linux-stable.git/Documentation, branch v6.5.7

arm64: errata: Add Cortex-A520 speculative unprivileged load workaround

2023-10-10T20:02:57+00:00

commit 471470bc7052d28ce125901877dd10e4c048e513 upstream.

Implement the workaround for ARM Cortex-A520 erratum 2966298. On an
affected Cortex-A520 core, a speculatively executed unprivileged load
might leak data from a privileged load via a cache side channel. The
issue only exists for loads within a translation regime with the same
translation (e.g. same ASID and VMID). Therefore, the issue only affects
the return to EL0.

The workaround is to execute a TLBI before returning to EL0 after all
loads of privileged data. A non-shareable TLBI to any address is
sufficient.

The workaround isn't necessary if page table isolation (KPTI) is
enabled, but for simplicity it will be. Page table isolation should
normally be disabled for Cortex-A520 as it supports the CSV3 feature
and the E0PD feature (used when KASLR is enabled).

Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring 
Link: https://lore.kernel.org/r/20230921194156.1050055-2-robh@kernel.org
Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

net: change accept_ra_min_rtr_lft to affect all RA lifetimes

2023-10-10T20:02:55+00:00

commit 5027d54a9c30bc7ec808360378e2b4753f053f25 upstream.

accept_ra_min_rtr_lft only considered the lifetime of the default route
and discarded entire RAs accordingly.

This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and
applies the value to individual RA sections; in particular, router
lifetime, PIO preferred lifetime, and RIO lifetime. If any of those
lifetimes are lower than the configured value, the specific RA section
is ignored.

In order for the sysctl to be useful to Android, it should really apply
to all lifetimes in the RA, since that is what determines the minimum
frequency at which RAs must be processed by the kernel. Android uses
hardware offloads to drop RAs for a fraction of the minimum of all
lifetimes present in the RA (some networks have very frequent RAs (5s)
with high lifetimes (2h)). Despite this, we have encountered networks
that set the router lifetime to 30s which results in very frequent CPU
wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the
WiFi firmware) entirely on such networks, it seems better to ignore the
misconfigured routers while still processing RAs from other IPv6 routers
on the same network (i.e. to support IoT applications).

The previous implementation dropped the entire RA based on router
lifetime. This turned out to be hard to expand to the other lifetimes
present in the RA in a consistent manner; dropping the entire RA based
on RIO/PIO lifetimes would essentially require parsing the whole thing
twice.

Fixes: 1671bcfd76fd ("net: add sysctl accept_ra_min_rtr_lft")
Cc: Lorenzo Colitti 
Signed-off-by: Patrick Rohr 
Reviewed-by: Maciej Żenczykowski 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: add sysctl accept_ra_min_rtr_lft

2023-10-10T20:02:55+00:00

commit 1671bcfd76fdc0b9e65153cf759153083755fe4c upstream.

This change adds a new sysctl accept_ra_min_rtr_lft to specify the
minimum acceptable router lifetime in an RA. If the received RA router
lifetime is less than the configured value (and not 0), the RA is
ignored.
This is useful for mobile devices, whose battery life can be impacted
by networks that configure RAs with a short lifetime. On such networks,
the device should never gain IPv6 provisioning and should attempt to
drop RAs via hardware offload, if available.

Signed-off-by: Patrick Rohr 
Cc: Maciej Żenczykowski 
Cc: Lorenzo Colitti 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

mm, memcg: reconsider kmem.limit_in_bytes deprecation

2023-10-06T11:16:30+00:00

commit 4597648fddeadef5877610d693af11906aa666ac upstream.

This reverts commits 86327e8eb94c ("memcg: drop kmem.limit_in_bytes") and
partially reverts 58056f77502f ("memcg, kmem: further deprecate
kmem.limit_in_bytes") which have incrementally removed support for the
kernel memory accounting hard limit.  Unfortunately it has turned out that
there is still userspace depending on the existence of
memory.kmem.limit_in_bytes [1].  The underlying functionality is not
really required but the non-existent file just confuses the userspace
which fails in the result.  The patch to fix this on the userspace side
has been submitted but it is hard to predict how it will propagate through
the maze of 3rd party consumers of the software.

Now, reverting alone 86327e8eb94c is not an option because there is
another set of userspace which cannot cope with ENOTSUPP returned when
writing to the file.  Therefore we have to go and revisit 58056f77502f as
well.  There are two ways to go ahead.  Either we give up on the
deprecation and fully revert 58056f77502f as well or we can keep
kmem.limit_in_bytes but make the write a noop and warn about the fact.
This should work for both known breaking workloads which depend on the
existence but do not depend on the hard limit enforcement.

Note to backporters to stable trees.  a8c49af3be5f ("memcg: add per-memcg
total kernel memory stat") introduced in 4.18 has added memcg_account_kmem
so the accounting is not done by obj_cgroup_charge_pages directly for v1
anymore.  Prior kernels need to add it explicitly (thanks to Johannes for
pointing this out).

[akpm@linux-foundation.org: fix build - remove unused local]
Link: http://lkml.kernel.org/r/20230920081101.GA12096@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net [1]
Link: https://lkml.kernel.org/r/ZRE5VJozPZt9bRPy@dhcp22.suse.cz
Fixes: 86327e8eb94c ("memcg: drop kmem.limit_in_bytes")
Fixes: 58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes")
Signed-off-by: Michal Hocko 
Acked-by: Shakeel Butt 
Acked-by: Johannes Weiner 
Cc: Greg Kroah-Hartman 
Cc: Jeremi Piotrowski 
Cc: Muchun Song 
Cc: Roman Gushchin 
Cc: Tejun heo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

memcg: drop kmem.limit_in_bytes

2023-10-06T11:16:30+00:00

commit 86327e8eb94c52eca4f93cfece2e29d1bf52acbf upstream.

kmem.limit_in_bytes (v1 way to limit kernel memory usage) has been
deprecated since 58056f77502f ("memcg, kmem: further deprecate
kmem.limit_in_bytes") merged in 5.16.  We haven't heard about any serious
users since then but it seems that the mere presence of the file is
causing more harm thatn good.  We (SUSE) have had several bug reports from
customers where Docker based containers started to fail because a write to
kmem.limit_in_bytes has failed.

This was unexpected because runc code only expects ENOENT (kmem disabled)
or EBUSY (tasks already running within cgroup).  So a new error code was
unexpected and the whole container startup failed.  This has been later
addressed by
https://github.com/opencontainers/runc/commit/52390d68040637dfc77f9fda6bbe70952423d380
so current Docker runtimes do not suffer from the problem anymore.  There
are still older version of Docker in use and likely hard to get rid of
completely.

Address this by wiping out the file completely and effectively get back to
pre 4.5 era and CONFIG_MEMCG_KMEM=n configuration.

I would recommend backporting to stable trees which have picked up
58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes").

[mhocko@suse.com: restore _KMEM switch case]
  Link: https://lkml.kernel.org/r/ZKe5wxdbvPi5Cwd7@dhcp22.suse.cz
Link: https://lkml.kernel.org/r/20230704115240.14672-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Acked-by: Shakeel Butt 
Acked-by: Johannes Weiner 
Acked-by: Roman Gushchin 
Cc: Muchun Song 
Cc: Tejun Heo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

ALSA: docs: Fix a typo of midi2_ump_probe option for snd-usb-audio

2023-10-06T11:15:47+00:00

[ Upstream commit 60edec9beffebd01a49c005221230f3a61fe6587 ]

A simple typo fix: midi2_probe => midi2_ump_probe.

Fixes: febdfa0e9c8a ("ALSA: docs: Update MIDI 2.0 documentation for UMP 1.1 enhancement")
Link: https://lore.kernel.org/r/20230912075944.14032-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Signed-off-by: Sasha Levin

Revert "memcg: drop kmem.limit_in_bytes"

2023-09-23T09:14:38+00:00

This reverts commit 75bb29b6c44f486e9bd048759669c205dccb2048 which is
commit 86327e8eb94c52eca4f93cfece2e29d1bf52acbf upstream.

It breaks existing runc systems, as the tool always thinks the file
should be present.

Reported-by: Jeremi Piotrowski 
Link: https://lore.kernel.org/r/20230920081101.GA12096@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Cc: Michal Hocko 
Cc: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Roman Gushchin 
Cc: Muchun Song 
Cc: Tejun Heo 
Cc: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09

2023-09-23T09:14:18+00:00

[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang 
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon 
Signed-off-by: Sasha Levin

dt-bindings: clock: xlnx,versal-clk: drop select:false

2023-09-19T10:30:11+00:00

commit 172044e30b00977784269e8ab72132a48293c654 upstream.

select:false makes the schema basically ignored and not effective, which
is clearly not what we want for a device binding.

Fixes: 352546805a44 ("dt-bindings: clock: Add bindings for versal clock driver")
Cc: 
Signed-off-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20230728165923.108589-1-krzysztof.kozlowski@linaro.org
Reviewed-by: Conor Dooley 
Reviewed-by: Shubhrajyoti Datta 
Signed-off-by: Stephen Boyd 
Signed-off-by: Greg Kroah-Hartman

memcg: drop kmem.limit_in_bytes

2023-09-19T10:30:11+00:00

commit 86327e8eb94c52eca4f93cfece2e29d1bf52acbf upstream.

kmem.limit_in_bytes (v1 way to limit kernel memory usage) has been
deprecated since 58056f77502f ("memcg, kmem: further deprecate
kmem.limit_in_bytes") merged in 5.16.  We haven't heard about any serious
users since then but it seems that the mere presence of the file is
causing more harm thatn good.  We (SUSE) have had several bug reports from
customers where Docker based containers started to fail because a write to
kmem.limit_in_bytes has failed.

This was unexpected because runc code only expects ENOENT (kmem disabled)
or EBUSY (tasks already running within cgroup).  So a new error code was
unexpected and the whole container startup failed.  This has been later
addressed by
https://github.com/opencontainers/runc/commit/52390d68040637dfc77f9fda6bbe70952423d380
so current Docker runtimes do not suffer from the problem anymore.  There
are still older version of Docker in use and likely hard to get rid of
completely.

Address this by wiping out the file completely and effectively get back to
pre 4.5 era and CONFIG_MEMCG_KMEM=n configuration.

I would recommend backporting to stable trees which have picked up
58056f77502f ("memcg, kmem: further deprecate kmem.limit_in_bytes").

[mhocko@suse.com: restore _KMEM switch case]
  Link: https://lkml.kernel.org/r/ZKe5wxdbvPi5Cwd7@dhcp22.suse.cz
Link: https://lkml.kernel.org/r/20230704115240.14672-1-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Acked-by: Shakeel Butt 
Acked-by: Johannes Weiner 
Acked-by: Roman Gushchin 
Cc: Muchun Song 
Cc: Tejun Heo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman