Commit graph

36086 commits

Author SHA1 Message Date
Chanwoo Choi
1635d4fc76 PM / devfreq: Add new name attribute for sysfs
commit 2fee1a7cc6 upstream.

The commit 4585fbcb53 ("PM / devfreq: Modify the device name as devfreq(X) for
sysfs") changed the node name to devfreq(x). After this commit, it is not
possible to get the device name through /sys/class/devfreq/devfreq(X)/*.

Add new name attribute in order to get device name.

Cc: stable@vger.kernel.org
Fixes: 4585fbcb53 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs")
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-05 14:43:34 +00:00
Jeremy Linton
a243850af3 Documentation: Document arm64 kpti control
commit de19055564 upstream.

For a while Arm64 has been capable of force enabling
or disabling the kpti mitigations. Lets make sure the
documentation reflects that.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29 16:43:19 +01:00
Tony Lindgren
8b314bb069 hwrng: omap3-rom - Fix missing clock by probing with device tree
[ Upstream commit 0c0ef9ea6f ]

Commit 0ed266d7ae ("clk: ti: omap3: cleanup unnecessary clock aliases")
removed old omap3 clock framework aliases but caused omap3-rom-rng to
stop working with clock not found error.

Based on discussions on the mailing list it was requested by Tero Kristo
that it would be best to fix this issue by probing omap3-rom-rng using
device tree to provide a proper clk property. The other option would be
to add back the missing clock alias, but that does not help moving things
forward with removing old legacy platform_data.

Let's also add a proper device tree binding and keep it together with
the fix.

Cc: devicetree@vger.kernel.org
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Fixes: 0ed266d7ae ("clk: ti: omap3: cleanup unnecessary clock aliases")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27 14:51:20 +01:00
Tony Lindgren
fa3302ef72 bus: ti-sysc: Add mcasp optional clocks flag
[ Upstream commit 2c63a833e4 ]

We have OPT_CLKS_NEEDED in legacy platform data, but it's missing
from the ti-sysc driver for device tree based configuration.

In order to pass OPT_CLKS_NEEDED quirk flag we need to update omap4 module
data and add a new compatible for dra7 as the module layout is different
from sysc_regbits_omap4_mcasp.

Fixes: 70a65240ef ("bus: ti-sysc: Add register bits for interconnect
target modules")
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27 14:50:02 +01:00
Eugen Hristev
a9375dc8ce iio: fix position relative kernel version
[ Upstream commit 21eab78616 ]

Position relative channel type was added in 4.19 kernel version

Fixes: "3055a6cfa04ba" ("iio: Add channel for Position Relative")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-27 14:49:54 +01:00
Alexander Usyskin
66aa7e8ba4 mei: fix modalias documentation
commit 7366830921 upstream.

mei client bus added the client protocol version to the device alias,
but ABI documentation was not updated.

Fixes: b26864cad1 (mei: bus: add client protocol version to the device alias)
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Link: https://lore.kernel.org/r/20191008005735.12707-1-tomas.winkler@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-17 19:47:05 +01:00
Geert Uytterhoeven
f6aa433c8f dt-bindings: clock: renesas: rcar-usb2-clock-sel: Fix typo in example
commit 830dbce7c7 upstream.

The documented compatible value for R-Car H3 is
"renesas,r8a7795-rcar-usb2-clock-sel", not
"renesas,r8a77950-rcar-usb2-clock-sel".

Fixes: 311accb645 ("clk: renesas: rcar-usb2-clock-sel: Add R-Car USB 2.0 clock selector PHY")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191016145650.30003-1-geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09 10:19:06 +01:00
Yunfeng Ye
dba77370ad ACPI: sysfs: Change ACPI_MASKABLE_GPE_MAX to 0x100
commit a7583e72a5 upstream.

The commit 0f27cff859 ("ACPI: sysfs: Make ACPI GPE mask kernel
parameter cover all GPEs") says:
  "Use a bitmap of size 0xFF instead of a u64 for the GPE mask so 256
   GPEs can be masked"

But the masking of GPE 0xFF it not supported and the check condition
"gpe > ACPI_MASKABLE_GPE_MAX" is not valid because the type of gpe is
u8.

So modify the macro ACPI_MASKABLE_GPE_MAX to 0x100, and drop the "gpe >
ACPI_MASKABLE_GPE_MAX" check. In addition, update the docs "Format" for
acpi_mask_gpe parameter.

Fixes: 0f27cff859 ("ACPI: sysfs: Make ACPI GPE mask kernel parameter cover all GPEs")
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
[ rjw: Use u16 as gpe data type in acpi_gpe_apply_masked_gpes() ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-09 10:19:04 +01:00
Michal Hocko
c76adee347 mm, thp, proc: report THP eligibility for each vma
[ Upstream commit 7635d9cbe8 ]

Userspace falls short when trying to find out whether a specific memory
range is eligible for THP.  There are usecases that would like to know
that
http://lkml.kernel.org/r/alpine.DEB.2.21.1809251248450.50347@chino.kir.corp.google.com
: This is used to identify heap mappings that should be able to fault thp
: but do not, and they normally point to a low-on-memory or fragmentation
: issue.

The only way to deduce this now is to query for hg resp.  nh flags and
confronting the state with the global setting.  Except that there is also
PR_SET_THP_DISABLE that might change the picture.  So the final logic is
not trivial.  Moreover the eligibility of the vma depends on the type of
VMA as well.  In the past we have supported only anononymous memory VMAs
but things have changed and shmem based vmas are supported as well these
days and the query logic gets even more complicated because the
eligibility depends on the mount option and another global configuration
knob.

Simplify the current state and report the THP eligibility in
/proc/<pid>/smaps for each existing vma.  Reuse
transparent_hugepage_enabled for this purpose.  The original
implementation of this function assumes that the caller knows that the vma
itself is supported for THP so make the core checks into
__transparent_hugepage_enabled and use it for existing callers.
__show_smap just use the new transparent_hugepage_enabled which also
checks the vma support status (please note that this one has to be out of
line due to include dependency issues).

[mhocko@kernel.org: fix oops with NULL ->f_mapping]
  Link: http://lkml.kernel.org/r/20181224185106.GC16738@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20181211143641.3503-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Paul Oppenheimer <bepvte@gmail.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-17 20:35:45 +01:00
Oliver Neukum
9e002edde3 USB: documentation: flags on usb-storage versus UAS
commit 65cc8bf993 upstream.

Document which flags work storage, UAS or both

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191114112758.32747-4-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 20:34:30 +01:00
Baruch Siach
0281b46b52 rtc: dt-binding: abx80x: fix resistance scale
[ Upstream commit 73852e5682 ]

The abracon,tc-resistor property value is in kOhm.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-13 08:51:36 +01:00
Peter Hutterer
168779023d HID: doc: fix wrong data structure reference for UHID_OUTPUT
[ Upstream commit 46b14eef59 ]

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 09:20:36 +01:00
Waiman Long
0af5ae268e x86/speculation: Fix incorrect MDS/TAA mitigation status
commit 64870ed1b1 upstream.

For MDS vulnerable processors with TSX support, enabling either MDS or
TAA mitigations will enable the use of VERW to flush internal processor
buffers at the right code path. IOW, they are either both mitigated
or both not. However, if the command line options are inconsistent,
the vulnerabilites sysfs files may not report the mitigation status
correctly.

For example, with only the "mds=off" option:

  vulnerabilities/mds:Vulnerable; SMT vulnerable
  vulnerabilities/tsx_async_abort:Mitigation: Clear CPU buffers; SMT vulnerable

The mds vulnerabilities file has wrong status in this case. Similarly,
the taa vulnerability file will be wrong with mds mitigation on, but
taa off.

Change taa_select_mitigation() to sync up the two mitigation status
and have them turned off if both "mds=off" and "tsx_async_abort=off"
are present.

Update documentation to emphasize the fact that both "mds=off" and
"tsx_async_abort=off" have to be specified together for processors that
are affected by both TAA and MDS to be effective.

 [ bp: Massage and add kernel-parameters.txt change too. ]

Fixes: 1b42f01741 ("x86/speculation/taa: Add mitigation for TSX Async Abort")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-doc@vger.kernel.org
Cc: Mark Gross <mgross@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191115161445.30809-2-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-01 09:17:37 +01:00
Keiji Hayashibara
adcb6d9ff1 spi: uniphier: fix incorrect property items
[ Upstream commit 3511ba7d4c ]

This commit fixes incorrect property because it was different
from the actual.
The parameters of '#address-cells' and '#size-cells' were removed,
and 'interrupts', 'pinctrl-names' and 'pinctrl-0' were added.

Fixes: 4dcd5c2781 ("spi: add DT bindings for UniPhier SPI controller")
Signed-off-by: Keiji Hayashibara <hayashibara.keiji@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:16:58 +01:00
Florian Fainelli
590ee2e0ae net: phy: mdio-bcm-unimac: Allow configuring MDIO clock divider
[ Upstream commit b78ac6ecd1 ]

Allow the configuration of the MDIO clock divider when the Device Tree
contains 'clock-frequency' property (similar to I2C and SPI buses).
Because the hardware may have lost its state during suspend/resume,
re-apply the MDIO clock divider upon resumption.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:47:14 +01:00
Geert Uytterhoeven
6281d021bb media: dt-bindings: adv748x: Fix decimal unit addresses
[ Upstream commit 27582f0ea9 ]

With recent dtc and W=1:

    Warning (graph_port): video-receiver@70/port@10: graph node unit address error, expected "a"
    Warning (graph_port): video-receiver@70/port@11: graph node unit address error, expected "b"

Unit addresses are always hexadecimal (without prefix), while the bases
of reg property values depend on their prefixes.

Fixes: e69595170b ("media: adv748x: Add adv7481, adv7482 bindings")

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:46:32 +01:00
Junaid Shahid
46a4a014c4 kvm: x86: mmu: Recovery of shattered NX large pages
commit 1aa9b9572b 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>
2019-11-12 19:21:46 +01:00
Paolo Bonzini
5219505fcb kvm: mmu: ITLB_MULTIHIT mitigation
commit b8e8c8303f 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>
2019-11-12 19:21:44 +01:00
Junaid Shahid
30d8d8d6cd kvm: Convert kvm_lock to a mutex
commit 0d9ce162cf 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>
2019-11-12 19:21:40 +01:00
Gomez Iglesias, Antonio
580c79e7e3 Documentation: Add ITLB_MULTIHIT documentation
commit 7f00cc8d4a 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>
2019-11-12 19:21:38 +01:00
Vineela Tummalapalli
f9aa6b73a4 x86/bugs: Add ITLB_MULTIHIT bug infrastructure
commit db4d30fbb7 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>
2019-11-12 19:21:36 +01:00
Pawan Gupta
e3bf6b3ff5 x86/speculation/taa: Add documentation for TSX Async Abort
commit a7a248c593 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>
2019-11-12 19:21:34 +01:00
Pawan Gupta
2402432d55 x86/tsx: Add "auto" option to the tsx= cmdline parameter
commit 7531a3596e 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>
2019-11-12 19:21:34 +01:00
Pawan Gupta
b8eb348ae4 x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
commit 95c5824f75 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>
2019-11-12 19:21:32 +01:00
Dave Chiluk
502bd15144 sched/fair: Fix low cpu usage with high throttling by removing expiration of cpu-local slices
commit de53fd7aed upstream.

It has been observed, that highly-threaded, non-cpu-bound applications
running under cpu.cfs_quota_us constraints can hit a high percentage of
periods throttled while simultaneously not consuming the allocated
amount of quota. This use case is typical of user-interactive non-cpu
bound applications, such as those running in kubernetes or mesos when
run on multiple cpu cores.

This has been root caused to cpu-local run queue being allocated per cpu
bandwidth slices, and then not fully using that slice within the period.
At which point the slice and quota expires. This expiration of unused
slice results in applications not being able to utilize the quota for
which they are allocated.

The non-expiration of per-cpu slices was recently fixed by
'commit 512ac999d2 ("sched/fair: Fix bandwidth timer clock drift
condition")'. Prior to that it appears that this had been broken since
at least 'commit 51f2176d74 ("sched/fair: Fix unlocked reads of some
cfs_b->quota/period")' which was introduced in v3.16-rc1 in 2014. That
added the following conditional which resulted in slices never being
expired.

if (cfs_rq->runtime_expires != cfs_b->runtime_expires) {
	/* extend local deadline, drift is bounded above by 2 ticks */
	cfs_rq->runtime_expires += TICK_NSEC;

Because this was broken for nearly 5 years, and has recently been fixed
and is now being noticed by many users running kubernetes
(https://github.com/kubernetes/kubernetes/issues/67577) it is my opinion
that the mechanisms around expiring runtime should be removed
altogether.

This allows quota already allocated to per-cpu run-queues to live longer
than the period boundary. This allows threads on runqueues that do not
use much CPU to continue to use their remaining slice over a longer
period of time than cpu.cfs_period_us. However, this helps prevent the
above condition of hitting throttling while also not fully utilizing
your cpu quota.

This theoretically allows a machine to use slightly more than its
allotted quota in some periods. This overflow would be bounded by the
remaining quota left on each per-cpu runqueueu. This is typically no
more than min_cfs_rq_runtime=1ms per cpu. For CPU bound tasks this will
change nothing, as they should theoretically fully utilize all of their
quota in each period. For user-interactive tasks as described above this
provides a much better user/application experience as their cpu
utilization will more closely match the amount they requested when they
hit throttling. This means that cpu limits no longer strictly apply per
period for non-cpu bound applications, but that they are still accurate
over longer timeframes.

This greatly improves performance of high-thread-count, non-cpu bound
applications with low cfs_quota_us allocation on high-core-count
machines. In the case of an artificial testcase (10ms/100ms of quota on
80 CPU machine), this commit resulted in almost 30x performance
improvement, while still maintaining correct cpu quota restrictions.
That testcase is available at https://github.com/indeedeng/fibtest.

Fixes: 512ac999d2 ("sched/fair: Fix bandwidth timer clock drift condition")
Signed-off-by: Dave Chiluk <chiluk+linux@indeed.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Ben Segall <bsegall@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Hammond <jhammond@indeed.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kyle Anderson <kwa@yelp.com>
Cc: Gabriel Munos <gmunoz@netflix.com>
Cc: Peter Oskolkov <posk@posk.io>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Brendan Gregg <bgregg@netflix.com>
Link: https://lkml.kernel.org/r/1563900266-19734-2-git-send-email-chiluk+linux@indeed.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:20:50 +01:00
Boris Ostrovsky
af140367ae x86/xen: Return from panic notifier
[ Upstream commit c6875f3aac ]

Currently execution of panic() continues until Xen's panic notifier
(xen_panic_event()) is called at which point we make a hypercall that
never returns.

This means that any notifier that is supposed to be called later as
well as significant part of panic() code (such as pstore writes from
kmsg_dump()) is never executed.

There is no reason for xen_panic_event() to be this last point in
execution since panic()'s emergency_restart() will call into
xen_emergency_restart() from where we can perform our hypercall.

Nevertheless, we will provide xen_legacy_crash boot option that will
preserve original behavior during crash. This option could be used,
for example, if running kernel dumper (which happens after panic
notifiers) is undesirable.

Reported-by: James Dingwall <james@dingwall.me.uk>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06 13:05:55 +01:00
Bastien Nocera
86575b7f63 USB: rio500: Remove Rio 500 kernel driver
commit 015664d152 upstream.

The Rio500 kernel driver has not been used by Rio500 owners since 2001
not long after the rio500 project added support for a user-space USB stack
through the very first versions of usbdevfs and then libusb.

Support for the kernel driver was removed from the upstream utilities
in 2008:
943f624ab7

Cc: Cesar Miquel <miquel@df.uba.ar>
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/6251c17584d220472ce882a3d9c199c401a51a71.camel@hadess.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17 13:44:47 -07:00
Josh Poimboeuf
d976344d27 arm64/speculation: Support 'mitigations=' cmdline option
commit a111b7c0f2 upstream.

Configure arm64 runtime CPU speculation bug mitigations in accordance
with the 'mitigations=' cmdline option.  This affects Meltdown, Spectre
v2, and Speculative Store Bypass.

The default behavior is unchanged.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
[will: reorder checks so KASLR implies KPTI and SSBS is affected by cmdline]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11 18:21:38 +02:00
Jeremy Linton
59a6dc262c arm64: Provide a command line to disable spectre_v2 mitigation
[ Upstream commit e5ce5e7267 ]

There are various reasons, such as benchmarking, to disable spectrev2
mitigation on a machine. Provide a command-line option to do so.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11 18:21:34 +02:00
Will Deacon
09c22781dd arm64: docs: Document SSBS HWCAP
[ Upstream commit ee91176120 ]

We advertise the MRS/MSR instructions for toggling SSBS at EL0 using an
HWCAP, so document it along with the others.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-11 18:21:31 +02:00
Amir Goldstein
9c13e770cc ovl: fix regression caused by overlapping layers detection
commit 0be0bfd2de upstream.

Once upon a time, commit 2cac0c00a6 ("ovl: get exclusive ownership on
upper/work dirs") in v4.13 added some sanity checks on overlayfs layers.
This change caused a docker regression. The root cause was mount leaks
by docker, which as far as I know, still exist.

To mitigate the regression, commit 85fdee1eef ("ovl: fix regression
caused by exclusive upper/work dir protection") in v4.14 turned the
mount errors into warnings for the default index=off configuration.

Recently, commit 146d62e5a5 ("ovl: detect overlapping layers") in
v5.2, re-introduced exclusive upper/work dir checks regardless of
index=off configuration.

This changes the status quo and mount leak related bug reports have
started to re-surface. Restore the status quo to fix the regressions.
To clarify, index=off does NOT relax overlapping layers check for this
ovelayfs mount. index=off only relaxes exclusive upper/work dir checks
with another overlayfs mount.

To cover the part of overlapping layers detection that used the
exclusive upper/work dir checks to detect overlap with self upper/work
dir, add a trap also on the work base dir.

Link: https://github.com/moby/moby/issues/34672
Link: https://lore.kernel.org/linux-fsdevel/20171006121405.GA32700@veci.piliscsaba.szeredi.hu/
Link: https://github.com/containers/libpod/issues/3540
Fixes: 146d62e5a5 ("ovl: detect overlapping layers")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Colin Walters <walters@verbum.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-21 07:17:14 +02:00
Sébastien Szymanski
87c3692172 drm/panel: Add support for Armadeus ST0700 Adapt
[ Upstream commit c479450f61 ]

This patch adds support for the Armadeus ST0700 Adapt. It comes with a
Santek ST0700I5Y-RBSLW 7.0" WVGA (800x480) TFT and an adapter board so
that it can be connected on the TFT header of Armadeus Dev boards.

Cc: stable@vger.kernel.org # v4.19
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190507152713.27494-1-sebastien.szymanski@armadeus.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:21 +02:00
Christoph Muellner
e4ba157877 dt-bindings: mmc: Add disable-cqe-dcmd property.
[ Upstream commit 28f22fb755 ]

Add disable-cqe-dcmd as optional property for MMC hosts.
This property allows to disable or not enable the direct command
features of the command queue engine.

Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Fixes: 84362d79f4 ("mmc: sdhci-of-arasan: Add CQHCI support for arasan,sdhci-5.1")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:12 +02:00
Sowjanya Komatineni
eb83f9fa10 dt-bindings: mmc: Add supports-cqe property
[ Upstream commit c7fddbd5db ]

Add supports-cqe optional property for MMC hosts.

This property is used to identify the specific host controller
supporting command queue.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:11 +02:00
Krzysztof Kozlowski
0d7f329e24 iio: adc: exynos-adc: Use proper number of channels for Exynos4x12
[ Upstream commit 103cda6a3b ]

Exynos4212 and Exynos4412 have only four ADC channels so using
"samsung,exynos-adc-v1" compatible (for eight channels ADCv1) on them is
wrong.  Add a new compatible for Exynos4x12.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:06 +02:00
Jonathan Bakker
4e516b721a dt-bindings: iio: adc: exynos-adc: Add S5PV210 variant
[ Upstream commit a9b0a2a7c1 ]

Add information about new compatible for S5PV210

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16 08:22:06 +02:00
Tom Lendacky
e063b03b45 x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16h
commit c49a0a8013 upstream.

There have been reports of RDRAND issues after resuming from suspend on
some AMD family 15h and family 16h systems. This issue stems from a BIOS
not performing the proper steps during resume to ensure RDRAND continues
to function properly.

RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be
reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND
support using CPUID, including the kernel, will believe that RDRAND is
not supported.

Update the CPU initialization to clear the RDRAND CPUID bit for any family
15h and 16h processor that supports RDRAND. If it is known that the family
15h or family 16h system does not have an RDRAND resume issue or that the
system will not be placed in suspend, the "rdrand=force" kernel parameter
can be used to stop the clearing of the RDRAND CPUID bit.

Additionally, update the suspend and resume path to save and restore the
MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in
place after resuming from suspend.

Note, that clearing the RDRAND CPUID bit does not prevent a processor
that normally supports the RDRAND instruction from executing it. So any
code that determined the support based on family and model won't #UD.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Chen Yu <yu.c.chen@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>
Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: <stable@vger.kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "x86@kernel.org" <x86@kernel.org>
Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-29 08:28:53 +02:00
Josh Poimboeuf
7634b9cd27 Documentation: Add swapgs description to the Spectre v1 documentation
commit 4c92057661 upstream

Add documentation to the Spectre document about the new swapgs variant of
Spectre v1.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 19:06:58 +02:00
Josh Poimboeuf
23e7a7b3a7 x86/speculation: Enable Spectre v1 swapgs mitigations
commit a205982598 upstream

The previous commit added macro calls in the entry code which mitigate the
Spectre v1 swapgs issue if the X86_FEATURE_FENCE_SWAPGS_* features are
enabled.  Enable those features where applicable.

The mitigations may be disabled with "nospectre_v1" or "mitigations=off".

There are different features which can affect the risk of attack:

- When FSGSBASE is enabled, unprivileged users are able to place any
  value in GS, using the wrgsbase instruction.  This means they can
  write a GS value which points to any value in kernel space, which can
  be useful with the following gadget in an interrupt/exception/NMI
  handler:

	if (coming from user space)
		swapgs
	mov %gs:<percpu_offset>, %reg1
	// dependent load or store based on the value of %reg
	// for example: mov %(reg1), %reg2

  If an interrupt is coming from user space, and the entry code
  speculatively skips the swapgs (due to user branch mistraining), it
  may speculatively execute the GS-based load and a subsequent dependent
  load or store, exposing the kernel data to an L1 side channel leak.

  Note that, on Intel, a similar attack exists in the above gadget when
  coming from kernel space, if the swapgs gets speculatively executed to
  switch back to the user GS.  On AMD, this variant isn't possible
  because swapgs is serializing with respect to future GS-based
  accesses.

  NOTE: The FSGSBASE patch set hasn't been merged yet, so the above case
	doesn't exist quite yet.

- When FSGSBASE is disabled, the issue is mitigated somewhat because
  unprivileged users must use prctl(ARCH_SET_GS) to set GS, which
  restricts GS values to user space addresses only.  That means the
  gadget would need an additional step, since the target kernel address
  needs to be read from user space first.  Something like:

	if (coming from user space)
		swapgs
	mov %gs:<percpu_offset>, %reg1
	mov (%reg1), %reg2
	// dependent load or store based on the value of %reg2
	// for example: mov %(reg2), %reg3

  It's difficult to audit for this gadget in all the handlers, so while
  there are no known instances of it, it's entirely possible that it
  exists somewhere (or could be introduced in the future).  Without
  tooling to analyze all such code paths, consider it vulnerable.

  Effects of SMAP on the !FSGSBASE case:

  - If SMAP is enabled, and the CPU reports RDCL_NO (i.e., not
    susceptible to Meltdown), the kernel is prevented from speculatively
    reading user space memory, even L1 cached values.  This effectively
    disables the !FSGSBASE attack vector.

  - If SMAP is enabled, but the CPU *is* susceptible to Meltdown, SMAP
    still prevents the kernel from speculatively reading user space
    memory.  But it does *not* prevent the kernel from reading the
    user value from L1, if it has already been cached.  This is probably
    only a small hurdle for an attacker to overcome.

Thanks to Dave Hansen for contributing the speculative_smap() function.

Thanks to Andrew Cooper for providing the inside scoop on whether swapgs
is serializing on AMD.

[ tglx: Fixed the USER fence decision and polished the comment as suggested
  	by Dave Hansen ]

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 19:06:58 +02:00
Josua Mayer
404f59e265 dt-bindings: allow up to four clocks for orion-mdio
commit 80785f5a22 upstream.

Armada 8040 needs four clocks to be enabled for MDIO accesses to work.
Update the binding to allow the extra clock to be specified.

Cc: stable@vger.kernel.org
Fixes: 6d6a331f44 ("dt-bindings: allow up to three clocks for orion-mdio")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Josua Mayer <josua@solid-run.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-26 09:14:30 +02:00
Peter Zijlstra
9e0bcb59b6 x86/atomic: Fix smp_mb__{before,after}_atomic()
[ Upstream commit 69d927bba3 ]

Recent probing at the Linux Kernel Memory Model uncovered a
'surprise'. Strongly ordered architectures where the atomic RmW
primitive implies full memory ordering and
smp_mb__{before,after}_atomic() are a simple barrier() (such as x86)
fail for:

	*x = 1;
	atomic_inc(u);
	smp_mb__after_atomic();
	r0 = *y;

Because, while the atomic_inc() implies memory order, it
(surprisingly) does not provide a compiler barrier. This then allows
the compiler to re-order like so:

	atomic_inc(u);
	*x = 1;
	smp_mb__after_atomic();
	r0 = *y;

Which the CPU is then allowed to re-order (under TSO rules) like:

	atomic_inc(u);
	r0 = *y;
	*x = 1;

And this very much was not intended. Therefore strengthen the atomic
RmW ops to include a compiler barrier.

NOTE: atomic_{or,and,xor} and the bitops already had the compiler
barrier.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26 09:14:08 +02:00
Qian Cai
7fc96cd2b0 sched/fair: Fix "runnable_avg_yN_inv" not used warnings
[ Upstream commit 509466b7d4 ]

runnable_avg_yN_inv[] is only used in kernel/sched/pelt.c but was
included in several other places because they need other macros all
came from kernel/sched/sched-pelt.h which was generated by
Documentation/scheduler/sched-pelt. As the result, it causes compilation
a lot of warnings,

  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  ...

Silence it by appending the __maybe_unused attribute for it, so all
generated variables and macros can still be kept in the same file.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1559596304-31581-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26 09:14:08 +02:00
Andy Lutomirski
a2a24b57c2 Documentation/admin: Remove the vsyscall=native documentation
commit d974ffcfb7 upstream.

The vsyscall=native feature is gone -- remove the docs.

Fixes: 076ca272a1 ("x86/vsyscall/64: Drop "native" vsyscalls")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Kernel Hardening <kernel-hardening@lists.openwall.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/d77c7105eb4c57c1a95a95b6a5b8ba194a18e764.1561610354.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-14 08:11:18 +02:00
Tim Chen
8a815007f5 Documentation: Add section about CPU vulnerabilities for Spectre
commit 6e88559470 upstream.

Add documentation for Spectre vulnerability and the mitigation mechanisms:

- Explain the problem and risks
- Document the mitigation mechanisms
- Document the command line controls
- Document the sysfs files

Co-developed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Co-developed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-14 08:11:17 +02:00
Reinhard Speyerer
2da80536f6 qmi_wwan: extend permitted QMAP mux_id value range
[ Upstream commit 36815b416f ]

Permit mux_id values up to 254 to be used in qmimux_register_device()
for compatibility with ip(8) and the rmnet driver.

Fixes: c6adf77953 ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas <dnlplm@gmail.com>
Signed-off-by: Reinhard Speyerer <rspmn@arcor.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-14 08:11:13 +02:00
Sean Nyekjaer
33672c74b4 dt-bindings: can: mcp251x: add mcp25625 support
[ Upstream commit 0df82dcd55 ]

Fully compatible with mcp2515, the mcp25625 have integrated transceiver.

This patch add the mcp25625 to the device tree bindings documentation.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-14 08:11:07 +02:00
Will Deacon
a319c8ff4f futex: Update comments and docs about return values of arch futex code
commit 4275035197 upstream.

The architecture implementations of 'arch_futex_atomic_op_inuser()' and
'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT,
-EAGAIN or -ENOSYS in the case of failure.

Update the comments in the asm-generic/ implementation and also a stray
reference in the robust futex documentation.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 13:14:49 +02:00
Eric Dumazet
7f9f8a37e5 tcp: add tcp_min_snd_mss sysctl
commit 5f3e2bf008 upstream.

Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.

This forces the stack to send packets with a very high network/cpu
overhead.

Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.

In some cases, it can be useful to increase the minimal value
to a saner value.

We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.

Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f1 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.

We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-17 19:51:56 +02:00
Jonathan Corbet
21158982f6 doc: Cope with Sphinx logging deprecations
commit 096ea522e8 upstream.

Recent versions of sphinx will emit messages like:

  Documentation/sphinx/kerneldoc.py:103:
     RemovedInSphinx20Warning: app.warning() is now deprecated.
     Use sphinx.util.logging instead.

Switch to sphinx.util.logging to make this unsightly message go away.
Alas, that interface was only added in version 1.6, so we have to add a
version check to keep things working with older sphinxes.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09 09:17:21 +02:00
Jonathan Corbet
c0742228bb doc: Cope with the deprecation of AutoReporter
commit 2404dad1f6 upstream.

AutoReporter is going away; recent versions of sphinx emit a warning like:

  Documentation/sphinx/kerneldoc.py:125:
      RemovedInSphinx20Warning: AutodocReporter is now deprecated.
      Use sphinx.util.docutils.switch_source_input() instead.

Make the switch.  But switch_source_input() only showed up in 1.7, so we
have to do ugly version checks to keep things working in older versions.

Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09 09:17:20 +02:00