iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
964,700 Commits 104 Branches 1,843 Tags
Commit Graph

6 Commits

Author SHA1 Message Date
Stanislav Fomichev
e1cebd841b selftests/bpf: Fix a couple of broken test_btf cases 
Commit 51c39bb1d5d1 ("bpf: Introduce function-by-function verification")
introduced function linkage flag and changed the error message from
"vlen != 0" to "Invalid func linkage" and broke some fake BPF programs.

Adjust the test accordingly.

AFACT, the programs don't really need any arguments and only look
at BTF for maps, so let's drop the args altogether.

Before:
BTF raw test[103] (func (Non zero vlen)): do_test_raw:3703:FAIL expected
err_str:vlen != 0
magic: 0xeb9f
version: 1
flags: 0x0
hdr_len: 24
type_off: 0
type_len: 72
str_off: 72
str_len: 10
btf_total_size: 106
[1] INT (anon) size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[2] INT (anon) size=4 bits_offset=0 nr_bits=32 encoding=(none)
[3] FUNC_PROTO (anon) return=0 args=(1 a, 2 b)
[4] FUNC func type_id=3 Invalid func linkage

BTF libbpf test[1] (test_btf_haskv.o): libbpf: load bpf program failed:
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_haskv.o'
do_test_file:4201:FAIL bpf_object__load: -4007
BTF libbpf test[2] (test_btf_newkv.o): libbpf: load bpf program failed:
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_newkv.o'
do_test_file:4201:FAIL bpf_object__load: -4007
BTF libbpf test[3] (test_btf_nokv.o): libbpf: load bpf program failed:
Invalid argument
libbpf: -- BEGIN DUMP LOG ---
libbpf:
Validating test_long_fname_2() func#1...
Arg#0 type PTR in test_long_fname_2() is not supported yet.
processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0
peak_states 0 mark_read 0

libbpf: -- END LOG --
libbpf: failed to load program 'dummy_tracepoint'
libbpf: failed to load object 'test_btf_nokv.o'
do_test_file:4201:FAIL bpf_object__load: -4007

Fixes: 51c39bb1d5d1 ("bpf: Introduce function-by-function verification")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200422003753.124921-1-sdf@google.com
 2020-04-24 17:47:40 -07:00
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: 6910d7d3867a ("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
Andrii Nakryiko
a0d7da26ce libbpf: Fix call relocation offset calculation bug 
When relocating subprogram call, libbpf doesn't take into account
relo->text_off, which comes from symbol's value. This generally works fine for
subprograms implemented as static functions, but breaks for global functions.

Taking a simplified test_pkt_access.c as an example:

__attribute__ ((noinline))
static int test_pkt_access_subprog1(volatile struct __sk_buff *skb)
{
        return skb->len * 2;
}

__attribute__ ((noinline))
static int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb)
{
        return skb->len + val;
}

SEC("classifier/test_pkt_access")
int test_pkt_access(struct __sk_buff *skb)
{
        if (test_pkt_access_subprog1(skb) != skb->len * 2)
                return TC_ACT_SHOT;
        if (test_pkt_access_subprog2(2, skb) != skb->len + 2)
                return TC_ACT_SHOT;
        return TC_ACT_UNSPEC;
}

When compiled, we get two relocations, pointing to '.text' symbol. .text has
st_value set to 0 (it points to the beginning of .text section):

0000000000000008  000000050000000a R_BPF_64_32            0000000000000000 .text
0000000000000040  000000050000000a R_BPF_64_32            0000000000000000 .text

test_pkt_access_subprog1 and test_pkt_access_subprog2 offsets (targets of two
calls) are encoded within call instruction's imm32 part as -1 and 2,
respectively:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       4:       04 00 00 00 02 00 00 00 w0 += 2
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 08 00 00 00 00 00 if w1 != w2 goto +8 <LBB0_3>
       7:       bf 61 00 00 00 00 00 00 r1 = r6
===>   8:       85 10 00 00 02 00 00 00 call 2
       9:       bc 01 00 00 00 00 00 00 w1 = w0
      10:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      11:       04 02 00 00 02 00 00 00 w2 += 2
      12:       b4 00 00 00 ff ff ff ff w0 = -1
      13:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB0_3>
      14:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000078 LBB0_3:
      15:       95 00 00 00 00 00 00 00 exit

Now, if we compile example with global functions, the setup changes.
Relocations are now against specifically test_pkt_access_subprog1 and
test_pkt_access_subprog2 symbols, with test_pkt_access_subprog2 pointing 24
bytes into its respective section (.text), i.e., 3 instructions in:

0000000000000008  000000070000000a R_BPF_64_32            0000000000000000 test_pkt_access_subprog1
0000000000000048  000000080000000a R_BPF_64_32            0000000000000018 test_pkt_access_subprog2

Calls instructions now encode offsets relative to function symbols and are both
set ot -1:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0)
       4:       0c 10 00 00 00 00 00 00 w0 += w1
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 09 00 00 00 00 00 if w1 != w2 goto +9 <LBB2_3>
       7:       b4 01 00 00 02 00 00 00 w1 = 2
       8:       bf 62 00 00 00 00 00 00 r2 = r6
===>   9:       85 10 00 00 ff ff ff ff call -1
      10:       bc 01 00 00 00 00 00 00 w1 = w0
      11:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      12:       04 02 00 00 02 00 00 00 w2 += 2
      13:       b4 00 00 00 ff ff ff ff w0 = -1
      14:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB2_3>
      15:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000080 LBB2_3:
      16:       95 00 00 00 00 00 00 00 exit

Thus the right formula to calculate target call offset after relocation should
take into account relocation's target symbol value (offset within section),
call instruction's imm32 offset, and (subtracting, to get relative instruction
offset) instruction index of call instruction itself. All that is shifted by
number of instructions in main program, given all sub-programs are copied over
after main program.

Convert few selftests relying on bpf-to-bpf calls to use global functions
instead of static ones.

Fixes: 48cca7e44f9f ("libbpf: add support for bpf_call")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191119224447.3781271-1-andriin@fb.com
 2019-11-19 15:00:12 -08:00
Andrii Nakryiko
36b5d47113 selftests/bpf: samples/bpf: Split off legacy stuff from bpf_helpers.h 
Split off few legacy things from bpf_helpers.h into separate
bpf_legacy.h file:
- load_{byte|half|word};
- remove extra inner_idx and numa_node fields from bpf_map_def and
  introduce bpf_map_def_legacy for use in samples;
- move BPF_ANNOTATE_KV_PAIR into bpf_legacy.h.

Adjust samples and selftests accordingly by either including
bpf_legacy.h and using bpf_map_def_legacy, or switching to BTF-defined
maps altogether.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-3-andriin@fb.com
 2019-10-08 23:16:03 +02:00
Andrii Nakryiko
bc7430cc8b selftests/bpf: convert selftests using BTF-defined maps to new syntax 
Convert all the existing selftests that are already using BTF-defined
maps to use new syntax (with no static data initialization).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
 2019-07-05 22:52:25 +02:00
Andrii Nakryiko
9e3d709c47 selftests/bpf: add test for BTF-defined maps 
Add file test for BTF-defined map definition.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
 2019-06-18 00:10:42 +02:00