[PATCH v4 0/6] bpf: Extend the bpf_list family of APIs

[Chengkaitao]

From: Kaitao Cheng <chengkaitao@xxxxxxxxxx>

In BPF, a list can only be used to implement a stack structure.
Due to an incomplete API set, only FIFO or LIFO operations are
supported. The patches enhance the BPF list API, making it more
list-like.

Five new kfuncs have been added:
bpf_list_del: remove a node from the list
bpf_list_add_impl: insert a node after a given list node
bpf_list_is_first: check if a node is the first in the list
bpf_list_is_last: check if a node is the last in the list
bpf_list_empty: check if the list is empty

Changes in v4:
- [patch v3 1/6] Revert to version v1
- Change the parameters of bpf_list_add_impl to (head, new, prev, ...)

Changes in v3:
- Add a new lock_rec member to struct bpf_reference_state for lock
  holding detection.
- Add test cases to verify that the verifier correctly restricts calls
  to bpf_list_del when the spin_lock is not held.

Changes in v2:
- Remove the head parameter from bpf_list_del
- Add bpf_list_add/is_first/is_last/empty to API and test cases

Link to v3:
https://lore.kernel.org/all/20260302124028.82420-1-pilgrimtao@xxxxxxxxx/

Link to v2:
https://lore.kernel.org/all/20260225092651.94689-1-pilgrimtao@xxxxxxxxx/

Link to v1:
https://lore.kernel.org/all/20260209025250.55750-1-pilgrimtao@xxxxxxxxx/

Kaitao Cheng (6):
  bpf: Introduce the bpf_list_del kfunc.
  selftests/bpf: Add test cases for bpf_list_del
  bpf: add bpf_list_add_impl to insert node after a given list node
  selftests/bpf: Add test case for bpf_list_add_impl
  bpf: add bpf_list_is_first/last/empty kfuncs
  selftests/bpf: Add test cases for bpf_list_is_first/is_last/empty

 kernel/bpf/helpers.c                          |  87 +++++++++
 kernel/bpf/verifier.c                         |  29 ++-
 .../testing/selftests/bpf/bpf_experimental.h  |  42 ++++
 .../selftests/bpf/progs/refcounted_kptr.c     | 182 ++++++++++++++++++
 4 files changed, 336 insertions(+), 4 deletions(-)

-- 
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