive CPU topology from CPUID function 0xB when available
x86/CPU: Modify detect_extended_topology() to return result
x86/CPU/AMD: Calculate last level cache ID from number of sharing threads
x86/CPU: Rename intel_cacheinfo.c to cacheinfo.c
perf/events/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id
x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present
x86/Centaur: Initialize supported CPU features properly
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The SSBD enumeration is similarly to the other bits magically shared
between Intel and AMD though the mechanisms are different.
Make X86_FEATURE_SSBD synthetic and set it depending on the vendor specific
features or family dependent setup.
Change the Intel bit to X86_FEATURE_SPEC_CTRL_SSBD to denote that SSBD is
controlled via MSR_SPEC_CTRL and fix up the usage sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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The availability of the SPEC_CTRL MSR is enumerated by a CPUID bit on
Intel and implied by IBRS or STIBP support on AMD. That's just confusing
and in case an AMD CPU has IBRS not supported because the underlying
problem has been fixed but has another bit valid in the SPEC_CTRL MSR,
the thing falls apart.
Add a synthetic feature bit X86_FEATURE_MSR_SPEC_CTRL to denote the
availability on both Intel and AMD.
While at it replace the boot_cpu_has() checks with static_cpu_has() where
possible. This prevents late microcode loading from exposing SPEC_CTRL, but
late loading is already very limited as it does not reevaluate the
mitigation options and other bits and pieces. Having static_cpu_has() is
the simplest and least fragile solution.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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No point to have it at the call sites.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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There is no point in having the conditional cpu_detect_cache_sizes() call
at the callsite of init_intel_cacheinfo().
Move it into init_intel_cacheinfo() and make init_intel_cacheinfo() void.
[ tglx: Made the init_intel_cacheinfo() void as the return value was
pointless. Adjust changelog accordingly ]
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/1525314766-18910-3-git-send-email-davidwang@zhaoxin.com
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intel_num_cpu_cores() is a static function in intel.c which can't be used
by other files. Define another function called detect_num_cpu_cores() in
common.c to replace this function so it can be reused.
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/1525314766-18910-2-git-send-email-davidwang@zhaoxin.com
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Intel collateral will reference the SSB mitigation bit in IA32_SPEC_CTL[2]
as SSBD (Speculative Store Bypass Disable).
Hence changing it.
It is unclear yet what the MSR_IA32_ARCH_CAPABILITIES (0x10a) Bit(4) name
is going to be. Following the rename it would be SSBD_NO but that rolls out
to Speculative Store Bypass Disable No.
Also fixed the missing space in X86_FEATURE_AMD_SSBD.
[ tglx: Fixup x86_amd_rds_enable() and rds_tif_to_amd_ls_cfg() as well ]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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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>
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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
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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>
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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
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Conflicts:
arch/x86/mm/init_64.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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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
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IA32_TME_ACTIVATE MSR (0x982) can be used to check if BIOS has enabled
TME and MKTME. It includes which encryption policy/algorithm is selected
for TME or available for MKTME. For MKTME, the MSR also enumerates how
many KeyIDs are available.
We would need to exclude KeyID bits from physical address bits.
detect_tme() would adjust cpuinfo_x86::x86_phys_bits accordingly.
We have to do this even if we are not going to use KeyID bits
ourself. VM guests still have to know that these bits are not usable
for physical address.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kai Huang <kai.huang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180305162610.37510-3-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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As:
1) It's known that hypervisors lie about the environment anyhow (host
mismatch)
2) Even if the hypervisor (Xen, KVM, VMWare, etc) provided a valid
"correct" value, it all gets to be very murky when migration happens
(do you provide the "new" microcode of the machine?).
And in reality the cloud vendors are the ones that should make sure that
the microcode that is running is correct and we should just sing lalalala
and trust them.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Wanpeng Li <kernellwp@gmail.com>
Cc: kvm <kvm@vger.kernel.org>
Cc: Krčmář <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180226213019.GE9497@char.us.oracle.com
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x86_mask is a confusing name which is hard to associate with the
processor's stepping.
Additionally, correct an indent issue in lib/cpu.c.
Signed-off-by: Jia Zhang <qianyue.zj@alibaba-inc.com>
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Arjan points out that the Intel document only clears the 0xc2 microcode
on *some* parts with CPUID 506E3 (INTEL_FAM6_SKYLAKE_DESKTOP stepping 3).
For the Skylake H/S platform it's OK but for Skylake E3 which has the
same CPUID it isn't (yet) cleared.
So removing it from the blacklist was premature. Put it back for now.
Also, Arjan assures me that the 0x84 microcode for Kaby Lake which was
featured in one of the early revisions of the Intel document was never
released to the public, and won't be until/unless it is also validated
as safe. So those can change to 0x80 which is what all *other* versions
of the doc have identified.
Once the retrospective testing of existing public microcodes is done, we
should be back into a mode where new microcodes are only released in
batches and we shouldn't even need to update the blacklist for those
anyway, so this tweaking of the list isn't expected to be a thing which
keeps happening.
Requested-by: Arjan van de Ven <arjan.van.de.ven@intel.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: dave.hansen@intel.com
Cc: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1518449255-2182-1-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Intel have retroactively blessed the 0xc2 microcode on Skylake mobile
and desktop parts, and the Gemini Lake 0x22 microcode is apparently fine
too. We blacklisted the latter purely because it was present with all
the other problematic ones in the 2018-01-08 release, but now it's
explicitly listed as OK.
We still list 0x84 for the various Kaby Lake / Coffee Lake parts, as
that appeared in one version of the blacklist and then reverted to
0x80 again. We can change it if 0x84 is actually announced to be safe.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan.van.de.ven@intel.com
Cc: jmattson@google.com
Cc: karahmed@amazon.de
Cc: kvm@vger.kernel.org
Cc: pbonzini@redhat.com
Cc: rkrcmar@redhat.com
Cc: sironi@amazon.de
Link: http://lkml.kernel.org/r/1518305967-31356-2-git-send-email-dwmw@amazon.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Despite the fact that all the other code there seems to be doing it, just
using set_cpu_cap() in early_intel_init() doesn't actually work.
For CPUs with PKU support, setup_pku() calls get_cpu_cap() after
c->c_init() has set those feature bits. That resets those bits back to what
was queried from the hardware.
Turning the bits off for bad microcode is easy to fix. That can just use
setup_clear_cpu_cap() to force them off for all CPUs.
I was less keen on forcing the feature bits *on* that way, just in case
of inconsistencies. I appreciate that the kernel is going to get this
utterly wrong if CPU features are not consistent, because it has already
applied alternatives by the time secondary CPUs are brought up.
But at least if setup_force_cpu_cap() isn't being used, we might have a
chance of *detecting* the lack of the corresponding bit and either
panicking or refusing to bring the offending CPU online.
So ensure that the appropriate feature bits are set within get_cpu_cap()
regardless of how many extra times it's called.
Fixes: 2961298e ("x86/cpufeatures: Clean up Spectre v2 related CPUID flags")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: karahmed@amazon.de
Cc: peterz@infradead.org
Cc: bp@alien8.de
Link: https://lkml.kernel.org/r/1517322623-15261-1-git-send-email-dwmw@amazon.co.uk
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Time has come to switch PTI development over to a v4.15 base - we'll still
try to make sure that all PTI fixes backport cleanly to v4.14 and earlier.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We want to expose the hardware features simply in /proc/cpuinfo as "ibrs",
"ibpb" and "stibp". Since AMD has separate CPUID bits for those, use them
as the user-visible bits.
When the Intel SPEC_CTRL bit is set which indicates both IBRS and IBPB
capability, set those (AMD) bits accordingly. Likewise if the Intel STIBP
bit is set, set the AMD STIBP that's used for the generic hardware
capability.
Hide the rest from /proc/cpuinfo by putting "" in the comments. Including
RETPOLINE and RETPOLINE_AMD which shouldn't be visible there. There are
patches to make the sysfs vulnerabilities information non-readable by
non-root, and the same should apply to all information about which
mitigations are actually in use. Those *shouldn't* appear in /proc/cpuinfo.
The feature bit for whether IBPB is actually used, which is needed for
ALTERNATIVEs, is renamed to X86_FEATURE_USE_IBPB.
Originally-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ak@linux.intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1517070274-12128-2-git-send-email-dwmw@amazon.co.uk
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This doesn't refuse to load the affected microcodes; it just refuses to
use the Spectre v2 mitigation features if they're detected, by clearing
the appropriate feature bits.
The AMD CPUID bits are handled here too, because hypervisors *may* have
been exposing those bits even on Intel chips, for fine-grained control
of what's available.
It is non-trivial to use x86_match_cpu() for this table because that
doesn't handle steppings. And the approach taken in commit bd9240a18
almost made me lose my lunch.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: ak@linux.intel.com
Cc: ashok.raj@intel.com
Cc: dave.hansen@intel.com
Cc: karahmed@amazon.de
Cc: arjan@linux.intel.com
Cc: torvalds@linux-foundation.org
Cc: peterz@infradead.org
Cc: bp@alien8.de
Cc: pbonzini@redhat.com
Cc: tim.c.chen@linux.intel.com
Cc: gregkh@linux-foundation.org
Link: https://lkml.kernel.org/r/1516896855-7642-7-git-send-email-dwmw@amazon.co.uk
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Fix up makefiles, remove references, and git rm kmemcheck.
Link: http://lkml.kernel.org/r/20171007030159.22241-4-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
When enabled, the processor will fault on attempts to execute the CPUID
instruction with CPL>0. Exposing this feature to userspace will allow a
ptracer to trap and emulate the CPUID instruction.
When supported, this feature is controlled by toggling bit 0 of
MSR_MISC_FEATURES_ENABLES. It is documented in detail in Section 2.3.2 of
https://bugzilla.kernel.org/attachment.cgi?id=243991
Implement a new pair of arch_prctls, available on both x86-32 and x86-64.
ARCH_GET_CPUID: Returns the current CPUID state, either 0 if CPUID faulting
is enabled (and thus the CPUID instruction is not available) or 1 if
CPUID faulting is not enabled.
ARCH_SET_CPUID: Set the CPUID state to the second argument. If
cpuid_enabled is 0 CPUID faulting will be activated, otherwise it will
be deactivated. Returns ENODEV if CPUID faulting is not supported on
this system.
The state of the CPUID faulting flag is propagated across forks, but reset
upon exec.
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack <dmatlack@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170320081628.18952-9-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
When enabled, the processor will fault on attempts to execute the CPUID
instruction with CPL>0. This will allow a ptracer to emulate the CPUID
instruction.
Bit 31 of MSR_PLATFORM_INFO advertises support for this feature. It is
documented in detail in Section 2.3.2 of
https://bugzilla.kernel.org/attachment.cgi?id=243991
Detect support for this feature and expose it as X86_FEATURE_CPUID_FAULT.
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack <dmatlack@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170320081628.18952-8-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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This matches the only public Intel documentation of this MSR, in the
"Virtualization Technology FlexMigration Application Note"
(preserved at https://bugzilla.kernel.org/attachment.cgi?id=243991)
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Robert O'Callahan <robert@ocallahan.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack <dmatlack@google.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/r/20170320081628.18952-2-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Pull scheduler fixes from Ingo Molnar:
"A fix for KVM's scheduler clock which (erroneously) was always marked
unstable, a fix for RT/DL load balancing, plus latency fixes"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface
sched/core: Fix pick_next_task() for RT,DL
sched/fair: Make select_idle_cpu() more aggressive
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Wanpeng Li reported that since the following commit:
acb04058de49 ("sched/clock: Fix hotplug crash")
... KVM always runs with unstable sched-clock even though KVM's
kvm_clock _is_ stable.
The problem is that we've tied clear_sched_clock_stable() to the TSC
state, and overlooked that sched_clock() is a paravirt function.
Solve this by doing two things:
- tie the sched_clock() stable state more clearly to the TSC stable
state for the normal (!paravirt) case.
- only call clear_sched_clock_stable() when we mark TSC unstable
when we use native_sched_clock().
The first means we can actually run with stable sched_clock in more
situations then before, which is good. And since commit:
12907fbb1a69 ("sched/clock, clocksource: Add optional cs::mark_unstable() method")
... this should be reliable. Since any detection of TSC fail now results
in marking the TSC unstable.
Reported-by: Wanpeng Li <kernellwp@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: acb04058de49 ("sched/clock: Fix hotplug crash")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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We are going to split <linux/sched/clock.h> out of <linux/sched.h>, which
will have to be picked up from other headers and .c files.
Create a trivial placeholder <linux/sched/clock.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Pull x86 cpufeature updates from Ingo Molnar:
"The main changes in this cycle were related to enable ring-3
MONITOR/MWAIT instructions support on supported CPUs, by Grzegorz
Andrejczuk and Piotr Luc"
* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpufeature: Move RING3MWAIT feature to avoid conflicts
x86/cpufeature: Enable RING3MWAIT for Knights Mill
x86/cpufeature: Enable RING3MWAIT for Knights Landing
x86/cpufeature: Add RING3MWAIT to CPU features
x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT
x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit
x86/cpufeature: Add AVX512_VPOPCNTDQ feature
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Enable ring 3 MONITOR/MWAIT for Intel Xeon Phi codenamed Knights Mill. We
can't guarantee that this (KNM) will be the last CPU model that needs this
hack. But, we do recognize that this is far from optimal, and there is an
effort to ensure we don't keep doing extending this hack forever.
Signed-off-by: Piotr Luc <piotr.luc@intel.com>
Cc: Piotr.Luc@intel.com
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/r/1484918557-15481-6-git-send-email-grzegorz.andrejczuk@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Enable ring 3 MONITOR/MWAIT for Intel Xeon Phi x200 codenamed Knights
Landing.
Presence of this feature cannot be detected automatically (by reading any
other MSR) therefore it is required to explicitly check for the family and
model of the CPU before attempting to enable it.
Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Piotr.Luc@intel.com
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/r/1484918557-15481-5-git-send-email-grzegorz.andrejczuk@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Mike reported that he could trigger the WARN_ON_ONCE() in
set_sched_clock_stable() using hotplug.
This exposed a fundamental problem with the interface, we should never
mark the TSC stable if we ever find it to be unstable. Therefore
set_sched_clock_stable() is a broken interface.
The reason it existed is that not having it is a pain, it means all
relevant architecture code needs to call clear_sched_clock_stable()
where appropriate.
Of the three architectures that select HAVE_UNSTABLE_SCHED_CLOCK ia64
and parisc are trivial in that they never called
set_sched_clock_stable(), so add an unconditional call to
clear_sched_clock_stable() to them.
For x86 the story is a lot more involved, and what this patch tries to
do is ensure we preserve the status quo. So even is Cyrix or Transmeta
have usable TSC they never called set_sched_clock_stable() so they now
get an explicit mark unstable.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 9881b024b7d7 ("sched/clock: Delay switching sched_clock to stable")
Link: http://lkml.kernel.org/r/20170119133633.GB6536@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Since on Intel we're required to do CPUID(1) first, before reading
the microcode revision MSR, let's add a special helper which does the
required steps so that we don't forget to do them next time, when we
want to read the microcode revision.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Intel supplies the microcode revision value in MSR 0x8b
(IA32_BIOS_SIGN_ID) after CPUID(1) has been executed. Execute it each
time before reading that MSR.
It used to do sync_core() which did do CPUID but
c198b121b1a1 ("x86/asm: Rewrite sync_core() to use IRET-to-self")
changed the sync_core() implementation so we better make the microcode
loading case explicit, as the SDM documents it.
Reported-and-tested-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-3-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Pull x86 header cleanups from Ingo Molnar:
"This tree is a cleanup of the x86 tree reducing spurious uses of
module.h - which should improve build performance a bit"
* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, crypto: Restore MODULE_LICENSE() to glue_helper.c so it loads
x86/apic: Remove duplicated include from probe_64.c
x86/ce4100: Remove duplicated include from ce4100.c
x86/headers: Include spinlock_types.h in x8664_ksyms_64.c for missing spinlock_t
x86/platform: Delete extraneous MODULE_* tags fromm ts5500
x86: Audit and remove any remaining unnecessary uses of module.h
x86/kvm: Audit and remove any unnecessary uses of module.h
x86/xen: Audit and remove any unnecessary uses of module.h
x86/platform: Audit and remove any unnecessary uses of module.h
x86/lib: Audit and remove any unnecessary uses of module.h
x86/kernel: Audit and remove any unnecessary uses of module.h
x86/mm: Audit and remove any unnecessary uses of module.h
x86: Don't use module.h just for AUTHOR / LICENSE tags
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Monitored cached line may not wake up from mwait on certain
Goldmont based CPUs. This patch will avoid calling
current_set_polling_and_test() and thereby not set the TIF_ flag.
The result is that we'll always send IPIs for wakeups.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1468867270-18493-1-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.
Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed. Build testing
revealed some implicit header usage that was fixed up accordingly.
Note that some bool/obj-y instances remain since module.h is
the header for some exception table entry stuff, and for things
like __init_or_module (code that is tossed when MODULES=n).
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This erratum essentially causes the CPU to forget which privilege
level it is operating on (kernel vs. user) for the purposes of MPX.
This erratum can only be triggered when a system is not using
Supervisor Mode Execution Prevention (SMEP). Our workaround for
the erratum is to ensure that MPX can only be used in cases where
SMEP is present in the processor and is enabled.
This erratum only affects Core processors. Atom is unaffected.
But, there is no architectural way to determine Atom vs. Core.
So, we just apply this workaround to all processors. It's
possible that it will mistakenly disable MPX on some Atom
processsors or future unaffected Core processors. There are
currently no processors that have MPX and not SMEP. It would
take something akin to a hypervisor masking SMEP out on an Atom
processor for this to present itself on current hardware.
More details can be found at:
http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/desktop-6th-gen-core-family-spec-update.pdf
"
SKD046 Branch Instructions May Initialize MPX Bound Registers Incorrectly
Problem:
Depending on the current Intel MPX (Memory Protection
Extensions) configuration, execution of certain branch
instructions (near CALL, near RET, near JMP, and Jcc
instructions) without a BND prefix (F2H) initialize the MPX bound
registers. Due to this erratum, such a branch instruction that is
executed both with CPL = 3 and with CPL < 3 may not use the
correct MPX configuration register (BNDCFGU or BNDCFGS,
respectively) for determining whether to initialize the bound
registers; it may thus initialize the bound registers when it
should not, or fail to initialize them when it should.
Implication:
A branch instruction that has executed both in user mode and in
supervisor mode (from the same linear address) may cause a #BR
(bound range fault) when it should not have or may not cause a
#BR when it should have. Workaround An operating system can
avoid this erratum by setting CR4.SMEP[bit 20] to enable
supervisor-mode execution prevention (SMEP). When SMEP is
enabled, no code can be executed both with CPL = 3 and with CPL < 3.
"
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160512220400.3B35F1BC@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Pull x86 boot updates from Ingo Molnar:
"The biggest changes in this cycle were:
- prepare for more KASLR related changes, by restructuring, cleaning
up and fixing the existing boot code. (Kees Cook, Baoquan He,
Yinghai Lu)
- simplifly/concentrate subarch handling code, eliminate
paravirt_enabled() usage. (Luis R Rodriguez)"
* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
x86/KASLR: Clarify purpose of each get_random_long()
x86/KASLR: Add virtual address choosing function
x86/KASLR: Return earliest overlap when avoiding regions
x86/KASLR: Add 'struct slot_area' to manage random_addr slots
x86/boot: Add missing file header comments
x86/KASLR: Initialize mapping_info every time
x86/boot: Comment what finalize_identity_maps() does
x86/KASLR: Build identity mappings on demand
x86/boot: Split out kernel_ident_mapping_init()
x86/boot: Clean up indenting for asm/boot.h
x86/KASLR: Improve comments around the mem_avoid[] logic
x86/boot: Simplify pointer casting in choose_random_location()
x86/KASLR: Consolidate mem_avoid[] entries
x86/boot: Clean up pointer casting
x86/boot: Warn on future overlapping memcpy() use
x86/boot: Extract error reporting functions
x86/boot: Correctly bounds-check relocations
x86/KASLR: Clean up unused code from old 'run_size' and rename it to 'kernel_total_size'
x86/boot: Fix "run_size" calculation
x86/boot: Calculate decompression size during boot not build
...
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Rafael J. Wysocki
Andi Kleen
Linus Torvalds
Peter Feiner
Thomas Gleixner
Ingo Molnar
David Wang
Konrad Rzeszutek Wilk
jacek.tomaka@poczta.fm
Colin Ian King
Kirill A. Shutemov
Alexander Sergeyev
Jia Zhang
David Woodhouse
Levin, Alexander (Sasha Levin)
Greg Kroah-Hartman
Kyle Huey
Peter Zijlstra
Piotr Luc
Grzegorz Andrejczuk
Borislav Petkov
Paul Gortmaker
Dave Hansen