<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/kernel, branch v6.13-rc2</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'irq_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-12-08T19:54:04+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-12-08T19:54:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=eadaac4dd2e07292181d35858047bdb177d5194f'/>
<id>eadaac4dd2e07292181d35858047bdb177d5194f</id>
<content type='text'>
Pull irq fixes from Borislav Petkov:

 - Fix a /proc/interrupts formatting regression

 - Have the BCM2836 interrupt controller enter power management states
   properly

 - Other fixlets

* tag 'irq_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/stm32mp-exti: CONFIG_STM32MP_EXTI should not default to y when compile-testing
  genirq/proc: Add missing space separator back
  irqchip/bcm2836: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
  irqchip/gic-v3: Fix irq_complete_ack() comment
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull irq fixes from Borislav Petkov:

 - Fix a /proc/interrupts formatting regression

 - Have the BCM2836 interrupt controller enter power management states
   properly

 - Other fixlets

* tag 'irq_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/stm32mp-exti: CONFIG_STM32MP_EXTI should not default to y when compile-testing
  genirq/proc: Add missing space separator back
  irqchip/bcm2836: Enable SKIP_SET_WAKE and MASK_ON_SUSPEND
  irqchip/gic-v3: Fix irq_complete_ack() comment
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'timers_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-12-08T19:51:29+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-12-08T19:51:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c25ca0c2e42c77e0241411d374d44c41e253b3f5'/>
<id>c25ca0c2e42c77e0241411d374d44c41e253b3f5</id>
<content type='text'>
Pull timer fix from Borislav Petkov:

 - Handle the case where clocksources with small counter width can,
   in conjunction with overly long idle sleeps, falsely trigger the
   negative motion detection of clocksources

* tag 'timers_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Make negative motion detection more robust
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timer fix from Borislav Petkov:

 - Handle the case where clocksources with small counter width can,
   in conjunction with overly long idle sleeps, falsely trigger the
   negative motion detection of clocksources

* tag 'timers_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Make negative motion detection more robust
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mm-hotfixes-stable-2024-12-07-22-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-12-08T19:26:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-12-08T19:26:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=553c89ec31746ff96fc5562943fe5b1c9b1e9276'/>
<id>553c89ec31746ff96fc5562943fe5b1c9b1e9276</id>
<content type='text'>
Pull misc fixes from Andrew Morton:
 "24 hotfixes.  17 are cc:stable.  15 are MM and 9 are non-MM.

  The usual bunch of singletons - please see the relevant changelogs for
  details"

* tag 'mm-hotfixes-stable-2024-12-07-22-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (24 commits)
  iio: magnetometer: yas530: use signed integer type for clamp limits
  sched/numa: fix memory leak due to the overwritten vma-&gt;numab_state
  mm/damon: fix order of arguments in damos_before_apply tracepoint
  lib: stackinit: hide never-taken branch from compiler
  mm/filemap: don't call folio_test_locked() without a reference in next_uptodate_folio()
  scatterlist: fix incorrect func name in kernel-doc
  mm: correct typo in MMAP_STATE() macro
  mm: respect mmap hint address when aligning for THP
  mm: memcg: declare do_memsw_account inline
  mm/codetag: swap tags when migrate pages
  ocfs2: update seq_file index in ocfs2_dlm_seq_next
  stackdepot: fix stack_depot_save_flags() in NMI context
  mm: open-code page_folio() in dump_page()
  mm: open-code PageTail in folio_flags() and const_folio_flags()
  mm: fix vrealloc()'s KASAN poisoning logic
  Revert "readahead: properly shorten readahead when falling back to do_page_cache_ra()"
  selftests/damon: add _damon_sysfs.py to TEST_FILES
  selftest: hugetlb_dio: fix test naming
  ocfs2: free inode when ocfs2_get_init_inode() fails
  nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull misc fixes from Andrew Morton:
 "24 hotfixes.  17 are cc:stable.  15 are MM and 9 are non-MM.

  The usual bunch of singletons - please see the relevant changelogs for
  details"

* tag 'mm-hotfixes-stable-2024-12-07-22-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (24 commits)
  iio: magnetometer: yas530: use signed integer type for clamp limits
  sched/numa: fix memory leak due to the overwritten vma-&gt;numab_state
  mm/damon: fix order of arguments in damos_before_apply tracepoint
  lib: stackinit: hide never-taken branch from compiler
  mm/filemap: don't call folio_test_locked() without a reference in next_uptodate_folio()
  scatterlist: fix incorrect func name in kernel-doc
  mm: correct typo in MMAP_STATE() macro
  mm: respect mmap hint address when aligning for THP
  mm: memcg: declare do_memsw_account inline
  mm/codetag: swap tags when migrate pages
  ocfs2: update seq_file index in ocfs2_dlm_seq_next
  stackdepot: fix stack_depot_save_flags() in NMI context
  mm: open-code page_folio() in dump_page()
  mm: open-code PageTail in folio_flags() and const_folio_flags()
  mm: fix vrealloc()'s KASAN poisoning logic
  Revert "readahead: properly shorten readahead when falling back to do_page_cache_ra()"
  selftests/damon: add _damon_sysfs.py to TEST_FILES
  selftest: hugetlb_dio: fix test naming
  ocfs2: free inode when ocfs2_get_init_inode() fails
  nilfs2: fix potential out-of-bounds memory access in nilfs_find_entry()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2024-12-06T23:07:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-12-06T23:07:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b5f217084ab3ddd4bdd03cd437f8e3b7e2d1f5b6'/>
<id>b5f217084ab3ddd4bdd03cd437f8e3b7e2d1f5b6</id>
<content type='text'>
Pull bpf fixes from Daniel Borkmann::

 - Fix several issues for BPF LPM trie map which were found by syzbot
   and during addition of new test cases (Hou Tao)

 - Fix a missing process_iter_arg register type check in the BPF
   verifier (Kumar Kartikeya Dwivedi, Tao Lyu)

 - Fix several correctness gaps in the BPF verifier when interacting
   with the BPF stack without CAP_PERFMON (Kumar Kartikeya Dwivedi,
   Eduard Zingerman, Tao Lyu)

 - Fix OOB BPF map writes when deleting elements for the case of xsk map
   as well as devmap (Maciej Fijalkowski)

 - Fix xsk sockets to always clear DMA mapping information when
   unmapping the pool (Larysa Zaremba)

 - Fix sk_mem_uncharge logic in tcp_bpf_sendmsg to only uncharge after
   sent bytes have been finalized (Zijian Zhang)

 - Fix BPF sockmap with vsocks which was missing a queue check in poll
   and sockmap cleanup on close (Michal Luczaj)

 - Fix tools infra to override makefile ARCH variable if defined but
   empty, which addresses cross-building tools. (Björn Töpel)

 - Fix two resolve_btfids build warnings on unresolved bpf_lsm symbols
   (Thomas Weißschuh)

 - Fix a NULL pointer dereference in bpftool (Amir Mohammadi)

 - Fix BPF selftests to check for CONFIG_PREEMPTION instead of
   CONFIG_PREEMPT (Sebastian Andrzej Siewior)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (31 commits)
  selftests/bpf: Add more test cases for LPM trie
  selftests/bpf: Move test_lpm_map.c to map_tests
  bpf: Use raw_spinlock_t for LPM trie
  bpf: Switch to bpf mem allocator for LPM trie
  bpf: Fix exact match conditions in trie_get_next_key()
  bpf: Handle in-place update for full LPM trie correctly
  bpf: Handle BPF_EXIST and BPF_NOEXIST for LPM trie
  bpf: Remove unnecessary kfree(im_node) in lpm_trie_update_elem
  bpf: Remove unnecessary check when updating LPM trie
  selftests/bpf: Add test for narrow spill into 64-bit spilled scalar
  selftests/bpf: Add test for reading from STACK_INVALID slots
  selftests/bpf: Introduce __caps_unpriv annotation for tests
  bpf: Fix narrow scalar spill onto 64-bit spilled scalar slots
  bpf: Don't mark STACK_INVALID as STACK_MISC in mark_stack_slot_misc
  samples/bpf: Remove unnecessary -I flags from libbpf EXTRA_CFLAGS
  bpf: Zero index arg error string for dynptr and iter
  selftests/bpf: Add tests for iter arg check
  bpf: Ensure reg is PTR_TO_STACK in process_iter_arg
  tools: Override makefile ARCH variable if defined, but empty
  selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull bpf fixes from Daniel Borkmann::

 - Fix several issues for BPF LPM trie map which were found by syzbot
   and during addition of new test cases (Hou Tao)

 - Fix a missing process_iter_arg register type check in the BPF
   verifier (Kumar Kartikeya Dwivedi, Tao Lyu)

 - Fix several correctness gaps in the BPF verifier when interacting
   with the BPF stack without CAP_PERFMON (Kumar Kartikeya Dwivedi,
   Eduard Zingerman, Tao Lyu)

 - Fix OOB BPF map writes when deleting elements for the case of xsk map
   as well as devmap (Maciej Fijalkowski)

 - Fix xsk sockets to always clear DMA mapping information when
   unmapping the pool (Larysa Zaremba)

 - Fix sk_mem_uncharge logic in tcp_bpf_sendmsg to only uncharge after
   sent bytes have been finalized (Zijian Zhang)

 - Fix BPF sockmap with vsocks which was missing a queue check in poll
   and sockmap cleanup on close (Michal Luczaj)

 - Fix tools infra to override makefile ARCH variable if defined but
   empty, which addresses cross-building tools. (Björn Töpel)

 - Fix two resolve_btfids build warnings on unresolved bpf_lsm symbols
   (Thomas Weißschuh)

 - Fix a NULL pointer dereference in bpftool (Amir Mohammadi)

 - Fix BPF selftests to check for CONFIG_PREEMPTION instead of
   CONFIG_PREEMPT (Sebastian Andrzej Siewior)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: (31 commits)
  selftests/bpf: Add more test cases for LPM trie
  selftests/bpf: Move test_lpm_map.c to map_tests
  bpf: Use raw_spinlock_t for LPM trie
  bpf: Switch to bpf mem allocator for LPM trie
  bpf: Fix exact match conditions in trie_get_next_key()
  bpf: Handle in-place update for full LPM trie correctly
  bpf: Handle BPF_EXIST and BPF_NOEXIST for LPM trie
  bpf: Remove unnecessary kfree(im_node) in lpm_trie_update_elem
  bpf: Remove unnecessary check when updating LPM trie
  selftests/bpf: Add test for narrow spill into 64-bit spilled scalar
  selftests/bpf: Add test for reading from STACK_INVALID slots
  selftests/bpf: Introduce __caps_unpriv annotation for tests
  bpf: Fix narrow scalar spill onto 64-bit spilled scalar slots
  bpf: Don't mark STACK_INVALID as STACK_MISC in mark_stack_slot_misc
  samples/bpf: Remove unnecessary -I flags from libbpf EXTRA_CFLAGS
  bpf: Zero index arg error string for dynptr and iter
  selftests/bpf: Add tests for iter arg check
  bpf: Ensure reg is PTR_TO_STACK in process_iter_arg
  tools: Override makefile ARCH variable if defined, but empty
  selftests/bpf: Add apply_bytes test to test_txmsg_redir_wait_sndmem in test_sockmap
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Use raw_spinlock_t for LPM trie</title>
<updated>2024-12-06T17:14:26+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6a5c63d43c0216d64915baa0e0eacf2beb66b271'/>
<id>6a5c63d43c0216d64915baa0e0eacf2beb66b271</id>
<content type='text'>
After switching from kmalloc() to the bpf memory allocator, there will be
no blocking operation during the update of LPM trie. Therefore, change
trie-&gt;lock from spinlock_t to raw_spinlock_t to make LPM trie usable in
atomic context, even on RT kernels.

The max value of prefixlen is 2048. Therefore, update or deletion
operations will find the target after at most 2048 comparisons.
Constructing a test case which updates an element after 2048 comparisons
under a 8 CPU VM, and the average time and the maximal time for such
update operation is about 210us and 900us.

Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-8-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After switching from kmalloc() to the bpf memory allocator, there will be
no blocking operation during the update of LPM trie. Therefore, change
trie-&gt;lock from spinlock_t to raw_spinlock_t to make LPM trie usable in
atomic context, even on RT kernels.

The max value of prefixlen is 2048. Therefore, update or deletion
operations will find the target after at most 2048 comparisons.
Constructing a test case which updates an element after 2048 comparisons
under a 8 CPU VM, and the average time and the maximal time for such
update operation is about 210us and 900us.

Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-8-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Switch to bpf mem allocator for LPM trie</title>
<updated>2024-12-06T17:14:26+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3d8dc43eb2a3d179809f5fc27c88c93a57ea123d'/>
<id>3d8dc43eb2a3d179809f5fc27c88c93a57ea123d</id>
<content type='text'>
Multiple syzbot warnings have been reported. These warnings are mainly
about the lock order between trie-&gt;lock and kmalloc()'s internal lock.
See report [1] as an example:

======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc7-syzkaller-00003-g4376e966ecb7 #0 Not tainted
------------------------------------------------------
syz.3.2069/15008 is trying to acquire lock:
ffff88801544e6d8 (&amp;n-&gt;list_lock){-.-.}-{2:2}, at: get_partial_node ...

but task is already holding lock:
ffff88802dcc89f8 (&amp;trie-&gt;lock){-.-.}-{2:2}, at: trie_update_elem ...

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #1 (&amp;trie-&gt;lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x3a/0x60
       trie_delete_elem+0xb0/0x820
       ___bpf_prog_run+0x3e51/0xabd0
       __bpf_prog_run32+0xc1/0x100
       bpf_dispatcher_nop_func
       ......
       bpf_trace_run2+0x231/0x590
       __bpf_trace_contention_end+0xca/0x110
       trace_contention_end.constprop.0+0xea/0x170
       __pv_queued_spin_lock_slowpath+0x28e/0xcc0
       pv_queued_spin_lock_slowpath
       queued_spin_lock_slowpath
       queued_spin_lock
       do_raw_spin_lock+0x210/0x2c0
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x42/0x60
       __put_partials+0xc3/0x170
       qlink_free
       qlist_free_all+0x4e/0x140
       kasan_quarantine_reduce+0x192/0x1e0
       __kasan_slab_alloc+0x69/0x90
       kasan_slab_alloc
       slab_post_alloc_hook
       slab_alloc_node
       kmem_cache_alloc_node_noprof+0x153/0x310
       __alloc_skb+0x2b1/0x380
       ......

-&gt; #0 (&amp;n-&gt;list_lock){-.-.}-{2:2}:
       check_prev_add
       check_prevs_add
       validate_chain
       __lock_acquire+0x2478/0x3b30
       lock_acquire
       lock_acquire+0x1b1/0x560
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x3a/0x60
       get_partial_node.part.0+0x20/0x350
       get_partial_node
       get_partial
       ___slab_alloc+0x65b/0x1870
       __slab_alloc.constprop.0+0x56/0xb0
       __slab_alloc_node
       slab_alloc_node
       __do_kmalloc_node
       __kmalloc_node_noprof+0x35c/0x440
       kmalloc_node_noprof
       bpf_map_kmalloc_node+0x98/0x4a0
       lpm_trie_node_alloc
       trie_update_elem+0x1ef/0xe00
       bpf_map_update_value+0x2c1/0x6c0
       map_update_elem+0x623/0x910
       __sys_bpf+0x90c/0x49a0
       ...

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&amp;trie-&gt;lock);
                               lock(&amp;n-&gt;list_lock);
                               lock(&amp;trie-&gt;lock);
  lock(&amp;n-&gt;list_lock);

 *** DEADLOCK ***

[1]: https://syzkaller.appspot.com/bug?extid=9045c0a3d5a7f1b119f7

A bpf program attached to trace_contention_end() triggers after
acquiring &amp;n-&gt;list_lock. The program invokes trie_delete_elem(), which
then acquires trie-&gt;lock. However, it is possible that another
process is invoking trie_update_elem(). trie_update_elem() will acquire
trie-&gt;lock first, then invoke kmalloc_node(). kmalloc_node() may invoke
get_partial_node() and try to acquire &amp;n-&gt;list_lock (not necessarily the
same lock object). Therefore, lockdep warns about the circular locking
dependency.

Invoking kmalloc() before acquiring trie-&gt;lock could fix the warning.
However, since BPF programs call be invoked from any context (e.g.,
through kprobe/tracepoint/fentry), there may still be lock ordering
problems for internal locks in kmalloc() or trie-&gt;lock itself.

To eliminate these potential lock ordering problems with kmalloc()'s
internal locks, replacing kmalloc()/kfree()/kfree_rcu() with equivalent
BPF memory allocator APIs that can be invoked in any context. The lock
ordering problems with trie-&gt;lock (e.g., reentrance) will be handled
separately.

Three aspects of this change require explanation:

1. Intermediate and leaf nodes are allocated from the same allocator.
Since the value size of LPM trie is usually small, using a single
alocator reduces the memory overhead of the BPF memory allocator.

2. Leaf nodes are allocated before disabling IRQs. This handles cases
where leaf_size is large (e.g., &gt; 4KB - 8) and updates require
intermediate node allocation. If leaf nodes were allocated in
IRQ-disabled region, the free objects in BPF memory allocator would not
be refilled timely and the intermediate node allocation may fail.

3. Paired migrate_{disable|enable}() calls for node alloc and free. The
BPF memory allocator uses per-CPU struct internally, these paired calls
are necessary to guarantee correctness.

Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-7-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Multiple syzbot warnings have been reported. These warnings are mainly
about the lock order between trie-&gt;lock and kmalloc()'s internal lock.
See report [1] as an example:

======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc7-syzkaller-00003-g4376e966ecb7 #0 Not tainted
------------------------------------------------------
syz.3.2069/15008 is trying to acquire lock:
ffff88801544e6d8 (&amp;n-&gt;list_lock){-.-.}-{2:2}, at: get_partial_node ...

but task is already holding lock:
ffff88802dcc89f8 (&amp;trie-&gt;lock){-.-.}-{2:2}, at: trie_update_elem ...

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #1 (&amp;trie-&gt;lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x3a/0x60
       trie_delete_elem+0xb0/0x820
       ___bpf_prog_run+0x3e51/0xabd0
       __bpf_prog_run32+0xc1/0x100
       bpf_dispatcher_nop_func
       ......
       bpf_trace_run2+0x231/0x590
       __bpf_trace_contention_end+0xca/0x110
       trace_contention_end.constprop.0+0xea/0x170
       __pv_queued_spin_lock_slowpath+0x28e/0xcc0
       pv_queued_spin_lock_slowpath
       queued_spin_lock_slowpath
       queued_spin_lock
       do_raw_spin_lock+0x210/0x2c0
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x42/0x60
       __put_partials+0xc3/0x170
       qlink_free
       qlist_free_all+0x4e/0x140
       kasan_quarantine_reduce+0x192/0x1e0
       __kasan_slab_alloc+0x69/0x90
       kasan_slab_alloc
       slab_post_alloc_hook
       slab_alloc_node
       kmem_cache_alloc_node_noprof+0x153/0x310
       __alloc_skb+0x2b1/0x380
       ......

-&gt; #0 (&amp;n-&gt;list_lock){-.-.}-{2:2}:
       check_prev_add
       check_prevs_add
       validate_chain
       __lock_acquire+0x2478/0x3b30
       lock_acquire
       lock_acquire+0x1b1/0x560
       __raw_spin_lock_irqsave
       _raw_spin_lock_irqsave+0x3a/0x60
       get_partial_node.part.0+0x20/0x350
       get_partial_node
       get_partial
       ___slab_alloc+0x65b/0x1870
       __slab_alloc.constprop.0+0x56/0xb0
       __slab_alloc_node
       slab_alloc_node
       __do_kmalloc_node
       __kmalloc_node_noprof+0x35c/0x440
       kmalloc_node_noprof
       bpf_map_kmalloc_node+0x98/0x4a0
       lpm_trie_node_alloc
       trie_update_elem+0x1ef/0xe00
       bpf_map_update_value+0x2c1/0x6c0
       map_update_elem+0x623/0x910
       __sys_bpf+0x90c/0x49a0
       ...

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&amp;trie-&gt;lock);
                               lock(&amp;n-&gt;list_lock);
                               lock(&amp;trie-&gt;lock);
  lock(&amp;n-&gt;list_lock);

 *** DEADLOCK ***

[1]: https://syzkaller.appspot.com/bug?extid=9045c0a3d5a7f1b119f7

A bpf program attached to trace_contention_end() triggers after
acquiring &amp;n-&gt;list_lock. The program invokes trie_delete_elem(), which
then acquires trie-&gt;lock. However, it is possible that another
process is invoking trie_update_elem(). trie_update_elem() will acquire
trie-&gt;lock first, then invoke kmalloc_node(). kmalloc_node() may invoke
get_partial_node() and try to acquire &amp;n-&gt;list_lock (not necessarily the
same lock object). Therefore, lockdep warns about the circular locking
dependency.

Invoking kmalloc() before acquiring trie-&gt;lock could fix the warning.
However, since BPF programs call be invoked from any context (e.g.,
through kprobe/tracepoint/fentry), there may still be lock ordering
problems for internal locks in kmalloc() or trie-&gt;lock itself.

To eliminate these potential lock ordering problems with kmalloc()'s
internal locks, replacing kmalloc()/kfree()/kfree_rcu() with equivalent
BPF memory allocator APIs that can be invoked in any context. The lock
ordering problems with trie-&gt;lock (e.g., reentrance) will be handled
separately.

Three aspects of this change require explanation:

1. Intermediate and leaf nodes are allocated from the same allocator.
Since the value size of LPM trie is usually small, using a single
alocator reduces the memory overhead of the BPF memory allocator.

2. Leaf nodes are allocated before disabling IRQs. This handles cases
where leaf_size is large (e.g., &gt; 4KB - 8) and updates require
intermediate node allocation. If leaf nodes were allocated in
IRQ-disabled region, the free objects in BPF memory allocator would not
be refilled timely and the intermediate node allocation may fail.

3. Paired migrate_{disable|enable}() calls for node alloc and free. The
BPF memory allocator uses per-CPU struct internally, these paired calls
are necessary to guarantee correctness.

Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-7-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Fix exact match conditions in trie_get_next_key()</title>
<updated>2024-12-06T17:14:26+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=27abc7b3fa2e09bbe41e2924d328121546865eda'/>
<id>27abc7b3fa2e09bbe41e2924d328121546865eda</id>
<content type='text'>
trie_get_next_key() uses node-&gt;prefixlen == key-&gt;prefixlen to identify
an exact match, However, it is incorrect because when the target key
doesn't fully match the found node (e.g., node-&gt;prefixlen != matchlen),
these two nodes may also have the same prefixlen. It will return
expected result when the passed key exist in the trie. However when a
recently-deleted key or nonexistent key is passed to
trie_get_next_key(), it may skip keys and return incorrect result.

Fix it by using node-&gt;prefixlen == matchlen to identify exact matches.
When the condition is true after the search, it also implies
node-&gt;prefixlen equals key-&gt;prefixlen, otherwise, the search would
return NULL instead.

Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
trie_get_next_key() uses node-&gt;prefixlen == key-&gt;prefixlen to identify
an exact match, However, it is incorrect because when the target key
doesn't fully match the found node (e.g., node-&gt;prefixlen != matchlen),
these two nodes may also have the same prefixlen. It will return
expected result when the passed key exist in the trie. However when a
recently-deleted key or nonexistent key is passed to
trie_get_next_key(), it may skip keys and return incorrect result.

Fix it by using node-&gt;prefixlen == matchlen to identify exact matches.
When the condition is true after the search, it also implies
node-&gt;prefixlen equals key-&gt;prefixlen, otherwise, the search would
return NULL instead.

Fixes: b471f2f1de8b ("bpf: implement MAP_GET_NEXT_KEY command for LPM_TRIE map")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Handle in-place update for full LPM trie correctly</title>
<updated>2024-12-06T17:14:26+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=532d6b36b2bfac5514426a97a4df8d103d700d43'/>
<id>532d6b36b2bfac5514426a97a4df8d103d700d43</id>
<content type='text'>
When a LPM trie is full, in-place updates of existing elements
incorrectly return -ENOSPC.

Fix this by deferring the check of trie-&gt;n_entries. For new insertions,
n_entries must not exceed max_entries. However, in-place updates are
allowed even when the trie is full.

Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When a LPM trie is full, in-place updates of existing elements
incorrectly return -ENOSPC.

Fix this by deferring the check of trie-&gt;n_entries. For new insertions,
n_entries must not exceed max_entries. However, in-place updates are
allowed even when the trie is full.

Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Handle BPF_EXIST and BPF_NOEXIST for LPM trie</title>
<updated>2024-12-06T17:14:26+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=eae6a075e9537dd69891cf77ca5a88fa8a28b4a1'/>
<id>eae6a075e9537dd69891cf77ca5a88fa8a28b4a1</id>
<content type='text'>
Add the currently missing handling for the BPF_EXIST and BPF_NOEXIST
flags. These flags can be specified by users and are relevant since LPM
trie supports exact matches during update.

Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the currently missing handling for the BPF_EXIST and BPF_NOEXIST
flags. These flags can be specified by users and are relevant since LPM
trie supports exact matches during update.

Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Remove unnecessary kfree(im_node) in lpm_trie_update_elem</title>
<updated>2024-12-06T17:14:25+00:00</updated>
<author>
<name>Hou Tao</name>
<email>houtao1@huawei.com</email>
</author>
<published>2024-12-06T11:06:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3d5611b4d7efbefb85a74fcdbc35c603847cc022'/>
<id>3d5611b4d7efbefb85a74fcdbc35c603847cc022</id>
<content type='text'>
There is no need to call kfree(im_node) when updating element fails,
because im_node must be NULL. Remove the unnecessary kfree() for
im_node.

Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is no need to call kfree(im_node) when updating element fails,
because im_node must be NULL. Remove the unnecessary kfree() for
im_node.

Reviewed-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Hou Tao &lt;houtao1@huawei.com&gt;
Link: https://lore.kernel.org/r/20241206110622.1161752-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
