One can use "cpuset.cpus.partition" to create multiple scheduling domains
or to produce a set of isolated CPUs where load balancing is disabled.
The former use case is less common but the latter one can be frequently
used especially for the Telco use cases like DPDK.

The existing "isolated" partition can be used to produce isolated
CPUs if the applications have full control of a system. However, in a
containerized environment where all the apps are run in a container,
it is hard to distribute out isolated CPUs from the root down given
the unified hierarchy nature of cgroup v2.

The container running on isolated CPUs can be several layers down from
the root. The current partition feature requires that all the ancestors
of a leaf partition root must be parititon roots themselves. This can
be hard to configure.

This patch introduces a new type of partition called remote partition.
A remote partition is a partition whose parent is not a partition root
itself and its CPUs are acquired directly from available CPUs in the
top cpuset through a hierachical distribution of exclusive CPUs down
from it.

By contrast, the existing type of partitions where their parents have
to be valid partition roots are referred to as local partitions as they
have to be clustered around a parent partition root.

Child local partitons can be created under a remote partition, but
a remote partition cannot be created under a local partition. We may
relax this limitation in the future if there are use cases for such
configuration.

Manually writing to the "cpuset.cpus.exclusive" file is not necessary
when creating local partitions.  However, writing proper values to
"cpuset.cpus.exclusive" down the cgroup hierarchy before the target
remote partition root is mandatory for the creation of a remote
partition.

The value in "cpuset.cpus.exclusive.effective" may change if its
"cpuset.cpus" or its parent's "cpuset.cpus.exclusive.effective" changes.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

This patch introduces a new writable "cpuset.cpus.exclusive" control
file for v2 which will be added to non-root cpuset enabled cgroups. This new
file enables user to set a smaller list of exclusive CPUs to be used in
the creation of a cpuset partition.

The value written to "cpuset.cpus.exclusive" may not be the effective
value being used for the creation of cpuset partition, the effective
value will show up in "cpuset.cpus.exclusive.effective" and it is
subject to the constraint that it must also be a subset of cpus_allowed
and parent's "cpuset.cpus.exclusive.effective".

By writing to "cpuset.cpus.exclusive", "cpuset.cpus.exclusive.effective"
may be set to a non-empty value even for cgroups that are not valid
partition roots yet.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

The creation of a cpuset partition means dedicating a set of exclusive
CPUs to be used by a particular partition only. These exclusive CPUs
will not be used by any cpusets outside of that partition.

To enable more flexibility in creating partitions, we need a way to
distribute exclusive CPUs that can be used in new partitions. Currently,
we have a subparts_cpus cpumask in struct cpuset that tracks only
the exclusive CPUs used by all the sub-partitions underneath a given
cpuset.

This patch reworks the way we do exclusive CPUs tracking. The
subparts_cpus is now renamed to effective_xcpus which tracks the
exclusive CPUs allocated to a partition root including those that are
further distributed down to sub-partitions underneath it. IOW, it also
includes the exclusive CPUs used by the current partition root. Note
that effective_xcpus can contain offline CPUs and it will always be a
subset of cpus_allowed.

The renamed effective_xcpus is now exposed via a new read-only
"cpuset.cpus.exclusive.effective" control file. The new effective_xcpus
cpumask should be set to cpus_allowed when a cpuset becomes a partition
root and be cleared if it is not a valid partition root.

In the next patch, we will enable write to another new control file to
enable further control of what can get into effective_xcpus.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Commit a86ce680 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE
& CS_SCHED_LOAD_BALANCE handling") adds a new helper function
update_partition_sd_lb() to update the load balance state of the
cpuset. However the new load balance is determined by just looking at
whether the cpuset is a valid isolated partition root or not.  That is
not enough if the cpuset is not a valid partition root but its parent
is in the isolated state (load balance off). Update the function to
set the new state to be the same as its parent in this case like what
has been done in commit c8c92620 ("cgroup/cpuset: Inherit parent's
load balance state in v2").

Fixes: a86ce680 ("cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Use css directly instead of dereferencing it from &cgroup->self, while
adding the cgroup v2 cft base and psi files in css_populate_dir(). Both
points to the same css, when css->ss is NULL, this avoids extra deferences
and makes code consistent in usage across the function.
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

There is no check for possible failure while populating
cgroup1_base_files cft in css_populate_dir(), like its cgroup v2 counter
parts cgroup_{base,psi}_files.  In case of failure, the cgroup might not
be set up right.  Add ret value check to return on failure.
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - Fix an UV boot crash

   - Skip spurious ENDBR generation on _THIS_IP_

   - Fix ENDBR use in putuser() asm methods

   - Fix corner case boot crashes on 5-level paging

   - and fix a false positive WARNING on LTO kernels"

* tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/purgatory: Remove LTO flags
  x86/boot/compressed: Reserve more memory for page tables
  x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()
  x86/ibt: Suppress spurious ENDBR
  x86/platform/uv: Use alternate source for socket to node data

Pull scheduler fixes from Ingo Molnar:
 "Fix a performance regression on large SMT systems, an Intel SMT4
  balancing bug, and a topology setup bug on (Intel) hybrid processors"

* tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domain
  sched/fair: Fix SMT4 group_smt_balance handling
  sched/fair: Optimize should_we_balance() for large SMT systems

Pull objtool fix from Ingo Molnar:
 "Fix a cold functions related false-positive objtool warning that
  triggers on Clang"

* tag 'objtool-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix _THIS_IP_ detection for cold functions

Pull WARN fix from Ingo Molnar:
 "Fix a missing preempt-enable in the WARN() slowpath"

* tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  panic: Reenable preemption in WARN slowpath

The choose_32_64() macros were added to deal with an odd inconsistency
between the 32-bit and 64-bit layout of 'struct stat' way back when in
commit a52dd971 ("vfs: de-crapify "cp_new_stat()" function").

Then a decade later Mikulas noticed that said inconsistency had been a
mistake in the early x86-64 port, and shouldn't have existed in the
first place.  So commit 932aba1e ("stat: fix inconsistency between
struct stat and struct compat_stat") removed the uses of the helpers.

But the helpers remained around, unused.

Get rid of them.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull smb client fixes from Steve French:
 "Three small SMB3 client fixes, one to improve a null check and two
  minor cleanups"

* tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix some minor typos and repeated words
  smb3: correct places where ENOTSUPP is used instead of preferred EOPNOTSUPP
  smb3: move server check earlier when setting channel sequence number

Pull smb server fixes from Steve French:
 "Two ksmbd server fixes"

* tag '6.6-rc1-ksmbd' of git://git.samba.org/ksmbd:
  ksmbd: fix passing freed memory 'aux_payload_buf'
  ksmbd: remove unneeded mark_inode_dirty in set_info_sec()

Pull ext4 fixes from Ted Ts'o:
 "Regression and bug fixes for ext4"

* tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix rec_len verify error
  ext4: do not let fstrim block system suspend
  ext4: move setting of trimmed bit into ext4_try_to_trim_range()
  jbd2: Fix memory leak in journal_init_common()
  jbd2: Remove page size assumptions
  buffer: Make bh_offset() work for compound pages

-flto* implies -ffunction-sections. With LTO enabled, ld.lld generates
multiple .text sections for purgatory.ro:

  $ readelf -S purgatory.ro  | grep " .text"
    [ 1] .text             PROGBITS         0000000000000000  00000040
    [ 7] .text.purgatory   PROGBITS         0000000000000000  000020e0
    [ 9] .text.warn        PROGBITS         0000000000000000  000021c0
    [13] .text.sha256_upda PROGBITS         0000000000000000  000022f0
    [15] .text.sha224_upda PROGBITS         0000000000000000  00002be0
    [17] .text.sha256_fina PROGBITS         0000000000000000  00002bf0
    [19] .text.sha224_fina PROGBITS         0000000000000000  00002cc0

This causes WARNING from kexec_purgatory_setup_sechdrs():

  WARNING: CPU: 26 PID: 110894 at kernel/kexec_file.c:919
  kexec_load_purgatory+0x37f/0x390

Fix this by disabling LTO for purgatory.

[ AFAICT, x86 is the only arch that supports LTO and purgatory. ]

We could also fix this with an explicit linker script to rejoin .text.*
sections back into .text. However, given the benefit of LTOing purgatory
is small, simply disable the production of more .text.* sections for now.

Fixes: b33fff07 ("x86, build: allow LTO to be selected")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230914170138.995606-1-song@kernel.org

The decompressor has a hard limit on the number of page tables it can
allocate. This limit is defined at compile-time and will cause boot
failure if it is reached.

The kernel is very strict and calculates the limit precisely for the
worst-case scenario based on the current configuration. However, it is
easy to forget to adjust the limit when a new use-case arises. The
worst-case scenario is rarely encountered during sanity checks.

In the case of enabling 5-level paging, a use-case was overlooked. The
limit needs to be increased by one to accommodate the additional level.
This oversight went unnoticed until Aaron attempted to run the kernel
via kexec with 5-level paging and unaccepted memory enabled.

Update wost-case calculations to include 5-level paging.

To address this issue, let's allocate some extra space for page tables.
128K should be sufficient for any use-case. The logic can be simplified
by using a single value for all kernel configurations.

[ Also add a warning, should this memory run low - by Dave Hansen. ]

Fixes: 34bbb000 ("x86/boot/compressed: Enable 5-level paging during decompression stage")
Reported-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230915070221.10266-1-kirill.shutemov@linux.intel.com

Merge tag 'kbuild-fixes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild fixes from Masahiro Yamada:

 - Fix kernel-devel RPM and linux-headers Deb package

 - Fix too long argument list error in 'make modules_install'

* tag 'kbuild-fixes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: avoid long argument lists in make modules_install
  kbuild: fix kernel-devel RPM package and linux-headers Deb package

Commit 408579cd ("mm: Update do_vmi_align_munmap() return
semantics") seems to have updated one of the callers of do_vmi_munmap()
incorrectly: it used to check for the error case (which didn't
change: negative means error).

That commit changed the check to the success case (which did change:
before that commit, 0 was success, and 1 was "success and lock
downgraded".  After the change, it's always 0 for success, and the lock
will have been released if requested).

This didn't change any actual VM behavior _except_ for memory accounting
when 'VM_ACCOUNT' was set on the vma.  Which made the wrong return value
test fairly subtle, since everything continues to work.

Or rather - it continues to work but the "Committed memory" accounting
goes all wonky (Committed_AS value in /proc/meminfo), and depending on
settings that then causes problems much much later as the VM relies on
bogus statistics for its heuristics.

Revert that one line of the change back to the original logic.

Fixes: 408579cd ("mm: Update do_vmi_align_munmap() return semantics")
Reported-by: Christoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Reported-bisected-and-tested-by: Michael Labiuk <michael.labiuk@virtuozzo.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Link: https://lore.kernel.org/all/1694366957@msgid.manchmal.in-ulm.de/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull SCSI fixes from James Bottomley:
 "16 small(ish) fixes all in drivers.

  The major fixes are in pm8001 (fixes MSI-X issue going back to its
  origin), the qla2xxx endianness fix, which fixes a bug on big endian
  and the lpfc ones which can cause an oops on module removal without
  them"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: lpfc: Prevent use-after-free during rmmod with mapped NVMe rports
  scsi: lpfc: Early return after marking final NLP_DROPPED flag in dev_loss_tmo
  scsi: lpfc: Fix the NULL vs IS_ERR() bug for debugfs_create_file()
  scsi: target: core: Fix target_cmd_counter leak
  scsi: pm8001: Setup IRQs on resume
  scsi: pm80xx: Avoid leaking tags when processing OPC_INB_SET_CONTROLLER_CONFIG command
  scsi: pm80xx: Use phy-specific SAS address when sending PHY_START command
  scsi: ufs: core: Poll HCS.UCRDY before issuing a UIC command
  scsi: ufs: core: Move __ufshcd_send_uic_cmd() outside host_lock
  scsi: qedf: Add synchronization between I/O completions and abort
  scsi: target: Replace strlcpy() with strscpy()
  scsi: qla2xxx: Fix NULL vs IS_ERR() bug for debugfs_create_dir()
  scsi: qla2xxx: Use raw_smp_processor_id() instead of smp_processor_id()
  scsi: qla2xxx: Correct endianness for rqstlen and rsplen
  scsi: ppa: Fix accidentally reversed conditions for 16-bit and 32-bit EPP
  scsi: megaraid_sas: Fix deadlock on firmware crashdump

Pull ata fixes from Damien Le Moal:

 - Fix link power management transitions to disallow unsupported states
   (Niklas)

 - A small string handling fix for the sata_mv driver (Christophe)

 - Clear port pending interrupts before reset, as per AHCI
   specifications (Szuying).

   Followup fixes for this one are to not clear ATA_PFLAG_EH_PENDING in
   ata_eh_reset() to allow EH to continue on with other actions recorded
   with error interrupts triggered before EH completes. And an
   additional fix to avoid thawing a port twice in EH (Niklas)

 - Small code style fixes in the pata_parport driver to silence the
   build bot as it keeps complaining about bad indentation (me)

 - A fix for the recent CDL code to avoid fetching sense data for
   successful commands when not necessary for correct operation (Niklas)

* tag 'ata-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata: libata-core: fetch sense data for successful commands iff CDL enabled
  ata: libata-eh: do not thaw the port twice in ata_eh_reset()
  ata: libata-eh: do not clear ATA_PFLAG_EH_PENDING in ata_eh_reset()
  ata: pata_parport: Fix code style issues
  ata: libahci: clear pending interrupt status
  ata: sata_mv: Fix incorrect string length computation in mv_dump_mem()
  ata: libata: disallow dev-initiated LPM transitions to unsupported states

Pull USB fix from Greg KH:
 "Here is a single USB fix for a much-reported regression for 6.6-rc1.

  It resolves a crash in the typec debugfs code for many systems. It's
  been in linux-next with no reported issues, and many people have
  reported it resolving their problem with 6.6-rc1"

* tag 'usb-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: typec: ucsi: Fix NULL pointer dereference

Pull driver core fixes from Greg KH:
 "Here is a single driver core fix for a much-reported-by-sysbot issue
  that showed up in 6.6-rc1. It's been submitted by many people, all in
  the same way, so it obviously fixes things for them all.

  Also in here is a single documentation update adding riscv to the
  embargoed hardware document in case there are any future issues with
  that processor family.

  Both of these have been in linux-next with no reported problems"

* tag 'driver-core-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation: embargoed-hardware-issues.rst: Add myself for RISC-V
  driver core: return an error when dev_set_name() hasn't happened

Pull char/misc fix from Greg KH:
 "Here is a single patch for 6.6-rc2 that reverts a 6.5 change for the
  comedi subsystem that has ended up being incorrect and caused drivers
  that were working for people to be unable to be able to be selected to
  build at all.

  To fix this, the Kconfig change needs to be reverted and a future set
  of fixes for the ioport dependancies will show up in 6.7-rc1 (there's
  no rush for them.)

  This has been in linux-next with no reported issues"

* tag 'char-misc-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Revert "comedi: add HAS_IOPORT dependencies"

Pull i2c fixes from Wolfram Sang:
 "The main thing is the removal of 'probe_new' because all i2c client
  drivers are converted now. Thanks Uwe, this marks the end of a long
  conversion process.

  Other than that, we have a few Kconfig updates and driver bugfixes"

* tag 'i2c-for-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: cadence: Fix the kernel-doc warnings
  i2c: aspeed: Reset the i2c controller when timeout occurs
  i2c: I2C_MLXCPLD on ARM64 should depend on ACPI
  i2c: Make I2C_ATR invisible
  i2c: Drop legacy callback .probe_new()
  w1: ds2482: Switch back to use struct i2c_driver's .probe()

Currently, we fetch sense data for a _successful_ command if either:
1) Command was NCQ and ATA_DFLAG_CDL_ENABLED flag set (flag
   ATA_DFLAG_CDL_ENABLED will only be set if the Successful NCQ command
   sense data supported bit is set); or
2) Command was non-NCQ and regular sense data reporting is enabled.

This means that case 2) will trigger for a non-NCQ command which has
ATA_SENSE bit set, regardless if CDL is enabled or not.

This decision was by design. If the device reports that it has sense data
available, it makes sense to fetch that sense data, since the sk/asc/ascq
could be important information regardless if CDL is enabled or not.

However, the fetching of sense data for a successful command is done via
ATA EH. Considering how intricate the ATA EH is, we really do not want to
invoke ATA EH unless absolutely needed.

Before commit 18bd7718 ("scsi: ata: libata: Handle completion of CDL
commands using policy 0xD") we never fetched sense data for successful
commands.

In order to not invoke the ATA EH unless absolutely necessary, even if the
device claims support for sense data reporting, only fetch sense data for
successful (NCQ and non-NCQ commands) commands that are using CDL.

[Damien] Modified the check to test the qc flag ATA_QCFLAG_HAS_CDL
instead of the device support for CDL, which is implied for commands
using CDL.

Fixes: 3ac873c7 ("ata: libata-core: fix when to fetch sense data for successful commands")
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

commit 1e641060 ("libata: clear eh_info on reset completion") added
a workaround that broke the retry mechanism in ATA EH.

Tejun himself suggested to remove this workaround when it was identified
to cause additional problems:
https://lore.kernel.org/linux-ide/20110426135027.GI878@htj.dyndns.org/

He even said:
"Hmm... it seems I wasn't thinking straight when I added that work around."
https://lore.kernel.org/linux-ide/20110426155229.GM878@htj.dyndns.org/

While removing the workaround solved the issue, however, the workaround was
kept to avoid "spurious hotplug events during reset", and instead another
workaround was added on top of the existing workaround in commit
8c56cacc ("libata: fix unexpectedly frozen port after ata_eh_reset()").

Because these IRQs happened when the port was frozen, we know that they
were actually a side effect of PxIS and IS.IPS(x) not being cleared before
the COMRESET. This is now done in commit 94152042eaa9 ("ata: libahci: clear
pending interrupt status"), so these workarounds can now be removed.

Since commit 1e641060 ("libata: clear eh_info on reset completion") has
now been reverted, the ATA EH retry mechanism is functional again, so there
is once again no need to thaw the port more than once in ata_eh_reset().

This reverts "the workaround on top of the workaround" introduced in commit
8c56cacc ("libata: fix unexpectedly frozen port after ata_eh_reset()").
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

ata_scsi_port_error_handler() starts off by clearing ATA_PFLAG_EH_PENDING,
before calling ap->ops->error_handler() (without holding the ap->lock).

If an error IRQ is received while ap->ops->error_handler() is running,
the irq handler will set ATA_PFLAG_EH_PENDING.

Once ap->ops->error_handler() returns, ata_scsi_port_error_handler()
checks if ATA_PFLAG_EH_PENDING is set, and if it is, another iteration
of ATA EH is performed.

The problem is that ATA_PFLAG_EH_PENDING is not only cleared by
ata_scsi_port_error_handler(), it is also cleared by ata_eh_reset().

ata_eh_reset() is called by ap->ops->error_handler(). This additional
clearing done by ata_eh_reset() breaks the whole retry logic in
ata_scsi_port_error_handler(). Thus, if an error IRQ is received while
ap->ops->error_handler() is running, the port will currently remain
frozen and will never get re-enabled.

The additional clearing in ata_eh_reset() was introduced in commit
1e641060 ("libata: clear eh_info on reset completion").

Looking at the original error report:
https://marc.info/?l=linux-ide&m=124765325828495&w=2

We can see the following happening:
[    1.074659] ata3: XXX port freeze
[    1.074700] ata3: XXX hardresetting link, stopping engine
[    1.074746] ata3: XXX flipping SControl

[    1.411471] ata3: XXX irq_stat=400040 CONN|PHY
[    1.411475] ata3: XXX port freeze

[    1.420049] ata3: XXX starting engine
[    1.420096] ata3: XXX rc=0, class=1
[    1.420142] ata3: XXX clearing IRQs for thawing
[    1.420188] ata3: XXX port thawed
[    1.420234] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)

We are not supposed to be able to receive an error IRQ while the port is
frozen (PxIE is set to 0, i.e. all IRQs for the port are disabled).

AHCI 1.3.1 section 10.7.1.1 First Tier (IS Register) states:
"Each bit location can be thought of as reporting a '1' if the virtual
"interrupt line" for that port is indicating it wishes to generate an
interrupt. That is, if a port has one or more interrupt status bit set,
and the enables for those status bits are set, then this bit shall be set."

Additionally, AHCI state P:ComInit clearly shows that the state machine
will only jump to P:ComInitSetIS (which sets IS.IPS(x) to '1'), if PxIE.PCE
is set to '1'. In our case, PxIE is set to 0, so IS.IPS(x) won't get set.

So IS.IPS(x) only gets set if PxIS and PxIE is set.

AHCI 1.3.1 section 10.7.1.1 First Tier (IS Register) also states:
"The bits in this register are read/write clear. It is set by the level of
the virtual interrupt line being a set, and cleared by a write of '1' from
the software."

So if IS.IPS(x) is set, you need to explicitly clear it by writing a 1 to
IS.IPS(x) for that port.

Since PxIE is cleared, the only way to get an interrupt while the port is
frozen, is if IS.IPS(x) is set, and the only way IS.IPS(x) can be set when
the port is frozen, is if it was set before the port was frozen.

However, since commit 737dd811 ("ata: libahci: clear pending interrupt
status"), we clear both PxIS and IS.IPS(x) after freezing the port, but
before the COMRESET, so the problem that commit 1e641060 ("libata:
clear eh_info on reset completion") fixed can no longer happen.

Thus, revert commit 1e641060 ("libata: clear eh_info on reset
completion"), so that the retry logic in ata_scsi_port_error_handler()
works once again. (The retry logic is still needed, since we can still
get an error IRQ _after_ the port has been thawed, but before
ata_scsi_port_error_handler() takes the ap->lock in order to check
if ATA_PFLAG_EH_PENDING is set.)
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>

Merge tag 'linux-kselftest-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull more kselftest fixes from Shuah Khan
 "Fixes to user_events test and ftrace test.

  The user_events test was enabled by default in Linux 6.6-rc1. The
  following fixes are for bugs found since then:

   - add checks for dependencies and skip the test if they aren't met.

     The user_events test requires root access, and tracefs and
     user_events enabled. It leaves tracefs mounted and a fix is in
     progress for that missing piece.

   - create user_events test-specific Kconfig fragments

  ftrace test fixes:

   - unmount tracefs for recovering environment. Fix identified during
     the above mentioned user_events dependencies fix.

   - adds softlink to latest log directory improving usage"

* tag 'linux-kselftest-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tracing: Fix to unmount tracefs for recovering environment
  selftests: user_events: create test-specific Kconfig fragments
  ftrace/selftests: Add softlink to latest log directory
  selftests/user_events: Fix failures when user_events is not installed

Pull nfsd fixes from Chuck Lever:

 - Use correct order when encoding NFSv4 RENAME change_info

 - Fix a potential oops during NFSD shutdown

* tag 'nfsd-6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: fix possible oops when nfsd/pool_stats is closed.
  nfsd: fix change_info in NFSv4 RENAME replies

Pull power management fixes from Rafael Wysocki:
 "Fix the handling of block devices in the test_resume mode of
  hibernation (Chen Yu)"

* tag 'pm-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: Fix the exclusive get block device in test_resume mode
  PM: hibernate: Rename function parameter from snapshot_test to exclusive

Pull thermal control fixes from Rafael Wysocki:
 "These fix a thermal core breakage introduced by one of the recent
  changes, amend those changes by adding 'const' to a new callback
  argument and fix two memory leaks.

  Specifics:

   - Unbreak disabled trip point check in handle_thermal_trip() that may
     cause it to skip enabled trip points (Rafael Wysocki)

   - Add missing of_node_put() to of_find_trip_id() and
     thermal_of_for_each_cooling_maps() that each break out of a
     for_each_child_of_node() loop without dropping the reference to the
     child object (Julia Lawall)

   - Constify the recently added trip argument of the .get_trend()
     thermal zone callback (Rafael Wysocki)"

* tag 'thermal-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  thermal: core: Fix disabled trip point check in handle_thermal_trip()
  thermal: Constify the trip argument of the .get_trend() zone callback
  thermal/of: add missing of_node_put()

Merge tag 'for-6.6/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - Fix DM core retrieve_deps() UAF race due to missing locking of a DM
   table's list of devices that is managed using dm_{get,put}_device.

 - Revert DM core's half-baked RCU optimization if IO submitter has set
   REQ_NOWAIT. Can be revisited, and properly justified, after
   comprehensively auditing all of DM to also pass GFP_NOWAIT for any
   allocations if REQ_NOWAIT used.

* tag 'for-6.6/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: don't attempt to queue IO under RCU protection
  dm: fix a race condition in retrieve_deps

Pull block fixes from Jens Axboe:

 - NVMe pull via Keith:
      - nvme-tcp iov len fix (Varun)
      - nvme-hwmon const qualifier for safety (Krzysztof)
      - nvme-fc null pointer checks (Nigel)
      - nvme-pci no numa node fix (Pratyush)
      - nvme timeout fix for non-compliant controllers (Keith)

 - MD pull via Song fixing regressions with both 6.5 and 6.6

 - Fix a use-after-free regression in resizing blk-mq tags (Chengming)

* tag 'block-6.6-2023-09-15' of git://git.kernel.dk/linux:
  nvme: avoid bogus CRTO values
  md: Put the right device in md_seq_next
  nvme-pci: do not set the NUMA node of device if it has none
  blk-mq: fix tags UAF when shrinking q->nr_hw_queues
  md/raid1: fix error: ISO C90 forbids mixed declarations
  md: fix warning for holder mismatch from export_rdev()
  md: don't dereference mddev after export_rdev()
  nvme-fc: Prevent null pointer dereference in nvme_fc_io_getuuid()
  nvme: host: hwmon: constify pointers to hwmon_channel_info
  nvmet-tcp: pass iov_len instead of sg->length to bvec_set_page()

Pull io_uring fix from Jens Axboe:
 "Just a single fix, fixing a regression with poll first, recvmsg, and
  using a provided buffer"

* tag 'io_uring-6.6-2023-09-15' of git://git.kernel.dk/linux:
  io_uring/net: fix iter retargeting for selected buf

Merge tag 'firewire-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394

Pull firewire fix from Takashi Sakamoto:
 "A change applied to v6.5 kernel brings an issue that usual GFP
  allocation is done in atomic context under acquired spin-lock. Let us
  revert it"

* tag 'firewire-fixes-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394:
  Revert "firewire: core: obsolete usage of GFP_ATOMIC at building node tree"

Pull drm fixes from Dave Airlie:
 "Regular rc2 fixes pull, mostly made up of amdgpu stuff, one i915, and
  a bunch of others, one vkms locking violation is reverted.

  connector:
   - doc fix

  exec:
   - workaround lockdep issue

  tests:
   - fix a UAF

  vkms:
   - revert hrtimer fix

  fbdev:
   - g364fb: fix build failure with mips

  i915:
   - Only check eDP HPD when AUX CH is shared.

  amdgpu:
   - GC 9.4.3 fixes
   - Fix white screen issues with S/G display on system with >= 64G of ram
   - Replay fixes
   - SMU 13.0.6 fixes
   - AUX backlight fix
   - NBIO 4.3 SR-IOV fixes for HDP
   - RAS fixes
   - DP MST resume fix
   - Fix segfault on systems with no vbios
   - DPIA fixes

  amdkfd:
   - CWSR grace period fix
   - Unaligned doorbell fix
   - CRIU fix for GFX11
   - Add missing TLB flush on gfx10 and newer

  radeon:
   - make fence wait in suballocator uninterrruptable

  gm12u320:
   - Fix the timeout usage for usb_bulk_msg()"

* tag 'drm-fixes-2023-09-15' of git://anongit.freedesktop.org/drm/drm: (29 commits)
  drm/tests: helpers: Avoid a driver uaf
  Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"
  drm/amdkfd: Insert missing TLB flush on GFX10 and later
  drm/i915: Only check eDP HPD when AUX CH is shared
  drm/amd/display: Fix 2nd DPIA encoder Assignment
  drm/amd/display: Add DPIA Link Encoder Assignment Fix
  drm/amd/display: fix replay_mode kernel-doc warning
  drm/amdgpu: Handle null atom context in VBIOS info ioctl
  drm/amdkfd: Checkpoint and restore queues on GFX11
  drm/amd/display: Adjust the MST resume flow
  drm/amdgpu: fallback to old RAS error message for aqua_vanjaram
  drm/amdgpu/nbio4.3: set proper rmmio_remap.reg_offset for SR-IOV
  drm/amdgpu/soc21: don't remap HDP registers for SR-IOV
  drm/amd/display: Don't check registers, if using AUX BL control
  drm/amdgpu: fix retry loop test
  drm/amd/display: Add dirty rect support for Replay
  Revert "drm/amd: Disable S/G for APUs when 64GB or more host memory"
  drm/amd/display: fix the white screen issue when >= 64GB DRAM
  drm/amdkfd: Update CU masking for GFX 9.4.3
  drm/amdkfd: Update cache info reporting for GFX v9.4.3
  ...

Pull EFI fixes from Ard Biesheuvel:

 - Missing x86 patch for the runtime cleanup that was merged in -rc1

 - Kconfig tweak for kexec on x86 so EFI support does not get disabled
   inadvertently

 - Use the right EFI memory type for the unaccepted memory table so
   kexec/kdump exposes it to the crash kernel as well

 - Work around EFI implementations which do not implement
   QueryVariableInfo, which is now called by statfs() on efivarfs

* tag 'efi-fixes-for-v6.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efivarfs: fix statfs() on efivarfs
  efi/unaccepted: Use ACPI reclaim memory for unaccepted memory table
  efi/x86: Ensure that EFI_RUNTIME_MAP is enabled for kexec
  efi/x86: Move EFI runtime call setup/teardown helpers out of line

dm looks up the table for IO based on the request type, with an
assumption that if the request is marked REQ_NOWAIT, it's fine to
attempt to submit that IO while under RCU read lock protection. This
is not OK, as REQ_NOWAIT just means that we should not be sleeping
waiting on other IO, it does not mean that we can't potentially
schedule.

A simple test case demonstrates this quite nicely:

int main(int argc, char *argv[])
{
        struct iovec iov;
        int fd;

        fd = open("/dev/dm-0", O_RDONLY | O_DIRECT);
        posix_memalign(&iov.iov_base, 4096, 4096);
        iov.iov_len = 4096;
        preadv2(fd, &iov, 1, 0, RWF_NOWAIT);
        return 0;
}

which will instantly spew:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5580, name: dm-nowait
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
CPU: 7 PID: 5580 Comm: dm-nowait Not tainted 6.6.0-rc1-g39956d2dcd81 #132
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x11d/0x1b0
 __might_resched+0x3c3/0x5e0
 ? preempt_count_sub+0x150/0x150
 mempool_alloc+0x1e2/0x390
 ? mempool_resize+0x7d0/0x7d0
 ? lock_sync+0x190/0x190
 ? lock_release+0x4b7/0x670
 ? internal_get_user_pages_fast+0x868/0x2d40
 bio_alloc_bioset+0x417/0x8c0
 ? bvec_alloc+0x200/0x200
 ? internal_get_user_pages_fast+0xb8c/0x2d40
 bio_alloc_clone+0x53/0x100
 dm_submit_bio+0x27f/0x1a20
 ? lock_release+0x4b7/0x670
 ? blk_try_enter_queue+0x1a0/0x4d0
 ? dm_dax_direct_access+0x260/0x260
 ? rcu_is_watching+0x12/0xb0
 ? blk_try_enter_queue+0x1cc/0x4d0
 __submit_bio+0x239/0x310
 ? __bio_queue_enter+0x700/0x700
 ? kvm_clock_get_cycles+0x40/0x60
 ? ktime_get+0x285/0x470
 submit_bio_noacct_nocheck+0x4d9/0xb80
 ? should_fail_request+0x80/0x80
 ? preempt_count_sub+0x150/0x150
 ? lock_release+0x4b7/0x670
 ? __bio_add_page+0x143/0x2d0
 ? iov_iter_revert+0x27/0x360
 submit_bio_noacct+0x53e/0x1b30
 submit_bio_wait+0x10a/0x230
 ? submit_bio_wait_endio+0x40/0x40
 __blkdev_direct_IO_simple+0x4f8/0x780
 ? blkdev_bio_end_io+0x4c0/0x4c0
 ? stack_trace_save+0x90/0xc0
 ? __bio_clone+0x3c0/0x3c0
 ? lock_release+0x4b7/0x670
 ? lock_sync+0x190/0x190
 ? atime_needs_update+0x3bf/0x7e0
 ? timestamp_truncate+0x21b/0x2d0
 ? inode_owner_or_capable+0x240/0x240
 blkdev_direct_IO.part.0+0x84a/0x1810
 ? rcu_is_watching+0x12/0xb0
 ? lock_release+0x4b7/0x670
 ? blkdev_read_iter+0x40d/0x530
 ? reacquire_held_locks+0x4e0/0x4e0
 ? __blkdev_direct_IO_simple+0x780/0x780
 ? rcu_is_watching+0x12/0xb0
 ? __mark_inode_dirty+0x297/0xd50
 ? preempt_count_add+0x72/0x140
 blkdev_read_iter+0x2a4/0x530
 do_iter_readv_writev+0x2f2/0x3c0
 ? generic_copy_file_range+0x1d0/0x1d0
 ? fsnotify_perm.part.0+0x25d/0x630
 ? security_file_permission+0xd8/0x100
 do_iter_read+0x31b/0x880
 ? import_iovec+0x10b/0x140
 vfs_readv+0x12d/0x1a0
 ? vfs_iter_read+0xb0/0xb0
 ? rcu_is_watching+0x12/0xb0
 ? rcu_is_watching+0x12/0xb0
 ? lock_release+0x4b7/0x670
 do_preadv+0x1b3/0x260
 ? do_readv+0x370/0x370
 __x64_sys_preadv2+0xef/0x150
 do_syscall_64+0x39/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5af41ad806
Code: 41 54 41 89 fc 55 44 89 c5 53 48 89 cb 48 83 ec 18 80 3d e4 dd 0d 00 00 74 7a 45 89 c1 49 89 ca 45 31 c0 b8 47 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 be 00 00 00 48 85 c0 79 4a 48 8b 0d da 55
RSP: 002b:00007ffd3145c7f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000147
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5af41ad806
RDX: 0000000000000001 RSI: 00007ffd3145c850 RDI: 0000000000000003
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffd3145c850 R14: 000055f5f0431dd8 R15: 0000000000000001
 </TASK>

where in fact it is dm itself that attempts to allocate a bio clone with
GFP_NOIO under the rcu read lock, regardless of the request type.

Fix this by getting rid of the special casing for REQ_NOWAIT, and just
use the normal SRCU protected table lookup. Get rid of the bio based
table locking helpers at the same time, as they are now unused.

Cc: stable@vger.kernel.org
Fixes: 563a225c ("dm: introduce dm_{get,put}_live_table_bio called from dm_submit_bio")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Pull selinux fix from Paul Moore:
 "A relatively small SELinux patch to fix an issue with a
  vfs/LSM/SELinux patch that went upstream during the recent merge
  window.

  The short version is that the original patch changed how we
  initialized mount options to resolve a NFS issue and we inadvertently
  broke a use case due to the changed behavior.

  The fix restores this behavior for the cases that require it while
  keeping the original NFS fix in place"

* tag 'selinux-pr-20230914' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix handling of empty opts in selinux_fs_context_submount()