Pull x86 page table isolation fixes from Thomas Gleixner:
"A couple of urgent fixes for PTI:
- Fix a PTE mismatch between user and kernel visible mapping of the
cpu entry area (differs vs. the GLB bit) and causes a TLB mismatch
MCE on older AMD K8 machines
- Fix the misplaced CR3 switch in the SYSCALL compat entry code which
causes access to unmapped kernel memory resulting in double faults.
- Fix the section mismatch of the cpu_tss_rw percpu storage caused by
using a different mechanism for declaration and definition.
- Two fixes for dumpstack which help to decode entry stack issues
better
- Enable PTI by default in Kconfig. We should have done that earlier,
but it slipped through the cracks.
- Exclude AMD from the PTI enforcement. Not necessarily a fix, but if
AMD is so confident that they are not affected, then we should not
burden users with the overhead"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/process: Define cpu_tss_rw in same section as declaration
x86/pti: Switch to kernel CR3 at early in entry_SYSCALL_compat()
x86/dumpstack: Print registers for first stack frame
x86/dumpstack: Fix partial register dumps
x86/pti: Make sure the user/kernel PTEs match
x86/cpu, x86/pti: Do not enable PTI on AMD processors
x86/pti: Enable PTI by default
Pull x86 syscall entry code changes for PTI from Ingo Molnar:
"The main changes here are Andy Lutomirski's changes to switch the
x86-64 entry code to use the 'per CPU entry trampoline stack'. This,
besides helping fix KASLR leaks (the pending Page Table Isolation
(PTI) work), also robustifies the x86 entry code"
* 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
x86/cpufeatures: Make CPU bugs sticky
x86/paravirt: Provide a way to check for hypervisors
x86/paravirt: Dont patch flush_tlb_single
x86/entry/64: Make cpu_entry_area.tss read-only
x86/entry: Clean up the SYSENTER_stack code
x86/entry/64: Remove the SYSENTER stack canary
x86/entry/64: Move the IST stacks into struct cpu_entry_area
x86/entry/64: Create a per-CPU SYSCALL entry trampoline
x86/entry/64: Return to userspace from the trampoline stack
x86/entry/64: Use a per-CPU trampoline stack for IDT entries
x86/espfix/64: Stop assuming that pt_regs is on the entry stack
x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0
x86/entry: Remap the TSS into the CPU entry area
x86/entry: Move SYSENTER_stack to the beginning of struct tss_struct
x86/dumpstack: Handle stack overflow on all stacks
x86/entry: Fix assumptions that the HW TSS is at the beginning of cpu_tss
x86/kasan/64: Teach KASAN about the cpu_entry_area
x86/mm/fixmap: Generalize the GDT fixmap mechanism, introduce struct cpu_entry_area
x86/entry/gdt: Put per-CPU GDT remaps in ascending order
x86/dumpstack: Add get_stack_info() support for the SYSENTER stack
...
CR4 modifications are implemented as RMW operations which update a shadow
variable and write the result to CR4. The RMW operation is protected by
preemption disable, but there is no enforcement or debugging mechanism.
CR4 modifications happen also in interrupt context via
__native_flush_tlb_global(). This implementation does not affect a
interrupted thread context CR4 operation, because the CR4 toggle restores
the original content and does not modify the shadow variable.
So the current situation seems to be safe, but a recent patch tried to add
an actual RMW operation in interrupt context, which will cause subtle
corruptions.
To prevent that and make the CR4 handling future proof:
- Add a lockdep assertion to __cr4_set() which will catch interrupt
enabled invocations
- Disable interrupts in the cr4 manipulator inlines
- Rename cr4_toggle_bits() to cr4_toggle_bits_irqsoff(). This is called
from __switch_to_xtra() where interrupts are already disabled and
performance matters.
All other call sites are not performance critical, so the extra overhead of
an additional local_irq_save/restore() pair is not a problem. If new call
sites care about performance then the necessary _irqsoff() variants can be
added.
[ tglx: Condensed the patch by moving the irq protection inside the
manipulator functions. Updated changelog ]
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Luck <tony.luck@intel.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: nadav.amit@gmail.com
Cc: linux-edac@vger.kernel.org
Link: https://lkml.kernel.org/r/20171125032907.2241-3-namit@vmware.com
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>
The only user of thread_saved_pc() in non-arch-specific code was removed
in commit 8243d55977 ("sched/core: Remove pointless printout in
sched_show_task()"). Remove the implementations as well.
Some architectures use thread_saved_pc() in their arch-specific code.
Leave their thread_saved_pc() intact.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide and use a toggle helper instead of doing it with a branch.
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3008 8577 16 11601 2d51 Before
2976 8577 16 11569 2d31 After
i386: arch/x86/kernel/process.o
text data bss dec hex
2925 8673 8 11606 2d56 Before
2893 8673 8 11574 2d36 After
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-4-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The debug control MSR is "highly magical" as the blockstep bit can be
cleared by hardware under not well documented circumstances.
So a task switch relying on the bit set by the previous task (according to
the previous tasks thread flags) can trip over this and not update the flag
for the next task.
To fix this its required to handle DEBUGCTLMSR_BTF when either the previous
or the next or both tasks have the TIF_BLOCKSTEP flag set.
While at it avoid branching within the TIF_BLOCKSTEP case and evaluating
boot_cpu_data twice in kernels without CONFIG_X86_DEBUGCTLMSR.
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3024 8577 16 11617 2d61 Before
3008 8577 16 11601 2d51 After
i386: No change
[ tglx: Made the shift value explicit, use a local variable to make the
code readable and massaged changelog]
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-3-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Help the compiler to avoid reevaluating the thread flags for each checked
bit by reordering the bit checks and providing an explicit xor for
evaluation.
With default defconfigs for each arch,
x86_64: arch/x86/kernel/process.o
text data bss dec hex
3056 8577 16 11649 2d81 Before
3024 8577 16 11617 2d61 After
i386: arch/x86/kernel/process.o
text data bss dec hex
2957 8673 8 11638 2d76 Before
2925 8673 8 11606 2d56 After
Originally-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20170214081104.9244-2-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull more KVM updates from Radim Krčmář:
"Second batch of KVM changes for the 4.11 merge window:
PPC:
- correct assumption about ASDR on POWER9
- fix MMIO emulation on POWER9
x86:
- add a simple test for ioperm
- cleanup TSS (going through KVM tree as the whole undertaking was
caused by VMX's use of TSS)
- fix nVMX interrupt delivery
- fix some performance counters in the guest
... and two cleanup patches"
* tag 'kvm-4.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: nVMX: Fix pending events injection
x86/kvm/vmx: remove unused variable in segment_base()
selftests/x86: Add a basic selftest for ioperm
x86/asm: Tidy up TSS limit code
kvm: convert kvm.users_count from atomic_t to refcount_t
KVM: x86: never specify a sample period for virtualized in_tx_cp counters
KVM: PPC: Book3S HV: Don't use ASDR for real-mode HPT faults on POWER9
KVM: PPC: Book3S HV: Fix software walk of guest process page tables
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.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>
We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task.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>
We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/debug.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>
We are going to split <linux/sched/idle.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/idle.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>
In an earlier version of the patch ("x86/kvm/vmx: Defer TR reload
after VM exit") that introduced TSS limit validity tracking, I
confused which helper was which. On reflection, the names I chose
sucked. Rename the helpers to make it more obvious what's going on
and add some comments.
While I'm at it, clear __tss_limit_invalid when force-reloading as
well as when contitionally reloading, since any TR reload fixes the
limit.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Intel's VMX is daft and resets the hidden TSS limit register to 0x67
on VMX reload, and the 0x67 is not configurable. KVM currently
reloads TR using the LTR instruction on every exit, but this is quite
slow because LTR is serializing.
The 0x67 limit is entirely harmless unless ioperm() is in use, so
defer the reload until a task using ioperm() is actually running.
Here's some poorly done benchmarking using kvm-unit-tests:
Before:
cpuid 1313
vmcall 1195
mov_from_cr8 11
mov_to_cr8 17
inl_from_pmtimer 6770
inl_from_qemu 6856
inl_from_kernel 2435
outl_to_kernel 1402
After:
cpuid 1291
vmcall 1181
mov_from_cr8 11
mov_to_cr8 16
inl_from_pmtimer 6457
inl_from_qemu 6209
inl_from_kernel 2339
outl_to_kernel 1391
Signed-off-by: Andy Lutomirski <luto@kernel.org>
[Force-reload TR in invalidate_tss_limit. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer updates from Thomas Gleixner:
"This is the last functional update from the tip tree for 4.10. It got
delayed due to a newly reported and anlyzed variant of BIOS bug and
the resulting wreckage:
- Seperation of TSC being marked realiable and the fact that the
platform provides the TSC frequency via CPUID/MSRs and making use
for it for GOLDMONT.
- TSC adjust MSR validation and sanitizing:
The TSC adjust MSR contains the offset to the hardware counter. The
sum of the adjust MSR and the counter is the TSC value which is
read via RDTSC.
On at least two machines from different vendors the BIOS sets the
TSC adjust MSR to negative values. This happens on cold and warm
boot. While on cold boot the offset is a few milliseconds, on warm
boot it basically compensates the power on time of the system. The
BIOSes are not even using the adjust MSR to set all CPUs in the
package to the same offset. The offsets are different which renders
the TSC unusable,
What's worse is that the TSC deadline timer has a HW feature^Wbug.
It malfunctions when the TSC adjust value is negative or greater
equal 0x80000000 resulting in silent boot failures, hard lockups or
non firing timers. This looks like some hardware internal 32/64bit
issue with a sign extension problem. Intel has been silent so far
on the issue.
The update contains sanity checks and keeps the adjust register
within working limits and in sync on the package.
As it looks like this disease is spreading via BIOS crapware, we
need to address this urgently as the boot failures are hard to
debug for users"
* 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tsc: Limit the adjust value further
x86/tsc: Annotate printouts as firmware bug
x86/tsc: Force TSC_ADJUST register to value >= zero
x86/tsc: Validate TSC_ADJUST after resume
x86/tsc: Validate cpumask pointer before accessing it
x86/tsc: Fix broken CONFIG_X86_TSC=n build
x86/tsc: Try to adjust TSC if sync test fails
x86/tsc: Prepare warp test for TSC adjustment
x86/tsc: Move sync cleanup to a safe place
x86/tsc: Sync test only for the first cpu in a package
x86/tsc: Verify TSC_ADJUST from idle
x86/tsc: Store and check TSC ADJUST MSR
x86/tsc: Detect random warps
x86/tsc: Use X86_FEATURE_TSC_ADJUST in detect_art()
x86/tsc: Finalize the split of the TSC_RELIABLE flag
x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs
x86/tsc: Mark Intel ATOM_GOLDMONT TSC reliable
x86/tsc: Mark TSC frequency determined by CPUID as known
x86/tsc: Add X86_FEATURE_TSC_KNOWN_FREQ flag
Reorganize the E400 detection now that we have everything in place:
switch the CPUs to broadcast mode after the LAPIC has been initialized
and remove the facilities that were used previously on the idle path.
Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine
because alternatives have been applied when the actual detection happens,
so the static switching does not take effect and the test will stay
false. Use boot_cpu_has_bug() instead which is definitely an improvement
over the RDMSR and the cpumask handling.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
AMD CPUs affected by the E400 erratum suffer from the issue that the
local APIC timer stops when the CPU goes into C1E. Unfortunately there
is no way to detect the affected CPUs on early boot. It's only possible
to determine the range of possibly affected CPUs from the family/model
range.
The actual decision whether to enter C1E and thus cause the bug is done
by the firmware and we need to detect that case late, after ACPI has
been initialized.
The current solution is to check in the idle routine whether the CPU is
affected by reading the MSR_K8_INT_PENDING_MSG MSR and checking for the
K8_INTP_C1E_ACTIVE_MASK bits. If one of the bits is set then the CPU is
affected and the system is switched into forced broadcast mode.
This is ineffective and on non-affected CPUs every entry to idle does
the extra RDMSR.
After doing some research it turns out that the bits are visible on the
boot CPU right after the ACPI subsystem is initialized in the early
boot process. So instead of polling for the bits in the idle loop, add
a detection function after acpi_subsystem_init() and check for the MSR
bits. If set, then the X86_BUG_AMD_APIC_C1E is set on the boot CPU and
the TSC is marked unstable when X86_FEATURE_NONSTOP_TSC is not set as it
will stop in C1E state as well.
The switch to broadcast mode cannot be done at this point because the
boot CPU still uses HPET as a clockevent device and the local APIC timer
is not yet calibrated and installed. The switch to broadcast mode on the
affected CPUs needs to be done when the local APIC timer is actually set
up.
This allows to cleanup the amd_e400_idle() function in the next step.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The workaround for the AMD Erratum E400 (Local APIC timer stops in C1E
state) is a two step process:
- Selection of the E400 aware idle routine
- Detection whether the platform is affected
The idle routine selection happens for possibly affected CPUs depending on
family/model/stepping information. These range of CPUs is not necessarily
affected as the decision whether to enable the C1E feature is made by the
firmware. Unfortunately there is no way to query this at early boot.
The current implementation polls a MSR in the E400 aware idle routine to
detect whether the CPU is affected. This is inefficient on non affected
CPUs because every idle entry has to do the MSR read.
There is a better way to detect this before going idle for the first time
which requires to seperate the bug flags:
X86_BUG_AMD_E400 - Selects the E400 aware idle routine and
enables the detection
X86_BUG_AMD_APIC_C1E - Set when the platform is affected by E400
Replace the current X86_BUG_AMD_APIC_C1E usage by the new X86_BUG_AMD_E400
bug bit to select the idle routine which currently does an unconditional
detection poll. X86_BUG_AMD_APIC_C1E is going to be used in later patches
to remove the MSR polling and simplify the handling of this misfeature.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20161209182912.2726-3-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When entering idle, it's a good oportunity to verify that the TSC_ADJUST
MSR has not been tampered with (BIOS hiding SMM cycles). If tampering is
detected, emit a warning and restore it to the previous value.
This is especially important for machines, which mark the TSC reliable
because there is no watchdog clocksource available (SoCs).
This is not sufficient for HPC (NOHZ_FULL) situations where a CPU never
goes idle, but adding a timer to do the check periodically is not an option
either. On a machine, which has this issue, the check triggeres right
during boot, so there is a decent chance that the sysadmin will notice.
Rate limit the check to once per second and warn only once per cpu.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20161119134017.732180441@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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
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>
We need to call exit_thread from copy_process in a fail path. So make it
accept task_struct as a parameter.
[v2]
* s390: exit_thread_runtime_instr doesn't make sense to be called for
non-current tasks.
* arm: fix the comment in vfp_thread_copy
* change 'me' to 'tsk' for task_struct
* now we can change only archs that actually have exit_thread
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 asm updates from Ingo Molnar:
"This is another big update. Main changes are:
- lots of x86 system call (and other traps/exceptions) entry code
enhancements. In particular the complex parts of the 64-bit entry
code have been migrated to C code as well, and a number of dusty
corners have been refreshed. (Andy Lutomirski)
- vDSO special mapping robustification and general cleanups (Andy
Lutomirski)
- cpufeature refactoring, cleanups and speedups (Borislav Petkov)
- lots of other changes ..."
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
x86/cpufeature: Enable new AVX-512 features
x86/entry/traps: Show unhandled signal for i386 in do_trap()
x86/entry: Call enter_from_user_mode() with IRQs off
x86/entry/32: Change INT80 to be an interrupt gate
x86/entry: Improve system call entry comments
x86/entry: Remove TIF_SINGLESTEP entry work
x86/entry/32: Add and check a stack canary for the SYSENTER stack
x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
x86/entry: Vastly simplify SYSENTER TF (single-step) handling
x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
x86/entry/32: Restore FLAGS on SYSEXIT
x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
selftests/x86: In syscall_nt, test NT|TF as well
x86/asm-offsets: Remove PARAVIRT_enabled
x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
uprobes: __create_xol_area() must nullify xol_mapping.fault
x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
...
