From: Saket Kumar Bhaskar <skb99@linux.ibm.com>
To: bpf@vger.kernel.org
Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net,
puranjay@kernel.org, puranjay12@gmail.com,
hbathini@linux.ibm.com
Subject: [BUG] poweprc64/bpf: bpf arena broken after kmalloc_nolock() change
Date: Tue, 9 Dec 2025 12:49:40 +0530 [thread overview]
Message-ID: <aTfNjDu1Lbc-LPtO@linux.ibm.com> (raw)
Hi,
On powerpc, bpf arena support was enabled by:
a2485d06cad3 ("powerpc64/bpf: Implement bpf_addr_space_cast instruction")
and the status of selftests was:
# ./test_progs -t arena
#3/1 arena_atomics/add:OK
#3/2 arena_atomics/sub:OK
#3/3 arena_atomics/and:OK
#3/4 arena_atomics/or:OK
#3/5 arena_atomics/xor:OK
#3/6 arena_atomics/cmpxchg:OK
#3/7 arena_atomics/xchg:OK
#3/8 arena_atomics/uaf:OK
#3/9 arena_atomics/load_acquire:SKIP
#3/10 arena_atomics/store_release:SKIP
#3 arena_atomics:OK (SKIP: 2/10)
#4/1 arena_htab/arena_htab_llvm:OK
#4/2 arena_htab/arena_htab_asm:OK
#4 arena_htab:OK
#5/1 arena_list/arena_list_1:OK
#5/2 arena_list/arena_list_1000:OK
#5 arena_list:OK
#6/1 arena_spin_lock/arena_spin_lock_1:SKIP
#6/2 arena_spin_lock/arena_spin_lock_1000:SKIP
#6/3 arena_spin_lock/arena_spin_lock_50000:SKIP
#6 arena_spin_lock:SKIP
#7/1 arena_strsearch/arena_strsearch:OK
#7 arena_strsearch:OK
#417 stream_arena_fault_address:SKIP
tester_init:pass:tester_log_buf 0 nsec
process_subtest:pass:obj_open_mem 0 nsec
process_subtest:pass:specs_alloc 0 nsec
#504/1 verifier_arena/basic_alloc1:OK
#504/2 verifier_arena/basic_alloc2:OK
#504/3 verifier_arena/basic_alloc3:OK
#504/4 verifier_arena/basic_reserve1:OK
#504/5 verifier_arena/basic_reserve2:OK
#504/6 verifier_arena/reserve_twice:OK
run_subtest:pass:obj_open_mem 0 nsec
run_subtest:pass:unexpected_load_failure 0 nsec
do_prog_test_run:pass:bpf_prog_test_run 0 nsec
run_subtest:fail:1299 Unexpected retval: 4 != 0
#504/7 verifier_arena/reserve_invalid_region:FAIL
#504/8 verifier_arena/iter_maps1:OK
#504/9 verifier_arena/iter_maps2:OK
#504/10 verifier_arena/iter_maps3:OK
#504 verifier_arena:FAIL
#505/1 verifier_arena_large/big_alloc1:OK
#505/2 verifier_arena_large/access_reserved:OK
#505/3 verifier_arena_large/request_partially_reserved:OK
#505/4 verifier_arena_large/free_reserved:OK
#505/5 verifier_arena_large/big_alloc2:OK
#505 verifier_arena_large:OK
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
run_subtest:pass:obj_open_mem 0 nsec
run_subtest:pass:unexpected_load_failure 0 nsec
do_prog_test_run:pass:bpf_prog_test_run 0 nsec
run_subtest:fail:1299 Unexpected retval: 4 != 0
#504/7 verifier_arena/reserve_invalid_region:FAIL
#504 verifier_arena:FAIL
Summary: 7/27 PASSED, 6 SKIPPED, 1 FAILED
After commit f8c67d8550ee("bpf: Use kmalloc_nolock() in range tree") all
arena related selftests are failing for powerpc:
All error logs:
test_arena_atomics:pass:arena atomics skeleton open 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_atomics': -ENOMEM
test_arena_atomics:fail:arena atomics skeleton load unexpected error: -12 (errno 12)
#3 arena_atomics:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_htab': -ENOMEM
test_arena_htab_llvm:fail:arena_htab__open_and_load unexpected error: -12
#4/1 arena_htab/arena_htab_llvm:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_htab_asm': -ENOMEM
test_arena_htab_asm:fail:arena_htab_asm__open_and_load unexpected error: -12
#4/2 arena_htab/arena_htab_asm:FAIL
#4 arena_htab:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_list': -ENOMEM
test_arena_list_add_del:fail:arena_list__open_and_load unexpected error: -12
#5/1 arena_list/arena_list_1:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_list': -ENOMEM
test_arena_list_add_del:fail:arena_list__open_and_load unexpected error: -12
#5/2 arena_list/arena_list_1000:FAIL
#5 arena_list:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_spin_lock': -ENOMEM
test_arena_spin_lock_size:fail:arena_spin_lock__open_and_load unexpected error: -12
#6/1 arena_spin_lock/arena_spin_lock_1:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_spin_lock': -ENOMEM
test_arena_spin_lock_size:fail:arena_spin_lock__open_and_load unexpected error: -12
#6/2 arena_spin_lock/arena_spin_lock_1000:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_spin_lock': -ENOMEM
test_arena_spin_lock_size:fail:arena_spin_lock__open_and_load unexpected error: -12
#6/3 arena_spin_lock/arena_spin_lock_50000:FAIL
#6 arena_spin_lock:FAIL
libbpf: map 'arena': failed to create: -ENOMEM
libbpf: failed to load BPF skeleton 'arena_strsearch': -ENOMEM
test_arena_str:fail:arena_strsearch__open_and_load unexpected error: -12
#7/1 arena_strsearch/arena_strsearch:FAIL
#7 arena_strsearch:FAIL
tester_init:pass:tester_log_buf 0 nsec
process_subtest:pass:obj_open_mem 0 nsec
process_subtest:pass:specs_alloc 0 nsec
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/1 verifier_arena/basic_alloc1:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/2 verifier_arena/basic_alloc2:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/3 verifier_arena/basic_alloc3:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/4 verifier_arena/basic_reserve1:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/5 verifier_arena/basic_reserve2:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/6 verifier_arena/reserve_twice:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/7 verifier_arena/reserve_invalid_region:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#504/8 verifier_arena/iter_maps1:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:pass:unexpected_load_success 0 nsec
validate_msgs:fail:920 expect_msg
VERIFIER LOG:
=============
=============
EXPECTED SUBSTR: 'expected pointer to STRUCT bpf_map'
#504/9 verifier_arena/iter_maps2:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:pass:unexpected_load_success 0 nsec
validate_msgs:fail:920 expect_msg
VERIFIER LOG:
=============
=============
EXPECTED SUBSTR: 'untrusted_ptr_bpf_map'
#504/10 verifier_arena/iter_maps3:FAIL
#504 verifier_arena:FAIL
tester_init:pass:tester_log_buf 0 nsec
process_subtest:pass:obj_open_mem 0 nsec
process_subtest:pass:specs_alloc 0 nsec
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#505/1 verifier_arena_large/big_alloc1:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#505/2 verifier_arena_large/access_reserved:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#505/3 verifier_arena_large/request_partially_reserved:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
=============
=============
#505/4 verifier_arena_large/free_reserved:FAIL
run_subtest:pass:obj_open_mem 0 nsec
libbpf: map 'arena': failed to create: -ENOMEM
run_subtest:fail:unexpected_load_failure unexpected error: -12 (errno 12)
VERIFIER LOG:
=============
=============
#505/5 verifier_arena_large/big_alloc2:FAIL
#505 verifier_arena_large:FAIL
Summary: 1/0 PASSED, 1 SKIPPED, 7 FAILED
This is because powerpc currently does not support 128-bit cmpxchg and
in-turn kmalloc_nolock() but new range tree implementation unconditionally
uses kmalloc_nolock().
Can use of kmalloc_nolock() be avoided for now or made conditional on
availability of arch support for it? I’m ready to implement a patch
aligned with your preferred course of action.
Thanks,
Saket
next reply other threads:[~2025-12-09 7:20 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-09 7:19 Saket Kumar Bhaskar [this message]
2025-12-10 9:09 ` [BUG] poweprc64/bpf: bpf arena broken after kmalloc_nolock() change Alexei Starovoitov
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