[PATCH bpf-next 0/2] bpf,arm64: Add support for BPF Arena

From: Puranjay Mohan
Date: Thu Mar 14 2024 - 11:00:24 EST


This series adds the support for PROBE_MEM32 and bpf_addr_space_cast
instructions to the ARM64 BPF JIT. These two instructions allow the
enablement of BPF Arena.

All arena related selftests are passing.

[root@ip-172-31-6-62 bpf]# ./test_progs -a "*arena*"
#3/1 arena_htab/arena_htab_llvm:OK
#3/2 arena_htab/arena_htab_asm:OK
#3 arena_htab:OK
#4/1 arena_list/arena_list_1:OK
#4/2 arena_list/arena_list_1000:OK
#4 arena_list:OK
#434/1 verifier_arena/basic_alloc1:OK
#434/2 verifier_arena/basic_alloc2:OK
#434/3 verifier_arena/basic_alloc3:OK
#434/4 verifier_arena/iter_maps1:OK
#434/5 verifier_arena/iter_maps2:OK
#434/6 verifier_arena/iter_maps3:OK
#434 verifier_arena:OK
Summary: 3/10 PASSED, 0 SKIPPED, 0 FAILED

The implementation of bpf_addr_space_cast can be optimised by using ROR
(immediate) and CSEL instructions. Currently, lib/insn.c doesn't have APIs
to generate these intructions. I will send subsequent patches to implement
the APIs and then use these instructions in the JIT.

Puranjay Mohan (2):
bpf: Add arm64 JIT support for PROBE_MEM32 pseudo instructions.
bpf: Add arm64 JIT support for bpf_addr_space_cast instruction.

arch/arm64/net/bpf_jit.h | 1 +
arch/arm64/net/bpf_jit_comp.c | 105 +++++++++++++++++--
tools/testing/selftests/bpf/DENYLIST.aarch64 | 2 -
3 files changed, 96 insertions(+), 12 deletions(-)

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2.40.1