git.samba.org - sfrench/cifs-2.6.git/log

RDS: Check cmsg_len before dereferencing CMSG_DATA

RDS currently doesn't check if the length of the control message is
large enough to hold the required data, before dereferencing the control
message data. This results in following crash:

BUG: KASAN: stack-out-of-bounds in rds_rdma_bytes net/rds/send.c:1013
[inline]
BUG: KASAN: stack-out-of-bounds in rds_sendmsg+0x1f02/0x1f90
net/rds/send.c:1066
Read of size 8 at addr ffff8801c928fb70 by task syzkaller455006/3157

CPU: 0 PID: 3157 Comm: syzkaller455006 Not tainted 4.15.0-rc3+ #161
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:53
print_address_description+0x73/0x250 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x25b/0x340 mm/kasan/report.c:409
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
rds_rdma_bytes net/rds/send.c:1013 [inline]
rds_sendmsg+0x1f02/0x1f90 net/rds/send.c:1066
sock_sendmsg_nosec net/socket.c:628 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:638
___sys_sendmsg+0x320/0x8b0 net/socket.c:2018
__sys_sendmmsg+0x1ee/0x620 net/socket.c:2108
SYSC_sendmmsg net/socket.c:2139 [inline]
SyS_sendmmsg+0x35/0x60 net/socket.c:2134
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x43fe49
RSP: 002b:00007fffbe244ad8 EFLAGS: 00000217 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043fe49
RDX: 0000000000000001 RSI: 000000002020c000 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004017b0
R13: 0000000000401840 R14: 0000000000000000 R15: 0000000000000000

To fix this, we verify that the cmsg_len is large enough to hold the
data to be read, before proceeding further.

Reported-by: syzbot <syzkaller-bugs@googlegroups.com>
Signed-off-by: Avinash Repaka <avinash.repaka@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

usb: xhci: Add XHCI_TRUST_TX_LENGTH for Renesas uPD720201

When plugging in a USB webcam I see the following message:
xhci_hcd 0000:04:00.0: WARN Successful completion on short TX: needs
XHCI_TRUST_TX_LENGTH quirk?
handle_tx_event: 913 callbacks suppressed

All is quiet again with this patch (and I've done a fair but of soak
testing with the camera since).

Cc: <stable@vger.kernel.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci: Fix use-after-free in xhci debugfs

Trying to read from debugfs after the system has resumed from
hibernate causes a use-after-free and thus a protection fault.

Steps to reproduce:
Hibernate system, resume from hibernate, then run
$ cat /sys/kernel/debug/usb/xhci/*/command-ring/enqueue

[ 3902.765086] general protection fault: 0000 [#1] PREEMPT SMP
...
[ 3902.765136] RIP: 0010:xhci_trb_virt_to_dma.part.50+0x5/0x30
...
[ 3902.765178] Call Trace:
[ 3902.765188]  xhci_ring_enqueue_show+0x1e/0x40
[ 3902.765197]  seq_read+0xdb/0x3a0
[ 3902.765204]  ? __handle_mm_fault+0x5fb/0x1210
[ 3902.765211]  full_proxy_read+0x4a/0x70
[ 3902.765219]  __vfs_read+0x23/0x120
[ 3902.765228]  vfs_read+0x8e/0x130
[ 3902.765235]  SyS_read+0x42/0x90
[ 3902.765242]  do_syscall_64+0x6b/0x290
[ 3902.765251]  entry_SYSCALL64_slow_path+0x25/0x25

The issue is caused by the xhci ring structures being reallocated
when the system is resumed, but pointers to the old structures
being retained in the debugfs files "private" field:

The proposed patch fixes this issue by storing a pointer to the xhci_ring
field in the xhci device structure in debugfs rather than directly
storing a pointer to the xhci_ring.

Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver")
Signed-off-by: Alexander Kappner <agk@godking.net>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci: Fix xhci debugfs NULL pointer dereference in resume from hibernate

Free the virt_device and its debugfs_private member together.

When resuming from hibernate the .free_dev callback unconditionally
freed the debugfs_private member, but could leave virt_device intact.

This triggered a NULL pointer dereference after resume when usbmuxd
sent a USBDEVFS_SETCONFIGURATION ioctl to a device, trying to add a
endpoint debugfs entry to a already freed debugfs_private pointer.

Fixes: 02b6fdc2a153 ("usb: xhci: Add debugfs interface for xHCI driver")
Reported-by: Alexander Kappner <agk@godking.net>
Tested-by: Alexander Kappner <agk@godking.net>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge tag 'usb-serial-4.15-rc6' of https://git./linux/kernel/git/johan/usb-serial into usb-linus

Johan writes

USB-serial fixes for v4.15-rc6

Here are some new device ids for ftdi_sio, option and qcserial.

Note that the qcserial patch enables the SetControlLineState request
(used to raise DTR/RTS) for the GPS interface of all devices using the
Sierra Wireless layout. This was required for the Sierra Wireless EM7565
and has been tested using several other modems as well.

All but the final commit have been in linux-next without any reported
issues.

Signed-off-by: Johan Hovold <johan@kernel.org>

USB: serial: ftdi_sio: add id for Airbus DS P8GR

Add AIRBUS_DS_P8GR device IDs to ftdi_sio driver.

Signed-off-by: Max Schulze <max.schulze@posteo.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>

ALSA: hda - Fix missing COEF init for ALC225/295/299

There was a long-standing problem on HP Spectre X360 with Kabylake
where it lacks of the front speaker output in some situations. Also
there are other products showing the similar behavior. The culprit
seems to be the missing COEF setup on ALC codecs, ALC225/295/299,
which are all compatible.

This patch adds the proper COEF setup (to initialize idx 0x67 / bits
0x3000) for addressing the issue.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195457
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge tag 'hwmon-for-linus-v4.15-rc6' of git://git./linux/kernel/git/groeck/linux-staging

Pull hwmon fix from Guenter Roeck:
"Handle errors from thermal subsystem"

* tag 'hwmon-for-linus-v4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: Deal with errors from the thermal subsystem

Merge tag 'gpio-v4.15-3' of git://git./linux/kernel/git/linusw/linux-gpio

Pull GPIO fixes from Linus Walleij:
"Two fixes. They are both kind of important, so why not send a pull
  request on christmas eve.

   - Fix a build problem in the gpio single register created by
     refactorings.

   - Fix assignment of GPIO line names, something that was mangled by
     another patch"

* tag 'gpio-v4.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: fix "gpio-line-names" property retrieval
  gpio: gpio-reg: fix build

clk: use atomic runtime pm api in clk_core_is_enabled

Current clk_pm_runtime_put is using pm_runtime_put_sync which
is not safe to be called in clk_core_is_enabled as it should
be able to run in atomic context.

Thus use pm_runtime_put instead which is atomic safe.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 9a34b45397e5 ("clk: Add support for runtime PM")
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

Merge branch 'linux-4.15' of git://github.com/skeggsb/linux into drm-fixes

one nouveau regression fix

* 'linux-4.15' of git://github.com/skeggsb/linux:
drm/nouveau: fix race when adding delayed work items

tcp: Avoid preprocessor directives in tracepoint macro args

Using a preprocessor directive to check for CONFIG_IPV6 in the middle of
a DECLARE_EVENT_CLASS macro's arg list causes sparse to report a series
of errors:

./include/trace/events/tcp.h:68:1: error: directive in argument list
./include/trace/events/tcp.h:75:1: error: directive in argument list
./include/trace/events/tcp.h:144:1: error: directive in argument list
./include/trace/events/tcp.h:151:1: error: directive in argument list
./include/trace/events/tcp.h:216:1: error: directive in argument list
./include/trace/events/tcp.h:223:1: error: directive in argument list
./include/trace/events/tcp.h:274:1: error: directive in argument list
./include/trace/events/tcp.h:281:1: error: directive in argument list

Once sparse finds an error, it stops printing warnings for the file it
is checking. This masks any sparse warnings that would normally be
reported for the core TCP code.

Instead, handle the preprocessor conditionals in a couple of auxiliary
macros. This also has the benefit of reducing duplicate code.

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hwmon: Deal with errors from the thermal subsystem

If the thermal subsystem returne -EPROBE_DEFER or any other error
when hwmon calls devm_thermal_zone_of_sensor_register(), this is
silently ignored.

I ran into this with an incorrectly defined thermal zone, making
it non-existing and thus this call failed with -EPROBE_DEFER
assuming it would appear later. The sensor was still added
which is incorrect: sensors must strictly be added after the
thermal zones, so deferred probe must be respected.

Fixes: d560168b5d0f ("hwmon: (core) New hwmon registration API")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

tipc: fix memory leak of group member when peer node is lost

When a group member receives a member WITHDRAW event, this might have
two reasons: either the peer member is leaving the group, or the link
to the member's node has been lost.

In the latter case we need to issue a DOWN event to the user right away,
and let function tipc_group_filter_msg() perform delete of the member
item. However, in this case we miss to change the state of the member
item to MBR_LEAVING, so the member item is not deleted, and we have a
memory leak.

We now separate better between the four sub-cases of a WITHRAW event
and make sure that each case is handled correctly.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: fix possible null pointer deref in tcf_block_put

We need to check block for being null in both tcf_block_put and
tcf_block_put_ext.

Fixes: 343723dd51ef ("net: sched: fix clsact init error path")
Reported-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tipc: base group replicast ack counter on number of actual receivers

In commit 2f487712b893 ("tipc: guarantee that group broadcast doesn't
bypass group unicast") we introduced a mechanism that requires the first
(replicated) broadcast sent after a unicast to be acknowledged by all
receivers before permitting sending of the next (true) broadcast.

The counter for keeping track of the number of acknowledges to expect
is based on the tipc_group::member_cnt variable. But this misses that
some of the known members may not be ready for reception, and will never
acknowledge the message, either because they haven't fully joined the
group or because they are leaving the group. Such members are identified
by not fulfilling the condition tested for in the function
tipc_group_is_enabled().

We now set the counter for the actual number of acks to receive at the
moment the message is sent, by just counting the number of recipients
satisfying the tipc_group_is_enabled() test.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net_sched: fix a missing rcu barrier in mini_qdisc_pair_swap()

The rcu_barrier_bh() in mini_qdisc_pair_swap() is to wait for
flying RCU callback installed by a previous mini_qdisc_pair_swap(),
however we miss it on the tp_head==NULL path, which leads to that
the RCU callback still uses miniq_old->rcu after it is freed together
with qdisc in qdisc_graft(). So just add it on that path too.

Fixes: 46209401f8f6 ("net: core: introduce mini_Qdisc and eliminate usage of tp->q for clsact fastpath ")
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: phy: micrel: ksz9031: reconfigure autoneg after phy autoneg workaround

Under some circumstances driver will perform PHY reset in
ksz9031_read_status() to fix autoneg failure case (idle error count =
0xFF). When this happens ksz9031 will not detect link status change any
more when connecting to Netgear 1G switch (link can be recovered sometimes by
restarting netdevice "ifconfig down up"). Reproduced with TI am572x board
equipped with ksz9031 PHY while connecting to Netgear 1G switch.

Fix the issue by reconfiguring autonegotiation after PHY reset in
ksz9031_read_status().

Fixes: d2fd719bcb0e ("net/phy: micrel: Add workaround for bad autoneg")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6_gre: fix device features for ioctl setup

When ip6gre is created using ioctl, its features, such as
scatter-gather, GSO and tx-checksumming will be turned off:

  # ip -f inet6 tunnel add gre6 mode ip6gre remote fd00::1
  # ethtool -k gre6 (truncated output)
    tx-checksumming: off
    scatter-gather: off
    tcp-segmentation-offload: off
    generic-segmentation-offload: off [requested on]

But when netlink is used, they will be enabled:
  # ip link add gre6 type ip6gre remote fd00::1
  # ethtool -k gre6 (truncated output)
    tx-checksumming: on
    scatter-gather: on
    tcp-segmentation-offload: on
    generic-segmentation-offload: on

This results in a loss of performance when gre6 is created via ioctl.
The issue was found with LTP/gre tests.

Fix it by moving the setup of device features to a separate function
and invoke it with ndo_init callback because both netlink and ioctl
will eventually call it via register_netdevice():

   register_netdevice()
       - ndo_init() callback -> ip6gre_tunnel_init() or ip6gre_tap_init()
           - ip6gre_tunnel_init_common()
                - ip6gre_tnl_init_features()

The moved code also contains two minor style fixes:
  * removed needless tab from GRE6_FEATURES on NETIF_F_HIGHDMA line.
  * fixed the issue reported by checkpatch: "Unnecessary parentheses around
    'nt->encap.type == TUNNEL_ENCAP_NONE'"

Fixes: ac4eb009e477 ("ip6gre: Add support for basic offloads offloads excluding GSO")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

phylink: ensure AN is enabled

Ensure that we mark AN as enabled at boot time, rather than leaving
it disabled. This is noticable if your SFP module is fiber, and
it supports faster speeds than 1G with 2.5G support in place.

Fixes: 9525ae83959b ("phylink: add phylink infrastructure")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

phylink: ensure the PHY interface mode is appropriately set

When setting the ethtool settings, ensure that the validated PHY
interface mode is propagated to the current link settings, so that
2500BaseX can be selected.

Fixes: 9525ae83959b ("phylink: add phylink infrastructure")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pid: Handle failure to allocate the first pid in a pid namespace

With the replacement of the pid bitmap and hashtable with an idr in
alloc_pid started occassionally failing when allocating the first pid
in a pid namespace.  Things were not completely reset resulting in
the first allocated pid getting the number 2 (not 1).  Which
further resulted in ns->proc_mnt not getting set and eventually
causing an oops in proc_flush_task.

Oops: 0000 [#1] SMP
CPU: 2 PID: 6743 Comm: trinity-c117 Not tainted 4.15.0-rc4-think+ #2
RIP: 0010:proc_flush_task+0x8e/0x1b0
RSP: 0018:ffffc9000bbffc40 EFLAGS: 00010286
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 00000000fffffffb
RDX: 0000000000000000 RSI: ffffc9000bbffc50 RDI: 0000000000000000
RBP: ffffc9000bbffc63 R08: 0000000000000000 R09: 0000000000000002
R10: ffffc9000bbffb70 R11: ffffc9000bbffc64 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000003 R15: ffff8804c10d7840
FS:  00007f7cb8965700(0000) GS:ffff88050a200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000003e21ae003 CR4: 00000000001606e0
DR0: 00007fb1d6c22000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
? release_task+0xaf/0x680
release_task+0xd2/0x680
? wait_consider_task+0xb82/0xce0
wait_consider_task+0xbe9/0xce0
? do_wait+0xe1/0x330
do_wait+0x151/0x330
kernel_wait4+0x8d/0x150
? task_stopped_code+0x50/0x50
SYSC_wait4+0x95/0xa0
? rcu_read_lock_sched_held+0x6c/0x80
? syscall_trace_enter+0x2d7/0x340
? do_syscall_64+0x60/0x210
do_syscall_64+0x60/0x210
entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7f7cb82603aa
RSP: 002b:00007ffd60770bc8 EFLAGS: 00000246
ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 00007f7cb6cd4000 RCX: 00007f7cb82603aa
RDX: 000000000000000b RSI: 00007ffd60770bd0 RDI: 0000000000007cca
RBP: 0000000000007cca R08: 00007f7cb8965700 R09: 00007ffd607c7080
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd60770bd0 R14: 00007f7cb6cd4058 R15: 00000000cccccccd
Code: c1 e2 04 44 8b 60 30 48 8b 40 38 44 8b 34 11 48 c7 c2 60 3a f5 81 44 89 e1 4c 8b 68 58 e8 4b b4 77 00 89 44 24 14 48 8d 74 24 10 <49> 8b 7d 00 e8 b9 6a f9 ff 48 85 c0 74 1a 48 89 c7 48 89 44 24
RIP: proc_flush_task+0x8e/0x1b0 RSP: ffffc9000bbffc40
CR2: 0000000000000000
---[ end trace 53d67a6481059862 ]---

Improve the quality of the implementation by resetting the place to
start allocating pids on failure to allocate the first pid.

As improving the quality of the implementation is the goal remove the now
unnecesarry disable_pid_allocations call when we fail to mount proc.

Fixes: 95846ecf9dac ("pid: replace pid bitmap implementation with IDR API")
Fixes: 8ef047aaaeb8 ("pid namespaces: make alloc_pid(), free_pid() and put_pid() work with struct upid")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Merge branch 'libnvdimm-fixes' of git://git./linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
"These fixes are all tagged for -stable and have received a build
  success notification from the kbuild robot.

   - NVDIMM namespaces, configured to enforce 1GB alignment, fail to
     initialize on platforms that mis-align the start or end of the
     physical address range.

   - The Linux implementation of the BTT (Block Translation Table) is
     incompatible with the UEFI 2.7 definition of the BTT format. The
     BTT layers a software atomic sector semantic on top of an NVDIMM
     namespace. Linux needs to be compatible with the UEFI definition to
     enable boot support or any pre-OS access of data on a BTT enabled
     namespace.

   - A fix for ACPI SMART notification events, this allows a userspace
     monitor to register for health events rather than poll. This has
     been broken since it was initially merged as the unit test
     inadvertently worked around the problem. The urgency for fixing
     this during the -rc series is driven by how expensive it is to poll
     for this data (System Management Mode entry)"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  libnvdimm, btt: Fix an incompatibility in the log layout
  libnvdimm, btt: add a couple of missing kernel-doc lines
  libnvdimm, dax: fix 1GB-aligned namespaces vs physical misalignment
  libnvdimm, pfn: fix start_pad handling for aligned namespaces
  acpi, nfit: fix health event notification

x86/ldt: Make the LDT mapping RO

Now that the LDT mapping is in a known area when PAGE_TABLE_ISOLATION is
enabled its a primary target for attacks, if a user space interface fails
to validate a write address correctly. That can never happen, right?

The SDM states:

    If the segment descriptors in the GDT or an LDT are placed in ROM, the
    processor can enter an indefinite loop if software or the processor
    attempts to update (write to) the ROM-based segment descriptors. To
    prevent this problem, set the accessed bits for all segment descriptors
    placed in a ROM. Also, remove operating-system or executive code that
    attempts to modify segment descriptors located in ROM.

So its a valid approach to set the ACCESS bit when setting up the LDT entry
and to map the table RO. Fixup the selftest so it can handle that new mode.

Remove the manual ACCESS bit setter in set_tls_desc() as this is now
pointless. Folded the patch from Peter Ziljstra.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/dump_pagetables: Allow dumping current pagetables

Add two debugfs files which allow to dump the pagetable of the current
task.

current_kernel dumps the regular page table. This is the page table which
is normally shared between kernel and user space. If kernel page table
isolation is enabled this is the kernel space mapping.

If kernel page table isolation is enabled the second file, current_user,
dumps the user space page table.

These files allow to verify the resulting page tables for page table
isolation, but even in the normal case its useful to be able to inspect
user space page tables of current for debugging purposes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/dump_pagetables: Check user space page table for WX pages

ptdump_walk_pgd_level_checkwx() checks the kernel page table for WX pages,
but does not check the PAGE_TABLE_ISOLATION user space page table.

Restructure the code so that dmesg output is selected by an explicit
argument and not implicit via checking the pgd argument for !NULL.

Add the check for the user space page table.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy

The upcoming support for dumping the kernel and the user space page tables
of the current process would create more random files in the top level
debugfs directory.

Add a page table directory and move the existing file to it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Add Kconfig

Finally allow CONFIG_PAGE_TABLE_ISOLATION to be enabled.

PARAVIRT generally requires that the kernel not manage its own page tables.
It also means that the hypervisor and kernel must agree wholeheartedly
about what format the page tables are in and what they contain.
PAGE_TABLE_ISOLATION, unfortunately, changes the rules and they
can not be used together.

I've seen conflicting feedback from maintainers lately about whether they
want the Kconfig magic to go first or last in a patch series. It's going
last here because the partially-applied series leads to kernels that can
not boot in a bunch of cases. I did a run through the entire series with
CONFIG_PAGE_TABLE_ISOLATION=y to look for build errors, though.

[ tglx: Removed SMP and !PARAVIRT dependencies as they not longer exist ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/dumpstack: Indicate in Oops whether PTI is configured and enabled

CONFIG_PAGE_TABLE_ISOLATION is relatively new and intrusive feature that may
still have some corner cases which could take some time to manifest and be
fixed. It would be useful to have Oops messages indicate whether it was
enabled for building the kernel, and whether it was disabled during boot.

Example of fully enabled:

Oops: 0001 [#1] SMP PTI

Example of enabled during build, but disabled during boot:

Oops: 0001 [#1] SMP NOPTI

We can decide to remove this after the feature has been tested in the field
long enough.

[ tglx: Made it use boot_cpu_has() as requested by Borislav ]

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eduardo Valentin <eduval@amazon.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: bpetkov@suse.de
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: jkosina@suse.cz
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming

Ideally we'd also use sparse to enforce this separation so it becomes much
more difficult to mess up.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Use INVPCID for __native_flush_tlb_single()

This uses INVPCID to shoot down individual lines of the user mapping
instead of marking the entire user map as invalid. This
could/might/possibly be faster.

This for sure needs tlb_single_page_flush_ceiling to be redetermined;
esp. since INVPCID is _slow_.

A detailed performance analysis is available here:

https://lkml.kernel.org/r/3062e486-3539-8a1f-5724-16199420be71@intel.com

[ Peterz: Split out from big combo patch ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Optimize RESTORE_CR3

Most NMI/paranoid exceptions will not in fact change pagetables and would
thus not require TLB flushing, however RESTORE_CR3 uses flushing CR3
writes.

Restores to kernel PCIDs can be NOFLUSH, because we explicitly flush the
kernel mappings and now that we track which user PCIDs need flushing we can
avoid those too when possible.

This does mean RESTORE_CR3 needs an additional scratch_reg, luckily both
sites have plenty available.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Use/Fix PCID to optimize user/kernel switches

We can use PCID to retain the TLBs across CR3 switches; including those now
part of the user/kernel switch. This increases performance of kernel
entry/exit at the cost of more expensive/complicated TLB flushing.

Now that we have two address spaces, one for kernel and one for user space,
we need two PCIDs per mm. We use the top PCID bit to indicate a user PCID
(just like we use the PFN LSB for the PGD). Since we do TLB invalidation
from kernel space, the existing code will only invalidate the kernel PCID,
we augment that by marking the corresponding user PCID invalid, and upon
switching back to userspace, use a flushing CR3 write for the switch.

In order to access the user_pcid_flush_mask we use PER_CPU storage, which
means the previously established SWAPGS vs CR3 ordering is now mandatory
and required.

Having to do this memory access does require additional registers, most
sites have a functioning stack and we can spill one (RAX), sites without
functional stack need to otherwise provide the second scratch register.

Note: PCID is generally available on Intel Sandybridge and later CPUs.
Note: Up until this point TLB flushing was broken in this series.

Based-on-code-from: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Abstract switching CR3

In preparation to adding additional PCID flushing, abstract the
loading of a new ASID into CR3.

[ PeterZ: Split out from big combo patch ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Allow flushing for future ASID switches

If changing the page tables in such a way that an invalidation of all
contexts (aka. PCIDs / ASIDs) is required, they can be actively invalidated
by:

1. INVPCID for each PCID (works for single pages too).

2. Load CR3 with each PCID without the NOFLUSH bit set

3. Load CR3 with the NOFLUSH bit set for each and do INVLPG for each address.

But, none of these are really feasible since there are ~6 ASIDs (12 with
PAGE_TABLE_ISOLATION) at the time that invalidation is required.
Instead of actively invalidating them, invalidate the *current* context and
also mark the cpu_tlbstate _quickly_ to indicate future invalidation to be
required.

At the next context-switch, look for this indicator
('invalidate_other' being set) invalidate all of the
cpu_tlbstate.ctxs[] entries.

This ensures that any future context switches will do a full flush
of the TLB, picking up the previous changes.

[ tglx: Folded more fixups from Peter ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/pti: Map the vsyscall page if needed

Make VSYSCALLs work fully in PTI mode by mapping them properly to the user
space visible page tables.

[ tglx: Hide unused functions (Patch by Arnd Bergmann) ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/pti: Put the LDT in its own PGD if PTI is on

With PTI enabled, the LDT must be mapped in the usermode tables somewhere.
The LDT is per process, i.e. per mm.

An earlier approach mapped the LDT on context switch into a fixmap area,
but that's a big overhead and exhausted the fixmap space when NR_CPUS got
big.

Take advantage of the fact that there is an address space hole which
provides a completely unused pgd. Use this pgd to manage per-mm LDT
mappings.

This has a down side: the LDT isn't (currently) randomized, and an attack
that can write the LDT is instant root due to call gates (thanks, AMD, for
leaving call gates in AMD64 but designing them wrong so they're only useful
for exploits). This can be mitigated by making the LDT read-only or
randomizing the mapping, either of which is strightforward on top of this
patch.

This will significantly slow down LDT users, but that shouldn't matter for
important workloads -- the LDT is only used by DOSEMU(2), Wine, and very
old libc implementations.

[ tglx: Cleaned it up. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/64: Make a full PGD-entry size hole in the memory map

Shrink vmalloc space from 16384TiB to 12800TiB to enlarge the hole starting
at 0xff90000000000000 to be a full PGD entry.

A subsequent patch will use this hole for the pagetable isolation LDT
alias.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/events/intel/ds: Map debug buffers in cpu_entry_area

The BTS and PEBS buffers both have their virtual addresses programmed into
the hardware.  This means that any access to them is performed via the page
tables.  The times that the hardware accesses these are entirely dependent
on how the performance monitoring hardware events are set up.  In other
words, there is no way for the kernel to tell when the hardware might
access these buffers.

To avoid perf crashes, place 'debug_store' allocate pages and map them into
the cpu_entry_area.

The PEBS fixup buffer does not need this treatment.

[ tglx: Got rid of the kaiser_add_mapping() complication ]

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/cpu_entry_area: Add debugstore entries to cpu_entry_area

The Intel PEBS/BTS debug store is a design trainwreck as it expects virtual
addresses which must be visible in any execution context.

So it is required to make these mappings visible to user space when kernel
page table isolation is active.

Provide enough room for the buffer mappings in the cpu_entry_area so the
buffers are available in the user space visible page tables.

At the point where the kernel side entry area is populated there is no
buffer available yet, but the kernel PMD must be populated. To achieve this
set the entries for these buffers to non present.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Map ESPFIX into user space

Map the ESPFIX pages into user space when PTI is enabled.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Share entry text PMD

Share the entry text PMD of the kernel mapping with the user space
mapping. If large pages are enabled this is a single PMD entry and at the
point where it is copied into the user page table the RW bit has not been
cleared yet. Clear it right away so the user space visible map becomes RX.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Align entry text section to PMD boundary

The (irq)entry text must be visible in the user space page tables. To allow
simple PMD based sharing, make the entry text PMD aligned.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Share cpu_entry_area with user space page tables

Share the cpu entry area so the user space and kernel space page tables
have the same P4D page.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Force entry through trampoline when PTI active

Force the entry through the trampoline only when PTI is active. Otherwise
go through the normal entry code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Add functions to clone kernel PMDs

Provide infrastructure to:

- find a kernel PMD for a mapping which must be visible to user space for
the entry/exit code to work.

- walk an address range and share the kernel PMD with it.

This reuses a small part of the original KAISER patches to populate the
user space page table.

[ tglx: Made it universally usable so it can be used for any kind of shared
mapping. Add a mechanism to clear specific bits in the user space
visible PMD entry. Folded Andys simplifactions ]

Originally-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Populate user PGD

In clone_pgd_range() copy the init user PGDs which cover the kernel half of
the address space, so a process has all the required kernel mappings
visible.

[ tglx: Split out from the big kaiser dump and folded Andys simplification ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Allocate a separate user PGD

Kernel page table isolation requires to have two PGDs. One for the kernel,
which contains the full kernel mapping plus the user space mapping and one
for user space which contains the user space mappings and the minimal set
of kernel mappings which are required by the architecture to be able to
transition from and to user space.

Add the necessary preliminaries.

[ tglx: Split out from the big kaiser dump. EFI fixup from Kirill ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Allow NX poison to be set in p4d/pgd

With PAGE_TABLE_ISOLATION the user portion of the kernel page tables is
poisoned with the NX bit so if the entry code exits with the kernel page
tables selected in CR3, userspace crashes.

But doing so trips the p4d/pgd_bad() checks. Make sure it does not do
that.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Add mapping helper functions

Add the pagetable helper functions do manage the separate user space page
tables.

[ tglx: Split out from the big combo kaiser patch. Folded Andys
simplification and made it out of line as Boris suggested ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/pti: Add the pti= cmdline option and documentation

Keep the "nopti" optional for traditional reasons.

[ tglx: Don't allow force on when running on XEN PV and made 'on'
printout conditional ]

Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171212133952.10177-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Add infrastructure for page table isolation

Add the initial files for kernel page table isolation, with a minimal init
function and the boot time detection for this misfeature.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Prepare the x86/entry assembly code for entry/exit CR3 switching

PAGE_TABLE_ISOLATION needs to switch to a different CR3 value when it
enters the kernel and switch back when it exits.  This essentially needs to
be done before leaving assembly code.

This is extra challenging because the switching context is tricky: the
registers that can be clobbered can vary.  It is also hard to store things
on the stack because there is an established ABI (ptregs) or the stack is
entirely unsafe to use.

Establish a set of macros that allow changing to the user and kernel CR3
values.

Interactions with SWAPGS:

  Previous versions of the PAGE_TABLE_ISOLATION code relied on having
  per-CPU scratch space to save/restore a register that can be used for the
  CR3 MOV.  The %GS register is used to index into our per-CPU space, so
  SWAPGS *had* to be done before the CR3 switch.  That scratch space is gone
  now, but the semantic that SWAPGS must be done before the CR3 MOV is
  retained.  This is good to keep because it is not that hard to do and it
  allows to do things like add per-CPU debugging information.

What this does in the NMI code is worth pointing out.  NMIs can interrupt
*any* context and they can also be nested with NMIs interrupting other
NMIs.  The comments below ".Lnmi_from_kernel" explain the format of the
stack during this situation.  Changing the format of this stack is hard.
Instead of storing the old CR3 value on the stack, this depends on the
*regular* register save/restore mechanism and then uses %r14 to keep CR3
during the NMI.  It is callee-saved and will not be clobbered by the C NMI
handlers that get called.

[ PeterZ: ESPFIX optimization ]

Based-on-code-from: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/pti: Disable global pages if PAGE_TABLE_ISOLATION=y

Global pages stay in the TLB across context switches. Since all contexts
share the same kernel mapping, these mappings are marked as global pages
so kernel entries in the TLB are not flushed out on a context switch.

But, even having these entries in the TLB opens up something that an
attacker can use, such as the double-page-fault attack:

http://www.ieee-security.org/TC/SP2013/papers/4977a191.pdf

That means that even when PAGE_TABLE_ISOLATION switches page tables
on return to user space the global pages would stay in the TLB cache.

Disable global pages so that kernel TLB entries can be flushed before
returning to user space. This way, all accesses to kernel addresses from
userspace result in a TLB miss independent of the existence of a kernel
mapping.

Suppress global pages via the __supported_pte_mask. The user space
mappings set PAGE_GLOBAL for the minimal kernel mappings which are
required for entry/exit. These mappings are set up manually so the
filtering does not take place.

[ The __supported_pte_mask simplification was written by Thomas Gleixner. ]
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/cpufeatures: Add X86_BUG_CPU_INSECURE

Many x86 CPUs leak information to user space due to missing isolation of
user space and kernel space page tables. There are many well documented
ways to exploit that.

The upcoming software migitation of isolating the user and kernel space
page tables needs a misfeature flag so code can be made runtime
conditional.

Add the BUG bits which indicates that the CPU is affected and add a feature
bit which indicates that the software migitation is enabled.

Assume for now that _ALL_ x86 CPUs are affected by this. Exceptions can be
made later.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge branch 'x86-pti-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 PTI preparatory patches from Thomas Gleixner:
"Todays Advent calendar window contains twentyfour easy to digest
  patches. The original plan was to have twenty three matching the date,
  but a late fixup made that moot.

   - Move the cpu_entry_area mapping out of the fixmap into a separate
     address space. That's necessary because the fixmap becomes too big
     with NRCPUS=8192 and this caused already subtle and hard to
     diagnose failures.

     The top most patch is fresh from today and cures a brain slip of
     that tall grumpy german greybeard, who ignored the intricacies of
     32bit wraparounds.

   - Limit the number of CPUs on 32bit to 64. That's insane big already,
     but at least it's small enough to prevent address space issues with
     the cpu_entry_area map, which have been observed and debugged with
     the fixmap code

   - A few TLB flush fixes in various places plus documentation which of
     the TLB functions should be used for what.

   - Rename the SYSENTER stack to CPU_ENTRY_AREA stack as it is used for
     more than sysenter now and keeping the name makes backtraces
     confusing.

   - Prevent LDT inheritance on exec() by moving it to arch_dup_mmap(),
     which is only invoked on fork().

   - Make vysycall more robust.

   - A few fixes and cleanups of the debug_pagetables code. Check
     PAGE_PRESENT instead of checking the PTE for 0 and a cleanup of the
     C89 initialization of the address hint array which already was out
     of sync with the index enums.

   - Move the ESPFIX init to a different place to prepare for PTI.

   - Several code moves with no functional change to make PTI
     integration simpler and header files less convoluted.

   - Documentation fixes and clarifications"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit
  init: Invoke init_espfix_bsp() from mm_init()
  x86/cpu_entry_area: Move it out of the fixmap
  x86/cpu_entry_area: Move it to a separate unit
  x86/mm: Create asm/invpcid.h
  x86/mm: Put MMU to hardware ASID translation in one place
  x86/mm: Remove hard-coded ASID limit checks
  x86/mm: Move the CR3 construction functions to tlbflush.h
  x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what
  x86/mm: Remove superfluous barriers
  x86/mm: Use __flush_tlb_one() for kernel memory
  x86/microcode: Dont abuse the TLB-flush interface
  x86/uv: Use the right TLB-flush API
  x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack
  x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation
  x86/mm/64: Improve the memory map documentation
  x86/ldt: Prevent LDT inheritance on exec
  x86/ldt: Rework locking
  arch, mm: Allow arch_dup_mmap() to fail
  x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode
  ...

x86/cpu_entry_area: Prevent wraparound in setup_cpu_entry_area_ptes() on 32bit

The loop which populates the CPU entry area PMDs can wrap around on 32bit
machines when the number of CPUs is small.

It worked wonderful for NR_CPUS=64 for whatever reason and the moron who
wrote that code did not bother to test it with !SMP.

Check for the wraparound to fix it.

Fixes: 92a0f81d8957 ("x86/cpu_entry_area: Move it out of the fixmap")
Reported-by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Thomas "Feels stupid" Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@alien8.de>

nvmem: meson-mx-efuse: fix reading from an offset other than 0

meson_mx_efuse_read calculates the address internal to the eFuse based
on the offset and the word size. This works fine with any given offset.
However, the offset is also included when writing to the output buffer.
This means that reading 4 bytes at offset 500 tries to write beyond the
array allocated by the nvmem core as it wants to write the 4 bytes to
"buffer address + offset (500)".
This issue did not show up in the previous tests since no driver uses
any value from the eFuse yet and reading the eFuse via sysfs simply
reads the whole eFuse, starting at offset 0.

Fix this by only including the offset in the internal address
calculation.

Fixes: 8caef1fa9176 ("nvmem: add a driver for the Amlogic Meson6/Meson8/Meson8b SoCs")
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge branch 'bpf-bpftool-various-fixes'

Jakub Kicinski says:

====================
Two small fixes here to listing maps and programs. The loop for showing
maps is written slightly differently to programs which was missed in JSON
output support, and output would be broken if any of the system calls
failed. Second fix is in very unlikely case that program or map disappears
after we get its ID we should just skip over that object instead of failing.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools: bpftool: protect against races with disappearing objects

On program/map show we may get an ID of an object from GETNEXT,
but the object may disappear before we call GET_FD_BY_ID. If
that happens, ignore the object and continue.

Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools: bpftool: maps: close json array on error paths of show

We can't return from the middle of do_show(), because
json_array will not be closed. Break out of the loop.
Note that the error handling after the loop depends on
errno, so no need to set err.

Fixes: 831a0aafe5c3 ("tools: bpftool: add JSON output for `bpftool map *` commands")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drm/nouveau: fix race when adding delayed work items

kernel.org bz#198221.

Reported-by: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Merge tag 'powerpc-4.15-5' of git://git./linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
"This is all fairly boring, except that there's two KVM fixes that
  you'd normally get via Paul's kvm-ppc tree. He's away so I picked them
  up. I was waiting to see if he would apply them, which is why they
  have only been in my tree since today. But they were on the list for a
  while and have been tested on the relevant hardware.

  Of note is two fixes for KVM XIVE (Power9 interrupt controller). These
  would normally go via the KVM tree but Paul is away so I've picked
  them up.

  Other than that, two fixes for error handling in the IMC driver, and
  one for a potential oops in the BHRB code if the hardware records a
  branch address that has subsequently been unmapped, and finally a
  s/%p/%px/ in our oops code.

  Thanks to: Anju T Sudhakar, Cédric Le Goater, Laurent Vivier, Madhavan
  Srinivasan, Naveen N. Rao, Ravi Bangoria"

* tag 'powerpc-4.15-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Book3S HV: Fix pending_pri value in kvmppc_xive_get_icp()
  KVM: PPC: Book3S: fix XIVE migration of pending interrupts
  powerpc/kernel: Print actual address of regs when oopsing
  powerpc/perf: Fix kfree memory allocated for nest pmus
  powerpc/perf/imc: Fix nest-imc cpuhotplug callback failure
  powerpc/perf: Dereference BHRB entries safely

Merge tag 'for-linus-4.15-rc5-tag' of git://git./linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:
"This contains two fixes for running under Xen:

   - a fix avoiding resource conflicts between adding mmio areas and
     memory hotplug

   - a fix setting NX bits in page table entries copied from Xen when
     running a PV guest"

* tag 'for-linus-4.15-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: Mark unallocated host memory as UNUSABLE
  x86-64/Xen: eliminate W+X mappings

Merge tag 'xfs-4.15-fixes-8' of git://git./fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:
"Here are some XFS fixes for 4.15-rc5. Apologies for the unusually
  large number of patches this late, but I wanted to make sure the
  corruption fixes were really ready to go.

  Changes since last update:

   - Fix a locking problem during xattr block conversion that could lead
     to the log checkpointing thread to try to write an incomplete
     buffer to disk, which leads to a corruption shutdown

   - Fix a null pointer dereference when removing delayed allocation
     extents

   - Remove post-eof speculative allocations when reflinking a block
     past current inode size so that we don't just leave them there and
     assert on inode reclaim

   - Relax an assert which didn't accurately reflect the way locking
     works and would trigger under heavy io load

   - Avoid infinite loop when cancelling copy on write extents after a
     writeback failure

   - Try to avoid copy on write transaction reservation overflows when
     remapping after a successful write

   - Fix various problems with the copy-on-write reservation automatic
     garbage collection not being cleaned up properly during a ro
     remount

   - Fix problems with rmap log items being processed in the wrong
     order, leading to corruption shutdowns

   - Fix problems with EFI recovery wherein the "remove any rmapping if
     present" mechanism wasn't actually doing anything, which would lead
     to corruption problems later when the extent is reallocated,
     leading to multiple rmaps for the same extent"

* tag 'xfs-4.15-fixes-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: only skip rmap owner checks for unknown-owner rmap removal
  xfs: always honor OWN_UNKNOWN rmap removal requests
  xfs: queue deferred rmap ops for cow staging extent alloc/free in the right order
  xfs: set cowblocks tag for direct cow writes too
  xfs: remove leftover CoW reservations when remounting ro
  xfs: don't be so eager to clear the cowblocks tag on truncate
  xfs: track cowblocks separately in i_flags
  xfs: allow CoW remap transactions to use reserve blocks
  xfs: avoid infinite loop when cancelling CoW blocks after writeback failure
  xfs: relax is_reflink_inode assert in xfs_reflink_find_cow_mapping
  xfs: remove dest file's post-eof preallocations before reflinking
  xfs: move xfs_iext_insert tracepoint to report useful information
  xfs: account for null transactions in bunmapi
  xfs: hold xfs_buf locked between shortform->leaf conversion and the addition of an attribute
  xfs: add the ability to join a held buffer to a defer_ops

Merge branch 'linus' of git://git./linux/kernel/git/herbert/crypto-2.6

Pull crypto fixes from Herbert Xu:
"This fixes the following issues:

   - fix chacha20 crash on zero-length input due to unset IV

   - fix potential race conditions in mcryptd with spinlock

   - only wait once at top of algif recvmsg to avoid inconsistencies

   - fix potential use-after-free in algif_aead/algif_skcipher"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: af_alg - fix race accessing cipher request
  crypto: mcryptd - protect the per-CPU queue with a lock
  crypto: af_alg - wait for data at beginning of recvmsg
  crypto: skcipher - set walk.iv for zero-length inputs

Merge tag 'pinctrl-v4.15-3' of git://git./linux/kernel/git/linusw/linux-pinctrl

Pull pin control fix from Linus Walleij:
"A single pin control fix for Intel machines, affecting a bunch of
Chromebooks. Nothing else collected up amazingly"

* tag 'pinctrl-v4.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: cherryview: Mask all interrupts on Intel_Strago based systems

Merge tag 'drm-fixes-for-v4.15-rc5' of git://people.freedesktop.org/~airlied/linux

Pull drm fixes from Dave Airlie:
"I've got most of two weeks worth of fixes here due to being on
  holidays last week.

  The main things are:

  - Core:
     * Syncobj fd reference count fix
     * Leasing ioctl misuse fix

   - nouveau regression fixes

   - further amdgpu DC fixes

   - sun4i regression fixes

  I'm not sure I'll see many fixes over next couple of weeks, we'll see
  how we go"

* tag 'drm-fixes-for-v4.15-rc5' of git://people.freedesktop.org/~airlied/linux: (27 commits)
  drm/syncobj: Stop reusing the same struct file for all syncobj -> fd
  drm: move lease init after validation in drm_lease_create
  drm/plane: Make framebuffer refcounting the responsibility of setplane_internal callers
  drm/sun4i: hdmi: Move the mode_valid callback to the encoder
  drm/nouveau: fix obvious memory leak
  drm/i915: Protect DDI port to DPLL map from theoretical race.
  drm/i915/lpe: Remove double-encapsulation of info string
  drm/sun4i: Fix error path handling
  drm/nouveau: use alternate memory type for system-memory buffers with kind != 0
  drm/nouveau: avoid GPU page sizes > PAGE_SIZE for buffer objects in host memory
  drm/nouveau/mmu/gp10b: use correct implementation
  drm/nouveau/pci: do a msi rearm on init
  drm/nouveau/imem/nv50: fix refcount_t warning
  drm/nouveau/bios/dp: support DP Info Table 2.0
  drm/nouveau/fbcon: fix NULL pointer access in nouveau_fbcon_destroy
  drm/amd/display: Fix rehook MST display not light back on
  drm/amd/display: fix missing pixel clock adjustment for dongle
  drm/amd/display: set chroma taps to 1 when not scaling
  drm/amd/display: add pipe locking before front end programing
  drm/sun4i: validate modes for HDMI
  ...

Merge tag 'clk-fixes-for-linus' of git://git./linux/kernel/git/clk/linux

Pull clk fixes from Stephen Boyd:
"Here's a trio of fixes:

   - The runtime PM clk patches that landed this merge window forgot to
     runtime resume devices that may be off while recalculating and
     setting rates of child clks of whatever clk is changing rates.

   - We had a NULL pointer deref in an old clk tracepoint when
     clk_set_parent() is called with a NULL parent pointer. This
     shouldn't really happen, but it's best to avoid this regardless.

   - The sun9i-mmc clk driver didn't provide 'reset' support, just
     'assert' and 'deassert' so the MMC driver stopped probing when the
     probe was changed to do a reset instead of assert/deassert pair.
     This implements the reset so things work again"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sunxi: sun9i-mmc: Implement reset callback for reset controls
  clk: fix a panic error caused by accessing NULL pointer
  clk: Manage proper runtime PM state in clk_change_rate()

init: Invoke init_espfix_bsp() from mm_init()

init_espfix_bsp() needs to be invoked before the page table isolation
initialization. Move it into mm_init() which is the place where pti_init()
will be added.

While at it get rid of the #ifdeffery and provide proper stub functions.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/cpu_entry_area: Move it out of the fixmap

Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big
and 0-day already hit a case where the fixmap PTEs were cleared by
cleanup_highmap().

Aside of that the fixmap API is a pain as it's all backwards.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/cpu_entry_area: Move it to a separate unit

Separate the cpu_entry_area code out of cpu/common.c and the fixmap.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Create asm/invpcid.h

Unclutter tlbflush.h a little.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Put MMU to hardware ASID translation in one place

There are effectively two ASID types:

1. The one stored in the mmu_context that goes from 0..5
2. The one programmed into the hardware that goes from 1..6

This consolidates the locations where converting between the two (by doing
a +1) to a single place which gives us a nice place to comment.
PAGE_TABLE_ISOLATION will also need to, given an ASID, know which hardware
ASID to flush for the userspace mapping.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Remove hard-coded ASID limit checks

First, it's nice to remove the magic numbers.

Second, PAGE_TABLE_ISOLATION is going to consume half of the available ASID
space. The space is currently unused, but add a comment to spell out this
new restriction.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Move the CR3 construction functions to tlbflush.h

For flushing the TLB, the ASID which has been programmed into the hardware
must be known. That differs from what is in 'cpu_tlbstate'.

Add functions to transform the 'cpu_tlbstate' values into to the one
programmed into the hardware (CR3).

It's not easy to include mmu_context.h into tlbflush.h, so just move the
CR3 building over to tlbflush.h.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Add comments to clarify which TLB-flush functions are supposed to flush what

Per popular request..

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Remove superfluous barriers

atomic64_inc_return() already implies smp_mb() before and after.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm: Use __flush_tlb_one() for kernel memory

__flush_tlb_single() is for user mappings, __flush_tlb_one() for
kernel mappings.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/microcode: Dont abuse the TLB-flush interface

Commit:

ec400ddeff20 ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU")

... grubbed into tlbflush internals without coherent explanation.

Since it says its a precaution and the SDM doesn't mention anything like
this, take it out back.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: fenghua.yu@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/uv: Use the right TLB-flush API

Since uv_flush_tlb_others() implements flush_tlb_others() which is
about flushing user mappings, we should use __flush_tlb_single(),
which too is about flushing user mappings.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andrew Banman <abanman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack

If the kernel oopses while on the trampoline stack, it will print
"<SYSENTER>" even if SYSENTER is not involved. That is rather confusing.

The "SYSENTER" stack is used for a lot more than SYSENTER now. Give it a
better string to display in stack dumps, and rename the kernel code to
match.

Also move the 32-bit code over to the new naming even though it still uses
the entry stack only for SYSENTER.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/doc: Remove obvious weirdnesses from the x86 MM layout documentation

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/64: Improve the memory map documentation

The old docs had the vsyscall range wrong and were missing the fixmap.
Fix both.

There used to be 8 MB reserved for future vsyscalls, but that's long gone.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/ldt: Prevent LDT inheritance on exec

The LDT is inherited across fork() or exec(), but that makes no sense
at all because exec() is supposed to start the process clean.

The reason why this happens is that init_new_context_ldt() is called from
init_new_context() which obviously needs to be called for both fork() and
exec().

It would be surprising if anything relies on that behaviour, so it seems to
be safe to remove that misfeature.

Split the context initialization into two parts. Clear the LDT pointer and
initialize the mutex from the general context init and move the LDT
duplication to arch_dup_mmap() which is only called on fork().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/ldt: Rework locking

The LDT is duplicated on fork() and on exec(), which is wrong as exec()
should start from a clean state, i.e. without LDT. To fix this the LDT
duplication code will be moved into arch_dup_mmap() which is only called
for fork().

This introduces a locking problem. arch_dup_mmap() holds mmap_sem of the
parent process, but the LDT duplication code needs to acquire
mm->context.lock to access the LDT data safely, which is the reverse lock
order of write_ldt() where mmap_sem nests into context.lock.

Solve this by introducing a new rw semaphore which serializes the
read/write_ldt() syscall operations and use context.lock to protect the
actual installment of the LDT descriptor.

So context.lock stabilizes mm->context.ldt and can nest inside of the new
semaphore or mmap_sem.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch, mm: Allow arch_dup_mmap() to fail

In order to sanitize the LDT initialization on x86 arch_dup_mmap() must be
allowed to fail. Fix up all instances.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: dan.j.williams@intel.com
Cc: hughd@google.com
Cc: keescook@google.com
Cc: kirill.shutemov@linux.intel.com
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/vsyscall/64: Warn and fail vsyscall emulation in NATIVE mode

If something goes wrong with pagetable setup, vsyscall=native will
accidentally fall back to emulation. Make it warn and fail so that we
notice.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/vsyscall/64: Explicitly set _PAGE_USER in the pagetable hierarchy

The kernel is very erratic as to which pagetables have _PAGE_USER set.  The
vsyscall page gets lucky: it seems that all of the relevant pagetables are
among the apparently arbitrary ones that set _PAGE_USER.  Rather than
relying on chance, just explicitly set _PAGE_USER.

This will let us clean up pagetable setup to stop setting _PAGE_USER.  The
added code can also be reused by pagetable isolation to manage the
_PAGE_USER bit in the usermode tables.

[ tglx: Folded paravirt fix from Juergen Gross ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/dump_pagetables: Make the address hints correct and readable

The address hints are a trainwreck. The array entry numbers have to kept
magically in sync with the actual hints, which is doomed as some of the
array members are initialized at runtime via the entry numbers.

Designated initializers have been around before this code was
implemented....

Use the entry numbers to populate the address hints array and add the
missing bits and pieces. Split 32 and 64 bit for readability sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/mm/dump_pagetables: Check PAGE_PRESENT for real

The check for a present page in printk_prot():

if (!pgprot_val(prot)) {
/* Not present */

is bogus. If a PTE is set to PAGE_NONE then the pgprot_val is not zero and
the entry is decoded in bogus ways, e.g. as RX GLB. That is confusing when
analyzing mapping correctness. Check for the present bit to make an
informed decision.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

x86/Kconfig: Limit NR_CPUS on 32-bit to a sane amount

The recent cpu_entry_area changes fail to compile on 32-bit when BIGSMP=y
and NR_CPUS=512, because the fixmap area becomes too big.

Limit the number of CPUs with BIGSMP to 64, which is already way to big for
32-bit, but it's at least a working limitation.

We performed a quick survey of 32-bit-only machines that might be affected
by this change negatively, but found none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

IB/hfi: Only read capability registers if the capability exists

During driver init, various registers are saved to allow restoration
after an FLR or gen3 bump. Some of these registers are not available
in some circumstances (i.e. Virtual machines).

This bug makes the driver unusable when the PCI device is passed into
a VM, it fails during probe.

Delete unnecessary register read/write, and only access register if
the capability exists.

Cc: <stable@vger.kernel.org> # 4.14.x
Fixes: a618b7e40af2 ("IB/hfi1: Move saving PCI values to a separate function")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

gpio: fix "gpio-line-names" property retrieval

Following commit 9427ecbed46cc ("gpio: Rework of_gpiochip_set_names()
to use device property accessors"), "gpio-line-names" DT property is
not retrieved anymore when chip->parent is not set by the driver.
This is due to OF based property reads having been replaced by device
based property reads.

This patch fixes that by making use of
fwnode_property_read_string_array() instead of
device_property_read_string_array() and handing over either
of_fwnode_handle(chip->of_node) or dev_fwnode(chip->parent)
to that function.

Fixes: 9427ecbed46cc ("gpio: Rework of_gpiochip_set_names() to use device property accessors")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

gpio: gpio-reg: fix build

Revert changes introduced by commit f0fbe7bce733 ("gpio: Move irqdomain
into struct gpio_irq_chip") as they are not aplicable to this driver.

Reported-by: Russell King - ARM Linux <linux@armlinux.org.uk>
Fixes: f0fbe7bce733 ("gpio: Move irqdomain into struct gpio_irq_chip")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

ALSA: hda: Drop useless WARN_ON()

Since the commit 97cc2ed27e5a ("ALSA: hda - Fix yet another i915
pointer leftover in error path") cleared hdac_acomp pointer, the
WARN_ON() non-NULL check in snd_hdac_i915_register_notifier() may give
a false-positive warning, as the function gets called no matter
whether the component is registered or not. For fixing it, let's get
rid of the spurious WARN_ON().

Fixes: 97cc2ed27e5a ("ALSA: hda - Fix yet another i915 pointer leftover in error path")
Cc: <stable@vger.kernel.org>
Reported-by: Kouta Okamoto <kouta.okamoto@toshiba.co.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>