linux-stable.git/arch/x86/kernel/cpu/common.c, branch linux-4.1.y

x86/cpufeatures: Make CPU bugs sticky

2018-03-01T03:09:37+00:00

[ Upstream commit 6cbd2171e89b13377261d15e64384df60ecb530e ]

There is currently no way to force CPU bug bits like CPU feature bits. That
makes it impossible to set a bug bit once at boot and have it stick for all
upcoming CPUs.

Extend the force set/clear arrays to handle bug bits as well.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Dave Hansen 
Cc: David Laight 
Cc: Denys Vlasenko 
Cc: Eduardo Valentin 
Cc: Greg KH 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Will Deacon 
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/cpu: Factor out application of forced CPU caps

2018-03-01T03:09:37+00:00

[ Upstream commit 8bf1ebca215c262e48c15a4a15f175991776f57f ]

There are multiple call sites that apply forced CPU caps.  Factor
them into a helper.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Matthew Whitehead 
Cc: Oleg Nesterov 
Cc: One Thousand Gnomes 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: Yu-cheng Yu 
Link: http://lkml.kernel.org/r/623ff7555488122143e4417de09b18be2085ad06.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/mm: Enable CR4.PCIDE on supported systems

2018-03-01T00:32:18+00:00

[ Upstream commit 660da7c9228f685b2ebe664f9fd69aaddcc420b5 ]

We can use PCID if the CPU has PCID and PGE and we're not on Xen.

By itself, this has no effect. A followup patch will start using PCID.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Nadav Amit 
Reviewed-by: Boris Ostrovsky 
Reviewed-by: Thomas Gleixner 
Cc: Andrew Morton 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/6327ecd907b32f79d5aa0d466f04503bbec5df88.1498751203.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/mm: Add the 'nopcid' boot option to turn off PCID

2018-03-01T00:32:18+00:00

[ Upstream commit 0790c9aad84901ca1bdc14746175549c8b5da215 ]

The parameter is only present on x86_64 systems to save a few bytes,
as PCID is always disabled on x86_32.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Nadav Amit 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Andrew Morton 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Linus Torvalds 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/8bbb2e65bcd249a5f18bfb8128b4689f08ac2b60.1498751203.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID

2018-03-01T00:32:12+00:00

[ Upstream commit d12a72b844a49d4162f24cefdab30bed3f86730e ]

This adds a chicken bit to turn off INVPCID in case something goes
wrong.  It's an early_param() because we do TLB flushes before we
parse __setup() parameters.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Andrew Morton 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Luis R. Rodriguez 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Toshi Kani 
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/f586317ed1bc2b87aee652267e515b90051af385.1454096309.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/cpu: Fix SMAP check in PVOPS environments

2015-12-09T19:03:18+00:00

commit 581b7f158fe0383b492acd1ce3fb4e99d4e57808 upstream.

There appears to be no formal statement of what pv_irq_ops.save_fl() is
supposed to return precisely.  Native returns the full flags, while lguest and
Xen only return the Interrupt Flag, and both have comments by the
implementations stating that only the Interrupt Flag is looked at.  This may
have been true when initially implemented, but no longer is.

To make matters worse, the Xen PVOP leaves the upper bits undefined, making
the BUG_ON() undefined behaviour.  Experimentally, this now trips for 32bit PV
guests on Broadwell hardware.  The BUG_ON() is consistent for an individual
build, but not consistent for all builds.  It has also been a sitting timebomb
since SMAP support was introduced.

Use native_save_fl() instead, which will obtain an accurate view of the AC
flag.

Signed-off-by: Andrew Cooper 
Reviewed-by: David Vrabel 
Tested-by: Rusty Russell 
Cc: Rusty Russell 
Cc: Konrad Rzeszutek Wilk 
Cc: Boris Ostrovsky 
Cc: 
Cc: Xen-devel 
Link: http://lkml.kernel.org/r/1433323874-6927-1-git-send-email-andrew.cooper3@citrix.com
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

x86/ldt: Make modify_ldt synchronous

2015-09-21T17:05:25+00:00

commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream.

modify_ldt() has questionable locking and does not synchronize
threads.  Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.

This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.

This fixes some fallout from the CVE-2015-5157 fixes.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Andrew Cooper 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Jan Beulich 
Cc: Konrad Rzeszutek Wilk 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Sasha Levin 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Cc: security@kernel.org 
Cc: xen-devel 
Link: http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.luto@kernel.org
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-14T21:37:47+00:00

Pull perf changes from Ingo Molnar:
 "Core kernel changes:

   - One of the more interesting features in this cycle is the ability
     to attach eBPF programs (user-defined, sandboxed bytecode executed
     by the kernel) to kprobes.

     This allows user-defined instrumentation on a live kernel image
     that can never crash, hang or interfere with the kernel negatively.
     (Right now it's limited to root-only, but in the future we might
     allow unprivileged use as well.)

     (Alexei Starovoitov)

   - Another non-trivial feature is per event clockid support: this
     allows, amongst other things, the selection of different clock
     sources for event timestamps traced via perf.

     This feature is sought by people who'd like to merge perf generated
     events with external events that were measured with different
     clocks:

       - cluster wide profiling

       - for system wide tracing with user-space events,

       - JIT profiling events

     etc.  Matching perf tooling support is added as well, available via
     the -k, --clockid  parameter to perf record et al.

     (Peter Zijlstra)

  Hardware enablement kernel changes:

   - x86 Intel Processor Trace (PT) support: which is a hardware tracer
     on steroids, available on Broadwell CPUs.

     The hardware trace stream is directly output into the user-space
     ring-buffer, using the 'AUX' data format extension that was added
     to the perf core to support hardware constraints such as the
     necessity to have the tracing buffer physically contiguous.

     This patch-set was developed for two years and this is the result.
     A simple way to make use of this is to use BTS tracing, the PT
     driver emulates BTS output - available via the 'intel_bts' PMU.
     More explicit PT specific tooling support is in the works as well -
     will probably be ready by 4.2.

     (Alexander Shishkin, Peter Zijlstra)

   - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
     feature of Intel Xeon CPUs that allows the measurement and
     allocation/partitioning of caches to individual workloads.

     These kernel changes expose the measurement side as a new PMU
     driver, which exposes various QoS related PMU events.  (The
     partitioning change is work in progress and is planned to be merged
     as a cgroup extension.)

     (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
     Waskiewicz Jr)

   - x86 Intel Haswell LBR call stack support: this is a new Haswell
     feature that allows the hardware recording of call chains, plus
     tooling support.  To activate this feature you have to enable it
     via the new 'lbr' call-graph recording option:

        perf record --call-graph lbr
        perf report

     or:

        perf top --call-graph lbr

     This hardware feature is a lot faster than stack walk or dwarf
     based unwinding, but has some limitations:

       - It reuses the current LBR facility, so LBR call stack and
         branch record can not be enabled at the same time.

       - It is only available for user-space callchains.

     (Yan, Zheng)

   - x86 Intel Broadwell CPU support and various event constraints and
     event table fixes for earlier models.

     (Andi Kleen)

   - x86 Intel HT CPUs event scheduling workarounds.  This is a complex
     CPU bug affecting the SNB,IVB,HSW families that results in counter
     value corruption.  The mitigation code is automatically enabled and
     is transparent.

     (Maria Dimakopoulou, Stephane Eranian)

  The perf tooling side had a ton of changes in this cycle as well, so
  I'm only able to list the user visible changes here, in addition to
  the tooling changes outlined above:

  User visible changes affecting all tools:

      - Improve support of compressed kernel modules (Jiri Olsa)
      - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
      - Bash completion for subcommands (Yunlong Song)
      - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
      - Support missing -f to override perf.data file ownership. (Yunlong Song)
      - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)

  User visible changes in individual tools:

    'perf data':

        New tool for converting perf.data to other formats, initially
        for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
        Sebastian Siewior)

    'perf diff':

        Add --kallsyms option (David Ahern)

    'perf list':

        Allow listing events with 'tracepoint' prefix (Yunlong Song)

        Sort the output of the command (Yunlong Song)

    'perf kmem':

        Respect -i option (Jiri Olsa)

        Print big numbers using thousands' group (Namhyung Kim)

        Allow -v option (Namhyung Kim)

        Fix alignment of slab result table (Namhyung Kim)

    'perf probe':

        Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

        Support unnamed union/structure members data collection. (Masami Hiramatsu)

        Check kprobes blacklist when adding new events. (Masami Hiramatsu)

    'perf record':

        Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

        Support recording running/enabled time (Andi Kleen)

    'perf sched':

        Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)

    'perf report' and 'perf top':

        Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)

        Indicate which callchain entries are annotated in the
        TUI hists browser (Arnaldo Carvalho de Melo)

        Add pid/tid filtering to 'report' and 'script' commands (David Ahern)

        Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
        cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
        events (Arnaldo Carvalho de Melo)

    'perf stat':

        Report unsupported events properly (Suzuki K. Poulose)

        Output running time and run/enabled ratio in CSV mode (Andi Kleen)

    'perf trace':

        Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)

        Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)

        Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)

        Dump stack on segfaults (Arnaldo Carvalho de Melo)

        No need to explicitely enable evsels for workload started from perf, let it
        be enabled via perf_event_attr.enable_on_exec, removing some events that take
        place in the 'perf trace' before a workload is really started by it.
        (Arnaldo Carvalho de Melo)

        Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)

  There's also been a ton of infrastructure work done, such as the
  split-out of perf's build system into tools/build/ and other changes -
  see the shortlog and changelog for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
  perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
  perf evlist: Fix type for references to data_head/tail
  perf probe: Check the orphaned -x option
  perf probe: Support multiple probes on different binaries
  perf buildid-list: Fix segfault when show DSOs with hits
  perf tools: Fix cross-endian analysis
  perf tools: Fix error path to do closedir() when synthesizing threads
  perf tools: Fix synthesizing fork_event.ppid for non-main thread
  perf tools: Add 'I' event modifier for exclude_idle bit
  perf report: Don't call map__kmap if map is NULL.
  perf tests: Fix attr tests
  perf probe: Fix ARM 32 building error
  perf tools: Merge all perf_event_attr print functions
  perf record: Add clockid parameter
  perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
  perf sched replay: Support using -f to override perf.data file ownership
  perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
  perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
  perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
  perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
  ...

x86/asm/entry/64: Use a define for an invalid segment selector

2015-04-03T13:29:13+00:00

... instead of a naked number, for better readability.

Signed-off-by: Borislav Petkov 
Cc: Alexei Starovoitov 
Cc: Andy Lutomirski 
Cc: Denys Vlasenko 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Steven Rostedt 
Cc: Will Drewry 
Link: http://lkml.kernel.org/r/1428054130-25847-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/asm/entry/64: Fix MSR_IA32_SYSENTER_CS MSR value

2015-04-03T13:29:12+00:00

Commit:

  d56fe4bf5f3c ("x86/asm/entry/64: Always set up SYSENTER MSRs")

missed to add "ULL" to the 0 and wrmsrl_safe() complains:

  arch/x86/kernel/cpu/common.c: In function ‘syscall_init’:
  arch/x86/kernel/cpu/common.c:1226:2: warning: right shift count >= width of type wrmsrl_safe(MSR_IA32_SYSENTER_CS, 0);

Fix it.

Signed-off-by: Borislav Petkov 
Cc: Alexei Starovoitov 
Cc: Andy Lutomirski 
Cc: Denys Vlasenko 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Steven Rostedt 
Cc: Will Drewry 
Link: http://lkml.kernel.org/r/1428054130-25847-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar