Fix warnings like: "Prefer seq_puts to seq_printf" by checkpatch.pl.
Replace seq_printf() calls with seq_puts() in show_cpuinfo() when
outputting simple constant strings without format specifiers.
This improves performance slightly as seq_puts() avoids parsing the
format string.
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Implement 128-bit atomic compare-and-exchange using LoongArch's
LL.D/SC.Q instructions.
At the same time, this fix the BPF scheduler test failures (scx_central
and scx_qmap) caused by kmalloc_nolock_noprof() returning NULL, due to
missing 128-bit atomics. The NULL returns lead to -ENOMEM errors during
scheduler initialization, causing test cases to fail.
Verified by testing with the scx_qmap scheduler
(located in tools/sched_ext/).
Building with `make` and running ./tools/sched_ext/build/bin/scx_qmap.
Link: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=5fb750e8a9ae
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Co-developed-by:: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Check the CPUCFG2_SCQ bit to determine if the current CPU supports the
SC.Q instruction.
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Co-developed-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: Yangyang Lian <lianyangyang@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
LoongArch has already implemented cmpxchg_local(), this_cpu_cmpxchg()
and similar functions, so select HAVE_CMPXCHG_LOCAL in Kconfig to avoid
incurring the overhead of local_irq_save()/local_irq_restore() for page
state helpers in mm/vmstat.c.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Relax the maximum allowed Secure Execution (SE) header size from
8 KiB to 1 MiB. This allows individual secure guest images to run on a
wider range of physical machines.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Farhan has been doing a masterful job coming on in the
s390 PCI space, and my own attention has been lacking.
Let's make MAINTAINERS reflect reality.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Acked-by: Alex Williamson <alex@shazbot.org>
Acked-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Felix Maurer says:
====================
hsr: Implement more robust duplicate discard algorithm
The duplicate discard algorithms for PRP and HSR do not work reliably
with certain link faults. Especially with packet loss on one link, the
duplicate discard algorithms drop valid packets. For a more thorough
description see patches 4 (for PRP) and 6 (for HSR).
This patchset replaces the current algorithms (based on a drop window
for PRP and highest seen sequence number for HSR) with a single new one
that tracks the received sequence numbers individually (descriptions
again in patches 4 and 6).
The changes will lead to higher memory usage and more work to do for
each packet. But I argue that this is an acceptable trade-off to make
for a more robust PRP and HSR behavior with faulty links. After all,
both protocols are to be used in environments where redundancy is needed
and people are willing to setup special network topologies to achieve
that.
Some more reasoning on the overhead and expected scale of the deployment
from the RFC discussion:
> As for the expected scale, there are two dimensions: the number of nodes
> in the network and the data rate with which they send.
>
> The number of nodes in the network affect the memory usage because each
> node now has the block buffer. For PRP that's 64 blocks * 32 byte =
> 2kbyte for each node in the node table. A PRP network doesn't have an
> explicit limit for the number of nodes. However, the whole network is a
> single layer-2 segment which shouldn't grow too large anyways. Even if
> one really tries to put 1000 nodes into the PRP network, the memory
> overhead (2Mbyte) is acceptable in my opinion.
>
> For HSR, the blocks would be larger because we need to track the
> sequence numbers per port. I expect 64 blocks * 80 byte = 5kbyte per
> node in the node table. There is no explicit limit for the size of an
> HSR ring either. But I expect them to be of limited size because the
> forwarding delays add up throughout the ring. I've seen vendors limiting
> the ring size to 50 nodes with 100Mbit/s links and 300 with 1Gbit/s
> links. In both cases I consider the memory overhead acceptable.
>
> The data rates are harder to reason about. In general, the data rates
> for HSR and PRP are limited because too high packet rates would lead to
> very fast re-use of the 16bit sequence numbers. The IEC 62439-3:2021
> mentions 100Mbit/s links and 1Gbit/s links. I don't expect HSR or PRP
> networks to scale out to, e.g., 10Gbit/s links with the current
> specification as this would mean that sequence numbers could repeat as
> often as every ~4ms. The default constants in the IEC standard, which we
> also use, are oriented at a 100Mbit/s network.
>
> In my tests with veth pairs, the CPU overhead didn't lead to
> significantly lower data rates. The main factor limiting the data rate
> at the moment, I assume, is the per-node spinlock that is taken for each
> received packet. IMHO, there is a lot more to gain in terms of CPU
> overhead from making this lock smaller or getting rid of it, than we
> loose with the more accurate duplicate discard algorithm in this patchset.
>
> The CPU overhead of the algorithm benefits from the fact that in high
> packet rate scenarios (where it really matters) many packets will have
> sequence numbers in already initialized blocks. These packets just have
> additionally: one xarray lookup, one comparison, and one bit setting. If
> a block needs to be initialized (once every 128 packets plus their 128
> duplicates if all sequence numbers are seen), we will have: one
> xa_erase, a bunch of memory writes, and one xa_store.
>
> In theory, all packets could end up in the slow path if a node sends
> every 128th packet to us. If this is sent from a well behaving node, the
> packet rate wouldn't be an issue anymore, though.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
====================
Link: https://patch.msgid.link/cover.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Despite the HSR subsystem being orphaned at the moment due to the original
maintainer being unreachable for a while, assign the selftests to the
subsystem for the future.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/f4a356b96f5e0c99d9db3984ea62596c99a97469.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Run the packet loss and reordering tests also for both HSR versions. Now
they can be removed from the hsr_ping tests completely. The timeout needs
to be increased because there are 15 link fault test cases now, with each
of them taking 5-6sec for the test and at most 5sec for the HSR node tables
to get merged and we also want some room to make the test runs stable.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/eb6f667d3804ce63d86f0ee3fbc0e0ac9e1a209a.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The HSR duplicate discard algorithm had even more basic problems than the
described for PRP in the previous patch. It relied only on the last
received sequence number to decide if a new frame should be forwarded to
any port. This does not work correctly in any case where frames are
received out of order. The linked bug report claims that this can even
happen with perfectly fine links due to the order in which incoming frames
are processed (which can be unexpected on multi-core systems). The issue
also occasionally shows up in the HSR selftests. The main reason is that
the sequence number that was last forwarded to the master port may have
skipped a number which will in turn never be delivered to the host.
As the problem (we accidentally skip over a sequence number that has not
been received but will be received in the future) is similar to PRP, we can
apply a similar solution. The duplicate discard algorithm based on the
"sparse bitmap" works well for HSR if it is extended to track one bitmap
for each port (A, B, master, interlink). To do this, change the sequence
number blocks to contain a flexible array member as the last member that
can keep chunks for as many bitmaps as we need. This design makes it easy
to reuse the same algorithm in a potential PRP RedBox implementation.
The duplicate discard algorithm functions are modified to deal with
sequence number blocks of different sizes and to correctly use the array of
bitmap chunks. There is a notable speciality for HSR: the port type has a
special port type NONE with value 0. This leads to the number of port types
being 5 instead of actually 4. To save memory, remove the NONE port from
the bitmap (by subtracting 1) when setting up the block buffer and when
accessing the bitmap chunks in the array.
Removing the old algorithm allows us to get rid of a few fields that are
not needed any more: time_out and seq_out for each port. We can also remove
some functions that were only necessary for the previous duplicate discard
algorithm.
The removal of seq_out is possible despite its previous usage in
hsr_register_frame_in: it was used to prevent updates to time_in when
"invalid" sequence numbers were received. With the new duplicate discard
algorithm, time_in has no relevance for the expiry of sequence numbers
anymore. They will expire based on the timestamps in the sequence number
blocks after at most 400ms. There is no need that a node "re-registers" to
"resume communication": after 400ms, all sequence numbers are accepted
again. Also, according to the IEC 62439-3:2021, all nodes are supposed to
send no traffic for 500ms after boot to lead exactly to this expiry of seen
sequence numbers. time_in is still used for pruning nodes from the node
table after no traffic has been received for 60sec. Pruning is only needed
if the node is really gone and has not been sending any traffic for that
period.
seq_out was also used to report the last incoming sequence number from a
node through netlink. I am not sure how useful this value is to userspace
at all, but added getting it from the sequence number blocks. This number
can be outdated after node merging until a new block has been added.
Update the KUnit test for the PRP duplicate discard so that the node
allocation matches and expectations on the removed fields are removed.
Reported-by: Yoann Congal <yoann.congal@smile.fr>
Closes: https://lore.kernel.org/netdev/7d221a07-8358-4c0b-a09c-3b029c052245@smile.fr/
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/36dc3bc5bdb7e68b70bb5ef86f53ca95a3f35418.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add tests where one link has different rates of packet loss or reorders
packets. PRP should still be able to recover from these link faults and
show no packet loss. However, it is acceptable to receive some level of
duplicate packets. This matches the current specification (IEC
62439-3:2021) of the duplicate discard algorithm that requires it to be
"designed such that it never rejects a legitimate frame, while occasional
acceptance of a duplicate can be tolerated." The rate of acceptable
duplicates in this test is intentionally high (10%) to make the test
stable, the values I observed in the worst test cases (20% loss) are around
5% duplicates.
The duplicates occur because of the 10ms ping interval in the test. As
blocks expire after 400ms based on the timestamp of the first received
sequence number in the block, every approx. 40th will lead to a new, clean
block being used where the sequence number hasn't been seen before. As this
occurs on both nodes in the test (for requests and replies), we observe
around 20 duplicate frames.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/7b36506d3a80e53786fe56526cf6046c74dfeee1.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The PRP duplicate discard algorithm does not work reliably with certain
link faults. Especially with packet loss on one link, the duplicate discard
algorithm drops valid packets which leads to packet loss on the PRP
interface where the link fault should in theory be perfectly recoverable by
PRP. This happens because the algorithm opens the drop window on the lossy
link, covering received and lost sequence numbers. If the other, non-lossy
link receives the duplicate for a lost frame, it is within the drop window
of the lossy link and therefore dropped.
Since IEC 62439-3:2012, a node has one sequence number counter for frames
it sends, instead of one sequence number counter for each destination.
Therefore, a node can not expect to receive contiguous sequence numbers
from a sender. A missing sequence number can be totally normal (if the
sender intermittently communicates with another node) or mean a frame was
lost.
The algorithm, as previously implemented in commit 05fd00e5e7 ("net: hsr:
Fix PRP duplicate detection"), was part of IEC 62439-3:2010 (HSRv0/PRPv0)
but was removed with IEC 62439-3:2012 (HSRv1/PRPv1). Since that, no
algorithm is specified but up to implementers. It should be "designed such
that it never rejects a legitimate frame, while occasional acceptance of a
duplicate can be tolerated" (IEC 62439-3:2021).
For the duplicate discard algorithm, this means that 1) we need to track
the sequence numbers individually to account for non-contiguous sequence
numbers, and 2) we should always err on the side of accepting a duplicate
than dropping a valid frame.
The idea of the new algorithm is to store the seen sequence numbers in a
bitmap. To keep the size of the bitmap in control, we store it as a "sparse
bitmap" where the bitmap is split into blocks and not all blocks exist at
the same time. The sparse bitmap is implemented using an xarray that keeps
the references to the individual blocks and a backing ring buffer that
stores the actual blocks. New blocks are initialized in the buffer and
added to the xarray as needed when new frames arrive. Existing blocks are
removed in two conditions:
1. The block found for an arriving sequence number is old and therefore not
relevant to the duplicate discard algorithm anymore, i.e., it has been
added more than the entry forget time ago. In this case, the block is
removed from the xarray and marked as forgotten (by setting its
timestamp to 0).
2. Space is needed in the ring buffer for a new block. In this case, the
block is removed from the xarray, if it hasn't already been forgotten
(by 1.). Afterwards, the new block is initialized in its place.
This has the nice property that we can reliably track sequence numbers on
low traffic situations (where they expire based on their timestamp) and
more quickly forget sequence numbers in high traffic situations before they
potentially wrap over and repeat before they are expired.
When nodes are merged, the blocks are merged as well. The timestamp of a
merged block is set to the minimum of the two timestamps to never keep
around a seen sequence number for too long. The bitmaps are or'd to mark
all seen sequence numbers as seen.
All of this still happens under seq_out_lock, to prevent concurrent
access to the blocks.
The KUnit test for the algorithm is updated as well. The updates are done
in a way to match the original intends pretty closely. Currently, there is
much knowledge about the actual algorithm baked into the tests (especially
the expectations) which may need some redesign in the future.
Reported-by: Steffen Lindner <steffen.lindner@de.abb.com>
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Steffen Lindner <steffen.lindner@de.abb.com>
Link: https://patch.msgid.link/8ce15a996099df2df5b700969a39e7df400e8dbb.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add a test case that can support different types of faulty links for all
protocol versions (HSRv0, HSRv1, PRPv1). It starts with a baseline with
fully functional links. The first faulty case is one link being cut during
the ping. This test uses a different function for ping that sends more
packets in shorter intervals to stress the duplicate detection algorithms a
bit more and allow for future tests with other link faults (packet loss,
reordering, etc.).
As the link fault tests now cover the cut link for HSR and PRP, it can be
removed from the hsr_ping test. Note that the removed cut link test did not
really test the fault because do_ping_long takes about 1sec while the link
is only cut after a 3sec sleep.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/dad52276e2c349ecb96168bef7e3001bf7becc81.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Previously the hsr_ping test only checked that all nodes in a VLAN are
reachable (using do_ping). Update the test to also check that there is no
packet loss and no duplicate packets by running the same tests for VLANs as
without VLANs (including using do_ping_long). This also adds tests for IPv6
over VLAN. To unify the test code, the topology without VLANs now uses IP
addresses from dead:beef:0::/64 to align with the 100.64.0.0/24 range for
IPv4. Error messages are updated across the board to make it easier to find
what actually failed.
Also update the VLAN test to only run in VLAN 2, as there is no need to
check if ping really works with VLAN IDs 2, 3, 4, and 5. This lowers the
number of long ping tests on VLANs to keep the overall test runtime in
bounds.
It's still necessary to bump the test timeout a bit, though: a ping long
tests takes 1sec, do_ping_tests performs 12 of them, do_link_problem_tests
6, and the VLAN tests again 12. With some buffer for setup and waiting and
for two protocol versions, 90sec timeout seems reasonable.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/e3ded0e2547b5f720524b62fabeb96debc579697.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Add a selftest for PRP that performs a basic ping test on IPv4 and IPv6,
over the plain PRP interface and a VLAN interface, similar to the existing
ping test for HSR. The test first checks reachability of the other node,
then checks for no loss and no duplicates.
Signed-off-by: Felix Maurer <fmaurer@redhat.com>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/4a342189e842d7308d037da72af566729ee75834.1770299429.git.fmaurer@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Commit c5741c5c11 ("drm/i915/display: Do not use stolen on MTL") added
some checks for MTL in overlay code. However, this is never run on
MTL. Clean it up.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260206125949.243643-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Cosmetic change. Unlike all other similar helpers task_ppid_nr_ns() doesn't
have a _vnr() version; add one for consistency.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://patch.msgid.link/20251015123633.GB9456@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
OBJEXTS_NOSPIN_ALLOC was used to remember whether a slabobj_ext vector
was allocated via kmalloc_nolock(), so that free_slab_obj_exts() could
call kfree_nolock() instead of kfree().
Now that kfree() supports freeing kmalloc_nolock() objects, this flag is
no longer needed. Instead, pass the allow_spin parameter down to
free_slab_obj_exts() to determine whether kfree_nolock() or kfree()
should be called in the free path, and free one bit in
enum objext_flags.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Hao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260210044642.139482-3-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
This paves the way for scalable PID allocation later.
The 32 bit variant merely takes a spinlock for simplicity, the 64 bit
variant uses a scalable scheme.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260120184539.1480930-1-mjguzik@gmail.com
Co-developed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This reverts commit abdfd4948e.
The changelog in this commit explains why it is not easy to avoid ns == NULL
when the caller is exiting, but pid_vnr() is equally unsafe in this case.
However, commit 006568ab4c ("pid: Add a judgment for ns null in pid_nr_ns")
already added the ns != NULL check in pid_nr_ns(), so we can remove the same
check from __task_pid_nr_ns().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://patch.msgid.link/20251015123613.GA9456@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Slab objects that are allocated with kmalloc_nolock() must be freed
using kfree_nolock() because only a subset of alloc hooks are called,
since kmalloc_nolock() can't spin on a lock during allocation.
This imposes a limitation: such objects cannot be freed with kfree_rcu(),
forcing users to work around this limitation by calling call_rcu()
with a callback that frees the object using kfree_nolock().
Remove this limitation by teaching kmemleak to gracefully ignore cases
when kmemleak_free() or kmemleak_ignore() is called without a prior
kmemleak_alloc().
Unlike kmemleak, kfence already handles this case, because,
due to its design, only a subset of allocations are served from kfence.
With this change, kfree() and kfree_rcu() can be used to free objects
that are allocated using kmalloc_nolock().
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210044642.139482-2-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
alloc_pid() loads pid_cachep, level and pid_max prior to taking the
lock.
It dirties idr and pid_allocated with the lock.
Some of these fields share the cacheline as is, split them up.
No change in the size of the struct.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260120204820.1497002-1-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Mateusz reported performance penalties [1] during task creation because
pidfs uses pidmap_lock to add elements into the rbtree. Switch to an
rhashtable to have separate fine-grained locking and to decouple from
pidmap_lock moving all heavy manipulations outside of it.
Convert the pidfs inode-to-pid mapping from an rb-tree with seqcount
protection to an rhashtable. This removes the global pidmap_lock
contention from pidfs_ino_get_pid() lookups and allows the hashtable
insert to happen outside the pidmap_lock.
pidfs_add_pid() is split. pidfs_prepare_pid() allocates inode number and
initializes pid fields and is called inside pidmap_lock. pidfs_add_pid()
inserts pid into rhashtable and is called outside pidmap_lock. Insertion
into the rhashtable can fail and memory allocation may happen so we need
to drop the spinlock.
To guard against accidently opening an already reaped task
pidfs_ino_get_pid() uses additional checks beyond pid_vnr(). If
pid->attr is PIDFS_PID_DEAD or NULL the pid either never had a pidfd or
it already went through pidfs_exit() aka the process as already reaped.
If pid->attr is valid check PIDFS_ATTR_BIT_EXIT to figure out whether
the task has exited.
This slightly changes visibility semantics: pidfd creation is denied
after pidfs_exit() runs, which is just before the pid number is removed
from the via free_pid(). That should not be an issue though.
Link: https://lore.kernel.org/20251206131955.780557-1-mjguzik@gmail.com [1]
Link: https://patch.msgid.link/20260120-work-pidfs-rhashtable-v2-1-d593c4d0f576@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The shadow gmap returned by gmap_create_shadow() could get dropped
before taking the gmap->children_lock. This meant that the shadow gmap
was sometimes being used while its reference count was 0.
Fix this by taking the additional reference inside gmap_create_shadow()
while still holding gmap->children_lock, instead of afterwards.
Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
It is possible that walk_guest_tables() is called on a shadow gmap that
has been removed already, in which case its parent will be NULL.
In such case, return -EAGAIN and let the callers deal with it.
Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Stop using the userspace address to mark the guest page dirty.
mark_page_dirty() expects a guest frame number, but was being passed a
host virtual frame number. When slot == NULL, mark_page_dirty_in_slot()
does nothing and does not complain.
This means that in some circumstances the dirtiness of the guest page
might have been lost.
Fix by adding two fields in struct kvm_s390_adapter_int to keep the
guest addressses, and use those for mark_page_dirty().
Fixes: f65470661f ("KVM: s390/interrupt: do not pin adapter interrupt pages")
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reproducer available at [1].
The ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc
pointer from msg->vcc and uses it directly without any validation. This
pointer comes from userspace via sendmsg() and can be arbitrarily forged:
int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);
ioctl(fd, ATMSIGD_CTRL); // become ATM signaling daemon
struct msghdr msg = { .msg_iov = &iov, ... };
*(unsigned long *)(buf + 4) = 0xdeadbeef; // fake vcc pointer
sendmsg(fd, &msg, 0); // kernel dereferences 0xdeadbeef
In normal operation, the kernel sends the vcc pointer to the signaling
daemon via sigd_enq() when processing operations like connect(), bind(),
or listen(). The daemon is expected to return the same pointer when
responding. However, a malicious daemon can send arbitrary pointer values.
Fix this by introducing find_get_vcc() which validates the pointer by
searching through vcc_hash (similar to how sigd_close() iterates over
all VCCs), and acquires a reference via sock_hold() if found.
Since struct atm_vcc embeds struct sock as its first member, they share
the same lifetime. Therefore using sock_hold/sock_put is sufficient to
keep the vcc alive while it is being used.
Note that there may be a race with sigd_close() which could mark the vcc
with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.
However, sock_hold() guarantees the memory remains valid, so this race
only affects the logical state, not memory safety.
[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+1f22cb1769f249df9fa0@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69039850.a70a0220.5b2ed.005d.GAE@google.com/T/
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Link: https://patch.msgid.link/20260205095501.131890-1-jiayuan.chen@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
`objtool` with Rust 1.84.0 reports:
rust/kernel.o: error: objtool: _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
falls through to next function _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()
This is very similar to commit c18f35e490 ("objtool/rust: add one more
`noreturn` Rust function"), which added `from_ascii_radix_panic` for Rust
1.86.0, except that Rust 1.84.0 ends up needing `from_str_radix_panic`.
Thus add it to the list to fix the warning.
Cc: FUJITA Tomonori <fujita.tomonori@gmail.com>
Fixes: 51d9ee90ea ("rust: str: add radix prefixed integer parsing functions")
Reported-by: Alice Ryhl <aliceryhl@google.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/with/572427627
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260206204336.38462-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
A couple small changes:
- Validate the magic value at the head of FWCCB commands, and
- Mask off the magic value before logging unknown command types to make
them easier to interpret on sight.
Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Link: https://patch.msgid.link/20260206-improve-bad-fwccb-cmd-v1-1-831a852ca127@imgtec.com
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Wei Fang says:
====================
net: fec: improve XDP copy mode and add AF_XDP zero-copy support
This patch set optimizes the XDP copy mode logic as follows.
1. Separate the processing of RX XDP frames from fec_enet_rx_queue(),
and adds a separate function fec_enet_rx_queue_xdp() for handling XDP
frames.
2. For TX XDP packets, using the batch sending method to avoid frequent
MMIO writes.
3. Use the switch statement to check the tx_buf type instead of the
if...else... statement, making the cleanup logic of TX BD ring cleared
and more efficient.
We compared the performance of XDP copy mode before and after applying
this patch set, and the results show that the performance has improved.
Before applying this patch set.
root@imx93evk:~# ./xdp-bench tx eth0
Summary 396,868 rx/s 0 err,drop/s
Summary 396,024 rx/s 0 err,drop/s
root@imx93evk:~# ./xdp-bench drop eth0
Summary 684,781 rx/s 0 err/s
Summary 675,746 rx/s 0 err/s
root@imx93evk:~# ./xdp-bench pass eth0
Summary 208,552 rx/s 0 err,drop/s
Summary 208,654 rx/s 0 err,drop/s
root@imx93evk:~# ./xdp-bench redirect eth0 eth0
eth0->eth0 311,210 rx/s 0 err,drop/s 311,208 xmit/s
eth0->eth0 310,808 rx/s 0 err,drop/s 310,809 xmit/s
After applying this patch set.
root@imx93evk:~# ./xdp-bench tx eth0
Summary 425,778 rx/s 0 err,drop/s
Summary 426,042 rx/s 0 err,drop/s
root@imx93evk:~# ./xdp-bench drop eth0
Summary 698,351 rx/s 0 err/s
Summary 701,882 rx/s 0 err/s
root@imx93evk:~# ./xdp-bench pass eth0
Summary 210,348 rx/s 0 err,drop/s
Summary 210,016 rx/s 0 err,drop/s
root@imx93evk:~# ./xdp-bench redirect eth0 eth0
eth0->eth0 354,407 rx/s 0 err,drop/s 354,401 xmit/s
eth0->eth0 350,381 rx/s 0 err,drop/s 350,389 xmit/s
This patch set also addes the AF_XDP zero-copy support, and we tested
the performance on i.MX93 platform with xdpsock tool. The following is
the performance comparison of copy mode and zero-copy mode. It can be
seen that the performance of zero-copy mode is better than that of copy
mode.
1. MAC swap L2 forwarding
1.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -z
sock0@eth0:0 l2fwd xdp-drv
pps pkts 1.00
rx 414715 415455
tx 414715 415455
1.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -c
sock0@eth0:0 l2fwd xdp-drv
pps pkts 1.00
rx 356396 356609
tx 356396 356609
2. TX only
2.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -z
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 1119573 1126720
2.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -c
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 406864 407616
====================
Link: https://patch.msgid.link/20260205085742.2685134-1-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This patch adds AF_XDP zero-copy support for both TX and RX on the FEC
driver. It introduces new functions for XSK buffer allocation, RX/TX
queue processing in zero-copy mode, and XSK pool setup/teardown.
For RX, fec_alloc_rxq_buffers_zc() is added to allocate RX buffers from
XSK pool. And fec_enet_rx_queue_xsk() is used to process the frames from
the RX queue which is bound to the AF_XDP socket. Similar to the copy
mode, the zero-copy mode also supports XDP_TX, XDP_PASS, XDP_DROP and
XDP_REDIRECT actions. In addition, fec_enet_xsk_tx_xmit() is similar to
fec_enet_xdp_tx_xmit() and is used to handle XDP_TX action in zero-copy
mode.
For TX, there are two cases, one is the frames from the AF_XDP socket,
so fec_enet_xsk_xmit() is added to directly transmit the frames from
the socket and the buffer type is marked as FEC_TXBUF_T_XSK_XMIT. The
other one is the frames from the RX queue (XDP_TX action), the buffer
type is marked as FEC_TXBUF_T_XSK_TX. Therefore, fec_enet_tx_queue()
could correctly clean the TX queue base on the buffer type.
Also, some tests have been done on the i.MX93-EVK board with the xdpsock
tool, the following are the results.
Env: i.MX93 connects to a packet generator, the link speed is 1Gbps, and
flow-control is off. The RX packet size is 64 bytes including FCS. Only
one RX queue (CPU) is used to receive frames.
1. MAC swap L2 forwarding
1.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -z
sock0@eth0:0 l2fwd xdp-drv
pps pkts 1.00
rx 414715 415455
tx 414715 415455
1.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -c
sock0@eth0:0 l2fwd xdp-drv
pps pkts 1.00
rx 356396 356609
tx 356396 356609
2. TX only
2.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -z
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 1119573 1126720
2.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -c
sock0@eth0:0 txonly xdp-drv
pps pkts 1.00
rx 0 0
tx 406864 407616
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-16-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
To support AF_XDP zero-copy mode in the subsequent patch, the following
adjustments have been made to fec_tx_queue().
1. Change the parameters of fec_tx_queue().
2. Some variables are initialized at the time of declaration, and the
order of local variables is updated to follow the reverse xmas tree
style.
3. Remove the variable xdpf and add the variable tx_buf.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-15-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the buffers of RX queue are allocated from the page pool. In
the subsequent patches to support XDP zero copy, the RX buffers will be
allocated from the UMEM. Therefore, extract fec_alloc_rxq_buffers_pp()
from fec_enet_alloc_rxq_buffers() and we will add another helper to
allocate RX buffers from UMEM for the XDP zero copy mode. In addition,
fec_alloc_rxq_buffers_pp() only initializes bdp->bufaddr and does not
initialize other fields of bdp, because these will be initialized in
fec_enet_bd_init().
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-14-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Extract fec_xdp_rxq_info_reg() from fec_enet_create_page_pool() and move
it out of fec_enet_create_page_pool(), so that it can be reused in the
subsequent patches to support XDP zero copy mode.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-13-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Remove the size parameter from fec_enet_create_page_pool(), since
rxq->bd.ring_size already contains this information.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-12-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The tx_buf has three types: FEC_TXBUF_T_SKB, FEC_TXBUF_T_XDP_NDO and
FEC_TXBUF_T_XDP_TX. Currently, the driver uses 'if...else...' statements
to check the type and perform the corresponding processing. This is very
detrimental to future expansion. To support AF_XDP zero-copy mode, two
new types will be added in the future, continuing to use 'if...else...'
would be a very bad coding style. So the 'if...else...' statements in
the current driver are replaced with switch statements.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-11-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The tx_buf pointer will not NULL when its type is FEC_TXBUF_T_XDP_NDO or
FEC_TXBUF_T_XDP_TX. If the type is FEC_TXBUF_T_SKB, dev_kfree_skb_any()
will do NULL pointer check. So it is unnecessary to do NULL pointer check
in fec_enet_bd_init() and fec_enet_tx_queue().
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-10-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the driver writes the ENET_TDAR register for every XDP frame
to trigger transmit start. Frequent MMIO writes consume more CPU cycles
and may reduce XDP TX performance, so transmit XDP frames in bulk.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-9-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Remove fec_enet_xdp_get_tx_queue() from fec_enet_xdp_tx_xmit() and add
the tx_qid parameter to it. Then, calculate the TX queue ID for XDP_TX
frames in fec_enet_rx_queue_xdp(). This way, the TX queue ID only needs
to be calculated once for XDP_TX frames during each NAPI polling. And
since the number of RX queues and TX queues in FEC is generally equal,
the RX queue ID can be directly used as the TX queue ID. In exceptional
cases, fec_enet_xdp_get_tx_queue() is used to calculate the TX queue ID.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-8-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the processing of XDP path packets and protocol stack packets
are both mixed in fec_enet_rx_queue(), which makes the logic somewhat
confusing and debugging more difficult. Furthermore, some logic is not
needed by each other. Such as the kernel path does not need to call
xdp_init_buff(), XDP path does not support swap_buffer(), because
fec_enet_bpf() returns "-EOPNOTSUPP" for those platforms which need
swap_buffer()), and so on. This prevents XDP from achieving its maximum
performance. Therefore, XDP path packets processing has been separated
from fec_enet_rx_queue() by adding the fec_enet_rx_queue_xdp() function
to optimize XDP path logic and improve XDP performance.
The XDP performance on the iMX93 platform was compared before and after
applying this patch. Detailed results are as follows and we can see the
performance has been improved.
Env: i.MX93, packet size 64 bytes including FCS, only single core and RX
BD ring are used to receive packets, flow-control is off.
Before the patch is applied:
xdp-bench tx eth0
Summary 396,868 rx/s 0 err,drop/s
Summary 396,024 rx/s 0 err,drop/s
xdp-bench drop eth0
Summary 684,781 rx/s 0 err/s
Summary 675,746 rx/s 0 err/s
xdp-bench pass eth0
Summary 208,552 rx/s 0 err,drop/s
Summary 208,654 rx/s 0 err,drop/s
xdp-bench redirect eth0 eth0
eth0->eth0 311,210 rx/s 0 err,drop/s 311,208 xmit/s
eth0->eth0 310,808 rx/s 0 err,drop/s 310,809 xmit/s
After the patch is applied:
xdp-bench tx eth0
Summary 409,975 rx/s 0 err,drop/s
Summary 411,073 rx/s 0 err,drop/s
xdp-bench drop eth0
Summary 700,681 rx/s 0 err/s
Summary 698,102 rx/s 0 err/s
xdp-bench pass eth0
Summary 211,356 rx/s 0 err,drop/s
Summary 210,629 rx/s 0 err,drop/s
xdp-bench redirect eth0 eth0
eth0->eth0 320,351 rx/s 0 err,drop/s 320,348 xmit/s
eth0->eth0 318,988 rx/s 0 err,drop/s 318,988 xmit/s
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-7-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This patch has made the following adjustments to fec_enet_rx_queue().
1. The function parameters are modified to maintain the same style as
subsequently added XDP-related interfaces.
2. Some variables are initialized at the time of declaration, and the
order of local variables is updated to follow the reverse xmas tree
style.
3. Replace variable cbd_bufaddr with dma.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-6-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Extract the helper fec_build_skb() from fec_enet_rx_queue(), so that the
code for building a skb is centralized in fec_build_skb(), which makes
the code of fec_enet_rx_queue() more concise and readable.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-5-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The FEC of some platforms supports RX FIFO shift-16, it means the actual
frame data starts at bit 16 of the first word read from RX FIFO aligning
the Ethernet payload on a 32-bit boundary. The MAC writes two additional
bytes in front of each frame received into the RX FIFO. Currently, the
fec_enet_rx_queue() updates the data_start, sub_len and the rx_bytes
statistics by checking whether FEC_QUIRK_HAS_RACC is set. This makes the
code less concise, so rx_shift is added to represent the number of extra
bytes padded in front of the RX frame. Furthermore, when adding separate
RX handling functions for XDP copy mode and zero copy mode in the future,
it will no longer be necessary to check FEC_QUIRK_HAS_RACC to update the
corresponding variables.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-4-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Extract fec_rx_error_check() from fec_enet_rx_queue(), this helper is
used to check RX errors. And it will be used in XDP and XDP zero copy
paths in subsequent patches.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-3-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the workaround for FEC_QUIRK_ERR007885 has three call sites,
so add the helper fec_txq_trigger_xmit() to make the code more concise
and reusable.
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-2-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When CONFIG_SLAB_FREELIST_RANDOM is enabled and get_random_u32()
is called in an NMI context, lockdep complains because it acquires
a local_lock:
================================
WARNING: inconsistent lock state
6.19.0-rc5-slab-for-next+ #325 Tainted: G N
--------------------------------
inconsistent {INITIAL USE} -> {IN-NMI} usage.
kunit_try_catch/8312 [HC2[2]:SC0[0]:HE0:SE1] takes:
ffff88a02ec49cc0 (batched_entropy_u32.lock){-.-.}-{3:3}, at: get_random_u32+0x7f/0x2e0
{INITIAL USE} state was registered at:
lock_acquire+0xd9/0x2f0
get_random_u32+0x93/0x2e0
__get_random_u32_below+0x17/0x70
cache_random_seq_create+0x121/0x1c0
init_cache_random_seq+0x5d/0x110
do_kmem_cache_create+0x1e0/0xa30
__kmem_cache_create_args+0x4ec/0x830
create_kmalloc_caches+0xe6/0x130
kmem_cache_init+0x1b1/0x660
mm_core_init+0x1d8/0x4b0
start_kernel+0x620/0xcd0
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0xf3/0x140
common_startup_64+0x13e/0x148
irq event stamp: 76
hardirqs last enabled at (75): [<ffffffff8298b77a>] exc_nmi+0x11a/0x240
hardirqs last disabled at (76): [<ffffffff8298b991>] sysvec_irq_work+0x11/0x110
softirqs last enabled at (0): [<ffffffff813b2dda>] copy_process+0xc7a/0x2350
softirqs last disabled at (0): [<0000000000000000>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(batched_entropy_u32.lock);
<Interrupt>
lock(batched_entropy_u32.lock);
*** DEADLOCK ***
Fix this by using pseudo-random number generator if !allow_spin.
This means kmalloc_nolock() users won't get truly random numbers,
but there is not much we can do about it.
Note that an NMI handler might interrupt prandom_u32_state() and
change the random state, but that's safe.
Link: https://lore.kernel.org/all/0c33bdee-6de8-4d9f-92ca-4f72c1b6fb9f@suse.cz
Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210081900.329447-3-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Lockdep complains when get_from_any_partial() is called in an NMI
context, because current->mems_allowed_seq is seqcount_spinlock_t and
not NMI-safe:
================================
WARNING: inconsistent lock state
6.19.0-rc5-kfree-rcu+ #315 Tainted: G N
--------------------------------
inconsistent {INITIAL USE} -> {IN-NMI} usage.
kunit_try_catch/9989 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffff889085799820 (&____s->seqcount#3){.-.-}-{0:0}, at: ___slab_alloc+0x58f/0xc00
{INITIAL USE} state was registered at:
lock_acquire+0x185/0x320
kernel_init_freeable+0x391/0x1150
kernel_init+0x1f/0x220
ret_from_fork+0x736/0x8f0
ret_from_fork_asm+0x1a/0x30
irq event stamp: 56
hardirqs last enabled at (55): [<ffffffff850a68d7>] _raw_spin_unlock_irq+0x27/0x70
hardirqs last disabled at (56): [<ffffffff850858ca>] __schedule+0x2a8a/0x6630
softirqs last enabled at (0): [<ffffffff81536711>] copy_process+0x1dc1/0x6a10
softirqs last disabled at (0): [<0000000000000000>] 0x0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&____s->seqcount#3);
<Interrupt>
lock(&____s->seqcount#3);
*** DEADLOCK ***
According to Documentation/locking/seqlock.rst, seqcount_t is not
NMI-safe and seqcount_latch_t should be used when read path can interrupt
the write-side critical section. In this case, do not access
current->mems_allowed_seq and avoid retry.
Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210081900.329447-2-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
