[PATCH bpf-next v3 0/7] Follow ups for verifier errors set

[Kumar Kartikeya Dwivedi <memxor@gmail.com>]

Some follow up changes based on comments from Eduard, Sashiko, and BPF
CI Bot. See commits for details.

Changelog:
----------
v2 -> v3
v2: https://lore.kernel.org/bpf/20260924092941.3174809-1-memxor@gmail.com

 * Rebase on bpf-next/master, which now applies CO-RE relocations before
   subprogram discovery, and only move func_info and line_info validation
   ahead of the layout checks.
 * Drop the truncated final LD_IMM64 relocation guard and its test, as
   bpf_check() now rejects that form up front and core_reloc_raw covers it.

v1 -> v2
v1: https://lore.kernel.org/bpf/20260816015746.2632990-1-memxor@gmail.com

 * Drop v1 patches 3, 5-7, 11, and 13-14 because they are already present
   in bpf-next.
 * Use instruction-neutral wording for variable-offset stack accesses
   rather than inferring an atomic operation from value_regno == -1. (Eduard)
 * Update the variable-offset assertions and cover the retained
   uninitialized stack-read diagnostic through the existing CAP_PERFMON-less
   read inside the allocated stack. (BPF CI)
 * Keep v1 patch 4 unchanged after confirming that the write filter is
   reachable for lineage-preserving ALU operations with unchanged
   diagnostic snapshots; only its spill arm is impossible. Say so in the
   commit message. (Eduard)
 * Consider active critical sections only for sleepable programs and let
   non-sleepable programs reach the existing no-active-context fallback
   instead of adding an early branch. A non-sleepable program can still
   hold RCU, preempt, IRQ, or lock state, so the fallback alone would
   keep blaming the region. Keep the "non-sleepable prog" description.
   (Eduard, BPF CI)
 * Select the helper and global-function suggestions by cause, matching
   the kfunc site. (BPF CI)
 * Split the kfunc coverage into a non-sleepable program case and a
   sleepable program inside an RCU read-side critical section. (Eduard)
 * Scan subprogram properties with nested loops and drop the partial
   recursive-edge details together with their assertion. (Eduard)
 * Reject CO-RE relocations targeting a truncated final LD_IMM64 before
   applying them, since BTF validation now runs before the subprogram
   layout check, and add raw CO-RE coverage for the rejection. Add the
   Fixes tag. (BPF CI)
 * Rebase on the current bpf-next/master and let the new property scan
   also set the callx marker that check_subprogs() collects upstream.

Kumar Kartikeya Dwivedi (7):
  bpf: Correct verifier diagnostic attribution for stack reads
  selftests/bpf: Test verifier stack-read diagnostic attribution
  bpf: Drop dead spill diagnostic condition
  bpf: Report non-sleepable kfunc programs accurately
  selftests/bpf: Test non-sleepable kfunc context
  bpf: Correct Program Structure diagnostic context
  selftests/bpf: Test Program Structure diagnostic context

 kernel/bpf/cfg.c                              |   6 +-
 kernel/bpf/diagnostics.c                      |  24 +--
 kernel/bpf/verifier.c                         | 179 ++++++++++++------
 .../testing/selftests/bpf/progs/dynptr_fail.c |   3 +
 tools/testing/selftests/bpf/progs/irq.c       |  13 ++
 .../selftests/bpf/progs/iters_state_safety.c  |   3 +
 .../selftests/bpf/progs/preempt_lock.c        |  26 +++
 .../selftests/bpf/progs/verifier_cfg.c        |  40 ++++
 .../selftests/bpf/progs/verifier_gotox.c      |   2 +
 .../selftests/bpf/progs/verifier_spill_fill.c |   2 +
 .../selftests/bpf/progs/verifier_xadd.c       |  27 +++
 11 files changed, 250 insertions(+), 75 deletions(-)


base-commit: 44e4e52c11d97a9076c611270e52c6965e3255ee
-- 
2.53.0