[bpf-next,v3,0/4] bpf: Support kernel function call in 32-bit ARM

Message

Yang Jihong Nov. 26, 2022, 9:45 a.m. UTC

1. Patch1 is dependent patch to fix zext extension error in 32-bit ARM.
2. Patch2 supports bpf fkunc in 32-bit ARM for EABI.
3. Patch3 is used to add test cases to cover some parameter scenarios
   states by AAPCS.
4. Patch4 fix a comment error.

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_test5:OK
  #1/12    kfunc_call/kfunc_call_test6:OK
  #1/13    kfunc_call/kfunc_call_test_ref_btf_id:OK
  #1/14    kfunc_call/kfunc_call_test_get_mem:OK
  #1/15    kfunc_call/kfunc_syscall_test:OK
  #1/16    kfunc_call/kfunc_syscall_test_null:OK
  #1/19    kfunc_call/destructive:OK

---
Changes since v2:
  - Remove patches to adjust sk size check for CO_RE in 32-bit arch.
  - Add check of kfunc's return value in insn_def_regno.
  - Adjust is_reg64 for insn_def_regno.
  - The check of CONFIG_AEABI is moved from emit_kfunc_call to
    bpf_jit_supports_kfunc_call.
  - Fix a comment error in fixup_kfunc_call.

Yang Jihong (4):
  bpf: Adapt 32-bit return value kfunc for 32-bit ARM when zext
    extension
  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
  bpf: Fix comment error in fixup_kfunc_call function

 arch/arm/net/bpf_jit_32.c                     | 137 ++++++++++++++++++
 kernel/bpf/verifier.c                         |  46 +++++-
 net/bpf/test_run.c                            |  18 +++
 .../selftests/bpf/prog_tests/kfunc_call.c     |   3 +
 .../selftests/bpf/progs/kfunc_call_test.c     |  52 +++++++
 5 files changed, 252 insertions(+), 4 deletions(-)