linux.git/arch/x86/kernel/cpu/microcode/intel.c, branch v6.0

x86/microcode/intel: Expose collect_cpu_info_early() for IFS

2022-05-12T13:35:29+00:00

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 

Make cpu_signatures_match() an inline function in x86 ,
and also give it an "intel_" prefix.

No functional change intended.

Reviewed-by: Dan Williams 
Signed-off-by: Jithu Joseph 
Co-developed-by: Tony Luck 
Signed-off-by: Tony Luck 
Reviewed-by: Thomas Gleixner 
Acked-by: Borislav Petkov 
Reviewed-by: Greg Kroah-Hartman 
Link: https://lore.kernel.org/r/20220506225410.1652287-2-tony.luck@intel.com
Signed-off-by: Hans de Goede

x86/microcode: Use the firmware_loader built-in API

2021-10-22T12:13:50+00:00

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 
Signed-off-by: Luis Chamberlain 
Link: https://lore.kernel.org/r/20211021155843.1969401-4-mcgrof@kernel.org
Signed-off-by: Greg Kroah-Hartman

x86/microcode/intel: Check patch signature before saving microcode for early loading

2020-11-17T09:33:18+00:00

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: ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")
Signed-off-by: Chen Yu 
Signed-off-by: Borislav Petkov 
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

x86/microcode/intel: Issue the revision updated message only on the BSP

2019-10-01T14:06:35+00:00

... in order to not pollute dmesg with a line for each updated microcode
engine.

Signed-off-by: Borislav Petkov 
Cc: Ashok Raj 
Cc: Boris Ostrovsky 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Jon Grimm 
Cc: kanth.ghatraju@oracle.com
Cc: konrad.wilk@oracle.com
Cc: Mihai Carabas 
Cc: patrick.colp@oracle.com
Cc: Thomas Gleixner 
Cc: Tom Lendacky 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20190824085341.GC16813@zn.tnic

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

x86/microcode/intel: Refactor Intel microcode blob loading

2019-04-10T20:40:25+00:00

Change generic_load_microcode() to use the iov_iter API instead of a
clumsy open-coded version which has to pay attention to __user data
or kernel data, depending on the loading method. This allows to avoid
explicit casting between user and kernel pointers.

Because the iov_iter API makes it hard to read the same location twice,
as a side effect, also fix a double-read of the microcode header (which
could e.g. lead to out-of-bounds reads in microcode_sanity_check()).

Not that it matters much, only root is allowed to load microcode
anyway...

 [ bp: Massage a bit, sort function-local variables. ]

Signed-off-by: Jann Horn 
Signed-off-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20190404111128.131157-1-jannh@google.com

x86/microcode: Update the new microcode revision unconditionally

2018-09-02T12:10:54+00:00

Handle the case where microcode gets loaded on the BSP's hyperthread
sibling first and the boot_cpu_data's microcode revision doesn't get
updated because of early exit due to the siblings sharing a microcode
engine.

For that, simply write the updated revision on all CPUs unconditionally.

Signed-off-by: Filippo Sironi 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: prarit@redhat.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1533050970-14385-1-git-send-email-sironi@amazon.de

x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

2018-09-02T12:10:54+00:00

When preparing an MCE record for logging, boot_cpu_data.microcode is used
to read out the microcode revision on the box.

However, on systems where late microcode update has happened, the microcode
revision output in a MCE log record is wrong because
boot_cpu_data.microcode is not updated when the microcode gets updated.

But, the microcode revision saved in boot_cpu_data's microcode member
should be kept up-to-date, regardless, for consistency.

Make it so.

Fixes: fa94d0c6e0f3 ("x86/MCE: Save microcode revision in machine check records")
Signed-off-by: Prarit Bhargava 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Tony Luck 
Cc: sironi@amazon.de
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180731112739.32338-1-prarit@redhat.com

x86/microcode/intel: Fix memleak in save_microcode_patch()

2018-06-22T12:42:59+00:00

Free useless ucode_patch entry when it's replaced.

[ bp: Drop the memfree_patch() two-liner. ]

Signed-off-by: Zhenzhong Duan 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Srinivas REDDY Eeda 
Link: http://lkml.kernel.org/r/888102f0-fd22-459d-b090-a1bd8a00cb2b@default

x86/microcode/intel: Save microcode patch unconditionally

2018-04-24T07:48:22+00:00

save_mc_for_early() was a no-op on !CONFIG_HOTPLUG_CPU but the
generic_load_microcode() path saves the microcode patches it has found into
the cache of patches which is used for late loading too. Regardless of
whether CPU hotplug is used or not.

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

Reported-by: Vitezslav Samel 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Tested-by: Vitezslav Samel 
Tested-by: Ashok Raj 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz
Link: https://lkml.kernel.org/r/20180421081930.15741-1-bp@alien8.de