Merge tag 'v6.6.51' into for/openbmc/dev-6.6

This is the 6.6.51 stable release

powerpc/qspinlock: Fix deadlock in MCS queue

commit 734ad0af3609464f8f93e00b6c0de1e112f44559 upstream.

If an interrupt occurs in queued_spin_lock_slowpath() after we increment
qnodesp->count and be

powerpc/qspinlock: Fix deadlock in MCS queue

commit 734ad0af3609464f8f93e00b6c0de1e112f44559 upstream.

If an interrupt occurs in queued_spin_lock_slowpath() after we increment
qnodesp->count and before node->lock is initialized, another CPU might
see stale lock values in get_tail_qnode(). If the stale lock value happens
to match the lock on that CPU, then we write to the "next" pointer of
the wrong qnode. This causes a deadlock as the former CPU, once it becomes
the head of the MCS queue, will spin indefinitely until it's "next" pointer
is set by its successor in the queue.

Running stress-ng on a 16 core (16EC/16VP) shared LPAR, results in
occasional lockups similar to the following:

$ stress-ng --all 128 --vm-bytes 80% --aggressive \
--maximize --oomable --verify --syslog \
--metrics --times --timeout 5m

watchdog: CPU 15 Hard LOCKUP
......
NIP [c0000000000b78f4] queued_spin_lock_slowpath+0x1184/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
Call Trace:
0xc000002cfffa3bf0 (unreliable)
_raw_spin_lock+0x6c/0x90
raw_spin_rq_lock_nested.part.135+0x4c/0xd0
sched_ttwu_pending+0x60/0x1f0
__flush_smp_call_function_queue+0x1dc/0x670
smp_ipi_demux_relaxed+0xa4/0x100
xive_muxed_ipi_action+0x20/0x40
__handle_irq_event_percpu+0x80/0x240
handle_irq_event_percpu+0x2c/0x80
handle_percpu_irq+0x84/0xd0
generic_handle_irq+0x54/0x80
__do_irq+0xac/0x210
__do_IRQ+0x74/0xd0
0x0
do_IRQ+0x8c/0x170
hardware_interrupt_common_virt+0x29c/0x2a0
--- interrupt: 500 at queued_spin_lock_slowpath+0x4b8/0x1490
......
NIP [c0000000000b6c28] queued_spin_lock_slowpath+0x4b8/0x1490
LR [c000000001037c5c] _raw_spin_lock+0x6c/0x90
--- interrupt: 500
0xc0000029c1a41d00 (unreliable)
_raw_spin_lock+0x6c/0x90
futex_wake+0x100/0x260
do_futex+0x21c/0x2a0
sys_futex+0x98/0x270
system_call_exception+0x14c/0x2f0
system_call_vectored_common+0x15c/0x2ec

The following code flow illustrates how the deadlock occurs.
For the sake of brevity, assume that both locks (A and B) are
contended and we call the queued_spin_lock_slowpath() function.

CPU0 CPU1
---- ----
spin_lock_irqsave(A) |
spin_unlock_irqrestore(A) |
spin_lock(B) |
| |
▼ |
id = qnodesp->count++; |
(Note that nodes[0].lock == A) |
| |
▼ |
Interrupt |
(happens before "nodes[0].lock = B") |
| |
▼ |
spin_lock_irqsave(A) |
| |
▼ |
id = qnodesp->count++ |
nodes[1].lock = A |
| |
▼ |
Tail of MCS queue |
| spin_lock_irqsave(A)
▼ |
Head of MCS queue ▼
| CPU0 is previous tail
▼ |
Spin indefinitely ▼
(until "nodes[1].next != NULL") prev = get_tail_qnode(A, CPU0)
|
▼
prev == &qnodes[CPU0].nodes[0]
(as qnodes[CPU0].nodes[0].lock == A)
|
▼
WRITE_ONCE(prev->next, node)
|
▼
Spin indefinitely
(until nodes[0].locked == 1)

Thanks to Saket Kumar Bhaskar for help with recreating the issue

Fixes: 84990b169557 ("powerpc/qspinlock: add mcs queueing for contended waiters")
Cc: stable@vger.kernel.org # v6.2+
Reported-by: Geetika Moolchandani <geetika@linux.ibm.com>
Reported-by: Vaishnavi Bhat <vaish123@in.ibm.com>
Reported-by: Jijo Varghese <vargjijo@in.ibm.com>
Signed-off-by: Nysal Jan K.A. <nysal@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240829022830.1164355-1-nysal@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

show more ...

Merge tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

- Fix stale propagated yield_cpu in qspinlocks leading to lockups

Merge tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:

- Fix stale propagated yield_cpu in qspinlocks leading to lockups

- Fix broken hugepages on some configs due to ARCH_FORCE_MAX_ORDER

- Fix a spurious warning when copros are in use at exit time

Thanks to Nicholas Piggin, Christophe Leroy, Nysal Jan K.A Sachin Sant,
and Shrikanth Hegde.

* tag 'powerpc-6.6-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/qspinlock: Fix stale propagated yield_cpu
powerpc/64s/radix: Don't warn on copros in radix__tlb_flush()
powerpc/mm: Allow ARCH_FORCE_MAX_ORDER up to 12

show more ...

powerpc/qspinlock: Fix stale propagated yield_cpu

yield_cpu is a sample of a preempted lock holder that gets propagated
back through the queue. Queued waiters use this to yield to the
preempted lock

powerpc/qspinlock: Fix stale propagated yield_cpu

yield_cpu is a sample of a preempted lock holder that gets propagated
back through the queue. Queued waiters use this to yield to the
preempted lock holder without continually sampling the lock word (which
would defeat the purpose of MCS queueing by bouncing the cache line).

The problem is that yield_cpu can become stale. It can take some time to
be passed down the chain, and if any queued waiter gets preempted then
it will cease to propagate the yield_cpu to later waiters.

This can result in yielding to a CPU that no longer holds the lock,
which is bad, but particularly if it is currently in H_CEDE (idle),
then it appears to be preempted and some hypervisors (PowerVM) can
cause very long H_CONFER latencies waiting for H_CEDE wakeup. This
results in latency spikes and hard lockups on oversubscribed
partitions with lock contention.

This is a minimal fix. Before yielding to yield_cpu, sample the lock
word to confirm yield_cpu is still the owner, and bail out of it is not.

Thanks to a bunch of people who reported this and tracked down the
exact problem using tracepoints and dispatch trace logs.

Fixes: 28db61e207ea ("powerpc/qspinlock: allow propagation of yield CPU down the queue")
Cc: stable@vger.kernel.org # v6.2+
Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: Laurent Dufour <ldufour@linux.ibm.com>
Reported-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Debugged-by: "Nysal Jan K.A" <nysal@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231016124305.139923-2-npiggin@gmail.com

show more ...

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

ASoC: Merge v6.5-rc2

Get a similar baseline to my other branches, and fixes for people using
the branch.

Merge v6.5-rc1 into drm-misc-fixes

Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge branch 'master' into mm-hotfixes-stable

Merge tag 'powerpc-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Extend KCSAN support to 32-bit and BookE. Add some KCSAN anno

Merge tag 'powerpc-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

- Extend KCSAN support to 32-bit and BookE. Add some KCSAN annotations

- Make ELFv2 ABI the default for 64-bit big-endian kernel builds, and
use the -mprofile-kernel option (kernel specific ftrace ABI) for big
endian ELFv2 kernels

- Add initial Dynamic Execution Control Register (DEXCR) support, and
allow the ROP protection instructions to be used on Power 10

- Various other small features and fixes

Thanks to Aditya Gupta, Aneesh Kumar K.V, Benjamin Gray, Brian King,
Christophe Leroy, Colin Ian King, Dmitry Torokhov, Gaurav Batra, Jean
Delvare, Joel Stanley, Marco Elver, Masahiro Yamada, Nageswara R Sastry,
Nathan Chancellor, Naveen N Rao, Nayna Jain, Nicholas Piggin, Paul
Gortmaker, Randy Dunlap, Rob Herring, Rohan McLure, Russell Currey,
Sachin Sant, Timothy Pearson, Tom Rix, and Uwe Kleine-König.

* tag 'powerpc-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (76 commits)
powerpc: remove checks for binutils older than 2.25
powerpc: Fail build if using recordmcount with binutils v2.37
powerpc/iommu: TCEs are incorrectly manipulated with DLPAR add/remove of memory
powerpc/iommu: Only build sPAPR access functions on pSeries
powerpc: powernv: Annotate data races in opal events
powerpc: Mark writes registering ipi to host cpu through kvm and polling
powerpc: Annotate accesses to ipi message flags
powerpc: powernv: Fix KCSAN datarace warnings on idle_state contention
powerpc: Mark [h]ssr_valid accesses in check_return_regs_valid
powerpc: qspinlock: Enforce qnode writes prior to publishing to queue
powerpc: qspinlock: Mark accesses to qnode lock checks
powerpc/powernv/pci: Remove last IODA1 defines
powerpc/powernv/pci: Remove MVE code
powerpc/powernv/pci: Remove ioda1 support
powerpc: 52xx: Make immr_id DT match tables static
powerpc: mpc512x: Remove open coded "ranges" parsing
powerpc: fsl_soc: Use of_range_to_resource() for "ranges" parsing
powerpc: fsl: Use of_property_read_reg() to parse "reg"
powerpc: fsl_rio: Use of_range_to_resource() for "ranges" parsing
macintosh: Use of_property_read_reg() to parse "reg"
...

show more ...

powerpc: qspinlock: Enforce qnode writes prior to publishing to queue

Annotate the release barrier and memory clobber (in effect, producing a
compiler barrier) in the publish_tail_cpu call. These ba

powerpc: qspinlock: Enforce qnode writes prior to publishing to queue

Annotate the release barrier and memory clobber (in effect, producing a
compiler barrier) in the publish_tail_cpu call. These barriers have the
effect of ensuring that qnode attributes are all written to prior to
publish the node to the waitqueue.

Even while the initial write to the 'locked' attribute is guaranteed to
terminate prior to the node being visible, KCSAN still complains that
the write is reorderable by the compiler. Issue a kcsan_release() to
inform KCSAN of the release barrier contained in publish_tail_cpu().

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-3-rmclure@linux.ibm.com

show more ...

powerpc: qspinlock: Mark accesses to qnode lock checks

The powerpc implementation of qspinlocks will both poll and spin on the
bitlock guarding a qnode. Mark these accesses with READ_ONCE to convey

powerpc: qspinlock: Mark accesses to qnode lock checks

The powerpc implementation of qspinlocks will both poll and spin on the
bitlock guarding a qnode. Mark these accesses with READ_ONCE to convey
to KCSAN that polling is intentional here.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230510033117.1395895-2-rmclure@linux.ibm.com

show more ...

Merge branch 'next' into for-linus

Prepare input updates for 6.3 merge window.

Merge drm/drm-next into drm-misc-next

Backmerging into drm-misc-next to get DRM accelerator infrastructure,
which is required by ipuv driver.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge wireless into wireless-next

Due to the two cherry picked commits from wireless to wireless-next we have
several conflicts in mt76. To avoid any bugs with conflicts merge wireless into
wireless

Merge wireless into wireless-next

Due to the two cherry picked commits from wireless to wireless-next we have
several conflicts in mt76. To avoid any bugs with conflicts merge wireless into
wireless-next.

96f134dc1964 wifi: mt76: handle possible mt76_rx_token_consume failures
fe13dad8992b wifi: mt76: dma: do not increment queue head if mt76_dma_add_buf fails

show more ...

Merge tag 'v6.2-rc3' into next

Merge with mainline to bring in timer_shutdown_sync() API.

Merge drm/drm-fixes into drm-misc-fixes

Let's start the fixes cycle.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

Merge drm/drm-next into drm-intel-next

Sync up with v6.2-rc1.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Merge drm/drm-next into drm-intel-gt-next

Sync after v6.2-rc1 landed in drm-next.

We need to get some dependencies in place before we can merge
the fixes series from Gwan-gyeong and Chris.

Referen

Merge drm/drm-next into drm-intel-gt-next

Sync after v6.2-rc1 landed in drm-next.

We need to get some dependencies in place before we can merge
the fixes series from Gwan-gyeong and Chris.

References: https://lore.kernel.org/all/Y6x5JCDnh2rvh4lA@intel.com/
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...

Merge tag 'v6.2-rc1' into media_tree

Linux 6.2-rc1

* tag 'v6.2-rc1': (14398 commits)
Linux 6.2-rc1
treewide: Convert del_timer*() to timer_shutdown*()
pstore: Properly assign mem_type propert

Merge tag 'v6.2-rc1' into media_tree

Linux 6.2-rc1

* tag 'v6.2-rc1': (14398 commits)
Linux 6.2-rc1
treewide: Convert del_timer*() to timer_shutdown*()
pstore: Properly assign mem_type property
pstore: Make sure CONFIG_PSTORE_PMSG selects CONFIG_RT_MUTEXES
cfi: Fix CFI failure with KASAN
perf python: Fix splitting CC into compiler and options
afs: Stop implementing ->writepage()
afs: remove afs_cache_netfs and afs_zap_permits() declarations
afs: remove variable nr_servers
afs: Fix lost servers_outstanding count
ALSA: usb-audio: Add new quirk FIXED_RATE for JBL Quantum810 Wireless
ALSA: azt3328: Remove the unused function snd_azf3328_codec_outl()
gcov: add support for checksum field
test_maple_tree: add test for mas_spanning_rebalance() on insufficient data
maple_tree: fix mas_spanning_rebalance() on insufficient data
hugetlb: really allocate vma lock for all sharable vmas
kmsan: export kmsan_handle_urb
kmsan: include linux/vmalloc.h
mm/mempolicy: fix memory leak in set_mempolicy_home_node system call
mm, mremap: fix mremap() expanding vma with addr inside vma
...

show more ...

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Merge branch 'master' into mm-nonmm-stable

Merge branch 'master' into mm-stable

Merge branch 'linus'