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(unknown [9.39.26.73]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 22 Jan 2026 16:57:38 +0000 (GMT) From: adubey@linux.ibm.com To: bpf@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: hbathini@linux.ibm.com, sachinpb@linux.ibm.com, venkat88@linux.ibm.com, andrii@kernel.org, eddyz87@gmail.com, mykolal@fb.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, christophe.leroy@csgroup.eu, naveen@kernel.org, maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, memxor@gmail.com, iii@linux.ibm.com, shuah@kernel.org, Abhishek Dubey Subject: [PATCH v3 0/6] powerpc64/bpf: Support tailcalls with subprogs & BPF exceptions Date: Thu, 22 Jan 2026 22:27:10 +0530 Message-ID: <20260122165716.10508-1-adubey@linux.ibm.com> X-Mailer: git-send-email 2.48.1 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMTIyMDEyOSBTYWx0ZWRfX6s30fZC/NhV6 OZvilTEC+HyDCxRuEiNpw1edPgx54N0BST3BLufSnH4UmNBFIATTaE3UBJxjTDagh544SF5h4xd DiYDOGHqqZLF3HfLptObTDck5AxfFtiuxAOtcEHFpyw2PMNDoTpUu06fiQyJI2/v+pkTUGwHssG aMpimOVvobNbSteomMo4xHpZDP+DRA3KCaXnXAjCtQkLIN6Cz4vVAnEG2ktqKO+4LyCz6mSptAE mRUM2UFpaXTQLs6GhZjdMP2xys7nWPkdi+0PLt9jVaMePCsoHhK8OgrWRv1eaCcHa504IL3jIJ3 RRVqidbI78MGfX/JPfS9oVd1Gv6eARqQxNoI9nGcbjrsFD2k8jv9M2DmVK9TLbCVkMrSAojjUad WYWG+0g0RTViRT+YNZOOrIL1gRHrNHBnPGXHwIf+1cv7j8Xrwxb7r52AdtZs4vp0bAxIEikvZe/ Bg9jTWVgXtwO8qromsQ== X-Authority-Analysis: v=2.4 cv=BpSQAIX5 c=1 sm=1 tr=0 ts=69725712 cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=vUbySO9Y5rIA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VwQbUJbxAAAA:8 a=VnNF1IyMAAAA:8 a=iIzsfX1pHA8hvRYzEnUA:9 X-Proofpoint-GUID: KuW7bYMegJz6bkt5gO4fMccP2vX7PUGb X-Proofpoint-ORIG-GUID: FRur8Q3Dy1cPBvQqZULQJ_HZTf5j09_J X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.20,FMLib:17.12.100.49 definitions=2026-01-22_03,2026-01-22_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 bulkscore=0 clxscore=1015 adultscore=0 phishscore=0 malwarescore=0 impostorscore=0 suspectscore=0 priorityscore=1501 lowpriorityscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2601150000 definitions=main-2601220129 From: Abhishek Dubey This patch series enables support for two BPF JIT features on powerpc64. The first three patches target support for tail calls with subprogram combinations. The first patch supports realignment of tail_call_cnt offset in stack frame. Implementation details are provided in the commit messages. The last three patches add support for BPF exceptions. An architecture-specific stack walker is implemented to assist with stack walk during exceptions. All selftests related to tailcalls and exceptions are passing: # ./test_progs -t tailcalls #442/1 tailcalls/tailcall_1:OK #442/2 tailcalls/tailcall_2:OK #442/3 tailcalls/tailcall_3:OK #442/4 tailcalls/tailcall_4:OK #442/5 tailcalls/tailcall_5:OK #442/6 tailcalls/tailcall_6:OK #442/7 tailcalls/tailcall_bpf2bpf_1:OK #442/8 tailcalls/tailcall_bpf2bpf_2:OK #442/9 tailcalls/tailcall_bpf2bpf_3:OK #442/10 tailcalls/tailcall_bpf2bpf_4:OK #442/11 tailcalls/tailcall_bpf2bpf_5:OK #442/12 tailcalls/tailcall_bpf2bpf_6:OK #442/13 tailcalls/tailcall_bpf2bpf_fentry:OK #442/14 tailcalls/tailcall_bpf2bpf_fexit:OK #442/15 tailcalls/tailcall_bpf2bpf_fentry_fexit:OK #442/16 tailcalls/tailcall_bpf2bpf_fentry_entry:OK #442/17 tailcalls/tailcall_poke:OK #442/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK #442/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK #442/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK #442/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK #442/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK #442/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK #442/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK #442/25 tailcalls/tailcall_freplace:OK #442/26 tailcalls/tailcall_bpf2bpf_freplace:OK #442/27 tailcalls/tailcall_failure:OK #442/28 tailcalls/reject_tail_call_spin_lock:OK #442/29 tailcalls/reject_tail_call_rcu_lock:OK #442/30 tailcalls/reject_tail_call_preempt_lock:OK #442/31 tailcalls/reject_tail_call_ref:OK #442 tailcalls:OK Summary: 1/31 PASSED, 0 SKIPPED, 0 FAILED # ./test_progs -t exceptions #105/1 exceptions/exception_throw_always_1:OK #105/2 exceptions/exception_throw_always_2:OK #105/3 exceptions/exception_throw_unwind_1:OK #105/4 exceptions/exception_throw_unwind_2:OK #105/5 exceptions/exception_throw_default:OK #105/6 exceptions/exception_throw_default_value:OK #105/7 exceptions/exception_tail_call:OK #105/8 exceptions/exception_ext:OK #105/9 exceptions/exception_ext_mod_cb_runtime:OK #105/10 exceptions/exception_throw_subprog:OK #105/11 exceptions/exception_assert_nz_gfunc:OK #105/12 exceptions/exception_assert_zero_gfunc:OK #105/13 exceptions/exception_assert_neg_gfunc:OK #105/14 exceptions/exception_assert_pos_gfunc:OK #105/15 exceptions/exception_assert_negeq_gfunc:OK #105/16 exceptions/exception_assert_poseq_gfunc:OK #105/17 exceptions/exception_assert_nz_gfunc_with:OK #105/18 exceptions/exception_assert_zero_gfunc_with:OK #105/19 exceptions/exception_assert_neg_gfunc_with:OK #105/20 exceptions/exception_assert_pos_gfunc_with:OK #105/21 exceptions/exception_assert_negeq_gfunc_with:OK #105/22 exceptions/exception_assert_poseq_gfunc_with:OK #105/23 exceptions/exception_bad_assert_nz_gfunc:OK #105/24 exceptions/exception_bad_assert_zero_gfunc:OK #105/25 exceptions/exception_bad_assert_neg_gfunc:OK #105/26 exceptions/exception_bad_assert_pos_gfunc:OK #105/27 exceptions/exception_bad_assert_negeq_gfunc:OK #105/28 exceptions/exception_bad_assert_poseq_gfunc:OK #105/29 exceptions/exception_bad_assert_nz_gfunc_with:OK #105/30 exceptions/exception_bad_assert_zero_gfunc_with:OK #105/31 exceptions/exception_bad_assert_neg_gfunc_with:OK #105/32 exceptions/exception_bad_assert_pos_gfunc_with:OK #105/33 exceptions/exception_bad_assert_negeq_gfunc_with:OK #105/34 exceptions/exception_bad_assert_poseq_gfunc_with:OK #105/35 exceptions/exception_assert_range:OK #105/36 exceptions/exception_assert_range_with:OK #105/37 exceptions/exception_bad_assert_range:OK #105/38 exceptions/exception_bad_assert_range_with:OK #105/39 exceptions/non-throwing fentry -> exception_cb:OK #105/40 exceptions/throwing fentry -> exception_cb:OK #105/41 exceptions/non-throwing fexit -> exception_cb:OK #105/42 exceptions/throwing fexit -> exception_cb:OK #105/43 exceptions/throwing extension (with custom cb) -> exception_cb:OK #105/44 exceptions/throwing extension -> global func in exception_cb:OK #105/45 exceptions/exception_ext_mod_cb_runtime:OK #105/46 exceptions/throwing extension (with custom cb) -> global func in exception_cb:OK #105/47 exceptions/exception_ext:OK #105/48 exceptions/non-throwing fentry -> non-throwing subprog:OK #105/49 exceptions/throwing fentry -> non-throwing subprog:OK #105/50 exceptions/non-throwing fentry -> throwing subprog:OK #105/51 exceptions/throwing fentry -> throwing subprog:OK #105/52 exceptions/non-throwing fexit -> non-throwing subprog:OK #105/53 exceptions/throwing fexit -> non-throwing subprog:OK #105/54 exceptions/non-throwing fexit -> throwing subprog:OK #105/55 exceptions/throwing fexit -> throwing subprog:OK #105/56 exceptions/non-throwing fmod_ret -> non-throwing subprog:OK #105/57 exceptions/non-throwing fmod_ret -> non-throwing global subprog:OK #105/58 exceptions/non-throwing extension -> non-throwing subprog:OK #105/59 exceptions/non-throwing extension -> throwing subprog:OK #105/60 exceptions/non-throwing extension -> non-throwing subprog:OK #105/61 exceptions/non-throwing extension -> throwing global subprog:OK #105/62 exceptions/throwing extension -> throwing global subprog:OK #105/63 exceptions/throwing extension -> non-throwing global subprog:OK #105/64 exceptions/non-throwing extension -> main subprog:OK #105/65 exceptions/throwing extension -> main subprog:OK #105/66 exceptions/reject_exception_cb_type_1:OK #105/67 exceptions/reject_exception_cb_type_2:OK #105/68 exceptions/reject_exception_cb_type_3:OK #105/69 exceptions/reject_exception_cb_type_4:OK #105/70 exceptions/reject_async_callback_throw:OK #105/71 exceptions/reject_with_lock:OK #105/72 exceptions/reject_subprog_with_lock:OK #105/73 exceptions/reject_with_rcu_read_lock:OK #105/74 exceptions/reject_subprog_with_rcu_read_lock:OK #105/75 exceptions/reject_with_rbtree_add_throw:OK #105/76 exceptions/reject_with_reference:OK #105/77 exceptions/reject_with_cb_reference:OK #105/78 exceptions/reject_with_cb:OK #105/79 exceptions/reject_with_subprog_reference:OK #105/80 exceptions/reject_throwing_exception_cb:OK #105/81 exceptions/reject_exception_cb_call_global_func:OK #105/82 exceptions/reject_exception_cb_call_static_func:OK #105/83 exceptions/reject_multiple_exception_cb:OK #105/84 exceptions/reject_exception_throw_cb:OK #105/85 exceptions/reject_exception_throw_cb_diff:OK #105/86 exceptions/reject_set_exception_cb_bad_ret1:OK #105/87 exceptions/reject_set_exception_cb_bad_ret2:OK #105/88 exceptions/check_assert_eq_int_min:OK #105/89 exceptions/check_assert_eq_int_max:OK #105/90 exceptions/check_assert_eq_zero:OK #105/91 exceptions/check_assert_eq_llong_min:OK #105/92 exceptions/check_assert_eq_llong_max:OK #105/93 exceptions/check_assert_lt_pos:OK #105/94 exceptions/check_assert_lt_zero:OK #105/95 exceptions/check_assert_lt_neg:OK #105/96 exceptions/check_assert_le_pos:OK #105/97 exceptions/check_assert_le_zero:OK #105/98 exceptions/check_assert_le_neg:OK #105/99 exceptions/check_assert_gt_pos:OK #105/100 exceptions/check_assert_gt_zero:OK #105/101 exceptions/check_assert_gt_neg:OK #105/102 exceptions/check_assert_ge_pos:OK #105/103 exceptions/check_assert_ge_zero:OK #105/104 exceptions/check_assert_ge_neg:OK #105/105 exceptions/check_assert_range_s64:OK #105/106 exceptions/check_assert_range_u64:OK #105/107 exceptions/check_assert_single_range_s64:OK #105/108 exceptions/check_assert_single_range_u64:OK #105/109 exceptions/check_assert_generic:OK #105/110 exceptions/check_assert_with_return:OK #105 exceptions:OK Summary: 1/110 PASSED, 0 SKIPPED, 0 FAILED [v1]: https://lore.kernel.org/all/20260105105212.136645-1-adubey@linux.ibm.com/ [v2]: https://lore.kernel.org/all/20260114114450.30405-1-adubey@linux.ibm.com/ Changes v1->v2: Move tail_call_cnt to offset 0 in stack frame Remove trampoline NVR remapping-patch3/6[v1] Changes v2->v3: Added PPC_BCC_CONST_SHORT for short jumps of constant offset Optimize tailcall allocation for BPF_TRAMP_F_CALL_ORIG flag New helper for stack size calculation during exceptions Prologue JIT optimizations during non exception prog case Abhishek Dubey (6): powerpc64/bpf : Moving tail_call_cnt to bottom of frame powerpc64/bpf: Support tailcalls with subprogs powerpc64/bpf: Avoid tailcall restore from trampoline powerpc64/bpf: Add arch_bpf_stack_walk() for BPF JIT powerpc64/bpf: Support exceptions powerpc64/bpf: Additional NVR handling for bpf_throw arch/powerpc/net/bpf_jit.h | 16 ++ arch/powerpc/net/bpf_jit_comp.c | 90 ++++++++-- arch/powerpc/net/bpf_jit_comp64.c | 262 ++++++++++++++++++++++++------ 3 files changed, 303 insertions(+), 65 deletions(-) -- 2.48.1