Commit Graph

5 Commits

Author SHA1 Message Date
Toke Høiland-Jørgensen 3e689141e6 selftests: Use consistent include paths for libbpf
Fix all selftests to include libbpf header files with the bpf/ prefix, to
be consistent with external users of the library. Also ensure that all
includes of exported libbpf header files (those that are exported on 'make
install' of the library) use bracketed includes instead of quoted.

To not break the build, keep the old include path until everything has been
changed to the new one; a subsequent patch will remove that.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560568.1683545.9649335788846513446.stgit@toke.dk
2020-01-20 16:37:45 -08:00
Yonghong Song 2ea2612b98 selftests, bpf: Workaround an alu32 sub-register spilling issue
Currently, with latest llvm trunk, selftest test_progs failed obj
file test_seg6_loop.o with the following error in verifier:

  infinite loop detected at insn 76

The byte code sequence looks like below, and noted that alu32 has been
turned off by default for better generated codes in general:

      48:       w3 = 100
      49:       *(u32 *)(r10 - 68) = r3
      ...
  ;             if (tlv.type == SR6_TLV_PADDING) {
      76:       if w3 == 5 goto -18 <LBB0_19>
      ...
      85:       r1 = *(u32 *)(r10 - 68)
  ;     for (int i = 0; i < 100; i++) {
      86:       w1 += -1
      87:       if w1 == 0 goto +5 <LBB0_20>
      88:       *(u32 *)(r10 - 68) = r1

The main reason for verification failure is due to partial spills at
r10 - 68 for induction variable "i".

Current verifier only handles spills with 8-byte values. The above 4-byte
value spill to stack is treated to STACK_MISC and its content is not
saved. For the above example:

    w3 = 100
      R3_w=inv100 fp-64_w=inv1086626730498
    *(u32 *)(r10 - 68) = r3
      R3_w=inv100 fp-64_w=inv1086626730498
    ...
    r1 = *(u32 *)(r10 - 68)
      R1_w=inv(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff))
      fp-64=inv1086626730498

To resolve this issue, verifier needs to be extended to track sub-registers
in spilling, or llvm needs to enhanced to prevent sub-register spilling
in register allocation phase. The former will increase verifier complexity
and the latter will need some llvm "hacking".

Let us workaround this issue by declaring the induction variable as "long"
type so spilling will happen at non sub-register level. We can revisit this
later if sub-register spilling causes similar or other verification issues.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191117214036.1309510-1-yhs@fb.com
2019-11-18 21:37:00 +01:00
Ilya Leoshkevich b963267994 selftests/bpf: introduce bpf_cpu_to_be64 and bpf_be64_to_cpu
test_lwt_seg6local and test_seg6_loop use custom 64-bit endianness
conversion macros. Centralize their definitions in bpf_endian.h in order
to reduce code duplication. This will also be useful when bpf_endian.h
is promoted to an offical libbpf header.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-03 21:01:52 +02:00
Jiri Benc d2f5bbbc35 selftests: bpf: standardize to static __always_inline
The progs for bpf selftests use several different notations to force
function inlining. Standardize to what most of them use,
static __always_inline.

Suggested-by: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-03 15:06:33 +02:00
Alexei Starovoitov b061017f8b selftests/bpf: add realistic loop tests
Add a bunch of loop tests. Most of them are created by replacing
'#pragma unroll' with '#pragma clang loop unroll(disable)'

Several tests are artificially large:
  /* partial unroll. llvm will unroll loop ~150 times.
   * C loop count -> 600.
   * Asm loop count -> 4.
   * 16k insns in loop body.
   * Total of 5 such loops. Total program size ~82k insns.
   */
  "./pyperf600.o",

  /* no unroll at all.
   * C loop count -> 600.
   * ASM loop count -> 600.
   * ~110 insns in loop body.
   * Total of 5 such loops. Total program size ~1500 insns.
   */
  "./pyperf600_nounroll.o",

  /* partial unroll. 19k insn in a loop.
   * Total program size 20.8k insn.
   * ~350k processed_insns
   */
  "./strobemeta.o",

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-19 02:22:52 +02:00