Re: [PATCH bpf-next v2 00/11] LoongArch: BPF: arena features, exceptions, private stack and may_goto

[Huacai Chen]

Hi, Tiezhu and Hengqi,

Could you please pay some time to review this series?

Huacai

On Thu, Jul 2, 2026 at 10:23 AM George Guo <dongtai.guo@xxxxxxxxx> wrote:
>
> This series adds the remaining LoongArch BPF JIT features and enables the
> matching selftests:
>
>   - internal-only MOV for per-CPU address resolution
>   - timed may_goto
>   - per-program private stacks
>   - exceptions (bpf_throw)
>   - sign-extending loads from arena (PROBE_MEM32SX)
>   - atomics on arena pointers (PROBE_ATOMIC)
>   - selftests: struct_ops private stack, arena LDSX, arena atomics, and a
>     LoongArch deny list
>
> Patch 1 ("LoongArch: BPF: Fix tail call count pointer offset for arena
> programs") is the same fix already posted separately for the bpf tree;
> several patches in this series (notably exceptions, patch 5) build on
> top of the helper it introduces, so it is included here, unchanged, to
> keep the series self-contained and applicable on bpf-next. It can be
> dropped once it lands via the bpf tree.
>
>   LoongArch: BPF: Fix tail call count pointer offset for arena programs
>   https://lore.kernel.org/all/20260629085511.359546-1-dongtai.guo@xxxxxxxxx
>
> Based on 7.2-rc1.
>
> v2:
>  - Included the tail call count pointer offset fix as patch 1/11 (see
>    above) instead of only referencing it, so the series applies cleanly
>    on bpf-next without waiting on the bpf tree; the empty prog_array
>    off-by-one was fixed independently upstream by commit 0379d10f09bc
>    ("LoongArch: BPF: Fix off-by-one error in tail call"), now in 7.2-rc1.
>  - timed may_goto: store $ra at the ORC-mandated .ra_offset = -8 slot in
>    the trampoline (it was stored at the wrong slot in v1), per Tiezhu
>    Yang's review.
>  - Consolidated the earlier per-CPU MOV / timed may_goto and arena gating
>    postings into one series; rebased on 7.2-rc1.
>  - selftests: use the upstream __arch_loongarch / "LOONGARCH" test_loader
>    support now in 7.2-rc1 instead of introducing it.
>  - Prior postings:
>    https://lore.kernel.org/all/20260609041407.122384-1-dongtai.guo@xxxxxxxxx
>    https://lore.kernel.org/all/20260618033809.98253-1-dongtai.guo@xxxxxxxxx
>
> George Guo (11):
>   LoongArch: BPF: Fix tail call count pointer offset for arena programs
>   LoongArch: BPF: Support internal-only MOV to resolve per-CPU addrs
>   LoongArch: BPF: Add timed may_goto support
>   LoongArch: BPF: Add private stack support
>   LoongArch: BPF: Add exceptions (bpf_throw) support
>   LoongArch: BPF: Support sign-extending loads from arena
>   LoongArch: BPF: Support atomics on arena pointers
>   selftests/bpf: Enable struct_ops private stack test for LoongArch
>   selftests/bpf: Enable arena LDSX tests on LoongArch
>   selftests/bpf: Enable arena atomics tests on LoongArch
>   selftests/bpf: Add LoongArch deny list
>
>  arch/loongarch/include/asm/inst.h             |   1 +
>  arch/loongarch/kernel/stacktrace.c            |  52 +++
>  arch/loongarch/net/Makefile                   |   2 +-
>  arch/loongarch/net/bpf_jit.c                  | 397 ++++++++++++++++--
>  arch/loongarch/net/bpf_jit.h                  |   1 +
>  arch/loongarch/net/bpf_timed_may_goto.S       |  47 +++
>  .../testing/selftests/bpf/DENYLIST.loongarch  |   1 +
>  .../bpf/prog_tests/struct_ops_private_stack.c |   2 +-
>  .../selftests/bpf/progs/arena_atomics.c       |   3 +
>  .../selftests/bpf/progs/verifier_ldsx.c       |  17 +
>  10 files changed, 485 insertions(+), 38 deletions(-)
>  create mode 100644 arch/loongarch/net/bpf_timed_may_goto.S
>  create mode 100644 tools/testing/selftests/bpf/DENYLIST.loongarch
>
> --
> 2.25.1
>
>