[PATCH bpf v2 0/5] bpf: Support kernel function call in 32-bit ARM

Yang Jihong
2022-11-07T09:23:57Z

1. Patch1 is dependent patch to fix zext extension error in 32-bit ARM.
2. Patch2 and patch3 solve the problem that the bpf check fails because
load's mem size is modified in CO_RE from the kernel and user modes,
Currently, there are different opinions and a final solution needs to
be selected.
3. Patch4 supports bpf fkunc in 32-bit ARM for EABI.
4. Patch5 is used to add test cases to cover some parameter scenarios
states by AAPCS.

The following is the test_progs result in the 32-bit ARM environment:

# uname -m
armv7l
# echo 1 > /proc/sys/net/core/bpf_jit_enable
# ./test_progs -t kfunc_call
#1/1 kfunc_call/kfunc_syscall_test_fail:OK
#1/2 kfunc_call/kfunc_syscall_test_null_fail:OK
#1/3 kfunc_call/kfunc_call_test_get_mem_fail_rdonly:OK
#1/4 kfunc_call/kfunc_call_test_get_mem_fail_use_after_free:OK
#1/5 kfunc_call/kfunc_call_test_get_mem_fail_oob:OK
#1/6 kfunc_call/kfunc_call_test_get_mem_fail_not_const:OK
#1/7 kfunc_call/kfunc_call_test_mem_acquire_fail:OK
#1/8 kfunc_call/kfunc_call_test1:OK
#1/9 kfunc_call/kfunc_call_test2:OK
#1/10 kfunc_call/kfunc_call_test4:OK
#1/11 kfunc_call/kfunc_call_test_ref_btf_id:OK
#1/12 kfunc_call/kfunc_call_test_get_mem:OK
#1/13 kfunc_call/kfunc_syscall_test:OK
#1/14 kfunc_call/kfunc_syscall_test_null:OK
#1/17 kfunc_call/destructive:OK

Yang Jihong (5):
bpf: Adapt 32-bit return value kfunc for 32-bit ARM when zext
extension
bpf: Adjust sk size check for sk in bpf_skb_is_valid_access for CO_RE
in 32-bit arch
libbpf: Skip adjust mem size for load pointer in 32-bit arch in CO_RE
bpf: Add kernel function call support in 32-bit ARM for EABI
bpf:selftests: Add kfunc_call test for mixing 32-bit and 64-bit
parameters

arch/arm/net/bpf_jit_32.c | 142 ++++++++++++++++++
kernel/bpf/verifier.c | 3 +
net/bpf/test_run.c | 18 +++
net/core/filter.c | 8 +-
tools/lib/bpf/libbpf.c | 34 ++++-
.../selftests/bpf/prog_tests/kfunc_call.c | 3 +
.../selftests/bpf/progs/kfunc_call_test.c | 52 +++++++
7 files changed, 254 insertions(+), 6 deletions(-)

--
2.30.GIT