From: kernel test robot <lkp@intel.com>
To: oe-kbuild@lists.linux.dev
Cc: lkp@intel.com
Subject: [kkdwivedi:fermata 18/146] kernel/bpf/ringbuf.c:857:17: error: undefined named operand 'unwound'
Date: Tue, 20 Oct 2026 22:15:52 +0200 [thread overview]
Message-ID: <202610202202.TrW5w6UE-lkp@intel.com> (raw)
::::::
:::::: Manual check reason: "low confidence bisect report"
::::::
BCC: lkp@intel.com
CC: oe-kbuild-all@lists.linux.dev
TO: Kumar Kartikeya Dwivedi <memxor@gmail.com>
tree: https://github.com/kkdwivedi/linux fermata
head: 7b45e27f0f0faaa13da429815b6143b99eaa232c
commit: 539555d3c94ba07286fc1563a61d9016e586afca [18/146] bpf: Call the callbacks of bpf_find_vma and bpf_user_ringbuf_drain with a pad
:::::: branch date: 6 hours ago
:::::: commit date: 9 hours ago
config: arm64-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20261020/202610202202.TrW5w6UE-lkp@intel.com/config)
compiler: aarch64-linux-gnu-gcc (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261020/202610202202.TrW5w6UE-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/r/202610202202.TrW5w6UE-lkp@intel.com/
Note: the kkdwivedi/fermata HEAD 7b45e27f0f0faaa13da429815b6143b99eaa232c builds fine.
It only hurts bisectability.
All errors (new ones prefixed by >>):
kernel/bpf/ringbuf.c: In function '____bpf_user_ringbuf_drain':
>> kernel/bpf/ringbuf.c:857:17: error: undefined named operand 'unwound'
857 | bpf_call_cb(callback, &dynptr, callback_ctx, 0, 0, 0, ret, unwound_at);
| ^~~~~~~~~~~
vim +/unwound +857 kernel/bpf/ringbuf.c
20571567384428 David Vernet 2022-09-19 817
20571567384428 David Vernet 2022-09-19 818 BPF_CALL_4(bpf_user_ringbuf_drain, struct bpf_map *, map,
20571567384428 David Vernet 2022-09-19 819 void *, callback_fn, void *, callback_ctx, u64, flags)
20571567384428 David Vernet 2022-09-19 820 {
20571567384428 David Vernet 2022-09-19 821 struct bpf_ringbuf *rb;
20571567384428 David Vernet 2022-09-19 822 long samples, discarded_samples = 0, ret = 0;
20571567384428 David Vernet 2022-09-19 823 bpf_callback_t callback = (bpf_callback_t)callback_fn;
20571567384428 David Vernet 2022-09-19 824 u64 wakeup_flags = BPF_RB_NO_WAKEUP | BPF_RB_FORCE_WAKEUP;
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 825 bool unwound = false;
20571567384428 David Vernet 2022-09-19 826 int busy = 0;
20571567384428 David Vernet 2022-09-19 827
20571567384428 David Vernet 2022-09-19 828 if (unlikely(flags & ~wakeup_flags))
20571567384428 David Vernet 2022-09-19 829 return -EINVAL;
20571567384428 David Vernet 2022-09-19 830
20571567384428 David Vernet 2022-09-19 831 rb = container_of(map, struct bpf_ringbuf_map, map)->rb;
20571567384428 David Vernet 2022-09-19 832
20571567384428 David Vernet 2022-09-19 833 /* If another consumer is already consuming a sample, wait for them to finish. */
20571567384428 David Vernet 2022-09-19 834 if (!atomic_try_cmpxchg(&rb->busy, &busy, 1))
20571567384428 David Vernet 2022-09-19 835 return -EBUSY;
20571567384428 David Vernet 2022-09-19 836
20571567384428 David Vernet 2022-09-19 837 for (samples = 0; samples < BPF_MAX_USER_RINGBUF_SAMPLES && ret == 0; samples++) {
20571567384428 David Vernet 2022-09-19 838 int err;
20571567384428 David Vernet 2022-09-19 839 u32 size;
20571567384428 David Vernet 2022-09-19 840 void *sample;
20571567384428 David Vernet 2022-09-19 841 struct bpf_dynptr_kern dynptr;
20571567384428 David Vernet 2022-09-19 842
20571567384428 David Vernet 2022-09-19 843 err = __bpf_user_ringbuf_peek(rb, &sample, &size);
20571567384428 David Vernet 2022-09-19 844 if (err) {
20571567384428 David Vernet 2022-09-19 845 if (err == -ENODATA) {
20571567384428 David Vernet 2022-09-19 846 break;
20571567384428 David Vernet 2022-09-19 847 } else if (err == -EAGAIN) {
20571567384428 David Vernet 2022-09-19 848 discarded_samples++;
20571567384428 David Vernet 2022-09-19 849 continue;
20571567384428 David Vernet 2022-09-19 850 } else {
20571567384428 David Vernet 2022-09-19 851 ret = err;
20571567384428 David Vernet 2022-09-19 852 goto schedule_work_return;
20571567384428 David Vernet 2022-09-19 853 }
20571567384428 David Vernet 2022-09-19 854 }
20571567384428 David Vernet 2022-09-19 855
20571567384428 David Vernet 2022-09-19 856 bpf_dynptr_init(&dynptr, sample, BPF_DYNPTR_TYPE_LOCAL, 0, size);
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 @857 bpf_call_cb(callback, &dynptr, callback_ctx, 0, 0, 0, ret, unwound_at);
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 858 if (0) {
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 859 unwound_at:
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 860 /*
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 861 * The callback left with unwind_exit. The sample is
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 862 * consumed like after a return, and the helper leaves
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 863 * through the door below, as the error paths do.
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 864 */
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 865 unwound = true;
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 866 ret = 0;
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 867 }
20571567384428 David Vernet 2022-09-19 868 __bpf_user_ringbuf_sample_release(rb, size, flags);
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 869 if (unwound)
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 870 goto schedule_work_return;
20571567384428 David Vernet 2022-09-19 871 }
20571567384428 David Vernet 2022-09-19 872 ret = samples - discarded_samples;
20571567384428 David Vernet 2022-09-19 873
20571567384428 David Vernet 2022-09-19 874 schedule_work_return:
20571567384428 David Vernet 2022-09-19 875 /* Prevent the clearing of the busy-bit from being reordered before the
20571567384428 David Vernet 2022-09-19 876 * storing of any rb consumer or producer positions.
20571567384428 David Vernet 2022-09-19 877 */
06646da0145868 Paul E. McKenney 2023-10-18 878 atomic_set_release(&rb->busy, 0);
20571567384428 David Vernet 2022-09-19 879
20571567384428 David Vernet 2022-09-19 880 if (flags & BPF_RB_FORCE_WAKEUP)
20571567384428 David Vernet 2022-09-19 881 irq_work_queue(&rb->work);
20571567384428 David Vernet 2022-09-19 882 else if (!(flags & BPF_RB_NO_WAKEUP) && samples > 0)
20571567384428 David Vernet 2022-09-19 883 irq_work_queue(&rb->work);
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 884 if (unwound)
539555d3c94ba0 Kumar Kartikeya Dwivedi 2026-10-20 885 bpf_unwind_leave();
20571567384428 David Vernet 2022-09-19 886 return ret;
20571567384428 David Vernet 2022-09-19 887 }
20571567384428 David Vernet 2022-09-19 888
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
reply other threads:[~2026-10-20 20:16 UTC|newest]
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