Commit Graph

237 Commits

Author SHA1 Message Date
Borislav Petkov
0c0fe08c76 x86/microcode: Remove unnecessary perf callback
c93dc84cbe ("perf/x86: Add a microcode revision check for SNB-PEBS")
checks whether the microcode revision has fixed PEBS issues.

This can happen either:

1. At PEBS init time, where the early microcode has been loaded already

2. During late loading, in the microcode_check() callback.

So remove the unnecessary call in the microcode loader init routine.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-5-bp@alien8.de
2022-05-31 09:31:19 +02:00
Borislav Petkov
d23d33ea0f x86/microcode: Taint and warn on late loading
Warn before it is attempted and taint the kernel. Late loading microcode
can lead to malfunction of the kernel when the microcode update changes
behaviour. There is no way for the kernel to determine whether its safe or
not.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-4-bp@alien8.de
2022-05-31 09:31:19 +02:00
Borislav Petkov
a77a94f862 x86/microcode: Default-disable late loading
It is dangerous and it should not be used anyway - there's a nice early
loading already.

Requested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-3-bp@alien8.de
2022-05-31 09:31:19 +02:00
Borislav Petkov
181b6f40e9 x86/microcode: Rip out the OLD_INTERFACE
Everything should be using the early initrd loading by now.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220525161232.14924-2-bp@alien8.de
2022-05-31 09:31:19 +02:00
Linus Torvalds
8443516da6 Merge tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Hans de Goede:
 "This includes some small changes to kernel/stop_machine.c and arch/x86
  which are deps of the new Intel IFS support.

  Highlights:

   - New drivers:
       - Intel "In Field Scan" (IFS) support
       - Winmate FM07/FM07P buttons
       - Mellanox SN2201 support

   -  AMD PMC driver enhancements

   -  Lots of various other small fixes and hardware-id additions"

* tag 'platform-drivers-x86-v5.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (54 commits)
  platform/x86/intel/ifs: Add CPU_SUP_INTEL dependency
  platform/x86: intel_cht_int33fe: Set driver data
  platform/x86: intel-hid: fix _DSM function index handling
  platform/x86: toshiba_acpi: use kobj_to_dev()
  platform/x86: samsung-laptop: use kobj_to_dev()
  platform/x86: gigabyte-wmi: Add support for Z490 AORUS ELITE AC and X570 AORUS ELITE WIFI
  tools/power/x86/intel-speed-select: Fix warning for perf_cap.cpu
  tools/power/x86/intel-speed-select: Display error on turbo mode disabled
  Documentation: In-Field Scan
  platform/x86/intel/ifs: add ABI documentation for IFS
  trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations
  platform/x86/intel/ifs: Add IFS sysfs interface
  platform/x86/intel/ifs: Add scan test support
  platform/x86/intel/ifs: Authenticate and copy to secured memory
  platform/x86/intel/ifs: Check IFS Image sanity
  platform/x86/intel/ifs: Read IFS firmware image
  platform/x86/intel/ifs: Add stub driver for In-Field Scan
  stop_machine: Add stop_core_cpuslocked() for per-core operations
  x86/msr-index: Define INTEGRITY_CAPABILITIES MSR
  x86/microcode/intel: Expose collect_cpu_info_early() for IFS
  ...
2022-05-23 20:38:39 -07:00
Jithu Joseph
d3287fb0d3 x86/microcode/intel: Expose collect_cpu_info_early() for IFS
IFS is a CPU feature that allows a binary blob, similar to microcode,
to be loaded and consumed to perform low level validation of CPU
circuitry. In fact, it carries the same Processor Signature
(family/model/stepping) details that are contained in Intel microcode
blobs.

In support of an IFS driver to trigger loading, validation, and running
of these tests blobs, make the functionality of cpu_signatures_match()
and collect_cpu_info_early() available outside of the microcode driver.

Add an "intel_" prefix and drop the "_early" suffix from
collect_cpu_info_early() and EXPORT_SYMBOL_GPL() it. Add
declaration to x86 <asm/cpu.h>

Make cpu_signatures_match() an inline function in x86 <asm/cpu.h>,
and also give it an "intel_" prefix.

No functional change intended.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Co-developed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220506225410.1652287-2-tony.luck@intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
2022-05-12 15:35:29 +02:00
Borislav Petkov
f9e14dbbd4 x86/cpu: Load microcode during restore_processor_state()
When resuming from system sleep state, restore_processor_state()
restores the boot CPU MSRs. These MSRs could be emulated by microcode.
If microcode is not loaded yet, writing to emulated MSRs leads to
unchecked MSR access error:

  ...
  PM: Calling lapic_suspend+0x0/0x210
  unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0...0) at rIP: ... (native_write_msr)
  Call Trace:
    <TASK>
    ? restore_processor_state
    x86_acpi_suspend_lowlevel
    acpi_suspend_enter
    suspend_devices_and_enter
    pm_suspend.cold
    state_store
    kobj_attr_store
    sysfs_kf_write
    kernfs_fop_write_iter
    new_sync_write
    vfs_write
    ksys_write
    __x64_sys_write
    do_syscall_64
    entry_SYSCALL_64_after_hwframe
   RIP: 0033:0x7fda13c260a7

To ensure microcode emulated MSRs are available for restoration, load
the microcode on the boot CPU before restoring these MSRs.

  [ Pawan: write commit message and productize it. ]

Fixes: e2a1256b17 ("x86/speculation: Restore speculation related MSRs during S3 resume")
Reported-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Tested-by: Kyle D. Pelton <kyle.d.pelton@intel.com>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215841
Link: https://lore.kernel.org/r/4350dfbf785cd482d3fafa72b2b49c83102df3ce.1650386317.git.pawan.kumar.gupta@linux.intel.com
2022-04-19 19:37:05 +02:00
Borislav Petkov
9d48960414 x86/microcode: Use the firmware_loader built-in API
The microcode loader has been looping through __start_builtin_fw down to
__end_builtin_fw to look for possibly built-in firmware for microcode
updates.

Now that the firmware loader code has exported an API for looping
through the kernel's built-in firmware section, use it and drop the x86
implementation in favor.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20211021155843.1969401-4-mcgrof@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-22 14:13:50 +02:00
Sebastian Andrzej Siewior
2089f34f8c x86/microcode: Replace deprecated CPU-hotplug functions.
The functions get_online_cpus() and put_online_cpus() have been
deprecated during the CPU hotplug rework. They map directly to
cpus_read_lock() and cpus_read_unlock().

Replace deprecated CPU-hotplug functions with the official version.
The behavior remains unchanged.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210803141621.780504-9-bigeasy@linutronix.de
2021-08-10 14:46:27 +02:00
Otavio Pontes
7189b3c119 x86/microcode: Check for offline CPUs before requesting new microcode
Currently, the late microcode loading mechanism checks whether any CPUs
are offlined, and, in such a case, aborts the load attempt.

However, this must be done before the kernel caches new microcode from
the filesystem. Otherwise, when offlined CPUs are onlined later, those
cores are going to be updated through the CPU hotplug notifier callback
with the new microcode, while CPUs previously onine will continue to run
with the older microcode.

For example:

Turn off one core (2 threads):

  echo 0 > /sys/devices/system/cpu/cpu3/online
  echo 0 > /sys/devices/system/cpu/cpu1/online

Install the ucode fails because a primary SMT thread is offline:

  cp intel-ucode/06-8e-09 /lib/firmware/intel-ucode/
  echo 1 > /sys/devices/system/cpu/microcode/reload
  bash: echo: write error: Invalid argument

Turn the core back on

  echo 1 > /sys/devices/system/cpu/cpu3/online
  echo 1 > /sys/devices/system/cpu/cpu1/online
  cat /proc/cpuinfo |grep microcode
  microcode : 0x30
  microcode : 0xde
  microcode : 0x30
  microcode : 0xde

The rationale for why the update is aborted when at least one primary
thread is offline is because even if that thread is soft-offlined
and idle, it will still have to participate in broadcasted MCE's
synchronization dance or enter SMM, and in both examples it will execute
instructions so it better have the same microcode revision as the other
cores.

 [ bp: Heavily edit and extend commit message with the reasoning behind all
   this. ]

Fixes: 30ec26da99 ("x86/microcode: Do not upload microcode if CPUs are offline")
Signed-off-by: Otavio Pontes <otavio.pontes@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/20210319165515.9240-2-otavio.pontes@intel.com
2021-03-22 22:29:40 +01:00
Borislav Petkov
c769dcd423 x86/microcode: Make microcode_init() static
No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201230122147.26938-1-bp@alien8.de
2020-12-31 11:44:00 +01:00
Linus Torvalds
85fe40cad2 Merge tag 'x86_microcode_update_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 microcode loader update from Borislav Petkov:
 "This one wins the award for most boring pull request ever. But that's
  a good thing - this is how I like 'em and the microcode loader
  *should* be boring. :-)

  A single cleanup removing "break" after a return statement (Tom Rix)"

* tag 'x86_microcode_update_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/amd: Remove unneeded break
2020-12-14 13:13:15 -08:00
Chen Yu
1a371e67dc x86/microcode/intel: Check patch signature before saving microcode for early loading
Currently, scan_microcode() leverages microcode_matches() to check
if the microcode matches the CPU by comparing the family and model.
However, the processor stepping and flags of the microcode signature
should also be considered when saving a microcode patch for early
update.

Use find_matching_signature() in scan_microcode() and get rid of the
now-unused microcode_matches() which is a good cleanup in itself.

Complete the verification of the patch being saved for early loading in
save_microcode_patch() directly. This needs to be done there too because
save_mc_for_early() will call save_microcode_patch() too.

The second reason why this needs to be done is because the loader still
tries to support, at least hypothetically, mixed-steppings systems and
thus adds all patches to the cache that belong to the same CPU model
albeit with different steppings.

For example:

  microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
  microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
  microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
  microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
  microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
  microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23

The patch which is being saved for early loading, however, can only be
the one which fits the CPU this runs on so do the signature verification
before saving.

 [ bp: Do signature verification in save_microcode_patch()
       and rewrite commit message. ]

Fixes: ec400ddeff ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=208535
Link: https://lkml.kernel.org/r/20201113015923.13960-1-yu.c.chen@intel.com
2020-11-17 10:33:18 +01:00
Tom Rix
880396c86a x86/microcode/amd: Remove unneeded break
A break is not needed if it is preceded by a return.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20201019200629.17247-1-trix@redhat.com
2020-10-26 12:18:22 +01:00
Herbert Xu
c8a59a4d8e x86/microcode: Do not select FW_LOADER
The x86 microcode support works just fine without FW_LOADER. In fact,
these days most people load microcode early during boot so FW_LOADER
never gets into the picture anyway.

As almost everyone on x86 needs to enable MICROCODE, this by extension
means that FW_LOADER is always built into the kernel even if nothing
uses it. The FW_LOADER system is about two thousand lines long and
contains user-space facing interfaces that could potentially provide an
entry point into the kernel (or beyond).

Remove the unnecessary select of FW_LOADER by MICROCODE. People who need
the FW_LOADER capability can still enable it.

 [ bp: Massage a bit. ]

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200610042911.GA20058@gondor.apana.org.au
2020-06-15 11:59:19 +02:00
Mihai Carabas
9adbf3c609 x86/microcode: Fix return value for microcode late loading
The return value from stop_machine() might not be consistent.

stop_machine_cpuslocked() returns:
- zero if all functions have returned 0.
- a non-zero value if at least one of the functions returned
a non-zero value.

There is no way to know if it is negative or positive. So make
__reload_late() return 0 on success or negative otherwise.

 [ bp: Unify ret val check and touch up. ]

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1587497318-4438-1-git-send-email-mihai.carabas@oracle.com
2020-04-22 19:55:50 +02:00
Borislav Petkov
811ae8ba6d x86/microcode/intel: Issue the revision updated message only on the BSP
... in order to not pollute dmesg with a line for each updated microcode
engine.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jon Grimm <Jon.Grimm@amd.com>
Cc: kanth.ghatraju@oracle.com
Cc: konrad.wilk@oracle.com
Cc: Mihai Carabas <mihai.carabas@oracle.com>
Cc: patrick.colp@oracle.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190824085341.GC16813@zn.tnic
2019-10-01 16:06:35 +02:00
Ashok Raj
93946a33b5 x86/microcode: Update late microcode in parallel
Microcode update was changed to be serialized due to restrictions after
Spectre days. Updating serially on a large multi-socket system can be
painful since it is being done on one CPU at a time.

Cloud customers have expressed discontent as services disappear for
a prolonged time. The restriction is that only one core (or only one
thread of a core in the case of an SMT system) goes through the update
while other cores (or respectively, SMT threads) are quiesced.

Do the microcode update only on the first thread of each core while
other siblings simply wait for this to complete.

 [ bp: Simplify, massage, cleanup comments. ]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jon Grimm <Jon.Grimm@amd.com>
Cc: kanth.ghatraju@oracle.com
Cc: konrad.wilk@oracle.com
Cc: patrick.colp@oracle.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1566506627-16536-2-git-send-email-mihai.carabas@oracle.com
2019-10-01 15:58:54 +02:00
Borislav Petkov
2b73095206 x86/microcode/amd: Fix two -Wunused-but-set-variable warnings
The dummy variable is the high part of the microcode revision MSR which
is defined as reserved. Mark it unused so that W=1 builds don't trigger
the above warning.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: x86@kernel.org
Link: https://lkml.kernel.org/r/20190928162559.26294-1-bp@alien8.de
2019-10-01 11:36:09 +02:00
Linus Torvalds
e9a83bd232 Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Linus Torvalds
728254541e Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes all over the place:

   - might_sleep() atomicity fix in the microcode loader

   - resctrl boundary condition fix

   - APIC arithmethics bug fix for frequencies >= 4.2 GHz

   - three 5-level paging crash fixes

   - two speculation fixes

   - a perf/stacktrace fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/unwind/orc: Fall back to using frame pointers for generated code
  perf/x86: Always store regs->ip in perf_callchain_kernel()
  x86/speculation: Allow guests to use SSBD even if host does not
  x86/mm: Handle physical-virtual alignment mismatch in phys_p4d_init()
  x86/boot/64: Add missing fixup_pointer() for next_early_pgt access
  x86/boot/64: Fix crash if kernel image crosses page table boundary
  x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz
  x86/resctrl: Prevent possible overrun during bitmap operations
  x86/microcode: Fix the microcode load on CPU hotplug for real
2019-06-29 19:42:30 +08:00
Thomas Gleixner
5423f5ce5c x86/microcode: Fix the microcode load on CPU hotplug for real
A recent change moved the microcode loader hotplug callback into the early
startup phase which is running with interrupts disabled. It missed that
the callbacks invoke sysfs functions which might sleep causing nice 'might
sleep' splats with proper debugging enabled.

Split the callbacks and only load the microcode in the early startup phase
and move the sysfs handling back into the later threaded and preemptible
bringup phase where it was before.

Fixes: 78f4e932f7 ("x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906182228350.1766@nanos.tec.linutronix.de
2019-06-19 09:16:35 +02:00
Linus Torvalds
963172d9c7 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
 "The accumulated fixes from this and last week:

   - Fix vmalloc TLB flush and map range calculations which lead to
     stale TLBs, spurious faults and other hard to diagnose issues.

   - Use fault_in_pages_writable() for prefaulting the user stack in the
     FPU code as it's less fragile than the current solution

   - Use the PF_KTHREAD flag when checking for a kernel thread instead
     of current->mm as the latter can give the wrong answer due to
     use_mm()

   - Compute the vmemmap size correctly for KASLR and 5-Level paging.
     Otherwise this can end up with a way too small vmemmap area.

   - Make KASAN and 5-level paging work again by making sure that all
     invalid bits are masked out when computing the P4D offset. This
     worked before but got broken recently when the LDT remap area was
     moved.

   - Prevent a NULL pointer dereference in the resource control code
     which can be triggered with certain mount options when the
     requested resource is not available.

   - Enforce ordering of microcode loading vs. perf initialization on
     secondary CPUs. Otherwise perf tries to access a non-existing MSR
     as the boot CPU marked it as available.

   - Don't stop the resource control group walk early otherwise the
     control bitmaps are not updated correctly and become inconsistent.

   - Unbreak kgdb by returning 0 on success from
     kgdb_arch_set_breakpoint() instead of an error code.

   - Add more Icelake CPU model defines so depending changes can be
     queued in other trees"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
  x86/kasan: Fix boot with 5-level paging and KASAN
  x86/fpu: Don't use current->mm to check for a kthread
  x86/kgdb: Return 0 from kgdb_arch_set_breakpoint()
  x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
  x86/resctrl: Don't stop walking closids when a locksetup group is found
  x86/fpu: Update kernel's FPU state before using for the fsave header
  x86/mm/KASLR: Compute the size of the vmemmap section properly
  x86/fpu: Use fault_in_pages_writeable() for pre-faulting
  x86/CPU: Add more Icelake model numbers
  mm/vmalloc: Avoid rare case of flushing TLB with weird arguments
  mm/vmalloc: Fix calculation of direct map addr range
2019-06-16 07:28:14 -10:00
Borislav Petkov
78f4e932f7 x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
Adric Blake reported the following warning during suspend-resume:

  Enabling non-boot CPUs ...
  x86: Booting SMP configuration:
  smpboot: Booting Node 0 Processor 1 APIC 0x2
  unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0000000000000000) \
   at rIP: 0xffffffff8d267924 (native_write_msr+0x4/0x20)
  Call Trace:
   intel_set_tfa
   intel_pmu_cpu_starting
   ? x86_pmu_dead_cpu
   x86_pmu_starting_cpu
   cpuhp_invoke_callback
   ? _raw_spin_lock_irqsave
   notify_cpu_starting
   start_secondary
   secondary_startup_64
  microcode: sig=0x806ea, pf=0x80, revision=0x96
  microcode: updated to revision 0xb4, date = 2019-04-01
  CPU1 is up

The MSR in question is MSR_TFA_RTM_FORCE_ABORT and that MSR is emulated
by microcode. The log above shows that the microcode loader callback
happens after the PMU restoration, leading to the conjecture that
because the microcode hasn't been updated yet, that MSR is not present
yet, leading to the #GP.

Add a microcode loader-specific hotplug vector which comes before
the PERF vectors and thus executes earlier and makes sure the MSR is
present.

Fixes: 400816f60c ("perf/x86/intel: Implement support for TSX Force Abort")
Reported-by: Adric Blake <promarbler14@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: x86@kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203637
2019-06-15 10:00:29 +02:00
Jonathan Corbet
8afecfb0ec Merge tag 'v5.2-rc4' into mauro
We need to pick up post-rc1 changes to various document files so they don't
get lost in Mauro's massive RST conversion push.
2019-06-14 14:18:53 -06:00