A certain number of patch levels of applied microcode should not
be overwritten by the microcode loader, otherwise bad things
will happen.

Check those and abort update if the current core has one of
those final patch levels applied by the BIOS. 32-bit needs
special handling, of course.

See https://bugzilla.suse.com/show_bug.cgi?id=913996 for more
info.
Tested-by: NPeter Kirchgeßner <pkirchgessner@t-online.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1444641762-9437-7-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Pave the way for checking the current patch level of the
microcode in a core. We want to be able to do stuff depending on
the patch level - in this case decide whether to update or not.
But that will be added in a later patch.

Drop unused local var uci assignment, while at it.

Integrate a fix for 32-bit and CONFIG_PARAVIRT from Takashi Iwai:

 Use native_rdmsr() in check_current_patch_level() because with
 CONFIG_PARAVIRT enabled and on 32-bit, where we run before
 paging has been enabled, we cannot deref pv_info yet. Or we
 could, but we'd need to access its physical address. This way of
 fixing it is simpler. See:

   https://bugzilla.suse.com/show_bug.cgi?id=943179 for the background.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Takashi Iwai <tiwai@suse.com>:
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1444641762-9437-6-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Its return value is not used by the subsys core and nothing meaningful
can be done with it, even if we want to use it. The subsys device is
anyway getting removed.

Update prototype of ->remove_dev() to make its return type as void. Fix
all usage sites as well.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The __ref / __refdata annotations used to be needed because of
referencing functions / variables annotated __cpuinit /
__cpuinitdata.

But those annotations vanished during the development of v3.11.

Therefore most of the __ref / __refdata annotations are not needed
anymore. As they may hide legitimate sections mismatches, we
better get rid of them.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437409973-8927-1-git-send-email-minipli@googlemail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Change the type of variables and function prototypes to be in
alignment with what the x86_*() / __x86_*() family/model
functions return.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.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/1433436928-31903-21-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Andy Shevchenko reported machine freezes when booting latest tip
on 32-bit setups. Problem is, the builtin microcode handling cannot
really work that early, when we haven't even enabled paging.

A proper fix would involve handling that case specially as every
other early 32-bit boot case in the microcode loader and would
require much more involved changes for which it is too late now,
more than a week before the upcoming merge window.

So, disable the builtin microcode loading on 32-bit for now.
Reported-and-tested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.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/1433436928-31903-20-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

... to find_matching_signature() which is exactly what it does.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431860101-14847-5-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Unclutter function, make it a bit more readable, drop local
variables.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431860101-14847-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Drop unreadable macro, deconstruct compound conditional
statement into single ones and return early if they match. Add
comments.

There should be no functionality change resulting from this
patch.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431860101-14847-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

... to has_newer_microcode() as it does exactly that: checks
whether binary data @mc has newer microcode patch than the
applied one. Move @mc to be the first function arg too.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431860101-14847-2-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

It is useless at best and git history has it all detailed
anyway. Update copyright while at it.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431332153-18566-3-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Apparently, people do build microcode into the kernel image, i.e.
CONFIG_FIRMWARE_IN_KERNEL=y.

Make that work in the early loader which is where microcode should be
preferably loaded anyway.

Note that you need to specify the microcode filename with the path
relative to the toplevel firmware directory (the same like the late
loading method) in CONFIG_EXTRA_FIRMWARE=y so that early loader can
find it.

I.e., something like this (Intel variant):

  CONFIG_FIRMWARE_IN_KERNEL=y
  CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09"
  CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware/"

While at it, add me to the loader copyright boilerplate.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Daniel J Blueman <daniel@numascale.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

@rev wasn't used in get_matching_sig(), drop it.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

It is a one-liner for checking microcode header revisions. On top of
that, it can be used wrong as it was the case in _save_mc(). Get rid of
it.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

This file doesn't use any macros from pci_ids.h anymore, drop the include.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andreas Herrmann <herrmann.der.user@googlemail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1427635734-24786-80-git-send-email-mst@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When doing

  echo 1 > /sys/devices/system/cpu/microcode/reload

in order to reload microcode, I get:

  microcode: Total microcode saved: 1
  BUG: using smp_processor_id() in preemptible [00000000] code: bash/2606
  caller is debug_smp_processor_id+0x17/0x20
  CPU: 1 PID: 2606 Comm: bash Not tainted 3.19.0-rc7+ #9
  Hardware name: LENOVO 2320CTO/2320CTO, BIOS G2ET86WW (2.06 ) 11/13/2012
   ffffffff81a4266d ffff8802131db808 ffffffff81666588 0000000000000007
   0000000000000001 ffff8802131db838 ffffffff812e6eef ffff8802131db868
   00000000000306a9 0000000000000010 0000000000000015 ffff8802131db848
  Call Trace:
   dump_stack
   check_preemption_disabled
   debug_smp_processor_id
   show_saved_mc
   ? save_microcode.constprop.8
   save_mc_for_early
   ? print_context_stack
   ? dump_trace
   ? __bfs
   ? mark_held_locks
   ? get_page_from_freelist
   ? trace_hardirqs_on_caller
   ? trace_hardirqs_on
   ? __alloc_pages_nodemask
   ? __get_vm_area_node
   ? map_vm_area
   ? __vmalloc_node_range
   ? generic_load_microcode
   generic_load_microcode
   ? microcode_fini_cpu
   request_microcode_fw
   reload_store
   dev_attr_store
   sysfs_kf_write
   kernfs_fop_write
   vfs_write
   ? sysret_check
   SyS_write
   system_call_fastpath
  microcode: CPU1: sig=0x306a9, pf=0x10, rev=0x15
  microcode: mc_saved[0]: sig=0x306a9, pf=0x12, rev=0x1b, toal size=0x3000, date = 2014-05-29

because we're using smp_processor_id() in preemtible context. And we
don't really need to use it there because the microcode container we're
dumping is global and CPU-specific info is irrelevant.

While at it, make pr_* stuff use "microcode: " prefix for easier
grepping and document how to enable the DEBUG build.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... and do not attempt to load anything in case of error.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Shorten variable names and rename it to what it does.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... arguments list so that it comes more natural for those functions to
have the signature, processor flags and revision together, before the
rest of the args.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>

* remove state variable and out label
* get rid of completely unused mc_size
* shorten variable names
* get rid of local variables
* don't do assignments in local var declarations for less cluttered code
* finally rename it to the shorter and perfectly fine load_microcode_early()

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... to the header. Split the family acquiring function into a
main one, doing CPUID and a helper which computes the extended
family and is used in multiple places. Get rid of the locally-grown
get_x86_{family,model}().

While at it, rename local variables to something more descriptive and
vertically align assignments for better readability.

There should be no functionality change resulting from this patch.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... to revision_is_newer() and push it up into the header and make it an
inline function.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Shorten local variable names for better readability and flatten loop
indentation levels.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... of microcode patches instead of handing in a pointer which is used
for I/O in an otherwise void function.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Don't compute start and end from start and size in order to compute size
again down the path in scan_microcode(). So pass size directly instead
and simplify a bunch. Shorten variable names and remove useless ones.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Allocate it on the helper's _load_ucode_intel_bsp() stack instead and do
not hand it down.
Signed-off-by: NBorislav Petkov <bp@suse.de>

... and only then deref it. Also, shorten some variable names and rename
others so as to diminish the ubiquitous presence of the "mc_" prefix
everywhere and make it a bit more readable.

Use kcalloc so that we don't kfree() uninitialized memory on the unwind
path, as suggested by Quentin.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>

We should check the return value of the routines fishing out the proper
microcode and not try to apply if we haven't found a suitable blob.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Improper pointer arithmetics when calculating the address of the
extended header could lead to an out of bounds memory read and kernel
panic.
Signed-off-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Link: http://lkml.kernel.org/r/20150225094125.GB30434@chrystal.uk.oracle.comSigned-off-by: NBorislav Petkov <bp@suse.de>

We do not check the input data bounds containing the microcode before
copying a struct microcode_intel_header from it. A specially crafted
microcode could cause the kernel to read invalid memory and lead to a
denial-of-service.
Signed-off-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1422964824-22056-3-git-send-email-quentin.casasnovas@oracle.com
[ Made error message differ from the next one and flipped comparison. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>

mc_saved_tmp is a static array allocated on the stack, we need to make
sure mc_saved_count stays within its bounds, otherwise we're overflowing
the stack in _save_mc(). A specially crafted microcode header could lead
to a kernel crash or potentially kernel execution.
Signed-off-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1422964824-22056-1-git-send-email-quentin.casasnovas@oracle.comSigned-off-by: NBorislav Petkov <bp@suse.de>

Commits 65cef131 ("x86, microcode: Add a disable chicken bit") and
a18a0f68 ("x86, microcode: Don't initialize microcode code on
paravirt") allow microcode driver skip initialization when microcode
loading is not permitted.

However, they don't prevent the driver from being loaded since the
init code returns 0. If at some point later the driver gets unloaded
this will result in an oops while trying to deregister the (never
registered) device.

To avoid this, make init code return an error on paravirt or when
microcode loading is disabled. The driver will then never be loaded.
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1422411669-25147-1-git-send-email-boris.ostrovsky@oracle.comReported-by: NJames Digwall <james@dingwall.me.uk>
Cc: stable@vger.kernel.org # 3.18
Signed-off-by: NBorislav Petkov <bp@suse.de>

I'm such a moron! The simple solution of saving the BSP patch
for use on resume was too simple (and wrong!), hint:
sizeof(struct microcode_intel).

What needs to be done instead is to fish out the microcode patch
we have stashed previously and apply that on the BSP in case the
late loader hasn't been utilized.

So do that instead.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20141208110820.GB20057@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>

Normally, we do reapply microcode on resume. However, in the cases where
that microcode comes from the early loader and the late loader hasn't
been utilized yet, there's no easy way for us to go and apply the patch
applied during boot by the early loader.

Thus, reuse the patch stashed by the early loader for the BSP.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Paravirtual guests are not expected to load microcode into processors
and therefore it is not necessary to initialize microcode loading
logic.

In fact, under certain circumstances initializing this logic may cause
the guest to crash. Specifically, 32-bit kernels use __pa_nodebug()
macro which does not work in Xen (the code path that leads to this macro
happens during resume when we call mc_bp_resume()->load_ucode_ap()
->check_loader_disabled_ap())
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1417469264-31470-1-git-send-email-boris.ostrovsky@oracle.comSigned-off-by: NBorislav Petkov <bp@suse.de>

apply_microcode_early() doesn't use mc_saved_data, kill it.
Signed-off-by: NBorislav Petkov <bp@suse.de>

Hand down the cpu number instead, otherwise lockdep screams when doing

echo 1 > /sys/devices/system/cpu/microcode/reload.

BUG: using smp_processor_id() in preemptible [00000000] code: amd64-microcode/2470
caller is debug_smp_processor_id+0x12/0x20
CPU: 1 PID: 2470 Comm: amd64-microcode Not tainted 3.18.0-rc6+ #26
...
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1417428741-4501-1-git-send-email-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

First, there was this: https://bugzilla.kernel.org/show_bug.cgi?id=88001

The problem there was that microcode patches are not being reapplied
after suspend-to-ram. It was important to reapply them, though, because
of for example Haswell's TSX erratum which disabled TSX instructions
with a microcode patch.

A simple fix was fb86b973 ("x86, microcode: Update BSPs microcode
on resume") but, as it is often the case, simple fixes are too
simple. This one causes 32-bit resume to fail:

https://bugzilla.kernel.org/show_bug.cgi?id=88391

Properly fixing this would require more involved changes for which it
is too late now, right before the merge window. Thus, limit this to
64-bit only temporarily.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1417353999-32236-1-git-send-email-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

In the situation when we apply early microcode but do *not* apply late
microcode, we fail to update the BSP's microcode on resume because we
haven't initialized the uci->mc microcode pointer. So, in order to
alleviate that, we go and dig out the stashed microcode patch during
early boot. It is basically the same thing that is done on the APs early
during boot so do that too here.

Tested-by: alex.schnaidt@gmail.com
Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=88001
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20141118094657.GA6635@pd.tnicSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Save the patch while we're running on the BSP instead of later, before
the initrd has been jettisoned. More importantly, on 32-bit we need to
access the physical address instead of the virtual.

This way we actually do find it on the APs instead of having to go
through the initrd each time.
Tested-by: NRichard Hendershot <rshendershot@mchsi.com>
Fixes: 5335ba5c ("x86, microcode, AMD: Fix early ucode loading")
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: NBorislav Petkov <bp@suse.de>