[ciqlts9_6] Multiple patches tested (6 commits)

[ciq-kernel-automation]

Summary

This PR has been automatically created after successful completion of all CI stages.

Commit Message(s)

bpf: name the enum for BPF_FUNC_skb_adjust_room flags

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=5e4bcad6171d4baf426e49a39580cdb79254ea36

bpf: refactor masks for ADJ_ROOM flags and encap validation

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=7b2ea1151e04d3506030db8734c48c5c2bec1392
upstream-diff |
  applied with line offset fuzz due to absence of bool decap
    variable (present in bpf-next, not in this tree). Code changes
    are identical to upstream.

bpf: add BPF_F_ADJ_ROOM_DECAP_* flags for tunnel decapsulation

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=da199070bc6209bf5db970f8f84c7db4210fe511

bpf: allow new DECAP flags and add guard rails

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=3a39c214fd2c3dd8266649e7f9f85ca1439eb738

bpf: clear decap state on skb_adjust_room shrink path

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=ec20dee2f2c4796c0f7c0a7d8a3a3e8a9e9da7a4

selftests/bpf: tc_tunnel - pass decap flags for tunnel type

commit-author Nick Hudson <nhudson@akamai.com>
commit -
commit-source https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=adb771973026efe54627bcbe927e7205d04d6c68
upstream-diff |
  The upstream patch targets bpf-next where the BPF program has been
  converted to use vmlinux.h (commit 86433db93256) and the test runner
  has been migrated from a shell script to a C-based test_progs harness
  (commit 8517b1abe5ea). This tree has neither of those prerequisites,
  so the following upstream changes were dropped:
  - CO-RE enum existence checks (bpf_core_enum_value_exists). The
    test_tc_tunnel.sh runner loads BPF via iproute2's legacy tc loader,
    which does not process CO-RE relocations.
  - Post-decap GSO gso_type and skb->encapsulation validation
    via bpf_cast_to_kern_ctx/bpf_core_cast into skb_shared_info.
    These require vmlinux.h to access kernel-internal structs
    (sk_buff, skb_shared_info) and SKB_GSO_* constants.
  - TSO disable removal from prog_tests/test_tc_tunnel.c (file absent;
    this tree still uses test_tc_tunnel.sh).
  The functional flag-passing changes (DECAP_L4_GRE, DECAP_L4_UDP,
  DECAP_IPXIP4, DECAP_IPXIP6) and ipxip_flag parameter plumbing
  through decap_internal/decap_ipv4/decap_ipv6 are applied as in
  upstream. The test exercises the new kernel flag acceptance path
  but does not validate post-decap skb state.

Test Results

✅ Build Stage

Architecture	Build Time	Total Time
x86_64	33m 2s	34m 6s
aarch64	19m 26s	20m 13s

• View build logs

✅ Boot Verification

• Status: Passed (all architectures)
• View boot logs

✅ Kernel Selftests

Architecture	Passed	Failed	Compared Against	Status
x86_64	206	43	ciqlts9_6	⚠️ No baseline available
aarch64	154	45	ciqlts9_6	⚠️ No baseline available

• View kselftest logs

✅ LTP Results

Architecture	Passed	Failed	Compared Against	Status
x86_64	1453	82	ciqlts9_6	⚠️ No baseline available
aarch64	1426	83	ciqlts9_6	⚠️ No baseline available

• View LTP logs

---

🤖 This PR was automatically generated by GitHub Actions
Run ID: 32487341524

[github-actions]

🤖 Validation Checks In Progress Workflow run: https://github.com/ctrliq/kernel-src-tree/actions/runs/32487725765

[github-actions]

✅ Validation checks completed successfully View full results: https://github.com/ctrliq/kernel-src-tree/actions/runs/32487725765

[bmastbergen]

Test results:

Test: BPF_F_ADJ_ROOM_DECAP_* GSO state verification
Date: 2026-08-21

== Method ==

A kprobe BPF checker program hooks ip_rcv() and reads the real
sk_buff fields (skb->encapsulation and skb_shinfo(skb)->gso_type)
after tc ingress processing (where the BPF decap program runs)
but before TCP delivery. This directly verifies that the kernel
cleared the tunnel GSO bits and encapsulation flag, rather than
just checking whether traffic flows.

The test sends 64KB payloads with TSO enabled to trigger GSO
segmentation, then verifies that no tunnel GSO bits (SKB_GSO_GRE,
SKB_GSO_IPXIP4, SKB_GSO_UDP_TUNNEL, etc.) remain set after
bpf_skb_adjust_room() with the new DECAP flags.

== Results: 6.18 kernel ==

=== building checker ===
  checker built OK
=== loading checker kprobe ===
  attached to ip_rcv

=== BPF decap flags GSO test ===
  kernel: 6.18.43-bmastbergen_bpf_skb_adjust_room_ciq-6.18.y-eb2f26ded6+

--- GSO path (64KB, TSO on) ---
  ipip     (DECAP_IPXIP4)                           PASS (13 pkts, GSO clean)
  gre      (DECAP_L4_GRE+IPXIP4)                    SKIP (checker saw 0 pkts)
  gre+eth  (DECAP_L4_GRE+IPXIP4)                    SKIP (checker saw 0 pkts)
  sit      (DECAP_IPXIP4)                           PASS (12 pkts, GSO clean)

--- non-GSO baseline (100B) ---
  ipip 100B                                         PASS (5 pkts, GSO clean)
  gre  100B                                         SKIP (checker saw 0 pkts)

=== Results: 3 passed, 0 failed ===

== Results: 5.14 kernel ==

=== building checker ===
  checker built OK
=== loading checker kprobe ===
  attached to ip_rcv

=== BPF decap flags GSO test ===
  kernel: 5.14.0-bmastbergen_bpf_skb_adjust_room_ciqlts9_6-cab895457f4+

--- GSO path (64KB, TSO on) ---
  ipip     (DECAP_IPXIP4)                           PASS (14 pkts, GSO clean)
  gre      (DECAP_L4_GRE+IPXIP4)                    SKIP (checker saw 0 pkts)
  gre+eth  (DECAP_L4_GRE+IPXIP4)                    SKIP (checker saw 0 pkts)
  sit      (DECAP_IPXIP4)                           PASS (13 pkts, GSO clean)

--- non-GSO baseline (100B) ---
  ipip 100B                                         PASS (5 pkts, GSO clean)
  gre  100B                                         SKIP (checker saw 0 pkts)

=== Results: 3 passed, 0 failed ===

== Notes ==

- PASS means the kprobe checker confirmed gso_type has no tunnel
  bits set and skb->encapsulation == 0 after BPF decap.
- gso_type=0x1 (SKB_GSO_TCPV4) is the only GSO bit that should
  remain after tunnel decapsulation. The tunnel-specific bits
  (SKB_GSO_IPXIP4, SKB_GSO_GRE, etc.) are confirmed cleared.
- SKIP on GRE: the BPF GRE encap/decap requires packet-level GRE
  header construction that doesn't complete the round trip through
  a plain veth pair without a kernel tunnel device. The IPIP/SIT
  tunnel types exercise the core DECAP_IPXIP4 flag path which is
  the primary GSO cleanup codepath.
- Sample trace output showing the checker reading skb state:

    nc-14804 [006] ..s31 934.159609: bpf_trace_printk: CHECKER: gso_type=0x1 encap=0 CLEAN (GOOD)
    nc-14804 [006] ..s31 934.159699: bpf_trace_printk: CHECKER: gso_type=0x1 encap=0 CLEAN (GOOD)

test-decap-gso.sh