On 16/02/26 4:38 pm, Venkat wrote:
Hello Hari,
With this patch, tailcalls selftest is failing.
# ./test_progs -t tailcalls
tester_init:PASS:tester_log_buf 0 nsec
process_subtest:PASS:obj_open_mem 0 nsec
process_subtest:PASS:specs_alloc 0 nsec
#448/1 tailcalls/tailcall_1:OK
#448/2 tailcalls/tailcall_2:OK
test_tailcall_count:PASS:tailcall 0 nsec
test_tailcall_count:PASS:tailcall retval 0 nsec
test_tailcall_count:PASS:tailcall count 0 nsec
test_tailcall_count:FAIL:tailcall count unexpected tailcall count: actual 32 !=
expected 33
test_tailcall_count:PASS:tailcall 0 nsec
test_tailcall_count:PASS:tailcall retval 0 nsec
#448/3 tailcalls/tailcall_3:FAIL
#448/4 tailcalls/tailcall_4:OK
#448/5 tailcalls/tailcall_5:OK
#448/6 tailcalls/tailcall_6:OK
#448/7 tailcalls/tailcall_bpf2bpf_1:OK
#448/8 tailcalls/tailcall_bpf2bpf_2:OK
#448/9 tailcalls/tailcall_bpf2bpf_3:OK
#448/10 tailcalls/tailcall_bpf2bpf_4:OK
#448/11 tailcalls/tailcall_bpf2bpf_5:OK
#448/12 tailcalls/tailcall_bpf2bpf_6:OK
#448/13 tailcalls/tailcall_bpf2bpf_fentry:OK
#448/14 tailcalls/tailcall_bpf2bpf_fexit:OK
#448/15 tailcalls/tailcall_bpf2bpf_fentry_fexit:OK
#448/16 tailcalls/tailcall_bpf2bpf_fentry_entry:OK
#448/17 tailcalls/tailcall_poke:OK
#448/18 tailcalls/tailcall_bpf2bpf_hierarchy_1:OK
#448/19 tailcalls/tailcall_bpf2bpf_hierarchy_fentry:OK
#448/20 tailcalls/tailcall_bpf2bpf_hierarchy_fexit:OK
#448/21 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_fexit:OK
#448/22 tailcalls/tailcall_bpf2bpf_hierarchy_fentry_entry:OK
#448/23 tailcalls/tailcall_bpf2bpf_hierarchy_2:OK
#448/24 tailcalls/tailcall_bpf2bpf_hierarchy_3:OK
#448/25 tailcalls/tailcall_freplace:OK
#448/26 tailcalls/tailcall_bpf2bpf_freplace:OK
#448/27 tailcalls/tailcall_failure:OK
#448/28 tailcalls/reject_tail_call_spin_lock:OK
#448/29 tailcalls/reject_tail_call_rcu_lock:OK
#448/30 tailcalls/reject_tail_call_preempt_lock:OK
#448/31 tailcalls/reject_tail_call_ref:OK
#448/32 tailcalls/tailcall_sleepable:OK
#448 tailcalls:FAIL
All error logs:
tester_init:PASS:tester_log_buf 0 nsec
process_subtest:PASS:obj_open_mem 0 nsec
process_subtest:PASS:specs_alloc 0 nsec
test_tailcall_count:PASS:tailcall 0 nsec
test_tailcall_count:PASS:tailcall retval 0 nsec
test_tailcall_count:PASS:tailcall count 0 nsec
test_tailcall_count:FAIL:tailcall count unexpected tailcall count: actual 32 !=
expected 33
test_tailcall_count:PASS:tailcall 0 nsec
test_tailcall_count:PASS:tailcall retval 0 nsec
#448/3 tailcalls/tailcall_3:FAIL
#448 tailcalls:FAIL
Summary: 0/31 PASSED, 0 SKIPPED, 1 FAILED
Regards,
Venkat.
On 16 Feb 2026, at 2:38 PM, Hari Bathini <[email protected]> wrote:
Test whether tail call count is incorrectly accounted for, when the
tail call fails due to a missing BPF program.
Signed-off-by: Hari Bathini <[email protected]>
---
- powerpc64 BPF JIT has been incorrectly accounting for tailcall count
even when BPF program to tailcall into is missing. A simple change
to one of the tailcall selftests could have flagged it earlier.
https://lore.kernel.org/all/[email protected]/
Hi Venkat,
Can you confirm if the above kernel patch was used or not?
- Hari
