GitHub/LineageOS/G12/android_kernel_amlogic_linux-4.9.git
5 years agoMIPS: perf: ath79: Fix perfcount IRQ assignment
Petr Štetiar [Fri, 12 Apr 2019 21:08:32 +0000 (23:08 +0200)]
MIPS: perf: ath79: Fix perfcount IRQ assignment

[ Upstream commit a1e8783db8e0d58891681bc1e6d9ada66eae8e20 ]

Currently it's not possible to use perf on ath79 due to genirq flags
mismatch happening on static virtual IRQ 13 which is used for
performance counters hardware IRQ 5.

On TP-Link Archer C7v5:

           CPU0
  2:          0      MIPS   2  ath9k
  4:        318      MIPS   4  19000000.eth
  7:      55034      MIPS   7  timer
  8:       1236      MISC   3  ttyS0
 12:          0      INTC   1  ehci_hcd:usb1
 13:          0  gpio-ath79   2  keys
 14:          0  gpio-ath79   5  keys
 15:         31  AR724X PCI    1  ath10k_pci

 $ perf top
 genirq: Flags mismatch irq 13. 00014c83 (mips_perf_pmu) vs. 00002003 (keys)

On TP-Link Archer C7v4:

         CPU0
  4:          0      MIPS   4  19000000.eth
  5:       7135      MIPS   5  1a000000.eth
  7:      98379      MIPS   7  timer
  8:         30      MISC   3  ttyS0
 12:      90028      INTC   0  ath9k
 13:       5520      INTC   1  ehci_hcd:usb1
 14:       4623      INTC   2  ehci_hcd:usb2
 15:      32844  AR724X PCI    1  ath10k_pci
 16:          0  gpio-ath79  16  keys
 23:          0  gpio-ath79  23  keys

 $ perf top
 genirq: Flags mismatch irq 13. 00014c80 (mips_perf_pmu) vs. 00000080 (ehci_hcd:usb1)

This problem is happening, because currently statically assigned virtual
IRQ 13 for performance counters is not claimed during the initialization
of MIPS PMU during the bootup, so the IRQ subsystem doesn't know, that
this interrupt isn't available for further use.

So this patch fixes the issue by simply booking hardware IRQ 5 for MIPS PMU.

Tested-by: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Acked-by: John Crispin <john@phrozen.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoipvs: do not schedule icmp errors from tunnels
Julian Anastasov [Sun, 31 Mar 2019 10:24:52 +0000 (13:24 +0300)]
ipvs: do not schedule icmp errors from tunnels

[ Upstream commit 0261ea1bd1eb0da5c0792a9119b8655cf33c80a3 ]

We can receive ICMP errors from client or from
tunneling real server. While the former can be
scheduled to real server, the latter should
not be scheduled, they are decapsulated only when
existing connection is found.

Fixes: 6044eeffafbe ("ipvs: attempt to schedule icmp packets")
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoselftests: netfilter: check icmp pkttoobig errors are set as related
Florian Westphal [Mon, 25 Mar 2019 22:11:53 +0000 (23:11 +0100)]
selftests: netfilter: check icmp pkttoobig errors are set as related

[ Upstream commit becf2319f320cae43e20cf179cc51a355a0deb5f ]

When an icmp error such as pkttoobig is received, conntrack checks
if the "inner" header (header of packet that did not fit link mtu)
is matches an existing connection, and, if so, sets that packet as
being related to the conntrack entry it found.

It was recently reported that this "related" setting also works
if the inner header is from another, different connection (i.e.,
artificial/forged icmp error).

Add a test, followup patch will add additional "inner dst matches
outer dst in reverse direction" check before setting related state.

Link: https://www.synacktiv.com/posts/systems/icmp-reachable.html
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoinit: initialize jump labels before command line option parsing
Dan Williams [Fri, 19 Apr 2019 00:50:44 +0000 (17:50 -0700)]
init: initialize jump labels before command line option parsing

[ Upstream commit 6041186a32585fc7a1d0f6cfe2f138b05fdc3c82 ]

When a module option, or core kernel argument, toggles a static-key it
requires jump labels to be initialized early.  While x86, PowerPC, and
ARM64 arrange for jump_label_init() to be called before parse_args(),
ARM does not.

  Kernel command line: rdinit=/sbin/init page_alloc.shuffle=1 panic=-1 console=ttyAMA0,115200 page_alloc.shuffle=1
  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:303
  page_alloc_shuffle+0x12c/0x1ac
  static_key_enable(): static key 'page_alloc_shuffle_key+0x0/0x4' used
  before call to jump_label_init()
  Modules linked in:
  CPU: 0 PID: 0 Comm: swapper Not tainted
  5.1.0-rc4-next-20190410-00003-g3367c36ce744 #1
  Hardware name: ARM Integrator/CP (Device Tree)
  [<c0011c68>] (unwind_backtrace) from [<c000ec48>] (show_stack+0x10/0x18)
  [<c000ec48>] (show_stack) from [<c07e9710>] (dump_stack+0x18/0x24)
  [<c07e9710>] (dump_stack) from [<c001bb1c>] (__warn+0xe0/0x108)
  [<c001bb1c>] (__warn) from [<c001bb88>] (warn_slowpath_fmt+0x44/0x6c)
  [<c001bb88>] (warn_slowpath_fmt) from [<c0b0c4a8>]
  (page_alloc_shuffle+0x12c/0x1ac)
  [<c0b0c4a8>] (page_alloc_shuffle) from [<c0b0c550>] (shuffle_store+0x28/0x48)
  [<c0b0c550>] (shuffle_store) from [<c003e6a0>] (parse_args+0x1f4/0x350)
  [<c003e6a0>] (parse_args) from [<c0ac3c00>] (start_kernel+0x1c0/0x488)

Move the fallback call to jump_label_init() to occur before
parse_args().

The redundant calls to jump_label_init() in other archs are left intact
in case they have static key toggling use cases that are even earlier
than option parsing.

Link: http://lkml.kernel.org/r/155544804466.1032396.13418949511615676665.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Guenter Roeck <groeck@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Russell King <rmk@armlinux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agotools lib traceevent: Fix missing equality check for strcmp
Rikard Falkeborn [Tue, 9 Apr 2019 09:15:29 +0000 (11:15 +0200)]
tools lib traceevent: Fix missing equality check for strcmp

[ Upstream commit f32c2877bcb068a718bb70094cd59ccc29d4d082 ]

There was a missing comparison with 0 when checking if type is "s64" or
"u64". Therefore, the body of the if-statement was entered if "type" was
"u64" or not "s64", which made the first strcmp() redundant since if
type is "u64", it's not "s64".

If type is "s64", the body of the if-statement is not entered but since
the remainder of the function consists of if-statements which will not
be entered if type is "s64", we will just return "val", which is
correct, albeit at the cost of a few more calls to strcmp(), i.e., it
will behave just as if the if-statement was entered.

If type is neither "s64" or "u64", the body of the if-statement will be
entered incorrectly and "val" returned. This means that any type that is
checked after "s64" and "u64" is handled the same way as "s64" and
"u64", i.e., the limiting of "val" to fit in for example "s8" is never
reached.

This was introduced in the kernel tree when the sources were copied from
trace-cmd in commit f7d82350e597 ("tools/events: Add files to create
libtraceevent.a"), and in the trace-cmd repo in 1cdbae6035cei
("Implement typecasting in parser") when the function was introduced,
i.e., it has always behaved the wrong way.

Detected by cppcheck.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Fixes: f7d82350e597 ("tools/events: Add files to create libtraceevent.a")
Link: http://lkml.kernel.org/r/20190409091529.2686-1-rikard.falkeborn@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoKVM: x86: avoid misreporting level-triggered irqs as edge-triggered in tracing
Vitaly Kuznetsov [Wed, 27 Mar 2019 14:12:20 +0000 (15:12 +0100)]
KVM: x86: avoid misreporting level-triggered irqs as edge-triggered in tracing

[ Upstream commit 7a223e06b1a411cef6c4cd7a9b9a33c8d225b10e ]

In __apic_accept_irq() interface trig_mode is int and actually on some code
paths it is set above u8:

kvm_apic_set_irq() extracts it from 'struct kvm_lapic_irq' where trig_mode
is u16. This is done on purpose as e.g. kvm_set_msi_irq() sets it to
(1 << 15) & e->msi.data

kvm_apic_local_deliver sets it to reg & (1 << 15).

Fix the immediate issue by making 'tm' into u16. We may also want to adjust
__apic_accept_irq() interface and use proper sizes for vector, level,
trig_mode but this is not urgent.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agox86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51T
Jian-Hong Pan [Fri, 12 Apr 2019 08:01:53 +0000 (16:01 +0800)]
x86/reboot, efi: Use EFI reboot for Acer TravelMate X514-51T

[ Upstream commit 0082517fa4bce073e7cf542633439f26538a14cc ]

Upon reboot, the Acer TravelMate X514-51T laptop appears to complete the
shutdown process, but then it hangs in BIOS POST with a black screen.

The problem is intermittent - at some points it has appeared related to
Secure Boot settings or different kernel builds, but ultimately we have
not been able to identify the exact conditions that trigger the issue to
come and go.

Besides, the EFI mode cannot be disabled in the BIOS of this model.

However, after extensive testing, we observe that using the EFI reboot
method reliably avoids the issue in all cases.

So add a boot time quirk to use EFI reboot on such systems.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=203119
Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
Signed-off-by: Daniel Drake <drake@endlessm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux@endlessm.com
Link: http://lkml.kernel.org/r/20190412080152.3718-1-jian-hong@endlessm.com
[ Fix !CONFIG_EFI build failure, clarify the code and the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agomISDN: Check address length before reading address family
Tetsuo Handa [Fri, 12 Apr 2019 10:52:36 +0000 (19:52 +0900)]
mISDN: Check address length before reading address family

[ Upstream commit 238ffdc49ef98b15819cfd5e3fb23194e3ea3d39 ]

KMSAN will complain if valid address length passed to bind() is shorter
than sizeof("struct sockaddr_mISDN"->family) bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agos390/3270: fix lockdep false positive on view->lock
Martin Schwidefsky [Wed, 3 Apr 2019 07:13:34 +0000 (09:13 +0200)]
s390/3270: fix lockdep false positive on view->lock

[ Upstream commit 5712f3301a12c0c3de9cc423484496b0464f2faf ]

The spinlock in the raw3270_view structure is used by con3270, tty3270
and fs3270 in different ways. For con3270 the lock can be acquired in
irq context, for tty3270 and fs3270 the highest context is bh.

Lockdep sees the view->lock as a single class and if the 3270 driver
is used for the console the following message is generated:

WARNING: inconsistent lock state
5.1.0-rc3-05157-g5c168033979d #12 Not tainted
--------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0/1 [HC0[0]:SC1[1]:HE1:SE0] takes:
(____ptrval____) (&(&view->lock)->rlock){?.-.}, at: tty3270_update+0x7c/0x330

Introduce a lockdep subclass for the view lock to distinguish bh from
irq locks.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agomac80211: fix unaligned access in mesh table hash function
Felix Fietkau [Wed, 13 Mar 2019 17:54:27 +0000 (18:54 +0100)]
mac80211: fix unaligned access in mesh table hash function

[ Upstream commit 40586e3fc400c00c11151804dcdc93f8c831c808 ]

The pointer to the last four bytes of the address is not guaranteed to be
aligned, so we need to use __get_unaligned_cpu32 here

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agos390/dasd: Fix capacity calculation for large volumes
Peter Oberparleiter [Fri, 22 Mar 2019 15:01:17 +0000 (16:01 +0100)]
s390/dasd: Fix capacity calculation for large volumes

[ Upstream commit 2cc9637ce825f3a9f51f8f78af7474e9e85bfa5f ]

The DASD driver incorrectly limits the maximum number of blocks of ECKD
DASD volumes to 32 bit numbers. Volumes with a capacity greater than
2^32-1 blocks are incorrectly recognized as smaller volumes.

This results in the following volume capacity limits depending on the
formatted block size:

  BLKSIZE  MAX_GB   MAX_CYL
      512    2047   5843492
     1024    4095   8676701
     2048    8191  13634816
     4096   16383  23860929

The same problem occurs when a volume with more than 17895697 cylinders
is accessed in raw-track-access mode.

Fix this problem by adding an explicit type cast when calculating the
maximum number of blocks.

Signed-off-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agolibnvdimm/btt: Fix a kmemdup failure check
Aditya Pakki [Mon, 25 Mar 2019 21:55:27 +0000 (16:55 -0500)]
libnvdimm/btt: Fix a kmemdup failure check

[ Upstream commit 486fa92df4707b5df58d6508728bdb9321a59766 ]

In case kmemdup fails, the fix releases resources and returns to
avoid the NULL pointer dereference.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoHID: input: add mapping for "Toggle Display" key
Dmitry Torokhov [Fri, 18 Jan 2019 22:35:45 +0000 (14:35 -0800)]
HID: input: add mapping for "Toggle Display" key

[ Upstream commit c01908a14bf735b871170092807c618bb9dae654 ]

According to HUT 1.12 usage 0xb5 from the generic desktop page is reserved
for switching between external and internal display, so let's add the
mapping.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoHID: input: add mapping for keyboard Brightness Up/Down/Toggle keys
Dmitry Torokhov [Fri, 18 Jan 2019 22:05:52 +0000 (14:05 -0800)]
HID: input: add mapping for keyboard Brightness Up/Down/Toggle keys

[ Upstream commit 7975a1d6a7afeb3eb61c971a153d24dd8fa032f3 ]

According to HUTRR73 usages 0x79, 0x7a and 0x7c from the consumer page
correspond to Brightness Up/Down/Toggle keys, so let's add the mappings.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoHID: input: add mapping for Expose/Overview key
Dmitry Torokhov [Fri, 18 Jan 2019 21:59:08 +0000 (13:59 -0800)]
HID: input: add mapping for Expose/Overview key

[ Upstream commit 96dd86871e1fffbc39e4fa61c9c75ec54ee9af0f ]

According to HUTRR77 usage 0x29f from the consumer page is reserved for
the Desktop application to present all running user’s application windows.
Linux defines KEY_SCALE to request Compiz Scale (Expose) mode, so let's
add the mapping.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agolibnvdimm/namespace: Fix a potential NULL pointer dereference
Kangjie Lu [Tue, 12 Mar 2019 08:20:34 +0000 (03:20 -0500)]
libnvdimm/namespace: Fix a potential NULL pointer dereference

[ Upstream commit 55c1fc0af29a6c1b92f217b7eb7581a882e0c07c ]

In case kmemdup fails, the fix goes to blk_err to avoid NULL
pointer dereference.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoiio: adc: xilinx: fix potential use-after-free on remove
Sven Van Asbroeck [Sun, 10 Mar 2019 18:58:24 +0000 (14:58 -0400)]
iio: adc: xilinx: fix potential use-after-free on remove

[ Upstream commit 62039b6aef63380ba7a37c113bbaeee8a55c5342 ]

When cancel_delayed_work() returns, the delayed work may still
be running. This means that the core could potentially free
the private structure (struct xadc) while the delayed work
is still using it. This is a potential use-after-free.

Fix by calling cancel_delayed_work_sync(), which waits for
any residual work to finish before returning.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoUSB: serial: fix unthrottle races
Johan Hovold [Thu, 25 Apr 2019 16:05:36 +0000 (18:05 +0200)]
USB: serial: fix unthrottle races

commit 3f5edd58d040bfa4b74fb89bc02f0bc6b9cd06ab upstream.

Fix two long-standing bugs which could potentially lead to memory
corruption or leave the port throttled until it is reopened (on weakly
ordered systems), respectively, when read-URB completion races with
unthrottle().

First, the URB must not be marked as free before processing is complete
to prevent it from being submitted by unthrottle() on another CPU.

CPU 1 CPU 2
================ ================
complete() unthrottle()
  process_urb();
  smp_mb__before_atomic();
  set_bit(i, free);   if (test_and_clear_bit(i, free))
     submit_urb();

Second, the URB must be marked as free before checking the throttled
flag to prevent unthrottle() on another CPU from failing to observe that
the URB needs to be submitted if complete() sees that the throttled flag
is set.

CPU 1 CPU 2
================ ================
complete() unthrottle()
  set_bit(i, free);   throttled = 0;
  smp_mb__after_atomic();   smp_mb();
  if (throttled)   if (test_and_clear_bit(i, free))
     return;   submit_urb();

Note that test_and_clear_bit() only implies barriers when the test is
successful. To handle the case where the URB is still in use an explicit
barrier needs to be added to unthrottle() for the second race condition.

Fixes: d83b405383c9 ("USB: serial: add support for multiple read urbs")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoplatform/x86: sony-laptop: Fix unintentional fall-through
Gustavo A. R. Silva [Wed, 24 Apr 2019 18:09:34 +0000 (13:09 -0500)]
platform/x86: sony-laptop: Fix unintentional fall-through

commit 1cbd7a64959d33e7a2a1fa2bf36a62b350a9fcbd upstream.

It seems that the default case should return AE_CTRL_TERMINATE, instead
of falling through to case ACPI_RESOURCE_TYPE_END_TAG and returning AE_OK;
otherwise the line of code at the end of the function is unreachable and
makes no sense:

return AE_CTRL_TERMINATE;

This fix is based on the following thread of discussion:

https://lore.kernel.org/patchwork/patch/959782/

Fixes: 33a04454527e ("sony-laptop: Add SNY6001 device handling (sonypi reimplementation)")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agobpf: convert htab map to hlist_nulls
Alexei Starovoitov [Fri, 10 May 2019 02:33:54 +0000 (19:33 -0700)]
bpf: convert htab map to hlist_nulls

commit 4fe8435909fddc97b81472026aa954e06dd192a5 upstream.

when all map elements are pre-allocated one cpu can delete and reuse htab_elem
while another cpu is still walking the hlist. In such case the lookup may
miss the element. Convert hlist to hlist_nulls to avoid such scenario.
When bucket lock is taken there is no need to take such precautions,
so only convert map_lookup and map_get_next to nulls.
The race window is extremely small and only reproducible with explicit
udelay() inside lookup_nulls_elem_raw()

Similar to hlist add hlist_nulls_for_each_entry_safe() and
hlist_nulls_entry_safe() helpers.

Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements")
Reported-by: Jonathan Perry <jonperry@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agobpf: fix struct htab_elem layout
Alexei Starovoitov [Fri, 10 May 2019 02:33:53 +0000 (19:33 -0700)]
bpf: fix struct htab_elem layout

commit 9f691549f76d488a0c74397b3e51e943865ea01f upstream.

when htab_elem is removed from the bucket list the htab_elem.hash_node.next
field should not be overridden too early otherwise we have a tiny race window
between lookup and delete.
The bug was discovered by manual code analysis and reproducible
only with explicit udelay() in lookup_elem_raw().

Fixes: 6c9059817432 ("bpf: pre-allocate hash map elements")
Reported-by: Jonathan Perry <jonperry@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agonetfilter: compat: initialize all fields in xt_init
Francesco Ruggeri [Fri, 10 May 2019 16:19:30 +0000 (09:19 -0700)]
netfilter: compat: initialize all fields in xt_init

commit 8d29d16d21342a0c86405d46de0c4ac5daf1760f upstream

If a non zero value happens to be in xt[NFPROTO_BRIDGE].cur at init
time, the following panic can be caused by running

% ebtables -t broute -F BROUTING

from a 32-bit user level on a 64-bit kernel. This patch replaces
kmalloc_array with kcalloc when allocating xt.

[  474.680846] BUG: unable to handle kernel paging request at 0000000009600920
[  474.687869] PGD 2037006067 P4D 2037006067 PUD 2038938067 PMD 0
[  474.693838] Oops: 0000 [#1] SMP
[  474.697055] CPU: 9 PID: 4662 Comm: ebtables Kdump: loaded Not tainted 4.19.17-11302235.AroraKernelnext.fc18.x86_64 #1
[  474.707721] Hardware name: Supermicro X9DRT/X9DRT, BIOS 3.0 06/28/2013
[  474.714313] RIP: 0010:xt_compat_calc_jump+0x2f/0x63 [x_tables]
[  474.720201] Code: 40 0f b6 ff 55 31 c0 48 6b ff 70 48 03 3d dc 45 00 00 48 89 e5 8b 4f 6c 4c 8b 47 60 ff c9 39 c8 7f 2f 8d 14 08 d1 fa 48 63 fa <41> 39 34 f8 4c 8d 0c fd 00 00 00 00 73 05 8d 42 01 eb e1 76 05 8d
[  474.739023] RSP: 0018:ffffc9000943fc58 EFLAGS: 00010207
[  474.744296] RAX: 0000000000000000 RBX: ffffc90006465000 RCX: 0000000002580249
[  474.751485] RDX: 00000000012c0124 RSI: fffffffff7be17e9 RDI: 00000000012c0124
[  474.758670] RBP: ffffc9000943fc58 R08: 0000000000000000 R09: ffffffff8117cf8f
[  474.765855] R10: ffffc90006477000 R11: 0000000000000000 R12: 0000000000000001
[  474.773048] R13: 0000000000000000 R14: ffffc9000943fcb8 R15: ffffc9000943fcb8
[  474.780234] FS:  0000000000000000(0000) GS:ffff88a03f840000(0063) knlGS:00000000f7ac7700
[  474.788612] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  474.794632] CR2: 0000000009600920 CR3: 0000002037422006 CR4: 00000000000606e0
[  474.802052] Call Trace:
[  474.804789]  compat_do_replace+0x1fb/0x2a3 [ebtables]
[  474.810105]  compat_do_ebt_set_ctl+0x69/0xe6 [ebtables]
[  474.815605]  ? try_module_get+0x37/0x42
[  474.819716]  compat_nf_setsockopt+0x4f/0x6d
[  474.824172]  compat_ip_setsockopt+0x7e/0x8c
[  474.828641]  compat_raw_setsockopt+0x16/0x3a
[  474.833220]  compat_sock_common_setsockopt+0x1d/0x24
[  474.838458]  __compat_sys_setsockopt+0x17e/0x1b1
[  474.843343]  ? __check_object_size+0x76/0x19a
[  474.847960]  __ia32_compat_sys_socketcall+0x1cb/0x25b
[  474.853276]  do_fast_syscall_32+0xaf/0xf6
[  474.857548]  entry_SYSENTER_compat+0x6b/0x7a

Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
5 years agoLinux 4.9.176
Greg Kroah-Hartman [Tue, 14 May 2019 17:19:42 +0000 (19:19 +0200)]
Linux 4.9.176

5 years agox86/cpu/bugs: Use __initconst for 'const' init data
Andi Kleen [Sat, 30 Mar 2019 00:47:43 +0000 (17:47 -0700)]
x86/cpu/bugs: Use __initconst for 'const' init data

commit 1de7edbb59c8f1b46071f66c5c97b8a59569eb51 upstream.

Some of the recently added const tables use __initdata which causes section
attribute conflicts.

Use __initconst instead.

Fixes: fa1202ef2243 ("x86/speculation: Add command line control")
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190330004743.29541-9-andi@firstfloor.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86: stop exporting msr-index.h to userland
Nicolas Dichtel [Mon, 27 Mar 2017 12:20:08 +0000 (14:20 +0200)]
x86: stop exporting msr-index.h to userland

commit 25dc1d6cc3082aab293e5dad47623b550f7ddd2a upstream.

Even if this file was not in an uapi directory, it was exported because
it was listed in the Kbuild file.

Fixes: b72e7464e4cf ("x86/uapi: Do not export <asm/msr-index.h> as part of the user API headers")
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Fix documentation typo
Josh Poimboeuf [Tue, 7 May 2019 20:05:22 +0000 (15:05 -0500)]
x86/speculation/mds: Fix documentation typo

commit 95310e348a321b45fb746c176961d4da72344282 upstream.

Fix a minor typo in the MDS documentation: "eanbled" -> "enabled".

Reported-by: Jeff Bastian <jbastian@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoDocumentation: Correct the possible MDS sysfs values
Tyler Hicks [Mon, 6 May 2019 23:52:58 +0000 (23:52 +0000)]
Documentation: Correct the possible MDS sysfs values

commit ea01668f9f43021b28b3f4d5ffad50106a1e1301 upstream.

Adjust the last two rows in the table that display possible values when
MDS mitigation is enabled. They both were slightly innacurate.

In addition, convert the table of possible values and their descriptions
to a list-table. The simple table format uses the top border of equals
signs to determine cell width which resulted in the first column being
far too wide in comparison to the second column that contained the
majority of the text.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/mds: Add MDSUM variant to the MDS documentation
speck for Pawan Gupta [Mon, 6 May 2019 19:23:50 +0000 (12:23 -0700)]
x86/mds: Add MDSUM variant to the MDS documentation

commit e672f8bf71c66253197e503f75c771dd28ada4a0 upstream.

Updated the documentation for a new CVE-2019-11091 Microarchitectural Data
Sampling Uncacheable Memory (MDSUM) which is a variant of
Microarchitectural Data Sampling (MDS). MDS is a family of side channel
attacks on internal buffers in Intel CPUs.

MDSUM is a special case of MSBDS, MFBDS and MLPDS. An uncacheable load from
memory that takes a fault or assist can leave data in a microarchitectural
structure that may later be observed using one of the same methods used by
MSBDS, MFBDS or MLPDS. There are no new code changes expected for MDSUM.
The existing mitigation for MDS applies to MDSUM as well.

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add 'mitigations=' support for MDS
Josh Poimboeuf [Wed, 17 Apr 2019 21:39:02 +0000 (16:39 -0500)]
x86/speculation/mds: Add 'mitigations=' support for MDS

commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream.

Add MDS to the new 'mitigations=' cmdline option.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Support 'mitigations=' cmdline option
Josh Poimboeuf [Fri, 12 Apr 2019 20:39:29 +0000 (15:39 -0500)]
x86/speculation: Support 'mitigations=' cmdline option

commit d68be4c4d31295ff6ae34a8ddfaa4c1a8ff42812 upstream.

Configure x86 runtime CPU speculation bug mitigations in accordance with
the 'mitigations=' cmdline option.  This affects Meltdown, Spectre v2,
Speculative Store Bypass, and L1TF.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/6616d0ae169308516cfdf5216bedd169f8a8291b.1555085500.git.jpoimboe@redhat.com
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agocpu/speculation: Add 'mitigations=' cmdline option
Josh Poimboeuf [Fri, 12 Apr 2019 20:39:28 +0000 (15:39 -0500)]
cpu/speculation: Add 'mitigations=' cmdline option

commit 98af8452945c55652de68536afdde3b520fec429 upstream.

Keeping track of the number of mitigations for all the CPU speculation
bugs has become overwhelming for many users.  It's getting more and more
complicated to decide which mitigations are needed for a given
architecture.  Complicating matters is the fact that each arch tends to
have its own custom way to mitigate the same vulnerability.

Most users fall into a few basic categories:

a) they want all mitigations off;

b) they want all reasonable mitigations on, with SMT enabled even if
   it's vulnerable; or

c) they want all reasonable mitigations on, with SMT disabled if
   vulnerable.

Define a set of curated, arch-independent options, each of which is an
aggregation of existing options:

- mitigations=off: Disable all mitigations.

- mitigations=auto: [default] Enable all the default mitigations, but
  leave SMT enabled, even if it's vulnerable.

- mitigations=auto,nosmt: Enable all the default mitigations, disabling
  SMT if needed by a mitigation.

Currently, these options are placeholders which don't actually do
anything.  They will be fleshed out in upcoming patches.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86)
Reviewed-by: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Steven Price <steven.price@arm.com>
Cc: Phil Auld <pauld@redhat.com>
Link: https://lkml.kernel.org/r/b07a8ef9b7c5055c3a4637c87d07c296d5016fe0.1555085500.git.jpoimboe@redhat.com
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off
Konrad Rzeszutek Wilk [Fri, 12 Apr 2019 21:50:58 +0000 (17:50 -0400)]
x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off

commit e2c3c94788b08891dcf3dbe608f9880523ecd71b upstream.

This code is only for CPUs which are affected by MSBDS, but are *not*
affected by the other two MDS issues.

For such CPUs, enabling the mds_idle_clear mitigation is enough to
mitigate SMT.

However if user boots with 'mds=off' and still has SMT enabled, we should
not report that SMT is mitigated:

$cat /sys//devices/system/cpu/vulnerabilities/mds
Vulnerable; SMT mitigated

But rather:
Vulnerable; SMT vulnerable

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Fix comment
Boris Ostrovsky [Fri, 12 Apr 2019 21:50:57 +0000 (17:50 -0400)]
x86/speculation/mds: Fix comment

commit cae5ec342645746d617dd420d206e1588d47768a upstream.

s/L1TF/MDS/

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add SMT warning message
Josh Poimboeuf [Tue, 2 Apr 2019 15:00:51 +0000 (10:00 -0500)]
x86/speculation/mds: Add SMT warning message

commit 39226ef02bfb43248b7db12a4fdccb39d95318e3 upstream.

MDS is vulnerable with SMT.  Make that clear with a one-time printk
whenever SMT first gets enabled.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Move arch_smt_update() call to after mitigation decisions
Josh Poimboeuf [Tue, 2 Apr 2019 15:00:14 +0000 (10:00 -0500)]
x86/speculation: Move arch_smt_update() call to after mitigation decisions

commit 7c3658b20194a5b3209a143f63bc9c643c6a3ae2 upstream.

arch_smt_update() now has a dependency on both Spectre v2 and MDS
mitigations.  Move its initial call to after all the mitigation decisions
have been made.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add mds=full,nosmt cmdline option
Josh Poimboeuf [Tue, 2 Apr 2019 14:59:33 +0000 (09:59 -0500)]
x86/speculation/mds: Add mds=full,nosmt cmdline option

commit d71eb0ce109a124b0fa714832823b9452f2762cf upstream.

Add the mds=full,nosmt cmdline option.  This is like mds=full, but with
SMT disabled if the CPU is vulnerable.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
[bwh: Backported to 4.9: adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoDocumentation: Add MDS vulnerability documentation
Thomas Gleixner [Mon, 18 Feb 2019 23:02:31 +0000 (00:02 +0100)]
Documentation: Add MDS vulnerability documentation

commit 5999bbe7a6ea3c62029532ec84dc06003a1fa258 upstream.

Add the initial MDS vulnerability documentation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoDocumentation: Move L1TF to separate directory
Thomas Gleixner [Tue, 19 Feb 2019 10:10:49 +0000 (11:10 +0100)]
Documentation: Move L1TF to separate directory

commit 65fd4cb65b2dad97feb8330b6690445910b56d6a upstream.

Move L!TF to a separate directory so the MDS stuff can be added at the
side. Otherwise the all hardware vulnerabilites have their own top level
entry. Should have done that right away.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add mitigation mode VMWERV
Thomas Gleixner [Wed, 20 Feb 2019 08:40:40 +0000 (09:40 +0100)]
x86/speculation/mds: Add mitigation mode VMWERV

commit 22dd8365088b6403630b82423cf906491859b65e upstream.

In virtualized environments it can happen that the host has the microcode
update which utilizes the VERW instruction to clear CPU buffers, but the
hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit
to guests.

Introduce an internal mitigation mode VMWERV which enables the invocation
of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the
system has no updated microcode this results in a pointless execution of
the VERW instruction wasting a few CPU cycles. If the microcode is updated,
but not exposed to a guest then the CPU buffers will be cleared.

That said: Virtual Machines Will Eventually Receive Vaccine

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add sysfs reporting for MDS
Thomas Gleixner [Mon, 18 Feb 2019 21:51:43 +0000 (22:51 +0100)]
x86/speculation/mds: Add sysfs reporting for MDS

commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream.

Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: test x86_hyper instead of using hypervisor_is_type()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add mitigation control for MDS
Thomas Gleixner [Mon, 18 Feb 2019 21:04:08 +0000 (22:04 +0100)]
x86/speculation/mds: Add mitigation control for MDS

commit bc1241700acd82ec69fde98c5763ce51086269f8 upstream.

Now that the mitigations are in place, add a command line parameter to
control the mitigation, a mitigation selector function and a SMT update
mechanism.

This is the minimal straight forward initial implementation which just
provides an always on/off mode. The command line parameter is:

  mds=[full|off]

This is consistent with the existing mitigations for other speculative
hardware vulnerabilities.

The idle invocation is dynamically updated according to the SMT state of
the system similar to the dynamic update of the STIBP mitigation. The idle
mitigation is limited to CPUs which are only affected by MSBDS and not any
other variant, because the other variants cannot be mitigated on SMT
enabled systems.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Conditionally clear CPU buffers on idle entry
Thomas Gleixner [Mon, 18 Feb 2019 22:04:01 +0000 (23:04 +0100)]
x86/speculation/mds: Conditionally clear CPU buffers on idle entry

commit 07f07f55a29cb705e221eda7894dd67ab81ef343 upstream.

Add a static key which controls the invocation of the CPU buffer clear
mechanism on idle entry. This is independent of other MDS mitigations
because the idle entry invocation to mitigate the potential leakage due to
store buffer repartitioning is only necessary on SMT systems.

Add the actual invocations to the different halt/mwait variants which
covers all usage sites. mwaitx is not patched as it's not available on
Intel CPUs.

The buffer clear is only invoked before entering the C-State to prevent
that stale data from the idling CPU is spilled to the Hyper-Thread sibling
after the Store buffer got repartitioned and all entries are available to
the non idle sibling.

When coming out of idle the store buffer is partitioned again so each
sibling has half of it available. Now CPU which returned from idle could be
speculatively exposed to contents of the sibling, but the buffers are
flushed either on exit to user space or on VMENTER.

When later on conditional buffer clearing is implemented on top of this,
then there is no action required either because before returning to user
space the context switch will set the condition flag which causes a flush
on the return to user path.

Note, that the buffer clearing on idle is only sensible on CPUs which are
solely affected by MSBDS and not any other variant of MDS because the other
MDS variants cannot be mitigated when SMT is enabled, so the buffer
clearing on idle would be a window dressing exercise.

This intentionally does not handle the case in the acpi/processor_idle
driver which uses the legacy IO port interface for C-State transitions for
two reasons:

 - The acpi/processor_idle driver was replaced by the intel_idle driver
   almost a decade ago. Anything Nehalem upwards supports it and defaults
   to that new driver.

 - The legacy IO port interface is likely to be used on older and therefore
   unaffected CPUs or on systems which do not receive microcode updates
   anymore, so there is no point in adding that.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/kvm/vmx: Add MDS protection when L1D Flush is not active
Thomas Gleixner [Wed, 27 Feb 2019 11:48:14 +0000 (12:48 +0100)]
x86/kvm/vmx: Add MDS protection when L1D Flush is not active

commit 650b68a0622f933444a6d66936abb3103029413b upstream.

CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on
VMENTER when updated microcode is installed.

If a CPU is not affected by L1TF or if the L1D Flush is not in use, then
MDS mitigation needs to be invoked explicitly.

For these cases, follow the host mitigation state and invoke the MDS
mitigation before VMENTER.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Clear CPU buffers on exit to user
Thomas Gleixner [Mon, 18 Feb 2019 22:42:51 +0000 (23:42 +0100)]
x86/speculation/mds: Clear CPU buffers on exit to user

commit 04dcbdb8057827b043b3c71aa397c4c63e67d086 upstream.

Add a static key which controls the invocation of the CPU buffer clear
mechanism on exit to user space and add the call into
prepare_exit_to_usermode() and do_nmi() right before actually returning.

Add documentation which kernel to user space transition this covers and
explain why some corner cases are not mitigated.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add mds_clear_cpu_buffers()
Thomas Gleixner [Mon, 18 Feb 2019 22:13:06 +0000 (23:13 +0100)]
x86/speculation/mds: Add mds_clear_cpu_buffers()

commit 6a9e529272517755904b7afa639f6db59ddb793e upstream.

The Microarchitectural Data Sampling (MDS) vulernabilities are mitigated by
clearing the affected CPU buffers. The mechanism for clearing the buffers
uses the unused and obsolete VERW instruction in combination with a
microcode update which triggers a CPU buffer clear when VERW is executed.

Provide a inline function with the assembly magic. The argument of the VERW
instruction must be a memory operand as documented:

  "MD_CLEAR enumerates that the memory-operand variant of VERW (for
   example, VERW m16) has been extended to also overwrite buffers affected
   by MDS. This buffer overwriting functionality is not guaranteed for the
   register operand variant of VERW."

Documentation also recommends to use a writable data segment selector:

  "The buffer overwriting occurs regardless of the result of the VERW
   permission check, as well as when the selector is null or causes a
   descriptor load segment violation. However, for lowest latency we
   recommend using a selector that indicates a valid writable data
   segment."

Add x86 specific documentation about MDS and the internal workings of the
mitigation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: add the "Architecture-specific documentation"
 section to the index]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/kvm: Expose X86_FEATURE_MD_CLEAR to guests
Andi Kleen [Sat, 19 Jan 2019 00:50:23 +0000 (16:50 -0800)]
x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests

commit 6c4dbbd14730c43f4ed808a9c42ca41625925c22 upstream.

X86_FEATURE_MD_CLEAR is a new CPUID bit which is set when microcode
provides the mechanism to invoke a flush of various exploitable CPU buffers
by invoking the VERW instruction.

Hand it through to guests so they can adjust their mitigations.

This also requires corresponding qemu changes, which are available
separately.

[ tglx: Massaged changelog ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add BUG_MSBDS_ONLY
Thomas Gleixner [Fri, 1 Mar 2019 19:21:08 +0000 (20:21 +0100)]
x86/speculation/mds: Add BUG_MSBDS_ONLY

commit e261f209c3666e842fd645a1e31f001c3a26def9 upstream.

This bug bit is set on CPUs which are only affected by Microarchitectural
Store Buffer Data Sampling (MSBDS) and not by any other MDS variant.

This is important because the Store Buffers are partitioned between
Hyper-Threads so cross thread forwarding is not possible. But if a thread
enters or exits a sleep state the store buffer is repartitioned which can
expose data from one thread to the other. This transition can be mitigated.

That means that for CPUs which are only affected by MSBDS SMT can be
enabled, if the CPU is not affected by other SMT sensitive vulnerabilities,
e.g. L1TF. The XEON PHI variants fall into that category. Also the
Silvermont/Airmont ATOMs, but for them it's not really relevant as they do
not support SMT, but mark them for completeness sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/mds: Add basic bug infrastructure for MDS
Andi Kleen [Sat, 19 Jan 2019 00:50:16 +0000 (16:50 -0800)]
x86/speculation/mds: Add basic bug infrastructure for MDS

commit ed5194c2732c8084af9fd159c146ea92bf137128 upstream.

Microarchitectural Data Sampling (MDS), is a class of side channel attacks
on internal buffers in Intel CPUs. The variants are:

 - Microarchitectural Store Buffer Data Sampling (MSBDS) (CVE-2018-12126)
 - Microarchitectural Fill Buffer Data Sampling (MFBDS) (CVE-2018-12130)
 - Microarchitectural Load Port Data Sampling (MLPDS) (CVE-2018-12127)

MSBDS leaks Store Buffer Entries which can be speculatively forwarded to a
dependent load (store-to-load forwarding) as an optimization. The forward
can also happen to a faulting or assisting load operation for a different
memory address, which can be exploited under certain conditions. Store
buffers are partitioned between Hyper-Threads so cross thread forwarding is
not possible. But if a thread enters or exits a sleep state the store
buffer is repartitioned which can expose data from one thread to the other.

MFBDS leaks Fill Buffer Entries. Fill buffers are used internally to manage
L1 miss situations and to hold data which is returned or sent in response
to a memory or I/O operation. Fill buffers can forward data to a load
operation and also write data to the cache. When the fill buffer is
deallocated it can retain the stale data of the preceding operations which
can then be forwarded to a faulting or assisting load operation, which can
be exploited under certain conditions. Fill buffers are shared between
Hyper-Threads so cross thread leakage is possible.

MLDPS leaks Load Port Data. Load ports are used to perform load operations
from memory or I/O. The received data is then forwarded to the register
file or a subsequent operation. In some implementations the Load Port can
contain stale data from a previous operation which can be forwarded to
faulting or assisting loads under certain conditions, which again can be
exploited eventually. Load ports are shared between Hyper-Threads so cross
thread leakage is possible.

All variants have the same mitigation for single CPU thread case (SMT off),
so the kernel can treat them as one MDS issue.

Add the basic infrastructure to detect if the current CPU is affected by
MDS.

[ tglx: Rewrote changelog ]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Consolidate CPU whitelists
Thomas Gleixner [Wed, 27 Feb 2019 09:10:23 +0000 (10:10 +0100)]
x86/speculation: Consolidate CPU whitelists

commit 36ad35131adacc29b328b9c8b6277a8bf0d6fd5d upstream.

The CPU vulnerability whitelists have some overlap and there are more
whitelists coming along.

Use the driver_data field in the x86_cpu_id struct to denote the
whitelisted vulnerabilities and combine all whitelists into one.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/msr-index: Cleanup bit defines
Thomas Gleixner [Thu, 21 Feb 2019 11:36:50 +0000 (12:36 +0100)]
x86/msr-index: Cleanup bit defines

commit d8eabc37310a92df40d07c5a8afc53cebf996716 upstream.

Greg pointed out that speculation related bit defines are using (1 << N)
format instead of BIT(N). Aside of that (1 << N) is wrong as it should use
1UL at least.

Clean it up.

[ Josh Poimboeuf: Fix tools build ]

Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Jon Masters <jcm@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
[bwh: Backported to 4.9: Drop change to x86_energy_perf_policy, which doesn't
 use msr-index.h here]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agokvm: x86: Report STIBP on GET_SUPPORTED_CPUID
Eduardo Habkost [Wed, 5 Dec 2018 19:19:56 +0000 (17:19 -0200)]
kvm: x86: Report STIBP on GET_SUPPORTED_CPUID

commit d7b09c827a6cf291f66637a36f46928dd1423184 upstream.

Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL
to the guest, which makes STIBP available to guests.  This was implemented
by commits d28b387fb74d ("KVM/VMX: Allow direct access to
MSR_IA32_SPEC_CTRL") and b2ac58f90540 ("KVM/SVM: Allow direct access to
MSR_IA32_SPEC_CTRL").

However, we never updated GET_SUPPORTED_CPUID to let userspace know that
STIBP can be enabled in CPUID.  Fix that by updating
kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Provide IBPB always command line options
Thomas Gleixner [Sun, 25 Nov 2018 18:33:56 +0000 (19:33 +0100)]
x86/speculation: Provide IBPB always command line options

commit 55a974021ec952ee460dc31ca08722158639de72 upstream.

Provide the possibility to enable IBPB always in combination with 'prctl'
and 'seccomp'.

Add the extra command line options and rework the IBPB selection to
evaluate the command instead of the mode selected by the STIPB switch case.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185006.144047038@linutronix.de
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Add seccomp Spectre v2 user space protection mode
Thomas Gleixner [Sun, 25 Nov 2018 18:33:55 +0000 (19:33 +0100)]
x86/speculation: Add seccomp Spectre v2 user space protection mode

commit 6b3e64c237c072797a9ec918654a60e3a46488e2 upstream.

If 'prctl' mode of user space protection from spectre v2 is selected
on the kernel command-line, STIBP and IBPB are applied on tasks which
restrict their indirect branch speculation via prctl.

SECCOMP enables the SSBD mitigation for sandboxed tasks already, so it
makes sense to prevent spectre v2 user space to user space attacks as
well.

The Intel mitigation guide documents how STIPB works:

   Setting bit 1 (STIBP) of the IA32_SPEC_CTRL MSR on a logical processor
   prevents the predicted targets of indirect branches on any logical
   processor of that core from being controlled by software that executes
   (or executed previously) on another logical processor of the same core.

Ergo setting STIBP protects the task itself from being attacked from a task
running on a different hyper-thread and protects the tasks running on
different hyper-threads from being attacked.

While the document suggests that the branch predictors are shielded between
the logical processors, the observed performance regressions suggest that
STIBP simply disables the branch predictor more or less completely. Of
course the document wording is vague, but the fact that there is also no
requirement for issuing IBPB when STIBP is used points clearly in that
direction. The kernel still issues IBPB even when STIBP is used until Intel
clarifies the whole mechanism.

IBPB is issued when the task switches out, so malicious sandbox code cannot
mistrain the branch predictor for the next user space task on the same
logical processor.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185006.051663132@linutronix.de
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Enable prctl mode for spectre_v2_user
Thomas Gleixner [Sun, 25 Nov 2018 18:33:54 +0000 (19:33 +0100)]
x86/speculation: Enable prctl mode for spectre_v2_user

commit 7cc765a67d8e04ef7d772425ca5a2a1e2b894c15 upstream.

Now that all prerequisites are in place:

 - Add the prctl command line option

 - Default the 'auto' mode to 'prctl'

 - When SMT state changes, update the static key which controls the
   conditional STIBP evaluation on context switch.

 - At init update the static key which controls the conditional IBPB
   evaluation on context switch.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.958421388@linutronix.de
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Add prctl() control for indirect branch speculation
Thomas Gleixner [Sun, 25 Nov 2018 18:33:53 +0000 (19:33 +0100)]
x86/speculation: Add prctl() control for indirect branch speculation

commit 9137bb27e60e554dab694eafa4cca241fa3a694f upstream.

Add the PR_SPEC_INDIRECT_BRANCH option for the PR_GET_SPECULATION_CTRL and
PR_SET_SPECULATION_CTRL prctls to allow fine grained per task control of
indirect branch speculation via STIBP and IBPB.

Invocations:
 Check indirect branch speculation status with
 - prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0);

 Enable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0);

 Disable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0);

 Force disable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0);

See Documentation/userspace-api/spec_ctrl.rst.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.866780996@linutronix.de
[bwh: Backported to 4.9:
 - Renumber the PFA flags
 - Drop changes in tools/include/uapi/linux/prctl.h
 - Adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Prevent stale SPEC_CTRL msr content
Thomas Gleixner [Wed, 28 Nov 2018 09:56:57 +0000 (10:56 +0100)]
x86/speculation: Prevent stale SPEC_CTRL msr content

commit 6d991ba509ebcfcc908e009d1db51972a4f7a064 upstream.

The seccomp speculation control operates on all tasks of a process, but
only the current task of a process can update the MSR immediately. For the
other threads the update is deferred to the next context switch.

This creates the following situation with Process A and B:

Process A task 2 and Process B task 1 are pinned on CPU1. Process A task 2
does not have the speculation control TIF bit set. Process B task 1 has the
speculation control TIF bit set.

CPU0 CPU1
MSR bit is set
ProcB.T1 schedules out
ProcA.T2 schedules in
MSR bit is cleared
ProcA.T1
  seccomp_update()
  set TIF bit on ProcA.T2
ProcB.T1 schedules in
MSR is not updated  <-- FAIL

This happens because the context switch code tries to avoid the MSR update
if the speculation control TIF bits of the incoming and the outgoing task
are the same. In the worst case ProcB.T1 and ProcA.T2 are the only tasks
scheduling back and forth on CPU1, which keeps the MSR stale forever.

In theory this could be remedied by IPIs, but chasing the remote task which
could be migrated is complex and full of races.

The straight forward solution is to avoid the asychronous update of the TIF
bit and defer it to the next context switch. The speculation control state
is stored in task_struct::atomic_flags by the prctl and seccomp updates
already.

Add a new TIF_SPEC_FORCE_UPDATE bit and set this after updating the
atomic_flags. Check the bit on context switch and force a synchronous
update of the speculation control if set. Use the same mechanism for
updating the current task.

Reported-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1811272247140.1875@nanos.tec.linutronix.de
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Prepare arch_smt_update() for PRCTL mode
Thomas Gleixner [Sun, 25 Nov 2018 18:33:52 +0000 (19:33 +0100)]
x86/speculation: Prepare arch_smt_update() for PRCTL mode

commit 6893a959d7fdebbab5f5aa112c277d5a44435ba1 upstream.

The upcoming fine grained per task STIBP control needs to be updated on CPU
hotplug as well.

Split out the code which controls the strict mode so the prctl control code
can be added later. Mark the SMP function call argument __unused while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.759457117@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Split out TIF update
Thomas Gleixner [Sun, 25 Nov 2018 18:33:51 +0000 (19:33 +0100)]
x86/speculation: Split out TIF update

commit e6da8bb6f9abb2628381904b24163c770e630bac upstream.

The update of the TIF_SSBD flag and the conditional speculation control MSR
update is done in the ssb_prctl_set() function directly. The upcoming prctl
support for controlling indirect branch speculation via STIBP needs the
same mechanism.

Split the code out and make it reusable. Reword the comment about updates
for other tasks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.652305076@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Prepare for conditional IBPB in switch_mm()
Thomas Gleixner [Sun, 25 Nov 2018 18:33:49 +0000 (19:33 +0100)]
x86/speculation: Prepare for conditional IBPB in switch_mm()

commit 4c71a2b6fd7e42814aa68a6dec88abf3b42ea573 upstream.

The IBPB speculation barrier is issued from switch_mm() when the kernel
switches to a user space task with a different mm than the user space task
which ran last on the same CPU.

An additional optimization is to avoid IBPB when the incoming task can be
ptraced by the outgoing task. This optimization only works when switching
directly between two user space tasks. When switching from a kernel task to
a user space task the optimization fails because the previous task cannot
be accessed anymore. So for quite some scenarios the optimization is just
adding overhead.

The upcoming conditional IBPB support will issue IBPB only for user space
tasks which have the TIF_SPEC_IB bit set. This requires to handle the
following cases:

  1) Switch from a user space task (potential attacker) which has
     TIF_SPEC_IB set to a user space task (potential victim) which has
     TIF_SPEC_IB not set.

  2) Switch from a user space task (potential attacker) which has
     TIF_SPEC_IB not set to a user space task (potential victim) which has
     TIF_SPEC_IB set.

This needs to be optimized for the case where the IBPB can be avoided when
only kernel threads ran in between user space tasks which belong to the
same process.

The current check whether two tasks belong to the same context is using the
tasks context id. While correct, it's simpler to use the mm pointer because
it allows to mangle the TIF_SPEC_IB bit into it. The context id based
mechanism requires extra storage, which creates worse code.

When a task is scheduled out its TIF_SPEC_IB bit is mangled as bit 0 into
the per CPU storage which is used to track the last user space mm which was
running on a CPU. This bit can be used together with the TIF_SPEC_IB bit of
the incoming task to make the decision whether IBPB needs to be issued or
not to cover the two cases above.

As conditional IBPB is going to be the default, remove the dubious ptrace
check for the IBPB always case and simply issue IBPB always when the
process changes.

Move the storage to a different place in the struct as the original one
created a hole.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.466447057@linutronix.de
[bwh: Backported to 4.9:
 - Drop changes in initialize_tlbstate_and_flush()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Avoid __switch_to_xtra() calls
Thomas Gleixner [Sun, 25 Nov 2018 18:33:48 +0000 (19:33 +0100)]
x86/speculation: Avoid __switch_to_xtra() calls

commit 5635d99953f04b550738f6f4c1c532667c3fd872 upstream.

The TIF_SPEC_IB bit does not need to be evaluated in the decision to invoke
__switch_to_xtra() when:

 - CONFIG_SMP is disabled

 - The conditional STIPB mode is disabled

The TIF_SPEC_IB bit still controls IBPB in both cases so the TIF work mask
checks might invoke __switch_to_xtra() for nothing if TIF_SPEC_IB is the
only set bit in the work masks.

Optimize it out by masking the bit at compile time for CONFIG_SMP=n and at
run time when the static key controlling the conditional STIBP mode is
disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.374062201@linutronix.de
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/process: Consolidate and simplify switch_to_xtra() code
Thomas Gleixner [Sun, 25 Nov 2018 18:33:47 +0000 (19:33 +0100)]
x86/process: Consolidate and simplify switch_to_xtra() code

commit ff16701a29cba3aafa0bd1656d766813b2d0a811 upstream.

Move the conditional invocation of __switch_to_xtra() into an inline
function so the logic can be shared between 32 and 64 bit.

Remove the handthrough of the TSS pointer and retrieve the pointer directly
in the bitmap handling function. Use this_cpu_ptr() instead of the
per_cpu() indirection.

This is a preparatory change so integration of conditional indirect branch
speculation optimization happens only in one place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.280855518@linutronix.de
[bwh: Backported to 4.9:
 - Use cpu_tss instead of cpu_tss_rw
 - __switch_to() still uses the tss variable, so don't delete it
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Prepare for per task indirect branch speculation control
Tim Chen [Sun, 25 Nov 2018 18:33:46 +0000 (19:33 +0100)]
x86/speculation: Prepare for per task indirect branch speculation control

commit 5bfbe3ad5840d941b89bcac54b821ba14f50a0ba upstream.

To avoid the overhead of STIBP always on, it's necessary to allow per task
control of STIBP.

Add a new task flag TIF_SPEC_IB and evaluate it during context switch if
SMT is active and flag evaluation is enabled by the speculation control
code. Add the conditional evaluation to x86_virt_spec_ctrl() as well so the
guest/host switch works properly.

This has no effect because TIF_SPEC_IB cannot be set yet and the static key
which controls evaluation is off. Preparatory patch for adding the control
code.

[ tglx: Simplify the context switch logic and make the TIF evaluation
   depend on SMP=y and on the static key controlling the conditional
   update. Rename it to TIF_SPEC_IB because it controls both STIBP and
   IBPB ]

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.176917199@linutronix.de
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Add command line control for indirect branch speculation
Thomas Gleixner [Sun, 25 Nov 2018 18:33:45 +0000 (19:33 +0100)]
x86/speculation: Add command line control for indirect branch speculation

commit fa1202ef224391b6f5b26cdd44cc50495e8fab54 upstream.

Add command line control for user space indirect branch speculation
mitigations. The new option is: spectre_v2_user=

The initial options are:

    -  on:   Unconditionally enabled
    - off:   Unconditionally disabled
    -auto:   Kernel selects mitigation (default off for now)

When the spectre_v2= command line argument is either 'on' or 'off' this
implies that the application to application control follows that state even
if a contradicting spectre_v2_user= argument is supplied.

Originally-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185005.082720373@linutronix.de
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Unify conditional spectre v2 print functions
Thomas Gleixner [Sun, 25 Nov 2018 18:33:44 +0000 (19:33 +0100)]
x86/speculation: Unify conditional spectre v2 print functions

commit 495d470e9828500e0155027f230449ac5e29c025 upstream.

There is no point in having two functions and a conditional at the call
site.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.986890749@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculataion: Mark command line parser data __initdata
Thomas Gleixner [Sun, 25 Nov 2018 18:33:43 +0000 (19:33 +0100)]
x86/speculataion: Mark command line parser data __initdata

commit 30ba72a990f5096ae08f284de17986461efcc408 upstream.

No point to keep that around.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.893886356@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Mark string arrays const correctly
Thomas Gleixner [Sun, 25 Nov 2018 18:33:42 +0000 (19:33 +0100)]
x86/speculation: Mark string arrays const correctly

commit 8770709f411763884535662744a3786a1806afd3 upstream.

checkpatch.pl muttered when reshuffling the code:
 WARNING: static const char * array should probably be static const char * const

Fix up all the string arrays.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.800018931@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Reorder the spec_v2 code
Thomas Gleixner [Sun, 25 Nov 2018 18:33:41 +0000 (19:33 +0100)]
x86/speculation: Reorder the spec_v2 code

commit 15d6b7aab0793b2de8a05d8a828777dd24db424e upstream.

Reorder the code so it is better grouped. No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.707122879@linutronix.de
[bwh: Backported to 4.9:
 - We still have the minimal mitigation modes
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/l1tf: Show actual SMT state
Thomas Gleixner [Sun, 25 Nov 2018 18:33:40 +0000 (19:33 +0100)]
x86/l1tf: Show actual SMT state

commit 130d6f946f6f2a972ee3ec8540b7243ab99abe97 upstream.

Use the now exposed real SMT state, not the SMT sysfs control knob
state. This reflects the state of the system when the mitigation status is
queried.

This does not change the warning in the VMX launch code. There the
dependency on the control knob makes sense because siblings could be
brought online anytime after launching the VM.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.613357354@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Rework SMT state change
Thomas Gleixner [Sun, 25 Nov 2018 18:33:39 +0000 (19:33 +0100)]
x86/speculation: Rework SMT state change

commit a74cfffb03b73d41e08f84c2e5c87dec0ce3db9f upstream.

arch_smt_update() is only called when the sysfs SMT control knob is
changed. This means that when SMT is enabled in the sysfs control knob the
system is considered to have SMT active even if all siblings are offline.

To allow finegrained control of the speculation mitigations, the actual SMT
state is more interesting than the fact that siblings could be enabled.

Rework the code, so arch_smt_update() is invoked from each individual CPU
hotplug function, and simplify the update function while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.521974984@linutronix.de
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agosched: Add sched_smt_active()
Ben Hutchings [Thu, 9 May 2019 23:46:25 +0000 (00:46 +0100)]
sched: Add sched_smt_active()

Add the sched_smt_active() function needed for some x86 speculation
mitigations.  This was introduced upstream by commits 1b568f0aabf2
"sched/core: Optimize SCHED_SMT", ba2591a5993e "sched/smt: Update
sched_smt_present at runtime", c5511d03ec09 "sched/smt: Make
sched_smt_present track topology", and 321a874a7ef8 "sched/smt: Expose
sched_smt_present static key".  The upstream implementation uses the
static_key_{disable,enable}_cpuslocked() functions, which aren't
practical to backport.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/Kconfig: Select SCHED_SMT if SMP enabled
Thomas Gleixner [Sun, 25 Nov 2018 18:33:37 +0000 (19:33 +0100)]
x86/Kconfig: Select SCHED_SMT if SMP enabled

commit dbe733642e01dd108f71436aaea7b328cb28fd87 upstream.

CONFIG_SCHED_SMT is enabled by all distros, so there is not a real point to
have it configurable. The runtime overhead in the core scheduler code is
minimal because the actual SMT scheduling parts are conditional on a static
key.

This allows to expose the scheduler's SMT state static key to the
speculation control code. Alternatively the scheduler's static key could be
made always available when CONFIG_SMP is enabled, but that's just adding an
unused static key to every other architecture for nothing.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.337452245@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Reorganize speculation control MSRs update
Tim Chen [Sun, 25 Nov 2018 18:33:35 +0000 (19:33 +0100)]
x86/speculation: Reorganize speculation control MSRs update

commit 01daf56875ee0cd50ed496a09b20eb369b45dfa5 upstream.

The logic to detect whether there's a change in the previous and next
task's flag relevant to update speculation control MSRs is spread out
across multiple functions.

Consolidate all checks needed for updating speculation control MSRs into
the new __speculation_ctrl_update() helper function.

This makes it easy to pick the right speculation control MSR and the bits
in MSR_IA32_SPEC_CTRL that need updating based on TIF flags changes.

Originally-by: Thomas Lendacky <Thomas.Lendacky@amd.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.151077005@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Rename SSBD update functions
Thomas Gleixner [Sun, 25 Nov 2018 18:33:34 +0000 (19:33 +0100)]
x86/speculation: Rename SSBD update functions

commit 26c4d75b234040c11728a8acb796b3a85ba7507c upstream.

During context switch, the SSBD bit in SPEC_CTRL MSR is updated according
to changes of the TIF_SSBD flag in the current and next running task.

Currently, only the bit controlling speculative store bypass disable in
SPEC_CTRL MSR is updated and the related update functions all have
"speculative_store" or "ssb" in their names.

For enhanced mitigation control other bits in SPEC_CTRL MSR need to be
updated as well, which makes the SSB names inadequate.

Rename the "speculative_store*" functions to a more generic name. No
functional change.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185004.058866968@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Disable STIBP when enhanced IBRS is in use
Tim Chen [Sun, 25 Nov 2018 18:33:33 +0000 (19:33 +0100)]
x86/speculation: Disable STIBP when enhanced IBRS is in use

commit 34bce7c9690b1d897686aac89604ba7adc365556 upstream.

If enhanced IBRS is active, STIBP is redundant for mitigating Spectre v2
user space exploits from hyperthread sibling.

Disable STIBP when enhanced IBRS is used.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185003.966801480@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()
Tim Chen [Sun, 25 Nov 2018 18:33:32 +0000 (19:33 +0100)]
x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()

commit a8f76ae41cd633ac00be1b3019b1eb4741be3828 upstream.

The Spectre V2 printout in cpu_show_common() handles conditionals for the
various mitigation methods directly in the sprintf() argument list. That's
hard to read and will become unreadable if more complex decisions need to
be made for a particular method.

Move the conditionals for STIBP and IBPB string selection into helper
functions, so they can be extended later on.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185003.874479208@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Remove unnecessary ret variable in cpu_show_common()
Tim Chen [Sun, 25 Nov 2018 18:33:31 +0000 (19:33 +0100)]
x86/speculation: Remove unnecessary ret variable in cpu_show_common()

commit b86bda0426853bfe8a3506c7d2a5b332760ae46b upstream.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185003.783903657@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Clean up spectre_v2_parse_cmdline()
Tim Chen [Sun, 25 Nov 2018 18:33:30 +0000 (19:33 +0100)]
x86/speculation: Clean up spectre_v2_parse_cmdline()

commit 24848509aa55eac39d524b587b051f4e86df3c12 upstream.

Remove the unnecessary 'else' statement in spectre_v2_parse_cmdline()
to save an indentation level.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185003.688010903@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Update the TIF_SSBD comment
Tim Chen [Sun, 25 Nov 2018 18:33:29 +0000 (19:33 +0100)]
x86/speculation: Update the TIF_SSBD comment

commit 8eb729b77faf83ac4c1f363a9ad68d042415f24c upstream.

"Reduced Data Speculation" is an obsolete term. The correct new name is
"Speculative store bypass disable" - which is abbreviated into SSBD.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20181125185003.593893901@linutronix.de
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation/l1tf: Drop the swap storage limit restriction when l1tf=off
Michal Hocko [Tue, 13 Nov 2018 18:49:10 +0000 (19:49 +0100)]
x86/speculation/l1tf: Drop the swap storage limit restriction when l1tf=off

commit 5b5e4d623ec8a34689df98e42d038a3b594d2ff9 upstream.

Swap storage is restricted to max_swapfile_size (~16TB on x86_64) whenever
the system is deemed affected by L1TF vulnerability. Even though the limit
is quite high for most deployments it seems to be too restrictive for
deployments which are willing to live with the mitigation disabled.

We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices which is
clearly out of the limit.

Drop the swap restriction when l1tf=off is specified. It also doesn't make
much sense to warn about too much memory for the l1tf mitigation when it is
forcefully disabled by the administrator.

[ tglx: Folded the documentation delta change ]

Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: <linux-mm@kvack.org>
Link: https://lkml.kernel.org/r/20181113184910.26697-1-mhocko@kernel.org
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Propagate information about RSB filling mitigation to sysfs
Jiri Kosina [Tue, 25 Sep 2018 12:39:28 +0000 (14:39 +0200)]
x86/speculation: Propagate information about RSB filling mitigation to sysfs

commit bb4b3b7762735cdaba5a40fd94c9303d9ffa147a upstream.

If spectrev2 mitigation has been enabled, RSB is filled on context switch
in order to protect from various classes of spectrev2 attacks.

If this mitigation is enabled, say so in sysfs for spectrev2.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "WoodhouseDavid" <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: "SchauflerCasey" <casey.schaufler@intel.com>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251438580.15880@cbobk.fhfr.pm
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation
Jiri Kosina [Tue, 25 Sep 2018 12:38:55 +0000 (14:38 +0200)]
x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation

commit 53c613fe6349994f023245519265999eed75957f upstream.

STIBP is a feature provided by certain Intel ucodes / CPUs. This feature
(once enabled) prevents cross-hyperthread control of decisions made by
indirect branch predictors.

Enable this feature if

- the CPU is vulnerable to spectre v2
- the CPU supports SMT and has SMT siblings online
- spectre_v2 mitigation autoselection is enabled (default)

After some previous discussion, this leaves STIBP on all the time, as wrmsr
on crossing kernel boundary is a no-no. This could perhaps later be a bit
more optimized (like disabling it in NOHZ, experiment with disabling it in
idle, etc) if needed.

Note that the synchronization of the mask manipulation via newly added
spec_ctrl_mutex is currently not strictly needed, as the only updater is
already being serialized by cpu_add_remove_lock, but let's make this a
little bit more future-proof.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "WoodhouseDavid" <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: "SchauflerCasey" <casey.schaufler@intel.com>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251438240.15880@cbobk.fhfr.pm
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Apply IBPB more strictly to avoid cross-process data leak
Jiri Kosina [Tue, 25 Sep 2018 12:38:18 +0000 (14:38 +0200)]
x86/speculation: Apply IBPB more strictly to avoid cross-process data leak

commit dbfe2953f63c640463c630746cd5d9de8b2f63ae upstream.

Currently, IBPB is only issued in cases when switching into a non-dumpable
process, the rationale being to protect such 'important and security
sensitive' processess (such as GPG) from data leaking into a different
userspace process via spectre v2.

This is however completely insufficient to provide proper userspace-to-userpace
spectrev2 protection, as any process can poison branch buffers before being
scheduled out, and the newly scheduled process immediately becomes spectrev2
victim.

In order to minimize the performance impact (for usecases that do require
spectrev2 protection), issue the barrier only in cases when switching between
processess where the victim can't be ptraced by the potential attacker (as in
such cases, the attacker doesn't have to bother with branch buffers at all).

[ tglx: Split up PTRACE_MODE_NOACCESS_CHK into PTRACE_MODE_SCHED and
  PTRACE_MODE_IBPB to be able to do ptrace() context tracking reasonably
  fine-grained ]

Fixes: 18bf3c3ea8 ("x86/speculation: Use Indirect Branch Prediction Barrier in context switch")
Originally-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "WoodhouseDavid" <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "SchauflerCasey" <casey.schaufler@intel.com>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251437340.15880@cbobk.fhfr.pm
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoDocumentation/l1tf: Fix small spelling typo
Salvatore Bonaccorso [Wed, 15 Aug 2018 05:46:04 +0000 (07:46 +0200)]
Documentation/l1tf: Fix small spelling typo

commit 60ca05c3b44566b70d64fbb8e87a6e0c67725468 upstream.

Fix small typo (wiil -> will) in the "3.4. Nested virtual machines"
section.

Fixes: 5b76a3cff011 ("KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry")
Cc: linux-kernel@vger.kernel.org
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-doc@vger.kernel.org
Cc: trivial@kernel.org
Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/cpu: Sanitize FAM6_ATOM naming
Peter Zijlstra [Tue, 7 Aug 2018 17:17:27 +0000 (10:17 -0700)]
x86/cpu: Sanitize FAM6_ATOM naming

commit f2c4db1bd80720cd8cb2a5aa220d9bc9f374f04e upstream.

Going primarily by:

  https://en.wikipedia.org/wiki/List_of_Intel_Atom_microprocessors

with additional information gleaned from other related pages; notably:

 - Bonnell shrink was called Saltwell
 - Moorefield is the Merriefield refresh which makes it Airmont

The general naming scheme is: FAM6_ATOM_UARCH_SOCTYPE

  for i in `git grep -l FAM6_ATOM` ; do
sed -i  -e 's/ATOM_PINEVIEW/ATOM_BONNELL/g' \
-e 's/ATOM_LINCROFT/ATOM_BONNELL_MID/' \
-e 's/ATOM_PENWELL/ATOM_SALTWELL_MID/g' \
-e 's/ATOM_CLOVERVIEW/ATOM_SALTWELL_TABLET/g' \
-e 's/ATOM_CEDARVIEW/ATOM_SALTWELL/g' \
-e 's/ATOM_SILVERMONT1/ATOM_SILVERMONT/g' \
-e 's/ATOM_SILVERMONT2/ATOM_SILVERMONT_X/g' \
-e 's/ATOM_MERRIFIELD/ATOM_SILVERMONT_MID/g' \
-e 's/ATOM_MOOREFIELD/ATOM_AIRMONT_MID/g' \
-e 's/ATOM_DENVERTON/ATOM_GOLDMONT_X/g' \
-e 's/ATOM_GEMINI_LAKE/ATOM_GOLDMONT_PLUS/g' ${i}
  done

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: dave.hansen@linux.intel.com
Cc: len.brown@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
 - Drop changes to CPU IDs that weren't already included
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation
Jiang Biao [Wed, 18 Jul 2018 00:03:14 +0000 (08:03 +0800)]
x86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation

commit d9f4426c73002957be5dd39936f44a09498f7560 upstream.

SPECTRE_V2_IBRS in enum spectre_v2_mitigation is never used. Remove it.

Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Cc: dwmw2@amazon.co.uk
Cc: konrad.wilk@oracle.com
Cc: bp@suse.de
Cc: zhong.weidong@zte.com.cn
Link: https://lkml.kernel.org/r/1531872194-39207-1-git-send-email-jiang.biao2@zte.com.cn
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agolocking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux...
Will Deacon [Tue, 19 Jun 2018 12:53:08 +0000 (13:53 +0100)]
locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file

commit 8bd9cb51daac89337295b6f037b0486911e1b408 upstream.

In preparation for implementing the asm-generic atomic bitops in terms
of atomic_long_*(), we need to prevent <asm/atomic.h> implementations from
pulling in <linux/bitops.h>. A common reason for this include is for the
BITS_PER_BYTE definition, so move this and some other BIT() and masking
macros into a new header file, <linux/bits.h>.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Cc: yamada.masahiro@socionext.com
Link: https://lore.kernel.org/lkml/1529412794-17720-4-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/speculation: Simplify the CPU bug detection logic
Dominik Brodowski [Tue, 22 May 2018 09:05:39 +0000 (11:05 +0200)]
x86/speculation: Simplify the CPU bug detection logic

commit 8ecc4979b1bd9c94168e6fc92960033b7a951336 upstream.

Only CPUs which speculate can speculate. Therefore, it seems prudent
to test for cpu_no_speculation first and only then determine whether
a specific speculating CPU is susceptible to store bypass speculation.
This is underlined by all CPUs currently listed in cpu_no_speculation
were present in cpu_no_spec_store_bypass as well.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Cc: konrad.wilk@oracle.com
Link: https://lkml.kernel.org/r/20180522090539.GA24668@light.dominikbrodowski.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agobitops: avoid integer overflow in GENMASK(_ULL)
Matthias Kaehlcke [Fri, 8 Sep 2017 23:14:33 +0000 (16:14 -0700)]
bitops: avoid integer overflow in GENMASK(_ULL)

commit c32ee3d9abd284b4fcaacc250b101f93829c7bae upstream.

GENMASK(_ULL) performs a left-shift of ~0UL(L), which technically
results in an integer overflow.  clang raises a warning if the overflow
occurs in a preprocessor expression.  Clear the low-order bits through a
substraction instead of the left-shift to avoid the overflow.

(akpm: no change in .text size in my testing)

Link: http://lkml.kernel.org/r/20170803212020.24939-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/mm: Use WRITE_ONCE() when setting PTEs
Nadav Amit [Sun, 2 Sep 2018 18:14:50 +0000 (11:14 -0700)]
x86/mm: Use WRITE_ONCE() when setting PTEs

commit 9bc4f28af75a91aea0ae383f50b0a430c4509303 upstream.

When page-table entries are set, the compiler might optimize their
assignment by using multiple instructions to set the PTE. This might
turn into a security hazard if the user somehow manages to use the
interim PTE. L1TF does not make our lives easier, making even an interim
non-present PTE a security hazard.

Using WRITE_ONCE() to set PTEs and friends should prevent this potential
security hazard.

I skimmed the differences in the binary with and without this patch. The
differences are (obviously) greater when CONFIG_PARAVIRT=n as more
code optimizations are possible. For better and worse, the impact on the
binary with this patch is pretty small. Skimming the code did not cause
anything to jump out as a security hazard, but it seems that at least
move_soft_dirty_pte() caused set_pte_at() to use multiple writes.

Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20180902181451.80520-1-namit@vmware.com
[bwh: Backported to 4.9:
 - Drop changes in pmdp_establish(), native_set_p4d(), pudp_set_access_flags()
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/microcode: Update the new microcode revision unconditionally
Filippo Sironi [Tue, 31 Jul 2018 15:29:30 +0000 (17:29 +0200)]
x86/microcode: Update the new microcode revision unconditionally

commit 8da38ebaad23fe1b0c4a205438676f6356607cfc upstream.

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 <sironi@amazon.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: prarit@redhat.com
Link: http://lkml.kernel.org/r/1533050970-14385-1-git-send-email-sironi@amazon.de
[bwh: Backported to 4.9:
 - Keep returning 0 on success
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/microcode: Make sure boot_cpu_data.microcode is up-to-date
Prarit Bhargava [Tue, 31 Jul 2018 11:27:39 +0000 (07:27 -0400)]
x86/microcode: Make sure boot_cpu_data.microcode is up-to-date

commit 370a132bb2227ff76278f98370e0e701d86ff752 upstream.

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 <prarit@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: sironi@amazon.de
Link: http://lkml.kernel.org/r/20180731112739.32338-1-prarit@redhat.com
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/microcode/intel: Check microcode revision before updating sibling threads
Ashok Raj [Wed, 28 Feb 2018 10:28:41 +0000 (11:28 +0100)]
x86/microcode/intel: Check microcode revision before updating sibling threads

commit c182d2b7d0ca48e0d6ff16f7d883161238c447ed upstream.

After updating microcode on one of the threads of a core, the other
thread sibling automatically gets the update since the microcode
resources on a hyperthreaded core are shared between the two threads.

Check the microcode revision on the CPU before performing a microcode
update and thus save us the WRMSR 0x79 because it is a particularly
expensive operation.

[ Borislav: Massage changelog and coding style. ]

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Tested-by: Ashok Raj <ashok.raj@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Link: http://lkml.kernel.org/r/1519352533-15992-2-git-send-email-ashok.raj@intel.com
Link: https://lkml.kernel.org/r/20180228102846.13447-3-bp@alien8.de
[bwh: Backported to 4.9: return 0 in this case]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/microcode/intel: Add a helper which gives the microcode revision
Borislav Petkov [Mon, 9 Jan 2017 11:41:45 +0000 (12:41 +0100)]
x86/microcode/intel: Add a helper which gives the microcode revision

commit 4167709bbf826512a52ebd6aafda2be104adaec9 upstream.

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: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/20170109114147.5082-4-bp@alien8.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 4.9:
 - Keep using sync_core(), which will alway includes the necessary CPUID
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR
Tom Lendacky [Mon, 2 Jul 2018 21:36:02 +0000 (16:36 -0500)]
x86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR

commit 612bc3b3d4be749f73a513a17d9b3ee1330d3487 upstream.

On AMD, the presence of the MSR_SPEC_CTRL feature does not imply that the
SSBD mitigation support should use the SPEC_CTRL MSR. Other features could
have caused the MSR_SPEC_CTRL feature to be set, while a different SSBD
mitigation option is in place.

Update the SSBD support to check for the actual SSBD features that will
use the SPEC_CTRL MSR.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6ac2f49edb1e ("x86/bugs: Add AMD's SPEC_CTRL MSR usage")
Link: http://lkml.kernel.org/r/20180702213602.29202.33151.stgit@tlendack-t1.amdoffice.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/bugs: Switch the selection of mitigation from CPU vendor to CPU features
Konrad Rzeszutek Wilk [Fri, 1 Jun 2018 14:59:21 +0000 (10:59 -0400)]
x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features

commit 108fab4b5c8f12064ef86e02cb0459992affb30f upstream.

Both AMD and Intel can have SPEC_CTRL_MSR for SSBD.

However AMD also has two more other ways of doing it - which
are !SPEC_CTRL MSR ways.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: kvm@vger.kernel.org
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: andrew.cooper3@citrix.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180601145921.9500-4-konrad.wilk@oracle.com
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/bugs: Add AMD's SPEC_CTRL MSR usage
Konrad Rzeszutek Wilk [Fri, 1 Jun 2018 14:59:20 +0000 (10:59 -0400)]
x86/bugs: Add AMD's SPEC_CTRL MSR usage

commit 6ac2f49edb1ef5446089c7c660017732886d62d6 upstream.

The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that if CPUID 8000_0008.EBX[24] is set we should be using
the SPEC_CTRL MSR (0x48) over the VIRT SPEC_CTRL MSR (0xC001_011f)
for speculative store bypass disable.

This in effect means we should clear the X86_FEATURE_VIRT_SSBD
flag so that we would prefer the SPEC_CTRL MSR.

See the document titled:
   124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf

A copy of this document is available at
   https://bugzilla.kernel.org/show_bug.cgi?id=199889

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: andrew.cooper3@citrix.com
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20180601145921.9500-3-konrad.wilk@oracle.com
[bwh: Backported to 4.9:
 - Update feature test in guest_cpuid_has_spec_ctrl() instead of
   svm_{get,set}_msr()
 - Adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/bugs: Add AMD's variant of SSB_NO
Konrad Rzeszutek Wilk [Fri, 1 Jun 2018 14:59:19 +0000 (10:59 -0400)]
x86/bugs: Add AMD's variant of SSB_NO

commit 24809860012e0130fbafe536709e08a22b3e959e upstream.

The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that the CPUID 8000_0008.EBX[26] will mean that the
speculative store bypass disable is no longer needed.

A copy of this document is available at:
    https://bugzilla.kernel.org/show_bug.cgi?id=199889

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: andrew.cooper3@citrix.com
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180601145921.9500-2-konrad.wilk@oracle.com
[bwh: Backported to 4.9: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/cpufeatures: Hide AMD-specific speculation flags
Ben Hutchings [Wed, 7 Nov 2018 17:09:42 +0000 (17:09 +0000)]
x86/cpufeatures: Hide AMD-specific speculation flags

Hide the AMD_{IBRS,IBPB,STIBP} flag from /proc/cpuinfo.  This was done
upstream as part of commit e7c587da1252 "x86/speculation: Use
synthetic bits for IBRS/IBPB/STIBP".  That commit has already been
backported but this part was omitted.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agox86/MCE: Save microcode revision in machine check records
Tony Luck [Tue, 6 Mar 2018 14:21:41 +0000 (15:21 +0100)]
x86/MCE: Save microcode revision in machine check records

commit fa94d0c6e0f3431523f5701084d799c77c7d4a4f upstream.

Updating microcode used to be relatively rare. Now that it has become
more common we should save the microcode version in a machine check
record to make sure that those people looking at the error have this
important information bundled with the rest of the logged information.

[ Borislav: Simplify a bit. ]

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180301233449.24311-1-tony.luck@intel.com
[bwh: Backported to 4.9:
 - Also add ppin field to struct mce, to match upstream UAPI
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5 years agoLinux 4.9.175
Greg Kroah-Hartman [Fri, 10 May 2019 15:52:11 +0000 (17:52 +0200)]
Linux 4.9.175