linux-stable.git/Documentation, branch v4.14.78

ARM: dts: at91: add new compatibility string for macb on sama5d3

2018-10-18T07:16:22+00:00

[ Upstream commit 321cc359d899a8e988f3725d87c18a628e1cc624 ]

We need this new compatibility string as we experienced different behavior
for this 10/100Mbits/s macb interface on this particular SoC.
Backward compatibility is preserved as we keep the alternative strings.

Signed-off-by: Nicolas Ferre 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

hwmon: (ina2xx) fix sysfs shunt resistor read access

2018-10-04T00:00:58+00:00

[ Upstream commit 3ad867001c91657c46dcf6656d52eb6080286fd5 ]

fix the sysfs shunt resistor read access: return the shunt resistor
value, not the calibration register contents.

update email address

Signed-off-by: Lothar Felten 
Signed-off-by: Guenter Roeck 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

inet: frags: break the 2GB limit for frags storage

2018-09-19T20:43:46+00:00

Some users are willing to provision huge amounts of memory to be able
to perform reassembly reasonnably well under pressure.

Current memory tracking is using one atomic_t and integers.

Switch to atomic_long_t so that 64bit arches can use more than 2GB,
without any cost for 32bit arches.

Note that this patch avoids an overflow error, if high_thresh was set
to ~2GB, since this test in inet_frag_alloc() was never true :

if (... || frag_mem_limit(nf) > nf->high_thresh)

Tested:

$ echo 16000000000 >/proc/sys/net/ipv4/ipfrag_high_thresh



$ grep FRAG /proc/net/sockstat
FRAG: inuse 14705885 memory 16000002880

$ nstat -n ; sleep 1 ; nstat | grep Reas
IpReasmReqds                    3317150            0.0
IpReasmFails                    3317112            0.0

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
(cherry picked from commit 3e67f106f619dcfaf6f4e2039599bdb69848c714)
Signed-off-by: Greg Kroah-Hartman

inet: frags: use rhashtables for reassembly units

2018-09-19T20:43:46+00:00

Some applications still rely on IP fragmentation, and to be fair linux
reassembly unit is not working under any serious load.

It uses static hash tables of 1024 buckets, and up to 128 items per bucket (!!!)

A work queue is supposed to garbage collect items when host is under memory
pressure, and doing a hash rebuild, changing seed used in hash computations.

This work queue blocks softirqs for up to 25 ms when doing a hash rebuild,
occurring every 5 seconds if host is under fire.

Then there is the problem of sharing this hash table for all netns.

It is time to switch to rhashtables, and allocate one of them per netns
to speedup netns dismantle, since this is a critical metric these days.

Lookup is now using RCU. A followup patch will even remove
the refcount hold/release left from prior implementation and save
a couple of atomic operations.

Before this patch, 16 cpus (16 RX queue NIC) could not handle more
than 1 Mpps frags DDOS.

After the patch, I reach 9 Mpps without any tuning, and can use up to 2GB
of storage for the fragments (exact number depends on frags being evicted
after timeout)

$ grep FRAG /proc/net/sockstat
FRAG: inuse 1966916 memory 2140004608

A followup patch will change the limits for 64bit arches.

Signed-off-by: Eric Dumazet 
Cc: Kirill Tkhai 
Cc: Herbert Xu 
Cc: Florian Westphal 
Cc: Jesper Dangaard Brouer 
Cc: Alexander Aring 
Cc: Stefan Schmidt 
Signed-off-by: David S. Miller 
(cherry picked from commit 648700f76b03b7e8149d13cc2bdb3355035258a9)
Signed-off-by: Greg Kroah-Hartman

kbuild: verify that $DEPMOD is installed

2018-08-17T19:01:10+00:00

commit 934193a654c1f4d0643ddbf4b2529b508cae926e upstream.

Verify that 'depmod' ($DEPMOD) is installed.
This is a partial revert of commit 620c231c7a7f
("kbuild: do not check for ancient modutils tools").

Also update Documentation/process/changes.rst to refer to
kmod instead of module-init-tools.

Fixes kernel bugzilla #198965:
https://bugzilla.kernel.org/show_bug.cgi?id=198965

Signed-off-by: Randy Dunlap 
Cc: Lucas De Marchi 
Cc: Lucas De Marchi 
Cc: Michal Marek 
Cc: Jessica Yu 
Cc: Chih-Wei Huang 
Cc: stable@vger.kernel.org # any kernel since 2012
Signed-off-by: Masahiro Yamada 
Signed-off-by: Greg Kroah-Hartman

KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry

2018-08-15T16:13:00+00:00

commit 5b76a3cff011df2dcb6186c965a2e4d809a05ad4 upstream

When nested virtualization is in use, VMENTER operations from the nested
hypervisor into the nested guest will always be processed by the bare metal
hypervisor, and KVM's "conditional cache flushes" mode in particular does a
flush on nested vmentry.  Therefore, include the "skip L1D flush on
vmentry" bit in KVM's suggested ARCH_CAPABILITIES setting.

Add the relevant Documentation.

Signed-off-by: Paolo Bonzini 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

KVM: x86: Add a framework for supporting MSR-based features

2018-08-15T16:12:59+00:00

commit 801e459a6f3a63af9d447e6249088c76ae16efc4 upstream

Provide a new KVM capability that allows bits within MSRs to be recognized
as features.  Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.

Signed-off-by: Tom Lendacky 
Signed-off-by: Paolo Bonzini 
[Tweaked documentation. - Radim]
Signed-off-by: Radim Krčmář 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Documentation/l1tf: Remove Yonah processors from not vulnerable list

2018-08-15T16:12:59+00:00

commit 58331136136935c631c2b5f06daf4c3006416e91 upstream

Dave reported, that it's not confirmed that Yonah processors are
unaffected. Remove them from the list.

Reported-by: ave Hansen 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Documentation/l1tf: Fix typos

2018-08-15T16:12:57+00:00

commit 1949f9f49792d65dba2090edddbe36a5f02e3ba3 upstream

Fix spelling and other typos

Signed-off-by: Tony Luck 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

Documentation: Add section about CPU vulnerabilities

2018-08-15T16:12:56+00:00

commit 3ec8ce5d866ec6a08a9cfab82b62acf4a830b35f upstream

Add documentation for the L1TF vulnerability and the mitigation mechanisms:

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

Signed-off-by: Thomas Gleixner 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Josh Poimboeuf 
Acked-by: Linus Torvalds 
Link: https://lkml.kernel.org/r/20180713142323.287429944@linutronix.de
Signed-off-by: Greg Kroah-Hartman