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commit 0362f326d86c645b5e96b7dbc3ee515986ed019d upstream.
An exiting task might belong to an offline cgroup. In this case an
attempt to grab a cgroup reference from the task can end up with an
infinite loop in hugetlb_cgroup_charge_cgroup(), because neither the
cgroup will become online, neither the task will be migrated to a live
cgroup.
Fix this by switching over to css_tryget(). As css_tryget_online()
can't guarantee that the cgroup won't go offline, in most cases the
check doesn't make sense. In this particular case users of
hugetlb_cgroup_charge_cgroup() are not affected by this change.
A similar problem is described by commit 18fa84a2db0e ("cgroup: Use
css_tryget() instead of css_tryget_online() in task_get_css()").
Link: http://lkml.kernel.org/r/20191106225131.3543616-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 00d484f354d85845991b40141d40ba9e5eb60faf upstream.
We've encountered a rcu stall in get_mem_cgroup_from_mm():
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 33-....: (21000 ticks this GP) idle=6c6/1/0x4000000000000002 softirq=35441/35441 fqs=5017
(t=21031 jiffies g=324821 q=95837) NMI backtrace for cpu 33
<...>
RIP: 0010:get_mem_cgroup_from_mm+0x2f/0x90
<...>
__memcg_kmem_charge+0x55/0x140
__alloc_pages_nodemask+0x267/0x320
pipe_write+0x1ad/0x400
new_sync_write+0x127/0x1c0
__kernel_write+0x4f/0xf0
dump_emit+0x91/0xc0
writenote+0xa0/0xc0
elf_core_dump+0x11af/0x1430
do_coredump+0xc65/0xee0
get_signal+0x132/0x7c0
do_signal+0x36/0x640
exit_to_usermode_loop+0x61/0xd0
do_syscall_64+0xd4/0x100
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The problem is caused by an exiting task which is associated with an
offline memcg. We're iterating over and over in the do {} while
(!css_tryget_online()) loop, but obviously the memcg won't become online
and the exiting task won't be migrated to a live memcg.
Let's fix it by switching from css_tryget_online() to css_tryget().
As css_tryget_online() cannot guarantee that the memcg won't go offline,
the check is usually useless, except some rare cases when for example it
determines if something should be presented to a user.
A similar problem is described by commit 18fa84a2db0e ("cgroup: Use
css_tryget() instead of css_tryget_online() in task_get_css()").
Johannes:
: The bug aside, it doesn't matter whether the cgroup is online for the
: callers. It used to matter when offlining needed to evacuate all charges
: from the memcg, and so needed to prevent new ones from showing up, but we
: don't care now.
Link: http://lkml.kernel.org/r/20191106225131.3543616-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Shakeel Butt <shakeeb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4e7120d79edb31e4ee68e6f8421448e4603be1e9 upstream.
For both PASID-based-Device-TLB Invalidate Descriptor and
Device-TLB Invalidate Descriptor, the Physical Function Source-ID
value is split according to this layout:
PFSID[3:0] is set at offset 12 and PFSID[15:4] is put at offset 52.
Fix the part laid out at offset 52.
Fixes: 0f725561e1684 ("iommu/vt-d: Add definitions for PFSID")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: stable@vger.kernel.org # v4.19+
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 762c69685ff7ad5ad7fee0656671e20a0c9c864d upstream.
We need to get the underlying dentry of parent; sure, absent the races
it is the parent of underlying dentry, but there's nothing to prevent
losing a timeslice to preemtion in the middle of evaluation of
lower_dentry->d_parent->d_inode, having another process move lower_dentry
around and have its (ex)parent not pinned anymore and freed on memory
pressure. Then we regain CPU and try to fetch ->d_inode from memory
that is freed by that point.
dentry->d_parent *is* stable here - it's an argument of ->lookup() and
we are guaranteed that it won't be moved anywhere until we feed it
to d_add/d_splice_alias. So we safely go that way to get to its
underlying dentry.
Cc: stable@vger.kernel.org # since 2009 or so
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e72b9dd6a5f17d0fb51f16f8685f3004361e83d0 upstream.
lower_dentry can't go from positive to negative (we have it pinned),
but it *can* go from negative to positive. So fetching ->d_inode
into a local variable, doing a blocking allocation, checking that
now ->d_inode is non-NULL and feeding the value we'd fetched
earlier to a function that won't accept NULL is not a good idea.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7574c0db2e68c4d0bae9d415a683bdd8b2a761e9 upstream.
Many cheap devices use Silead touchscreen controllers. Testing has shown
repeatedly that these touchscreen controllers work fine at 400KHz, but for
unknown reasons do not work properly at 100KHz. This has been seen on
both ARM and x86 devices using totally different i2c controllers.
On some devices the ACPI tables list another device at the same I2C-bus
as only being capable of 100KHz, testing has shown that these other
devices work fine at 400KHz (as can be expected of any recent I2C hw).
This commit makes i2c_acpi_find_bus_speed() always return 400KHz if a
Silead touchscreen controller is present, fixing the touchscreen not
working on devices which ACPI tables' wrongly list another device on the
same bus as only being capable of 100KHz.
Specifically this fixes the touchscreen on the Jumper EZpad 6 m4 not
working.
Reported-by: youling 257 <youling257@gmail.com>
Tested-by: youling 257 <youling257@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: rewording warning a little]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a9c3c4c597704b3a1a2b9bef990e7d8a881f6533 upstream.
If an hfi1 card is inserted in a Gen4 systems, the driver will avoid the
gen3 speed bump and the card will operate at half speed.
This is because the driver avoids the gen3 speed bump when the parent bus
speed isn't identical to gen3, 8.0GT/s. This is not compatible with gen4
and newer speeds.
Fix by relaxing the test to explicitly look for the lower capability
speeds which inherently allows for gen4 and all future speeds.
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Link: https://lore.kernel.org/r/20191101192059.106248.1699.stgit@awfm-01.aw.intel.com
Cc: <stable@vger.kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: James Erwin <james.erwin@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ba60cf9f78f0d7c8e73c7390608f7f818ee68aa0 upstream.
The driver forgets to destroy workqueue in remove() similarly to what is
done when probe() fails. Add a call to destroy_workqueue() to fix it.
Since unregistration will wait for the work to finish, we do not need to
cancel/flush the work instance in remove().
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191114023405.31477-1-hslester96@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 549766ac2ac1f6c8bb85906bbcea759541bb19a2 upstream.
The driver for F54 just polls the status and doesn't even have a IRQ
handler registered. Make sure to disable all F54 IRQs, so we don't crash
the kernel on a nonexistent handler.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://lore.kernel.org/r/20191105114402.6009-1-l.stach@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5d40d95e7e64756cc30606c2ba169271704d47cb upstream.
Currently, rmi_f11_attention() and rmi_f12_attention() functions update
the attn_data data pointer and size based on the size of the expected
size of the attention data. However, if the actual valid data in the
attn buffer is less then the expected value then the updated data
pointer will point to memory beyond the end of the attn buffer. Using
the calculated valid_bytes instead will prevent this from happening.
Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191025002527.3189-3-aduggan@synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f6aabe1ff1d9d7bad0879253011216438bdb2530 upstream.
This patch fixes an issue seen on HID touchpads which report finger
positions using RMI4 Function 12. The issue manifests itself as
spurious button presses as described in:
https://www.spinics.net/lists/linux-input/msg58618.html
Commit 24d28e4f1271 ("Input: synaptics-rmi4 - convert irq distribution
to irq_domain") switched the RMI4 driver to using an irq_domain to handle
RMI4 function interrupts. Functions with more then one interrupt now have
each interrupt mapped to their own IRQ and IRQ handler. The result of
this change is that the F12 IRQ handler was now getting called twice. Once
for the absolute data interrupt and once for the relative data interrupt.
For HID devices, calling rmi_f12_attention() a second time causes the
attn_data data pointer and size to be set incorrectly. When the touchpad
button is pressed, F30 will generate an interrupt and attempt to read the
F30 data from the invalid attn_data data pointer and report incorrect
button events.
This patch disables the F12 relative interrupt which prevents
rmi_f12_attention() from being called twice.
Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Reported-by: Simon Wood <simon@mungewell.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191025002527.3189-2-aduggan@synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 003f01c780020daa9a06dea1db495b553a868c29 upstream.
The video buffer used by the queue is a vb2_v4l2_buffer, not a plain
vb2_buffer. Using the wrong type causes the allocation of the buffer
storage to be too small, causing a out of bounds write when
__init_vb2_v4l2_buffer initializes the buffer.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Fixes: 3a762dbd5347 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191104114454.10500-1-l.stach@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 528699317dd6dc722dccc11b68800cf945109390 upstream.
While output urb's snd_complete_urb() is executing, calling
prepare_outbound_urb() may cause endpoint stopped before
prepare_outbound_urb() returns and result in next urb submitted
to stopped endpoint. usb-audio driver cannot re-use it afterwards as
the urb is still hold by usb stack.
This change checks EP_FLAG_RUNNING flag after prepare_outbound_urb() again
to let snd_complete_urb() know the endpoint already stopped and does not
submit next urb. Below kind of error will be fixed:
[ 213.153103] usb 1-2: timeout: still 1 active urbs on EP #1
[ 213.164121] usb 1-2: cannot submit urb 0, error -16: unknown error
Signed-off-by: Henry Lin <henryl@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191113021420.13377-1-henryl@nvidia.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 167beb1756791e0806365a3f86a0da10d7a327ee upstream.
A check of the return value from get_cur_mix_raw() is missing at the
resolution test code in get_min_max_with_quirks(), which may leave the
variable untouched, leading to a random uninitialized value, as
detected by syzkaller fuzzer.
Add the missing return error check for fixing that.
Reported-and-tested-by: syzbot+abe1ab7afc62c6bb6377@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191109181658.30368-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a9a51bd727d141a67b589f375fe69d0e54c4fe22 ]
If a malicious device gives a short MAC it can elicit up to
5 bytes of leaked memory out of the driver. We need to check for
ETH_ALEN instead.
Reported-by: syzbot+a8d4acdad35e6bbca308@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 110df8bd3e418b3476cae80babe8add48a8ea523 upstream.
imc_common_cpuhp_mem_free() is the common function for all
IMC (In-memory Collection counters) domains to unregister cpuhotplug
callback and free memory. Since kfree of memory allocated for
nest-imc (per_nest_pmu_arr) is in the common code, all
domains (core/nest/thread) can do the kfree in the failure case.
This could potentially create a call trace as shown below, where
core(/thread/nest) imc pmu initialization fails and in the failure
path imc_common_cpuhp_mem_free() free the memory(per_nest_pmu_arr),
which is allocated by successfully registered nest units.
The call trace is generated in a scenario where core-imc
initialization is made to fail and a cpuhotplug is performed in a p9
system. During cpuhotplug ppc_nest_imc_cpu_offline() tries to access
per_nest_pmu_arr, which is already freed by core-imc.
NIP [c000000000cb6a94] mutex_lock+0x34/0x90
LR [c000000000cb6a88] mutex_lock+0x28/0x90
Call Trace:
mutex_lock+0x28/0x90 (unreliable)
perf_pmu_migrate_context+0x90/0x3a0
ppc_nest_imc_cpu_offline+0x190/0x1f0
cpuhp_invoke_callback+0x160/0x820
cpuhp_thread_fun+0x1bc/0x270
smpboot_thread_fn+0x250/0x290
kthread+0x1a8/0x1b0
ret_from_kernel_thread+0x5c/0x74
To address this scenario do the kfree(per_nest_pmu_arr) only in case
of nest-imc initialization failure, and when there is no other nest
units registered.
Fixes: 73ce9aec65b1 ("powerpc/perf: Fix IMC_MAX_PMU macro")
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73ce9aec65b17433e18163d07eb5cb6bf114bd6c upstream.
IMC_MAX_PMU is used for static storage (per_nest_pmu_arr) which holds
nest pmu information. Current value for the macro is 32 based on
the initial number of nest pmu units supported by the nest microcode.
But going forward, microcode could support more nest units. Instead
of static storage, patch to fix the code to dynamically allocate an
array based on the number of nest imc units found in the device tree.
Fixes:8f95faaac56c1 ('powerpc/powernv: Detect and create IMC device')
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 7b9f7a928255a232012be55cb95db30e963b83a7.
That change should have had a fixes tag for
commit 24d28e4f1271 ("Input: synaptics-rmi4 - convert irq distribution to
irq_domain"). The conversion to irq_domain introduced the issue being
fixed by this commit.
In older kernels the bitmap IRQ accounting is done differently, and
it doesn't suffer from the same issue of calling handle_nested_irq(0).
Keeping this commit on kernels 4.14 and older causes problems with
touchpads due to the different semantics of the IRQ bitmasks.
Signed-off-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9393c8de628cf0968d81a17cc11841e42191e041 upstream.
In scsi_mq_setup_tags(), cmd_size is calculated based on zero size for the
scatter-gather list in case the low level driver uses SG_NONE in its host
template.
cmd_size is passed on to the block layer for calculation of the request
size, and we've seen NULL pointer dereference errors from the block layer
in drivers where SG_NONE is used and a mq IO scheduler is active,
apparently as a consequence of this (see commit 68ab2d76e4be ("scsi:
cxlflash: Set sg_tablesize to 1 instead of SG_NONE"), and a recent patch by
Finn Thain converting the three m68k NFR5380 drivers to avoid setting
SG_NONE).
Try to avoid these errors by accounting for at least one sg list entry when
calculating cmd_size, regardless of whether the low level driver set a zero
sg_tablesize.
Tested on 030 m68k with the atari_scsi driver - setting sg_tablesize to
SG_NONE no longer results in a crash when loading this driver.
CC: Finn Thain <fthain@telegraphics.com.au>
Link: https://lore.kernel.org/r/1572922150-4358-1-git-send-email-schmitzmic@gmail.com
Signed-off-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8a38dacf87180738d42b058334c951eba15d2d47 upstream.
The Ethernet Switch core mask was set to 0, causing the switch core to
be not reset on BCM6368 on boot. Provide the proper mask so the switch
core gets reset to a known good state.
Fixes: 799faa626c71 ("MIPS: BCM63XX: add core reset helper")
Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bf03d4f9334728bf7c8ffc7de787df48abd6340e ]
Checking for 32-bit PAE is quite common around code that fiddles with
the PDPTRs. Add a function to compress all checks into a single
invocation.
Moving to the common helper also fixes a subtle bug in kvm_set_cr3()
where it fails to check is_long_mode() and results in KVM incorrectly
attempting to load PDPTRs for a 64-bit guest.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[sean: backport to 4.x; handle vmx.c split in 5.x, call out the bugfix]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1aa9b9572b10529c2e64e2b8f44025d86e124308 upstream.
The page table pages corresponding to broken down large pages are zapped in
FIFO order, so that the large page can potentially be recovered, if it is
not longer being used for execution. This removes the performance penalty
for walking deeper EPT page tables.
By default, one large page will last about one hour once the guest
reaches a steady state.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c57c80467f90e5504c8df9ad3555d2c78800bf94 upstream.
Add a function to create a kernel thread associated with a given VM. In
particular, it ensures that the worker thread inherits the priority and
cgroups of the calling thread.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b8e8c8303ff28c61046a4d0f6ea99aea609a7dc0 upstream.
With some Intel processors, putting the same virtual address in the TLB
as both a 4 KiB and 2 MiB page can confuse the instruction fetch unit
and cause the processor to issue a machine check resulting in a CPU lockup.
Unfortunately when EPT page tables use huge pages, it is possible for a
malicious guest to cause this situation.
Add a knob to mark huge pages as non-executable. When the nx_huge_pages
parameter is enabled (and we are using EPT), all huge pages are marked as
NX. If the guest attempts to execute in one of those pages, the page is
broken down into 4K pages, which are then marked executable.
This is not an issue for shadow paging (except nested EPT), because then
the host is in control of TLB flushes and the problematic situation cannot
happen. With nested EPT, again the nested guest can cause problems shadow
and direct EPT is treated in the same way.
[ tglx: Fixup default to auto and massage wording a bit ]
Originally-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9167ab79936206118cc60e47dcb926c3489f3bd5 upstream.
VMX already does so if the host has SMEP, in order to support the combination of
CR0.WP=1 and CR4.SMEP=1. However, it is perfectly safe to always do so, and in
fact VMX also ends up running with EFER.NXE=1 on old processors that lack the
"load EFER" controls, because it may help avoiding a slow MSR write.
SVM does not have similar code, but it should since recent AMD processors do
support SMEP. So this patch makes the code for the two vendors simpler and
more similar, while fixing an issue with CR0.WP=1 and CR4.SMEP=1 on AMD.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 335e192a3fa415e1202c8b9ecdaaecd643f823cc upstream.
These are useful in debugging shadow paging.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e9f2a760b158551bfbef6db31d2cae45ab8072e5 upstream.
Note that in such a case it is quite likely that KVM will BUG_ON
in __pte_list_remove when the VM is closed. However, there is no
immediate risk of memory corruption in the host so a WARN_ON is
enough and it lets you gather traces for debugging.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d679b32611c0102ce33b9e1a4e4b94854ed1812a upstream.
After the previous patch, the low bits of the gfn are masked in
both FNAME(fetch) and __direct_map, so we do not need to clear them
in transparent_hugepage_adjust.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3fcf2d1bdeb6a513523cb2c77012a6b047aa859c upstream.
These two functions are basically doing the same thing through
kvm_mmu_get_page, link_shadow_page and mmu_set_spte; yet, for historical
reasons, their code looks very different. This patch tries to take the
best of each and make them very similar, so that it is easy to understand
changes that apply to both of them.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 43fdcda96e2550c6d1c46fb8a78801aa2f7276ed upstream.
Release the page at the call-site where it was originally acquired.
This makes the exit code cleaner for most call sites, since they
do not need to duplicate code between success and the failure
label.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0d9ce162cf46c99628cc5da9510b959c7976735b upstream.
It doesn't seem as if there is any particular need for kvm_lock to be a
spinlock, so convert the lock to a mutex so that sleepable functions (in
particular cond_resched()) can be called while holding it.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 833b45de69a6016c4b0cebe6765d526a31a81580 upstream.
The largepages debugfs entry is incremented/decremented as shadow
pages are created or destroyed. Clearing it will result in an
underflow, which is harmless to KVM but ugly (and could be
misinterpreted by tools that use debugfs information), so make
this particular statistic read-only.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7f00cc8d4a51074eb0ad4c3f16c15757b1ddfb7d upstream.
Add the initial ITLB_MULTIHIT documentation.
[ tglx: Add it to the index so it gets actually built. ]
Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Nelson D'Souza <nelson.dsouza@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 731dc9df975a5da21237a18c3384f811a7a41cc6 upstream.
A kernel module may need to check the value of the "mitigations=" kernel
command line parameter as part of its setup when the module needs
to perform software mitigations for a CPU flaw.
Uninline and export the helper functions surrounding the cpu_mitigations
enum to allow for their usage from a module.
Lastly, privatize the enum and cpu_mitigations variable since the value of
cpu_mitigations can be checked with the exported helper functions.
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cad14885a8d32c1c0d8eaa7bf5c0152a22b6080e upstream.
Add the new cpu family ATOM_TREMONT_D to the cpu vunerability
whitelist. ATOM_TREMONT_D is not affected by X86_BUG_ITLB_MULTIHIT.
ATOM_TREMONT_D might have mitigations against other issues as well, but
only the ITLB multihit mitigation is confirmed at this point.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream.
Some processors may incur a machine check error possibly resulting in an
unrecoverable CPU lockup when an instruction fetch encounters a TLB
multi-hit in the instruction TLB. This can occur when the page size is
changed along with either the physical address or cache type. The relevant
erratum can be found here:
https://bugzilla.kernel.org/show_bug.cgi?id=205195
There are other processors affected for which the erratum does not fully
disclose the impact.
This issue affects both bare-metal x86 page tables and EPT.
It can be mitigated by either eliminating the use of large pages or by
using careful TLB invalidations when changing the page size in the page
tables.
Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
are mitigated against this issue.
Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com>
Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 012206a822a8b6ac09125bfaa210a95b9eb8f1c1 upstream.
For new IBRS_ALL CPUs, the Enhanced IBRS check at the beginning of
cpu_bugs_smt_update() causes the function to return early, unintentionally
skipping the MDS and TAA logic.
This is not a problem for MDS, because there appears to be no overlap
between IBRS_ALL and MDS-affected CPUs. So the MDS mitigation would be
disabled and nothing would need to be done in this function anyway.
But for TAA, the TAA_MSG_SMT string will never get printed on Cascade
Lake and newer.
The check is superfluous anyway: when 'spectre_v2_enabled' is
SPECTRE_V2_IBRS_ENHANCED, 'spectre_v2_user' is always
SPECTRE_V2_USER_NONE, and so the 'spectre_v2_user' switch statement
handles it appropriately by doing nothing. So just remove the check.
Fixes: 1b42f017415b ("x86/speculation/taa: Add mitigation for TSX Async Abort")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit db616173d787395787ecc93eef075fa975227b10 upstream.
There is a general consensus that TSX usage is not largely spread while
the history shows there is a non trivial space for side channel attacks
possible. Therefore the tsx is disabled by default even on platforms
that might have a safe implementation of TSX according to the current
knowledge. This is a fair trade off to make.
There are, however, workloads that really do benefit from using TSX and
updating to a newer kernel with TSX disabled might introduce a
noticeable regressions. This would be especially a problem for Linux
distributions which will provide TAA mitigations.
Introduce config options X86_INTEL_TSX_MODE_OFF, X86_INTEL_TSX_MODE_ON
and X86_INTEL_TSX_MODE_AUTO to control the TSX feature. The config
setting can be overridden by the tsx cmdline options.
[ bp: Text cleanups from Josh. ]
Suggested-by: Borislav Petkov <bpetkov@suse.de>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a7a248c593e4fd7a67c50b5f5318fe42a0db335e upstream.
Add the documenation for TSX Async Abort. Include the description of
the issue, how to check the mitigation state, control the mitigation,
guidance for system administrators.
[ bp: Add proper SPDX tags, touch ups by Josh and me. ]
Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mark Gross <mgross@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream.
Platforms which are not affected by X86_BUG_TAA may want the TSX feature
enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto
disable TSX when X86_BUG_TAA is present, otherwise enable TSX.
More details on X86_BUG_TAA can be found here:
https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html
[ bp: Extend the arg buffer to accommodate "auto\0". ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e1d38b63acd843cfdd4222bf19a26700fd5c699e upstream.
Export the IA32_ARCH_CAPABILITIES MSR bit MDS_NO=0 to guests on TSX
Async Abort(TAA) affected hosts that have TSX enabled and updated
microcode. This is required so that the guests don't complain,
"Vulnerable: Clear CPU buffers attempted, no microcode"
when the host has the updated microcode to clear CPU buffers.
Microcode update also adds support for MSR_IA32_TSX_CTRL which is
enumerated by the ARCH_CAP_TSX_CTRL bit in IA32_ARCH_CAPABILITIES MSR.
Guests can't do this check themselves when the ARCH_CAP_TSX_CTRL bit is
not exported to the guests.
In this case export MDS_NO=0 to the guests. When guests have
CPUID.MD_CLEAR=1, they deploy MDS mitigation which also mitigates TAA.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream.
Add the sysfs reporting file for TSX Async Abort. It exposes the
vulnerability and the mitigation state similar to the existing files for
the other hardware vulnerabilities.
Sysfs file path is:
/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
Reviewed-by: Mark Gross <mgross@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1b42f017415b46c317e71d41c34ec088417a1883 upstream.
TSX Async Abort (TAA) is a side channel vulnerability to the internal
buffers in some Intel processors similar to Microachitectural Data
Sampling (MDS). In this case, certain loads may speculatively pass
invalid data to dependent operations when an asynchronous abort
condition is pending in a TSX transaction.
This includes loads with no fault or assist condition. Such loads may
speculatively expose stale data from the uarch data structures as in
MDS. Scope of exposure is within the same-thread and cross-thread. This
issue affects all current processors that support TSX, but do not have
ARCH_CAP_TAA_NO (bit 8) set in MSR_IA32_ARCH_CAPABILITIES.
On CPUs which have their IA32_ARCH_CAPABILITIES MSR bit MDS_NO=0,
CPUID.MD_CLEAR=1 and the MDS mitigation is clearing the CPU buffers
using VERW or L1D_FLUSH, there is no additional mitigation needed for
TAA. On affected CPUs with MDS_NO=1 this issue can be mitigated by
disabling the Transactional Synchronization Extensions (TSX) feature.
A new MSR IA32_TSX_CTRL in future and current processors after a
microcode update can be used to control the TSX feature. There are two
bits in that MSR:
* TSX_CTRL_RTM_DISABLE disables the TSX sub-feature Restricted
Transactional Memory (RTM).
* TSX_CTRL_CPUID_CLEAR clears the RTM enumeration in CPUID. The other
TSX sub-feature, Hardware Lock Elision (HLE), is unconditionally
disabled with updated microcode but still enumerated as present by
CPUID(EAX=7).EBX{bit4}.
The second mitigation approach is similar to MDS which is clearing the
affected CPU buffers on return to user space and when entering a guest.
Relevant microcode update is required for the mitigation to work. More
details on this approach can be found here:
https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html
The TSX feature can be controlled by the "tsx" command line parameter.
If it is force-enabled then "Clear CPU buffers" (MDS mitigation) is
deployed. The effective mitigation state can be read from sysfs.
[ bp:
- massage + comments cleanup
- s/TAA_MITIGATION_TSX_DISABLE/TAA_MITIGATION_TSX_DISABLED/g - Josh.
- remove partial TAA mitigation in update_mds_branch_idle() - Josh.
- s/tsx_async_abort_cmdline/tsx_async_abort_parse_cmdline/g
]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 upstream.
Add a kernel cmdline parameter "tsx" to control the Transactional
Synchronization Extensions (TSX) feature. On CPUs that support TSX
control, use "tsx=on|off" to enable or disable TSX. Not specifying this
option is equivalent to "tsx=off". This is because on certain processors
TSX may be used as a part of a speculative side channel attack.
Carve out the TSX controlling functionality into a separate compilation
unit because TSX is a CPU feature while the TSX async abort control
machinery will go to cpu/bugs.c.
[ bp: - Massage, shorten and clear the arg buffer.
- Clarifications of the tsx= possible options - Josh.
- Expand on TSX_CTRL availability - Pawan. ]
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
