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

Message

Yang Jihong Nov. 7, 2022, 9:20 a.m. UTC

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(-)