[PATCH bpf-next v2 0/8] bpf, riscv64: Support load-acquire and store-release instructions

[Peilin Ye <yepeilin@google.com>]

Hi all!

Patchset [1] introduced BPF load-acquire (BPF_LOAD_ACQ) and
store-release (BPF_STORE_REL) instructions, and added x86-64 and arm64
JIT compiler support.  As a follow-up, this v2 patchset supports
load-acquire and store-release instructions for the riscv64 JIT
compiler, and introduces some related selftests/ changes.

Specifically:

 * PATCH 1 makes insn_def_regno() handle load-acquires properly for
   bpf_jit_needs_zext() (true for riscv64) architectures
 * PATCH 2, 3 from Andrea Parri add the actual support to the riscv64
   JIT compiler
 * PATCH 4 optimizes code emission by skipping redundant zext
   instructions inserted by the verifier
 * PATCH 5, 6 and 7 are minor selftest/ improvements
 * PATCH 8 enables (non-arena) load-acquire/store-release selftests for
   riscv64

v1: https://lore.kernel.org/bpf/cover.1745970908.git.yepeilin@google.com/
Changes since v1:

 * add Acked-by:, Reviewed-by: and Tested-by: tags from Lehui and Björn
 * simplify code logic in PATCH 1 (Lehui)
 * in PATCH 3, avoid changing 'return 0;' to 'return ret;' at the end of
   bpf_jit_emit_insn() (Lehui)

Please refer to individual patches for details.  Thanks!

[1] https://lore.kernel.org/all/cover.1741049567.git.yepeilin@google.com/

Andrea Parri (2):
  bpf, riscv64: Introduce emit_load_*() and emit_store_*()
  bpf, riscv64: Support load-acquire and store-release instructions

Peilin Ye (6):
  bpf/verifier: Handle BPF_LOAD_ACQ instructions in insn_def_regno()
  bpf, riscv64: Skip redundant zext instruction after load-acquire
  selftests/bpf: Use CAN_USE_LOAD_ACQ_STORE_REL when appropriate
  selftests/bpf: Avoid passing out-of-range values to __retval()
  selftests/bpf: Verify zero-extension behavior in load-acquire tests
  selftests/bpf: Enable non-arena load-acquire/store-release selftests
    for riscv64

 arch/riscv/net/bpf_jit.h                      |  15 +
 arch/riscv/net/bpf_jit_comp64.c               | 332 ++++++++++++------
 arch/riscv/net/bpf_jit_core.c                 |   3 +-
 kernel/bpf/verifier.c                         |  12 +-
 tools/testing/selftests/bpf/progs/bpf_misc.h  |   5 +-
 .../bpf/progs/verifier_load_acquire.c         |  48 ++-
 .../selftests/bpf/progs/verifier_precision.c  |   5 +-
 .../bpf/progs/verifier_store_release.c        |  39 +-
 8 files changed, 313 insertions(+), 146 deletions(-)

-- 
2.49.0.967.g6a0df3ecc3-goog


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