Re: [PATCH stable 6.6.y v3 0/4] bpf: linked scalar precision fixes
From: Paul Chaignon <hidden>
Date: 2026-06-15 22:51:39
Also in:
bpf, lkml, stable
On Mon, Jun 15, 2026 at 12:58:37AM +0800, Zhenzhong Wu wrote:
Hi, This v3 targets 6.6.y and changes the backport strategy based on review feedback on v2.
[...]
Relevant QEMU selftest results on 6.6.y with this backport: verifier_scalar_ids passed all 18 subtests, including the newly backported linked-scalar precision tests and the related check_ids_in_regsafe tests.
The first patch in this backport series is actually breaking the "precise: test 1" selftest from test_verifier. You can see the full error at [1]. I haven't yet checked if it's the test or the backport that needs to be adjusted. 1: https://github.com/shunghsiyu/libbpf/actions/runs/27575831217/job/81523786835
Thanks to Shung-Hsi Yu for reviewing v2 and suggesting the upstream
linked-scalar precision series as the preferred backport direction.
Eduard Zingerman (4):
bpf: Track equal scalars history on per-instruction level
bpf: Remove mark_precise_scalar_ids()
selftests/bpf: Tests for per-insn sync_linked_regs() precision
tracking
selftests/bpf: Update comments find_equal_scalars->sync_linked_regs
include/linux/bpf_verifier.h | 4 +
kernel/bpf/verifier.c | 367 +++++++++++-------
.../selftests/bpf/progs/verifier_scalar_ids.c | 253 ++++++++----
.../selftests/bpf/progs/verifier_spill_fill.c | 4 +-
.../bpf/progs/verifier_subprog_precision.c | 2 +-
.../testing/selftests/bpf/verifier/precise.c | 2 +-
6 files changed, 417 insertions(+), 215 deletions(-)
base-commit: 924b4a879cbb75aef37c160b955b92f6894b11a4
--
2.43.0