linux-stable.git, branch v5.4.43

Linux 5.4.43

2020-05-27T15:46:53+00:00

sched/fair: Fix enqueue_task_fair() warning some more

2020-05-27T15:46:52+00:00

[ Upstream commit b34cb07dde7c2346dec73d053ce926aeaa087303 ]

sched/fair: Fix enqueue_task_fair warning some more

The recent patch, fe61468b2cb (sched/fair: Fix enqueue_task_fair warning)
did not fully resolve the issues with the rq->tmp_alone_branch !=
&rq->leaf_cfs_rq_list warning in enqueue_task_fair. There is a case where
the first for_each_sched_entity loop exits due to on_rq, having incompletely
updated the list.  In this case the second for_each_sched_entity loop can
further modify se. The later code to fix up the list management fails to do
what is needed because se does not point to the sched_entity which broke out
of the first loop. The list is not fixed up because the throttled parent was
already added back to the list by a task enqueue in a parallel child hierarchy.

Address this by calling list_add_leaf_cfs_rq if there are throttled parents
while doing the second for_each_sched_entity loop.

Fixes: fe61468b2cb ("sched/fair: Fix enqueue_task_fair warning")
Suggested-by: Vincent Guittot 
Signed-off-by: Phil Auld 
Signed-off-by: Peter Zijlstra (Intel) 
Reviewed-by: Dietmar Eggemann 
Reviewed-by: Vincent Guittot 
Link: https://lkml.kernel.org/r/20200512135222.GC2201@lorien.usersys.redhat.com
Signed-off-by: Sasha Levin

sched/fair: Fix reordering of enqueue/dequeue_task_fair()

2020-05-27T15:46:52+00:00

[ Upstream commit 5ab297bab984310267734dfbcc8104566658ebef ]

Even when a cgroup is throttled, the group se of a child cgroup can still
be enqueued and its gse->on_rq stays true. When a task is enqueued on such
child, we still have to update the load_avg and increase
h_nr_running of the throttled cfs. Nevertheless, the 1st
for_each_sched_entity() loop is skipped because of gse->on_rq == true and the
2nd loop because the cfs is throttled whereas we have to update both
load_avg with the old h_nr_running and increase h_nr_running in such case.

The same sequence can happen during dequeue when se moves to parent before
breaking in the 1st loop.

Note that the update of load_avg will effectively happen only once in order
to sync up to the throttled time. Next call for updating load_avg will stop
early because the clock stays unchanged.

Signed-off-by: Vincent Guittot 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Fixes: 6d4d22468dae ("sched/fair: Reorder enqueue/dequeue_task_fair path")
Link: https://lkml.kernel.org/r/20200306084208.12583-1-vincent.guittot@linaro.org
Signed-off-by: Sasha Levin

sched/fair: Reorder enqueue/dequeue_task_fair path

2020-05-27T15:46:52+00:00

[ Upstream commit 6d4d22468dae3d8757af9f8b81b848a76ef4409d ]

The walk through the cgroup hierarchy during the enqueue/dequeue of a task
is split in 2 distinct parts for throttled cfs_rq without any added value
but making code less readable.

Change the code ordering such that everything related to a cfs_rq
(throttled or not) will be done in the same loop.

In addition, the same steps ordering is used when updating a cfs_rq:

 - update_load_avg
 - update_cfs_group
 - update *h_nr_running

This reordering enables the use of h_nr_running in PELT algorithm.

No functional and performance changes are expected and have been noticed
during tests.

Signed-off-by: Vincent Guittot 
Signed-off-by: Mel Gorman 
Signed-off-by: Ingo Molnar 
Reviewed-by: "Dietmar Eggemann "
Acked-by: Peter Zijlstra 
Cc: Juri Lelli 
Cc: Valentin Schneider 
Cc: Phil Auld 
Cc: Hillf Danton 
Link: https://lore.kernel.org/r/20200224095223.13361-5-mgorman@techsingularity.net
Signed-off-by: Sasha Levin

tpm: check event log version before reading final events

2020-05-27T15:46:52+00:00

[ Upstream commit b4f1874c62168159fdb419ced4afc77c1b51c475 ]

This fixes the boot issues since 5.3 on several Dell models when the TPM
is enabled. Depending on the exact grub binary, booting the kernel would
freeze early, or just report an error parsing the final events log.

We get an event log in the SHA-1 format, which doesn't have a
tcg_efi_specid_event_head in the first event, and there is a final events
table which doesn't match the crypto agile format.
__calc_tpm2_event_size reads bad "count" and "efispecid->num_algs", and
either fails, or loops long enough for the machine to be appear frozen.

So we now only parse the final events table, which is per the spec always
supposed to be in the crypto agile format, when we got a event log in this
format.

Fixes: c46f3405692de ("tpm: Reserve the TPM final events table")
Fixes: 166a2809d65b2 ("tpm: Don't duplicate events from the final event log in the TCG2 log")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1779611
Signed-off-by: Loïc Yhuel 
Link: https://lore.kernel.org/r/20200512040113.277768-1-loic.yhuel@gmail.com
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Jerry Snitselaar 
Reviewed-by: Matthew Garrett 
[ardb: warn when final events table is missing or in the wrong format]
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Sasha Levin

rxrpc: Fix ack discard

2020-05-27T15:46:51+00:00

[ Upstream commit 441fdee1eaf050ef0040bde0d7af075c1c6a6d8b ]

The Rx protocol has a "previousPacket" field in it that is not handled in
the same way by all protocol implementations.  Sometimes it contains the
serial number of the last DATA packet received, sometimes the sequence
number of the last DATA packet received and sometimes the highest sequence
number so far received.

AF_RXRPC is using this to weed out ACKs that are out of date (it's possible
for ACK packets to get reordered on the wire), but this does not work with
OpenAFS which will just stick the sequence number of the last packet seen
into previousPacket.

The issue being seen is that big AFS FS.StoreData RPC (eg. of ~256MiB) are
timing out when partly sent.  A trace was captured, with an additional
tracepoint to show ACKs being discarded in rxrpc_input_ack().  Here's an
excerpt showing the problem.

 52873.203230: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 0002449c q=00024499 fl=09

A DATA packet with sequence number 00024499 has been transmitted (the "q="
field).

 ...
 52873.243296: rxrpc_rx_ack: c=000004ae 00012a2b DLY r=00024499 f=00024497 p=00024496 n=0
 52873.243376: rxrpc_rx_ack: c=000004ae 00012a2c IDL r=0002449b f=00024499 p=00024498 n=0
 52873.243383: rxrpc_rx_ack: c=000004ae 00012a2d OOS r=0002449d f=00024499 p=0002449a n=2

The Out-Of-Sequence ACK indicates that the server didn't see DATA sequence
number 00024499, but did see seq 0002449a (previousPacket, shown as "p=",
skipped the number, but firstPacket, "f=", which shows the bottom of the
window is set at that point).

 52873.252663: rxrpc_retransmit: c=000004ae q=24499 a=02 xp=14581537
 52873.252664: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244bc q=00024499 fl=0b *RETRANS*

The packet has been retransmitted.  Retransmission recurs until the peer
says it got the packet.

 52873.271013: rxrpc_rx_ack: c=000004ae 00012a31 OOS r=000244a1 f=00024499 p=0002449e n=6

More OOS ACKs indicate that the other packets that are already in the
transmission pipeline are being received.  The specific-ACK list is up to 6
ACKs and NAKs.

 ...
 52873.284792: rxrpc_rx_ack: c=000004ae 00012a49 OOS r=000244b9 f=00024499 p=000244b6 n=30
 52873.284802: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=63505500
 52873.284804: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c2 q=00024499 fl=0b *RETRANS*
 52873.287468: rxrpc_rx_ack: c=000004ae 00012a4a OOS r=000244ba f=00024499 p=000244b7 n=31
 52873.287478: rxrpc_rx_ack: c=000004ae 00012a4b OOS r=000244bb f=00024499 p=000244b8 n=32

At this point, the server's receive window is full (n=32) with presumably 1
NAK'd packet and 31 ACK'd packets.  We can't transmit any more packets.

 52873.287488: rxrpc_retransmit: c=000004ae q=24499 a=0a xp=61327980
 52873.287489: rxrpc_tx_data: c=000004ae DATA ed1a3584:00000002 000244c3 q=00024499 fl=0b *RETRANS*
 52873.293850: rxrpc_rx_ack: c=000004ae 00012a4c DLY r=000244bc f=000244a0 p=00024499 n=25

And now we've received an ACK indicating that a DATA retransmission was
received.  7 packets have been processed (the occupied part of the window
moved, as indicated by f= and n=).

 52873.293853: rxrpc_rx_discard_ack: c=000004ae r=00012a4c 000244a0<00024499 00024499<000244b8

However, the DLY ACK gets discarded because its previousPacket has gone
backwards (from p=000244b8, in the ACK at 52873.287478 to p=00024499 in the
ACK at 52873.293850).

We then end up in a continuous cycle of retransmit/discard.  kafs fails to
update its window because it's discarding the ACKs and can't transmit an
extra packet that would clear the issue because the window is full.
OpenAFS doesn't change the previousPacket value in the ACKs because no new
DATA packets are received with a different previousPacket number.

Fix this by altering the discard check to only discard an ACK based on
previousPacket if there was no advance in the firstPacket.  This allows us
to transmit a new packet which will cause previousPacket to advance in the
next ACK.

The check, however, needs to allow for the possibility that previousPacket
may actually have had the serial number placed in it instead - in which
case it will go outside the window and we should ignore it.

Fixes: 1a2391c30c0b ("rxrpc: Fix detection of out of order acks")
Reported-by: Dave Botsch 
Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

rxrpc: Trace discarded ACKs

2020-05-27T15:46:51+00:00

[ Upstream commit d1f129470e6cb79b8b97fecd12689f6eb49e27fe ]

Add a tracepoint to track received ACKs that are discarded due to being
outside of the Tx window.

Signed-off-by: David Howells 
Signed-off-by: Sasha Levin

iio: adc: stm32-dfsdm: fix device used to request dma

2020-05-27T15:46:51+00:00

[ Upstream commit b455d06e6fb3c035711e8aab1ca18082ccb15d87 ]

DMA channel request should use device struct from platform device struct.
Currently it's using iio device struct. But at this stage when probing,
device struct isn't yet registered (e.g. device_register is done in
iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
symlinks between DMA channels and slaves"), a warning message is printed
as the links in sysfs can't be created, due to device isn't yet registered:
- Cannot create DMA slave symlink
- Cannot create DMA dma:rx symlink

Fix this by using device struct from platform device to request dma chan.

Fixes: eca949800d2d ("IIO: ADC: add stm32 DFSDM support for PDM microphone")

Signed-off-by: Fabrice Gasnier 
Cc: 
Signed-off-by: Jonathan Cameron 
Signed-off-by: Sasha Levin

iio: adc: stm32-dfsdm: Use dma_request_chan() instead dma_request_slave_channel()

2020-05-27T15:46:50+00:00

[ Upstream commit a9ab624edd9186fbad734cfe5d606a6da3ca34db ]

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi 
Acked-by: Olivier Moysan 
Acked-by: Fabrice Gasnier 
Signed-off-by: Jonathan Cameron 
Signed-off-by: Sasha Levin

iio: adc: stm32-adc: fix device used to request dma

2020-05-27T15:46:50+00:00

[ Upstream commit 52cd91c27f3908b88e8b25aed4a4d20660abcc45 ]

DMA channel request should use device struct from platform device struct.
Currently it's using iio device struct. But at this stage when probing,
device struct isn't yet registered (e.g. device_register is done in
iio_device_register). Since commit 71723a96b8b1 ("dmaengine: Create
symlinks between DMA channels and slaves"), a warning message is printed
as the links in sysfs can't be created, due to device isn't yet registered:
- Cannot create DMA slave symlink
- Cannot create DMA dma:rx symlink

Fix this by using device struct from platform device to request dma chan.

Fixes: 2763ea0585c99 ("iio: adc: stm32: add optional dma support")

Signed-off-by: Fabrice Gasnier 
Cc: 
Signed-off-by: Jonathan Cameron 
Signed-off-by: Sasha Levin