Hi,
Atomics support in bpf has already been done by "Atomics for eBPF"
patch series [1], but it only adds support for x86, and this patchset
adds support for arm64.
Patch #1 & patch #2 are arm64 related. Patch #1 moves the common used
macro AARCH64_BREAK_FAULT into insn-def.h for insn.h. Patch #2 adds
necessary encoder helpers for atomic operations.
Patch #3 implements atomic[64]_fetch_add, atomic[64]_[fetch_]{and,or,xor}
and atomic[64]_{xchg|cmpxchg} for arm64 bpf. Patch #4 changes the type of
test program from fentry/ to raw_tp/ for atomics test.
For cpus_have_cap(ARM64_HAS_LSE_ATOMICS) case and no-LSE-ATOMICS case,
./test_verifier, "./test_progs -t atomic", and "insmod ./test_bpf.ko"
are exercised and passed correspondingly.
Comments are always welcome.
Regards,
Tao
[1]: https://lore.kernel.org/bpf/20210114181751.768687-2-jackmanb@xxxxxxxxxx/
Change Log:
v4:
* patch #2: update A64_STADD() accordingly to fix build failure after
applying patch #1 & patch #2.
v3: https://lore.kernel.org/bpf/20220129220452.194585-1-houtao1@xxxxxxxxxx/
* split arm64 insn related code into a separated patch (from Mark)
* update enum name in aarch64_insn_mem_atomic_op (from Mark)
* consider all cases for aarch64_insn_mem_order_type and
aarch64_insn_mb_type (from Mark)
* exercise and pass "insmod ./test_bpf.ko" test (suggested by Daniel)
* remove aarch64_insn_gen_store_release_ex() and extend
aarch64_insn_ldst_type instead
* compile aarch64_insn_gen_atomic_ld_op(), aarch64_insn_gen_cas() and
emit_lse_atomic() out when CONFIG_ARM64_LSE_ATOMICS is disabled.
v2: https://lore.kernel.org/bpf/20220127075322.675323-1-houtao1@xxxxxxxxxx/
* patch #1: use two separated ASSERT_OK() instead of ASSERT_TRUE()
* add Acked-by tag for both patches
v1: https://lore.kernel.org/bpf/20220121135632.136976-1-houtao1@xxxxxxxxxx
Hou Tao (4):
arm64: move AARCH64_BREAK_FAULT into insn-def.h
arm64: insn: add encoders for atomic operations
bpf, arm64: support more atomic operations
selftests/bpf: use raw_tp program for atomic test
arch/arm64/include/asm/debug-monitors.h | 12 -
arch/arm64/include/asm/insn-def.h | 14 ++
arch/arm64/include/asm/insn.h | 80 ++++++-
arch/arm64/lib/insn.c | 185 +++++++++++++--
arch/arm64/net/bpf_jit.h | 44 +++-
arch/arm64/net/bpf_jit_comp.c | 223 ++++++++++++++----
.../selftests/bpf/prog_tests/atomics.c | 91 ++-----
tools/testing/selftests/bpf/progs/atomics.c | 28 +--
8 files changed, 517 insertions(+), 160 deletions(-)
--
2.29.2
