From: Maxim Khmelevskii <max@linux.ibm.com>
To: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org, Ilya Leoshkevich <iii@linux.ibm.com>,
Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Alexander Gordeev <agordeev@linux.ibm.com>
Subject: [PATCH bpf-next 0/2] s390/bpf: Replace ly instruction with llgf
Date: Fri, 3 Jul 2026 14:51:34 +0200 [thread overview]
Message-ID: <20260703125648.919196-4-max@linux.ibm.com> (raw)
Sashiko found a bug [1] in 9012cf2491e3, where upper bits of a 64-bit
register are not zero-extended after ly instruction in used.
Tested:
./test_progs -v -t get_smp_processor_id
[1] https://sashiko.dev/#/patchset/20260414142930.528751-1-max%40linux.ibm.com
Maxim Khmelevskii (2):
s390/bpf: Replace ly instruction with llgf
selftests/bpf: Add test for bpf_get_smp_processor_id
arch/s390/net/bpf_jit_comp.c | 4 +-
.../bpf/prog_tests/get_smp_processor_id.c | 45 +++++++++++++++++++
.../bpf/progs/get_smp_processor_id.c | 20 +++++++++
3 files changed, 67 insertions(+), 2 deletions(-)
create mode 100644 tools/testing/selftests/bpf/prog_tests/get_smp_processor_id.c
create mode 100644 tools/testing/selftests/bpf/progs/get_smp_processor_id.c
--
2.54.0
next reply other threads:[~2026-07-03 12:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-03 12:51 Maxim Khmelevskii [this message]
2026-07-03 12:51 ` [PATCH bpf-next 1/2] s390/bpf: Replace ly instruction with llgf Maxim Khmelevskii
2026-07-03 12:51 ` [PATCH bpf-next 2/2] selftests/bpf: Add test for bpf_get_smp_processor_id Maxim Khmelevskii
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