commit 7b69154171b407844c273ab4c10b5f0ddcd6aa29 upstream.

Some spurious calls of snd_free_pages() have been overlooked and
remain in the error paths of wss driver code.  Since runtime->dma_area
is managed by the PCM core helper, we shouldn't release manually.

Drop the superfluous calls.
Reviewed-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 41e817bca3acd3980efe5dd7d28af0e6f4ab9247 upstream.

commit e2592217 ("fs: simplify the
generic_write_sync prototype") reworked callers of generic_write_sync(),
and ended up dropping the error return for the directio path. Prior to
that commit, in dio_complete(), an error would be bubbled up the stack,
but after that commit, errors passed on to dio_complete were eaten up.

This was reported on the list earlier, and a fix was proposed in
https://lore.kernel.org/lkml/20160921141539.GA17898@infradead.org/, but
never followed up with.  We recently hit this bug in our testing where
fencing io errors, which were previously erroring out with EIO, were
being returned as success operations after this commit.

The fix proposed on the list earlier was a little short -- it would have
still called generic_write_sync() in case `ret` already contained an
error. This fix ensures generic_write_sync() is only called when there's
no pending error in the write. Additionally, transferred is replaced
with ret to bring this code in line with other callers.

Fixes: e2592217 ("fs: simplify the generic_write_sync prototype")
Reported-by: NRavi Nankani <rnankani@amazon.com>
Signed-off-by: NMaximilian Heyne <mheyne@amazon.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
CC: Torsten Mehlan <tomeh@amazon.de>
CC: Uwe Dannowski <uwed@amazon.de>
CC: Amit Shah <aams@amazon.de>
CC: David Woodhouse <dwmw@amazon.co.uk>
CC: stable@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 472de49fdc53365c880ab81ae2b5cfdd83db0b06 upstream.

Vince reported a crash in the BTS flush code when touching the callchain
data, which was supposed to be initialized as an 'early' callchain,
but intel_pmu_drain_bts_buffer() does not do that:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
  ...
  Call Trace:
   <IRQ>
   intel_pmu_drain_bts_buffer+0x151/0x220
   ? intel_get_event_constraints+0x219/0x360
   ? perf_assign_events+0xe2/0x2a0
   ? select_idle_sibling+0x22/0x3a0
   ? __update_load_avg_se+0x1ec/0x270
   ? enqueue_task_fair+0x377/0xdd0
   ? cpumask_next_and+0x19/0x20
   ? load_balance+0x134/0x950
   ? check_preempt_curr+0x7a/0x90
   ? ttwu_do_wakeup+0x19/0x140
   x86_pmu_stop+0x3b/0x90
   x86_pmu_del+0x57/0x160
   event_sched_out.isra.106+0x81/0x170
   group_sched_out.part.108+0x51/0xc0
   __perf_event_disable+0x7f/0x160
   event_function+0x8c/0xd0
   remote_function+0x3c/0x50
   flush_smp_call_function_queue+0x35/0xe0
   smp_call_function_single_interrupt+0x3a/0xd0
   call_function_single_interrupt+0xf/0x20
   </IRQ>

It was triggered by fuzzer but can be easily reproduced by:

  # perf record -e cpu/branch-instructions/pu -g -c 1

Peter suggested not to allow branch tracing for precise events:

 > Now arguably, this is really stupid behaviour. Who in his right mind
 > wants callchain output on BTS entries. And even if they do, BTS +
 > precise_ip is nonsensical.
 >
 > So in my mind disallowing precise_ip on BTS would be the simplest fix.
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Reported-by: NVince Weaver <vincent.weaver@maine.edu>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6cbc304f ("perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)")
Link: http://lkml.kernel.org/r/20181121101612.16272-3-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 67266c1080ad56c31af72b9c18355fde8ccc124a upstream.

Currently we check the branch tracing only by checking for the
PERF_COUNT_HW_BRANCH_INSTRUCTIONS event of PERF_TYPE_HARDWARE
type. But we can define the same event with the PERF_TYPE_RAW
type.

Changing the intel_pmu_has_bts() code to check on event's final
hw config value, so both HW types are covered.

Adding unlikely to intel_pmu_has_bts() condition calls, because
it was used in the original code in intel_bts_constraints.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20181121101612.16272-2-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ed6101bbf6266ee83e620b19faa7c6ad56bb41ab upstream.

Moving branch tracing setup to Intel core object into separate
intel_pmu_bts_config function, because it's Intel specific.
Suggested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20181121101612.16272-1-jolsa@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 68239654acafe6aad5a3c1dc7237e60accfebc03 upstream.

The sequence

  fpu->initialized = 1;		/* step A */
  preempt_disable();		/* step B */
  fpu__restore(fpu);
  preempt_enable();

in __fpu__restore_sig() is racy in regard to a context switch.

For 32bit frames, __fpu__restore_sig() prepares the FPU state within
fpu->state. To ensure that a context switch (switch_fpu_prepare() in
particular) does not modify fpu->state it uses fpu__drop() which sets
fpu->initialized to 0.

After fpu->initialized is cleared, the CPU's FPU state is not saved
to fpu->state during a context switch. The new state is loaded via
fpu__restore(). It gets loaded into fpu->state from userland and
ensured it is sane. fpu->initialized is then set to 1 in order to avoid
fpu__initialize() doing anything (overwrite the new state) which is part
of fpu__restore().

A context switch between step A and B above would save CPU's current FPU
registers to fpu->state and overwrite the newly prepared state. This
looks like a tiny race window but the Kernel Test Robot reported this
back in 2016 while we had lazy FPU support. Borislav Petkov made the
link between that report and another patch that has been posted. Since
the removal of the lazy FPU support, this race goes unnoticed because
the warning has been removed.

Disable bottom halves around the restore sequence to avoid the race. BH
need to be disabled because BH is allowed to run (even with preemption
disabled) and might invoke kernel_fpu_begin() by doing IPsec.

 [ bp: massage commit message a bit. ]
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NIngo Molnar <mingo@kernel.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: stable@vger.kernel.org
Cc: x86-ml <x86@kernel.org>
Link: http://lkml.kernel.org/r/20181120102635.ddv3fvavxajjlfqk@linutronix.de
Link: https://lkml.kernel.org/r/20160226074940.GA28911@pd.tnicSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 60c8144afc287ef09ce8c1230c6aa972659ba1bb upstream.

Currently, the code sets up the thresholding interrupt vector and only
then goes about initializing the thresholding banks. Which is wrong,
because an early thresholding interrupt would cause a NULL pointer
dereference when accessing those banks and prevent the machine from
booting.

Therefore, set the thresholding interrupt vector only *after* having
initialized the banks successfully.

Fixes: 18807ddb ("x86/mce/AMD: Reset Threshold Limit after logging error")
Reported-by: NRafał Miłecki <rafal@milecki.pl>
Reported-by: NJohn Clemens <clemej@gmail.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NRafał Miłecki <rafal@milecki.pl>
Tested-by: NJohn Clemens <john@deater.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: linux-edac@vger.kernel.org
Cc: stable@vger.kernel.org
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86@kernel.org
Cc: Yazen Ghannam <Yazen.Ghannam@amd.com>
Link: https://lkml.kernel.org/r/20181127101700.2964-1-zajec5@gmail.com
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201291Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c1d91f86a1b4c9c05854d59c6a0abd5d0f75b849 upstream.

This patch fixes the wrong polarity setting for the PCIe host driver's
pre-reset pin for rk3399-puma-haikou. Without this patch link training
will most likely fail.

Fixes: 60fd9f72 ("arm64: dts: rockchip: add Haikou baseboard with RK3399-Q7 SoM")
Cc: stable@vger.kernel.org
Signed-off-by: NChristoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f1f90e254e46e0a14220e4090041f68256fbe297 upstream.

The macros PCI_EXP_LNKCAP_SLS_*GB are values, not bit masks.  We must mask
the register and compare it against them.

This fixes errors like this:

  amdgpu: [powerplay] failed to send message 261 ret is 0

when a PCIe-v3 card is plugged into a PCIe-v1 slot, because the slot is
being incorrectly reported as PCIe-v3 capable.

6cf57be0, which appeared in v4.17, added pcie_get_speed_cap() with the
incorrect test of PCI_EXP_LNKCAP_SLS as a bitmask.  5d9a6330, which
appeared in v4.19, changed amdgpu to use pcie_get_speed_cap(), so the
amdgpu bug reports below are regressions in v4.19.

Fixes: 6cf57be0 ("PCI: Add pcie_get_speed_cap() to find max supported link speed")
Fixes: 5d9a6330 ("drm/amdgpu: use pcie functions for link width and speed")
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108704
Link: https://bugs.freedesktop.org/show_bug.cgi?id=108778Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
[bhelgaas: update comment, remove use of PCI_EXP_LNKCAP_SLS_8_0GB and
PCI_EXP_LNKCAP_SLS_16_0GB since those should be covered by PCI_EXP_LNKCAP2,
remove test of PCI_EXP_LNKCAP for zero, since that register is required]
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org	# v4.17+
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 15cb127e3c8f6232096d5dba6a5b4046bc292d70 upstream.

Fix an error caused by 3-bit right rotation on offset address
calculation of MSI-X table in dw_pcie_ep_raise_msix_irq().

The initial testing code was setting by default the offset address of
MSI-X table to zero, so that even with a 3-bit right rotation the
computed result would still be zero and valid, therefore this bug went
unnoticed.

Fixes: beb4641a ("PCI: dwc: Add MSI-X callbacks handler")
Signed-off-by: NGustavo Pimentel <gustavo.pimentel@synopsys.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c6fd6fe9dea44732cdcd970f1130b8cc50ad685a upstream.

The order of parameters is not correct when invoking the outbound
window disable routine. Fix it.

Fixes: 4a2745d7 ("PCI: layerscape: Disable outbound windows configured by bootloader")
Signed-off-by: NHou Zhiqiang <Zhiqiang.Hou@nxp.com>
[lorenzo.pieralisi@arm.com: commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 42a657f57628402c73237547f0134e083e2f6764 upstream.

The function relocate_block_group calls btrfs_end_transaction to release
trans when update_backref_cache returns 1, and then continues the loop
body. If btrfs_block_rsv_refill fails this time, it will jump out the
loop and the freed trans will be accessed. This may result in a
use-after-free bug. The patch assigns NULL to trans after trans is
released so that it will not be accessed.

Fixes: 0647bf56 ("Btrfs: improve forever loop when doing balance relocation")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NPan Bian <bianpan2016@163.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 552f0329c75b3e1d7f9bb8c9e421d37403f192cd upstream.

We have a race between enabling quotas end subvolume creation that cause
subvolume creation to fail with -EINVAL, and the following diagram shows
how it happens:

              CPU 0                                          CPU 1

 btrfs_ioctl()
  btrfs_ioctl_quota_ctl()
   btrfs_quota_enable()
    mutex_lock(fs_info->qgroup_ioctl_lock)

                                                  btrfs_ioctl()
                                                   create_subvol()
                                                    btrfs_qgroup_inherit()
                                                     -> save fs_info->quota_root
                                                        into quota_root
                                                     -> stores a NULL value
                                                     -> tries to lock the mutex
                                                        qgroup_ioctl_lock
                                                        -> blocks waiting for
                                                           the task at CPU0

   -> sets BTRFS_FS_QUOTA_ENABLED in fs_info
   -> sets quota_root in fs_info->quota_root
      (non-NULL value)

   mutex_unlock(fs_info->qgroup_ioctl_lock)

                                                     -> checks quota enabled
                                                        flag is set
                                                     -> returns -EINVAL because
                                                        fs_info->quota_root was
                                                        NULL before it acquired
                                                        the mutex
                                                        qgroup_ioctl_lock
                                                   -> ioctl returns -EINVAL

Returning -EINVAL to user space will be confusing if all the arguments
passed to the subvolume creation ioctl were valid.

Fix it by grabbing the value from fs_info->quota_root after acquiring
the mutex.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit aab15e8ec25765cf7968c72cbec7583acf99d8a4 upstream.

After the simplification of the fast fsync patch done recently by commit
b5e6c3e1 ("btrfs: always wait on ordered extents at fsync time") and
commit e7175a69 ("btrfs: remove the wait ordered logic in the
log_one_extent path"), we got a very short time window where we can get
extents logged without writeback completing first or extents logged
without logging the respective data checksums. Both issues can only happen
when doing a non-full (fast) fsync.

As soon as we enter btrfs_sync_file() we trigger writeback, then lock the
inode and then wait for the writeback to complete before starting to log
the inode. However before we acquire the inode's lock and after we started
writeback, it's possible that more writes happened and dirtied more pages.
If that happened and those pages get writeback triggered while we are
logging the inode (for example, the VM subsystem triggering it due to
memory pressure, or another concurrent fsync), we end up seeing the
respective extent maps in the inode's list of modified extents and will
log matching file extent items without waiting for the respective
ordered extents to complete, meaning that either of the following will
happen:

1) We log an extent after its writeback finishes but before its checksums
   are added to the csum tree, leading to -EIO errors when attempting to
   read the extent after a log replay.

2) We log an extent before its writeback finishes.
   Therefore after the log replay we will have a file extent item pointing
   to an unwritten extent (and without the respective data checksums as
   well).

This could not happen before the fast fsync patch simplification, because
for any extent we found in the list of modified extents, we would wait for
its respective ordered extent to finish writeback or collect its checksums
for logging if it did not complete yet.

Fix this by triggering writeback again after acquiring the inode's lock
and before waiting for ordered extents to complete.

Fixes: e7175a69 ("btrfs: remove the wait ordered logic in the log_one_extent path")
Fixes: b5e6c3e1 ("btrfs: always wait on ordered extents at fsync time")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f505754fd6599230371cb01b9332754ddc104be1 upstream.

We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel.  The ioctl is protected by CAP_SYS_ADMIN.

So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit f8397d69daef06d358430d3054662fb597e37c00 upstream.

When a metadata read is served the endio routine btree_readpage_end_io_hook
is called which eventually runs the tree-checker. If tree-checker fails
to validate the read eb then it sets EXTENT_BUFFER_CORRUPT flag. This
leads to btree_read_extent_buffer_pages wrongly assuming that all
available copies of this extent buffer are wrong and failing prematurely.
Fix this modify btree_read_extent_buffer_pages to read all copies of
the data.

This failure was exhibitted in xfstests btrfs/124 which would
spuriously fail its balance operations. The reason was that when balance
was run following re-introduction of the missing raid1 disk
__btrfs_map_block would map the read request to stripe 0, which
corresponded to devid 2 (the disk which is being removed in the test):

    item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 3553624064) itemoff 15975 itemsize 112
	length 1073741824 owner 2 stripe_len 65536 type DATA|RAID1
	io_align 65536 io_width 65536 sector_size 4096
	num_stripes 2 sub_stripes 1
		stripe 0 devid 2 offset 2156920832
		dev_uuid 8466c350-ed0c-4c3b-b17d-6379b445d5c8
		stripe 1 devid 1 offset 3553624064
		dev_uuid 1265d8db-5596-477e-af03-df08eb38d2ca

This caused read requests for a checksum item that to be routed to the
stale disk which triggered the aforementioned logic involving
EXTENT_BUFFER_CORRUPT flag. This then triggered cascading failures of
the balance operation.

Fixes: a826d6dc ("Btrfs: check items for correctness as we search")
CC: stable@vger.kernel.org # 4.4+
Suggested-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit b54e41f5efcb4316b2f30b30c2535cc194270373 upstream.

Commit c26f6c61 ("udf: Fix conversion of 'dstring' fields to UTF8")
started to be more strict when checking whether converted strings are
properly formatted. Sudip reports that there are DVDs where the volume
identification string is actually too long - UDF reports:

[  632.309320] UDF-fs: incorrect dstring lengths (32/32)

during mount and fails the mount. This is mostly harmless failure as we
don't need volume identification (and even less volume set
identification) for anything. So just truncate the volume identification
string if it is too long and replace it with 'Invalid' if we just cannot
convert it for other reasons. This keeps slightly incorrect media still
mountable.

CC: stable@vger.kernel.org
Fixes: c26f6c61 ("udf: Fix conversion of 'dstring' fields to UTF8")
Reported-and-tested-by: NSudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 38a35a78c5e270cbe53c4fef6b0d3c2da90dd849 upstream.

Layout of coprocessor registers in the elf_xtregs_t and
xtregs_coprocessor_t may be different due to alignment. Thus it is not
always possible to copy data between the xtregs_coprocessor_t structure
and the elf_xtregs_t and get correct values for all registers.
Use a table of offsets and sizes of individual coprocessor register
groups to do coprocessor context copying in the ptrace_getxregs and
ptrace_setxregs.
This fixes incorrect coprocessor register values reading from the user
process by the native gdb on an xtensa core with multiple coprocessors
and registers with high alignment requirements.

Cc: stable@vger.kernel.org
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 03bc996af0cc71c7f30c384d8ce7260172423b34 upstream.

Coprocessor context offsets are used by the assembly code that moves
coprocessor context between the individual fields of the
thread_info::xtregs_cp structure and coprocessor registers.
This fixes coprocessor context clobbering on flushing and reloading
during normal user code execution and user process debugging in the
presence of more than one coprocessor in the core configuration.

Cc: stable@vger.kernel.org
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 2958b66694e018c552be0b60521fec27e8d12988 upstream.

coprocessor_flush_all may be called from a context of a thread that is
different from the thread being flushed. In that case contents of the
cpenable special register may not match ti->cpenable of the target
thread, resulting in unhandled coprocessor exception in the kernel
context.
Set cpenable special register to the ti->cpenable of the target register
for the duration of the flush and restore it afterwards.
This fixes the following crash caused by coprocessor register inspection
in native gdb:

  (gdb) p/x $w0
  Illegal instruction in kernel: sig: 9 [#1] PREEMPT
  Call Trace:
    ___might_sleep+0x184/0x1a4
    __might_sleep+0x41/0xac
    exit_signals+0x14/0x218
    do_exit+0xc9/0x8b8
    die+0x99/0xa0
    do_illegal_instruction+0x18/0x6c
    common_exception+0x77/0x77
    coprocessor_flush+0x16/0x3c
    arch_ptrace+0x46c/0x674
    sys_ptrace+0x2ce/0x3b4
    system_call+0x54/0x80
    common_exception+0x77/0x77
  note: gdb[100] exited with preempt_count 1
  Killed

Cc: stable@vger.kernel.org
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit a87c99e6 upstream.

Apparently, the ple_gap parameter was accidentally removed
by commit c8e88717. Add it
back.
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Cc: stable@vger.kernel.org
Fixes: c8e88717Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e97f852fd4561e77721bb9a4e0ea9d98305b1e93 upstream.

Reported by syzkaller:

 BUG: unable to handle kernel NULL pointer dereference at 00000000000001c8
 PGD 80000003ec4da067 P4D 80000003ec4da067 PUD 3f7bfa067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 7 PID: 5059 Comm: debug Tainted: G           OE     4.19.0-rc5 #16
 RIP: 0010:__lock_acquire+0x1a6/0x1990
 Call Trace:
  lock_acquire+0xdb/0x210
  _raw_spin_lock+0x38/0x70
  kvm_ioapic_scan_entry+0x3e/0x110 [kvm]
  vcpu_enter_guest+0x167e/0x1910 [kvm]
  kvm_arch_vcpu_ioctl_run+0x35c/0x610 [kvm]
  kvm_vcpu_ioctl+0x3e9/0x6d0 [kvm]
  do_vfs_ioctl+0xa5/0x690
  ksys_ioctl+0x6d/0x80
  __x64_sys_ioctl+0x1a/0x20
  do_syscall_64+0x83/0x6e0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The reason is that the testcase writes hyperv synic HV_X64_MSR_SINT6 msr
and triggers scan ioapic logic to load synic vectors into EOI exit bitmap.
However, irqchip is not initialized by this simple testcase, ioapic/apic
objects should not be accessed.
This can be triggered by the following program:

    #define _GNU_SOURCE

    #include <endian.h>
    #include <stdint.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <sys/syscall.h>
    #include <sys/types.h>
    #include <unistd.h>

    uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

    int main(void)
    {
    	syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
    	long res = 0;
    	memcpy((void*)0x20000040, "/dev/kvm", 9);
    	res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000040, 0, 0);
    	if (res != -1)
    		r[0] = res;
    	res = syscall(__NR_ioctl, r[0], 0xae01, 0);
    	if (res != -1)
    		r[1] = res;
    	res = syscall(__NR_ioctl, r[1], 0xae41, 0);
    	if (res != -1)
    		r[2] = res;
    	memcpy(
    			(void*)0x20000080,
    			"\x01\x00\x00\x00\x00\x5b\x61\xbb\x96\x00\x00\x40\x00\x00\x00\x00\x01\x00"
    			"\x08\x00\x00\x00\x00\x00\x0b\x77\xd1\x78\x4d\xd8\x3a\xed\xb1\x5c\x2e\x43"
    			"\xaa\x43\x39\xd6\xff\xf5\xf0\xa8\x98\xf2\x3e\x37\x29\x89\xde\x88\xc6\x33"
    			"\xfc\x2a\xdb\xb7\xe1\x4c\xac\x28\x61\x7b\x9c\xa9\xbc\x0d\xa0\x63\xfe\xfe"
    			"\xe8\x75\xde\xdd\x19\x38\xdc\x34\xf5\xec\x05\xfd\xeb\x5d\xed\x2e\xaf\x22"
    			"\xfa\xab\xb7\xe4\x42\x67\xd0\xaf\x06\x1c\x6a\x35\x67\x10\x55\xcb",
    			106);
    	syscall(__NR_ioctl, r[2], 0x4008ae89, 0x20000080);
    	syscall(__NR_ioctl, r[2], 0xae80, 0);
    	return 0;
    }

This patch fixes it by bailing out scan ioapic if ioapic is not initialized in
kernel.
Reported-by: NWei Wu <ww9210@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wei Wu <ww9210@gmail.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 38ab012f109caf10f471db1adf284e620dd8d701 upstream.

Reported by syzkaller:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000014
 PGD 800000040410c067 P4D 800000040410c067 PUD 40410d067 PMD 0
 Oops: 0000 [#1] PREEMPT SMP PTI
 CPU: 3 PID: 2567 Comm: poc Tainted: G           OE     4.19.0-rc5 #16
 RIP: 0010:kvm_pv_send_ipi+0x94/0x350 [kvm]
 Call Trace:
  kvm_emulate_hypercall+0x3cc/0x700 [kvm]
  handle_vmcall+0xe/0x10 [kvm_intel]
  vmx_handle_exit+0xc1/0x11b0 [kvm_intel]
  vcpu_enter_guest+0x9fb/0x1910 [kvm]
  kvm_arch_vcpu_ioctl_run+0x35c/0x610 [kvm]
  kvm_vcpu_ioctl+0x3e9/0x6d0 [kvm]
  do_vfs_ioctl+0xa5/0x690
  ksys_ioctl+0x6d/0x80
  __x64_sys_ioctl+0x1a/0x20
  do_syscall_64+0x83/0x6e0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

The reason is that the apic map has not yet been initialized, the testcase
triggers pv_send_ipi interface by vmcall which results in kvm->arch.apic_map
is dereferenced. This patch fixes it by checking whether or not apic map is
NULL and bailing out immediately if that is the case.

Fixes: 4180bf1b (KVM: X86: Implement "send IPI" hypercall)
Reported-by: NWei Wu <ww9210@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Wei Wu <ww9210@gmail.com>
Signed-off-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit bcbfbd8e upstream.

kvm_pv_clock_pairing() allocates local var
"struct kvm_clock_pairing clock_pairing" on stack and initializes
all it's fields besides padding (clock_pairing.pad[]).

Because clock_pairing var is written completely (including padding)
to guest memory, failure to init struct padding results in kernel
info-leak.

Fix the issue by making sure to also init the padding with zeroes.

Fixes: 55dd00a7 ("KVM: x86: add KVM_HC_CLOCK_PAIRING hypercall")
Reported-by: syzbot+a8ef68d71211ba264f56@syzkaller.appspotmail.com
Reviewed-by: NMark Kanda <mark.kanda@oracle.com>
Signed-off-by: NLiran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 326e7425 upstream.

Since commit e79f245d ("X86/KVM: Properly update 'tsc_offset' to
represent the running guest"), vcpu->arch.tsc_offset meaning was
changed to always reflect the tsc_offset value set on active VMCS.
Regardless if vCPU is currently running L1 or L2.

However, above mentioned commit failed to also change
kvm_vcpu_write_tsc_offset() to set vcpu->arch.tsc_offset correctly.
This is because vmx_write_tsc_offset() could set the tsc_offset value
in active VMCS to given offset parameter *plus vmcs12->tsc_offset*.
However, kvm_vcpu_write_tsc_offset() just sets vcpu->arch.tsc_offset
to given offset parameter. Without taking into account the possible
addition of vmcs12->tsc_offset. (Same is true for SVM case).

Fix this issue by changing kvm_x86_ops->write_tsc_offset() to return
actually set tsc_offset in active VMCS and modify
kvm_vcpu_write_tsc_offset() to set returned value in
vcpu->arch.tsc_offset.
In addition, rename write_tsc_offset() callback to write_l1_tsc_offset()
to make it clear that it is meant to set L1 TSC offset.

Fixes: e79f245d ("X86/KVM: Properly update 'tsc_offset' to represent the running guest")
Reviewed-by: NLiran Alon <liran.alon@oracle.com>
Reviewed-by: NMihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: NKrish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: NLeonid Shatz <leonid.shatz@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit fd65d314 upstream.

Previously, we only called indirect_branch_prediction_barrier on the
logical CPU that freed a vmcb. This function should be called on all
logical CPUs that last loaded the vmcb in question.

Fixes: 15d45071 ("KVM/x86: Add IBPB support")
Reported-by: NNeel Natu <neelnatu@google.com>
Signed-off-by: NJim Mattson <jmattson@google.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 0e0fee5c539b61fdd098332e0e2cc375d9073706 upstream.

When a guest page table is updated via an emulated write,
kvm_mmu_pte_write() is called to update the shadow PTE using the just
written guest PTE value. But if two emulated guest PTE writes happened
concurrently, it is possible that the guest PTE and the shadow PTE end
up being out of sync. Emulated writes do not mark the shadow page as
unsync-ed, so this inconsistency will not be resolved even by a guest TLB
flush (unless the page was marked as unsync-ed at some other point).

This is fixed by re-reading the current value of the guest PTE after the
MMU lock has been acquired instead of just using the value that was
written prior to calling kvm_mmu_pte_write().
Signed-off-by: NJunaid Shahid <junaids@google.com>
Reviewed-by: NWanpeng Li <wanpengli@tencent.com>
Cc: stable@vger.kernel.org
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 29ec9066 upstream.

After the VMA to register the uffd onto is found, check that it has
VM_MAYWRITE set before allowing registration.  This way we inherit all
common code checks before allowing to fill file holes in shmem and
hugetlbfs with UFFDIO_COPY.

The userfaultfd memory model is not applicable for readonly files unless
it's a MAP_PRIVATE.

Link: http://lkml.kernel.org/r/20181126173452.26955-4-aarcange@redhat.com
Fixes: ff62a342 ("hugetlb: implement memfd sealing")
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Reviewed-by: NHugh Dickins <hughd@google.com>
Reported-by: NJann Horn <jannh@google.com>
Fixes: 4c27fe4c ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Cc: <stable@vger.kernel.org>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 55a974021ec952ee460dc31ca08722158639de72 upstream

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

Add the extra command line options and rework the IBPB selection to
evaluate the command instead of the mode selected by the STIPB switch case.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185006.144047038@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6b3e64c237c072797a9ec918654a60e3a46488e2 upstream

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

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

The Intel mitigation guide documents how STIPB works:
    
   Setting bit 1 (STIBP) of the IA32_SPEC_CTRL MSR on a logical processor
   prevents the predicted targets of indirect branches on any logical
   processor of that core from being controlled by software that executes
   (or executed previously) on another logical processor of the same core.

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

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

IBPB is issued when the task switches out, so malicious sandbox code cannot
mistrain the branch predictor for the next user space task on the same
logical processor.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185006.051663132@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 7cc765a67d8e04ef7d772425ca5a2a1e2b894c15 upstream

Now that all prerequisites are in place:

 - Add the prctl command line option

 - Default the 'auto' mode to 'prctl'

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

 - At init update the static key which controls the conditional IBPB
   evaluation on context switch.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.958421388@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 9137bb27e60e554dab694eafa4cca241fa3a694f upstream

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

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

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

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

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

See Documentation/userspace-api/spec_ctrl.rst.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.866780996@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6893a959d7fdebbab5f5aa112c277d5a44435ba1 upstream

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

Split out the code which controls the strict mode so the prctl control code
can be added later. Mark the SMP function call argument __unused while at it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.759457117@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 6d991ba509ebcfcc908e009d1db51972a4f7a064 upstream

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

This creates the following situation with Process A and B:

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

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

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

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

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

Add a new TIF_SPEC_FORCE_UPDATE bit and set this after updating the
atomic_flags. Check the bit on context switch and force a synchronous
update of the speculation control if set. Use the same mechanism for
updating the current task.
Reported-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1811272247140.1875@nanos.tec.linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit e6da8bb6f9abb2628381904b24163c770e630bac upstream

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

Split the code out and make it reusable. Reword the comment about updates
for other tasks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.652305076@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 46f7ecb1e7359f183f5bbd1e08b90e10e52164f9 upstream

The IBPB control code in x86 removed the usage. Remove the functionality
which was introduced for this.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.559149393@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 4c71a2b6fd7e42814aa68a6dec88abf3b42ea573 upstream

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

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

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

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

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

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

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

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

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

Move the storage to a different place in the struct as the original one
created a hole.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.466447057@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5635d999 upstream

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

 - CONFIG_SMP is disabled

 - The conditional STIPB mode is disabled

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

Optimize it out by masking the bit at compile time for CONFIG_SMP=n and at
run time when the static key controlling the conditional STIBP mode is
disabled.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.374062201@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit ff16701a upstream

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

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

This is a preparatory change so integration of conditional indirect branch
speculation optimization happens only in one place.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.280855518@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 5bfbe3ad upstream

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

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

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

[ tglx: Simplify the context switch logic and make the TIF evaluation
  	depend on SMP=y and on the static key controlling the conditional
  	update. Rename it to TIF_SPEC_IB because it controls both STIBP and
  	IBPB ]
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.176917199@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>