Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So instead of
initializing this variable to -1, it can perfectly be initialized to 0
and use it as an unsigned variable instead.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Addresses-Coverity-ID: 1464429
Link: http://lkml.kernel.org/r/20180213192208.GA26414@embeddedor.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

x86_mask is a confusing name which is hard to associate with the
processor's stepping.

Additionally, correct an indent issue in lib/cpu.c.
Signed-off-by: NJia Zhang <qianyue.zj@alibaba-inc.com>
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@alien8.de
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Commit 24c25032 ("x86/microcode: Do not access the initrd after it has
been freed") fixed attempts to access initrd from the microcode loader
after it has been freed. However, a similar KASAN warning was reported
(stack trace edited):

  smpboot: Booting Node 0 Processor 1 APIC 0x11
  ==================================================================
  BUG: KASAN: use-after-free in find_cpio_data+0x9b5/0xa50
  Read of size 1 at addr ffff880035ffd000 by task swapper/1/0

  CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.8-slack #7
  Hardware name: System manufacturer System Product Name/A88X-PLUS, BIOS 3003 03/10/2016
  Call Trace:
   dump_stack
   print_address_description
   kasan_report
   ? find_cpio_data
   __asan_report_load1_noabort
   find_cpio_data
   find_microcode_in_initrd
   __load_ucode_amd
   load_ucode_amd_ap
      load_ucode_ap

After some investigation, it turned out that a merge was done using the
wrong side to resolve, leading to picking up the previous state, before
the 24c25032 fix. Therefore the Fixes tag below contains a merge
commit.

Revert the mismerge by catching the save_microcode_in_initrd_amd()
retval and thus letting the function exit with the last return statement
so that initrd_gone can be set to true.

Fixes: f26483ea ("Merge branch 'x86/urgent' into x86/microcode, to resolve conflicts")
Reported-by: <higuita@gmx.net>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=198295
Link: https://lkml.kernel.org/r/20180123104133.918-2-bp@alien8.de

Commit b94b7373 ("x86/microcode/intel: Extend BDW late-loading with a
revision check") reduced the impact of erratum BDF90 for Broadwell model
79.

The impact can be reduced further by checking the size of the last level
cache portion per core.

Tony: "The erratum says the problem only occurs on the large-cache SKUs.
So we only need to avoid the update if we are on a big cache SKU that is
also running old microcode."

For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.

Fixes: b94b7373 ("x86/microcode/intel: Extend BDW late-loading with a revision check")
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NTony Luck <tony.luck@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com

Convert DEVICE_ATTR uses to DEVICE_ATTR_WO where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
  xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IWUSR\s*|\s*0200\s*)\)?\s*,\s*NULL\s*,\s*\s_store\s*\)/DEVICE_ATTR_WO(\1)/g; print;}'
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of blacklisting all model 79 CPUs when attempting a late
microcode loading, limit that only to CPUs with microcode revisions <
0x0b000021 because only on those late loading may cause a system hang.

For such processors either:

a) a BIOS update which might contain a newer microcode revision

or

b) the early microcode loading method

should be considered.

Processors with revisions 0x0b000021 or higher will not experience such
hangs.

For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.

[ bp: Heavily massage commit message and pr_* statements. ]

Fixes: 723f2828 ("x86/microcode/intel: Disable late loading on model 79")
Signed-off-by: NJia Zhang <qianyue.zj@alibaba-inc.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NTony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: <stable@vger.kernel.org> # v4.14
Link: http://lkml.kernel.org/r/1514772287-92959-1-git-send-email-qianyue.zj@alibaba-inc.com

Commit:

  ec400dde ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")

... grubbed into tlbflush internals without coherent explanation.

Since it says its a precaution and the SDM doesn't mention anything like
this, take it out back.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: fenghua.yu@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The size for the Microcode Patch Block (MPB) for an AMD family 17h
processor is 3200 bytes.  Add a #define for fam17h so that it does
not default to 2048 bytes and fail a microcode load/update.
Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Link: https://lkml.kernel.org/r/20171130224640.15391.40247.stgit@tlendack-t1.amdoffice.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

Blacklist Broadwell X model 79 for late loading due to an erratum.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NTony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>
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/20171018111225.25635-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

On CPUs like AMD's Geode, for example, we shouldn't even try to load
microcode because they do not support the modern microcode loading
interface.

However, we do the family check *after* the other checks whether the
loader has been disabled on the command line or whether we're running in
a guest.

So move the family checks first in order to exit early if we're being
loaded on an unsupported family.
Reported-and-tested-by: NSven Glodowski <glodi1@arcor.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.11..
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://bugzilla.suse.com/show_bug.cgi?id=1061396
Link: http://lkml.kernel.org/r/20171012112316.977-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Avoid potentially dereferencing a NULL pointer when saving a microcode
patch for early loading on the application processors.

While at it, drop the IS_ERR() checking in favor of simpler, NULL-ptr
checks which are sufficient and rename __alloc_microcode_buf() to
memdup_patch() to more precisely denote what it does.

No functionality change.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20170825100456.n236w3jebteokfd6@pd.tnic

attribute_groups are not supposed to change at runtime and none of the
groups is modified.

Mark the non-const structs as const.

[ tglx: Folded into one big patch ]
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: tony.luck@intel.com
Cc: bp@alien8.de
Link: http://lkml.kernel.org/r/1500550238-15655-2-git-send-email-arvind.yadav.cs@gmail.com

verify_and_add_patch() allocates memory for a microcode patch and hands
it down to be added to the cache of patches. However, if the cache
already has the latest patch, the newly allocated one needs to be freed
before returning. Do that.

This issue has been found by kmemleak:

  unreferenced object 0xffff88010e780b40 (size 32):
    comm "bash", pid 860, jiffies 4294690939 (age 29.297s)
    backtrace:
       kmemleak_alloc
       kmem_cache_alloc_trace
       load_microcode_amd.isra.0
       request_microcode_amd
       reload_store
       dev_attr_store
       sysfs_kf_write
       kernfs_fop_write
       __vfs_write
       vfs_write
       SyS_write
       do_syscall_64
       return_from_SYSCALL_64
       0xffffffffffffffff

  (gdb) list *0xffffffff81050d60
  0xffffffff81050d60 is in load_microcode_amd
                (arch/x86/kernel/cpu/microcode/amd.c:616).

which is this:

	patch = kzalloc(sizeof(*patch), GFP_KERNEL);
-->	if (!patch) {
		pr_err("Patch allocation failure.\n");
		return -EINVAL;
	}
Signed-off-by: NShu Wang <shuwang@redhat.com>
[ Rewrite commit message. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: chuhu@redhat.com
Cc: liwang@redhat.com
Link: http://lkml.kernel.org/r/20170724101228.17326-2-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

The helper function __load_ucode_amd() and pointer intel_ucode_patch do
not need to be in global scope, so make them static.

Fixes those sparse warnings:
"symbol '__load_ucode_amd' was not declared. Should it be static?"
"symbol 'intel_ucode_patch' was not declared. Should it be static?"
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170622095736.11937-1-colin.king@canonical.com

Normally, when the initrd is gone, we can't search it for microcode
blobs to apply anymore. For that we need to stash away the patch in our
own storage.

And save_microcode_in_initrd_intel() looks like the proper place to
do that from. So in order for early loading to work, invalidate the
intel_ucode_patch pointer to the patch *before* scanning the initrd one
last time.

If the scanning code finds a microcode patch, it will assign that
pointer again, this time with our own storage's address.

This way, early microcode application during resume-from-RAM works too,
even after the initrd is long gone.
Tested-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NBorislav Petkov <bp@suse.de>
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/20170614140626.4462-2-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Early during boot, the BSP finds the ramdisk's position from boot_params
but by the time the APs get to boot, the BSP has continued in the mean
time and has potentially managed to relocate that ramdisk.

And in that case, the APs need to find the ramdisk at its new position,
in *physical* memory as they're running before paging has been enabled.

Thus, get the updated physical location of the ramdisk which is in the
relocated_ramdisk variable.
Signed-off-by: NBorislav Petkov <bp@suse.de>
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/20170614140626.4462-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

During early boot, load_ucode_intel_ap() uses __load_ucode_intel()
to obtain a pointer to the relevant microcode patch (embedded in the
initrd), and stores this value in 'intel_ucode_patch' to speed up the
microcode patch application for subsequent CPUs.

On resuming from suspend-to-RAM, however, load_ucode_ap() calls
load_ucode_intel_ap() for each non-boot-CPU. By then the initramfs is
long gone so the pointer stored in 'intel_ucode_patch' no longer points to
a valid microcode patch.

Clear that pointer so that we effectively fall back to the CPU hotplug
notifier callbacks to update the microcode.
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
[ Edit and massage commit message. ]
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org> # 4.10..
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/20170607095819.9754-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

With CONFIG_DEBUG_PREEMPT enabled, I get:

  BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
  caller is debug_smp_processor_id
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2+ #2
  Call Trace:
   dump_stack
   check_preemption_disabled
   debug_smp_processor_id
   save_microcode_in_initrd_amd
   ? microcode_init
   save_microcode_in_initrd
   ...

because, well, it says it above, we're using smp_processor_id() in
preemptible code.

But passing the CPU number is not really needed. It is only used to
determine whether we're on the BSP, and, if so, to save the microcode
patch for early loading.

 [ We don't absolutely need to do it on the BSP but we do that
   customarily there. ]

Instead, convert that function parameter to a boolean which denotes
whether the patch should be saved or not, thereby avoiding the use of
smp_processor_id() in preemptible code.
Signed-off-by: NBorislav Petkov <bp@suse.de>
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/20170528200414.31305-1-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Cc: Tigran Aivazian <aivazian.tigran@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mc is a pointer to the static u8 array amd_ucode_patch and
therefore can never be null, so the check is redundant. Remove it.

Detected by CoverityScan, CID#1372871 ("Logically Dead Code")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Cc: kernel-janitors@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20170315171010.17536-1-colin.king@canonical.comSigned-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

When we look for microcode blobs, we first try builtin and if that
doesn't succeed, we fallback to the initrd supplied to the kernel.

However, at some point doing boot, that initrd gets jettisoned and we
shouldn't access it anymore. But we do, as the below KASAN report shows.
That's because find_microcode_in_initrd() doesn't check whether the
initrd is still valid or not.

So do that.

  ==================================================================
  BUG: KASAN: use-after-free in find_cpio_data
  Read of size 1 by task swapper/1/0
  page:ffffea0000db9d40 count:0 mapcount:0 mapping:          (null) index:0x1
  flags: 0x100000000000000()
  raw: 0100000000000000 0000000000000000 0000000000000001 00000000ffffffff
  raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000
  page dumped because: kasan: bad access detected
  CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W       4.10.0-rc5-debug-00075-g2dbde22 #3
  Hardware name: Dell Inc. XPS 13 9360/0839Y6, BIOS 1.2.3 12/01/2016
  Call Trace:
   dump_stack
   ? _atomic_dec_and_lock
   ? __dump_page
   kasan_report_error
   ? pointer
   ? find_cpio_data
   __asan_report_load1_noabort
   ? find_cpio_data
   find_cpio_data
   ? vsprintf
   ? dump_stack
   ? get_ucode_user
   ? print_usage_bug
   find_microcode_in_initrd
   __load_ucode_intel
   ? collect_cpu_info_early
   ? debug_check_no_locks_freed
   load_ucode_intel_ap
   ? collect_cpu_info
   ? trace_hardirqs_on
   ? flat_send_IPI_mask_allbutself
   load_ucode_ap
   ? get_builtin_firmware
   ? flush_tlb_func
   ? do_raw_spin_trylock
   ? cpumask_weight
   cpu_init
   ? trace_hardirqs_off
   ? play_dead_common
   ? native_play_dead
   ? hlt_play_dead
   ? syscall_init
   ? arch_cpu_idle_dead
   ? do_idle
   start_secondary
   start_cpu
  Memory state around the buggy address:
   ffff880036e74f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   ffff880036e74f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  >ffff880036e75000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                     ^
   ffff880036e75080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
   ffff880036e75100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
  ==================================================================
Reported-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Tested-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
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/20170126165833.evjemhbqzaepirxo@pd.tnicSigned-off-by: NIngo Molnar <mingo@kernel.org>

The equivalence ID was needed outside of the container scanning logic
but now, after this has been cleaned up, not anymore. Now, cont_desc.mc
is used to denote whether the container we're looking at has the proper
microcode patch for this CPU or not.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-17-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The idea was to not scan the microcode blob on each AP (Application
Processor) during boot and thus save us some milliseconds. However, on
architectures where the microcode engine is shared between threads, this
doesn't work. Here's why:

The microcode on CPU0, i.e., the first thread, gets updated. The second
thread, i.e., CPU1, i.e., the first AP walks into load_ucode_amd_ap(),
sees that there's no container cached and goes and scans for the proper
blob.

It finds it and as a last step of apply_microcode_early_amd(), it tries
to apply the patch but that core has already the updated microcode
revision which it has received through CPU0's update. So it returns
false and we do desc->size = -1 to prevent other APs from scanning.

However, the next AP, CPU2, has a different microcode engine which
hasn't been updated yet. The desc->size == -1 test prevents it from
scanning the blob anew and we fail to update it.

The fix is much more straight-forward than it looks: the BSP
(BootStrapping Processor), i.e., CPU0, caches the microcode patch
in amd_ucode_patch. We use that on the AP and try to apply it.
In the 99.9999% of cases where we have homogeneous cores - *not*
mixed-steppings - the application will be successful and we're good to
go.

In the remaining small set of systems, we will simply rescan the blob
and find (or not, if none present) the proper patch and apply it then.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-16-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

No need to use the previously stashed info in the container - simply go
ahead and parse the initrd once more. It simplifies and streamlines the
code a whole lot.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-15-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Use a version for both bitness by adding a helper which does the actual
container finding and parsing which can be used on any CPU - BSP or AP.
Streamlines the paths more.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-14-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Check final patch levels for AMD only on the BSP. This way, we decide
early and only once whether to continue loading or to leave the loader
disabled on such systems.

Simplify a lot.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-13-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Use x86_cpuid_vendor() directly.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-12-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Use the generic helper instead of semi-open-coding the procedure.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-11-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

We have a container which we update/prepare each time before applying a
microcode patch instead of using a global.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-10-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Get CPUID(1).EAX value once per CPU and propagate value into the callers
instead of conveniently calling it every time.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-9-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

It was pretty clumsy before and the whole work of parsing the microcode
containers was spread around the functions wrongly.

Clean it up so that there's a main scan_containers() function which
iterates over the microcode blob and picks apart the containers glued
together. For each container, it calls a parse_container() helper which
concentrates on one container only: sanity-checking, parsing, counting
microcode patches in there, etc.

It makes much more sense now and it is actually very readable. Oh, and
we luvz a diffstat removing more crap than adding.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-8-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Make it into a container descriptor which is being passed around and
stores important info like the matching container and the patch for the
current CPU. Make it static too.

Later patches will use this and thus get rid of a double container
parsing.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-7-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The whole driver calls this "mc", do that here too.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-6-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

No need to have it marked "inline" - let gcc decide. Also, shorten the
argument name and simplify while-test.

While at it, make it into a proper for-loop and simplify it even more,
as tglx suggests.

No functionality change.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-5-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This was meant to save us the scanning of the microcode containter in
the initrd since the first AP had already done that but it can also hurt
us:

Imagine a single hyperthreaded CPU (Intel(R) Atom(TM) CPU N270, for
example) which updates the microcode on the BSP but since the microcode
engine is shared between the two threads, the update on CPU1 doesn't
happen because it has already happened on CPU0 and we don't find a newer
microcode revision on CPU1.

Which doesn't set the intel_ucode_patch pointer and at initrd
jettisoning time we don't save the microcode patch for later
application.

Now, when we suspend to RAM, the loaded microcode gets cleared so we
need to reload but there's no patch saved in the cache.

Removing the optimization fixes this issue and all is fine and dandy.

Fixes: 06b8534c ("x86/microcode: Rework microcode loading")
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170120202955.4091-2-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

In generic_load_microcode(), curr_mc_size is the size of the last
allocated buffer and since we have this performance "optimization"
there to vmalloc a new buffer only when the current one is bigger,
curr_mc_size ends up becoming the size of the biggest buffer we've seen
so far.

However, we end up saving the microcode patch which matches our CPU
and its size is not curr_mc_size but the respective mc_size during the
iteration while we're staring at it.

So save that mc_size into a separate variable and use it to store the
previously found microcode buffer.

Without this fix, we could get oops like this:

  BUG: unable to handle kernel paging request at ffffc9000e30f000
  IP: __memcpy+0x12/0x20
  ...
  Call Trace:
  ? kmemdup+0x43/0x60
  __alloc_microcode_buf+0x44/0x70
  save_microcode_patch+0xd4/0x150
  generic_load_microcode+0x1b8/0x260
  request_microcode_user+0x15/0x20
  microcode_write+0x91/0x100
  __vfs_write+0x34/0x120
  vfs_write+0xc1/0x130
  SyS_write+0x56/0xc0
  do_syscall_64+0x6c/0x160
  entry_SYSCALL64_slow_path+0x25/0x25

Fixes: 06b8534c ("x86/microcode: Rework microcode loading")
Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/4f33cbfd-44f2-9bed-3b66-7446cd14256f@ce.jp.nec.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

We allocate struct ucode_patch here. @size is the size of microcode data
and used for kmemdup() later in this function.

Fixes: 06b8534c ("x86/microcode: Rework microcode loading")
Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/7a730dc9-ac17-35c4-fe76-dfc94e5ecd95@ce.jp.nec.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Since on Intel we're required to do CPUID(1) first, before reading
the microcode revision MSR, let's add a special helper which does the
required steps so that we don't forget to do them next time, when we
want to read the microcode revision.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Intel supplies the microcode revision value in MSR 0x8b
(IA32_BIOS_SIGN_ID) after CPUID(1) has been executed. Execute it each
time before reading that MSR.

It used to do sync_core() which did do CPUID but

  c198b121 ("x86/asm: Rewrite sync_core() to use IRET-to-self")

changed the sync_core() implementation so we better make the microcode
loading case explicit, as the SDM documents it.
Reported-and-tested-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-3-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

When we switch to virtual addresses and, especially after
reserve_initrd()->relocate_initrd() have run, we have the updated initrd
address in initrd_start. Use initrd_start then instead of the address
which has been passed to us through boot params. (That still gets used
when we're running the very early routines on the BSP).
Reported-and-tested-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20161220144012.lc4cwrg6dphqbyqu@pd.tnicSigned-off-by: NThomas Gleixner <tglx@linutronix.de>