linux.git/tools/testing/selftests/bpf/bpf_testmod, branch v6.5

selftests/bpf: Add missing prototypes for several test kfuncs

2023-06-08T11:26:12+00:00

Adding missing prototypes for several kfuncs that are used by
test_verifier tests. We don't really need kfunc prototypes for
these tests, but adding them to silence 'make W=1' build and
to have all test kfuncs declarations in bpf_testmod_kfunc.h.

Also moving __diag_pop for -Wmissing-prototypes to cover also
bpf_testmod_test_write and bpf_testmod_test_read and adding
bpf_fentry_shadow_test in there as well. All of them need to
be exported, but there's no need for declarations.

Fixes: 65eb006d85a2 ("bpf: Move kernel test kfuncs to bpf_testmod")
Reported-by: kernel test robot 
Signed-off-by: Jiri Olsa 
Signed-off-by: Daniel Borkmann 
Closes: https://lore.kernel.org/oe-kbuild-all/202306051319.EihCQZPs-lkp@intel.com
Link: https://lore.kernel.org/bpf/20230607224046.236510-1-jolsa@kernel.org

bpf: Move kernel test kfuncs to bpf_testmod

2023-05-17T05:09:24+00:00

Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.

We need to keep following structs in kernel:
  struct prog_test_ref_kfunc
  struct prog_test_member (embedded in prog_test_ref_kfunc)

The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).

We need to keep also dtor functions for both objects in kernel:
  bpf_kfunc_call_test_release
  bpf_kfunc_call_memb_release

We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.

As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.

Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.

Signed-off-by: Jiri Olsa 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov

selftests/bpf: Remove extern from kfuncs declarations

2023-05-17T05:09:23+00:00

There's no need to keep the extern in kfuncs declarations.

Suggested-by: David Vernet 
Acked-by: David Vernet 
Signed-off-by: Jiri Olsa 
Link: https://lore.kernel.org/r/20230515133756.1658301-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov

selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.h

2023-05-17T05:09:23+00:00

Move all kfunc exports into separate bpf_testmod_kfunc.h header file
and include it in tests that need it.

We will move all test kfuncs into bpf_testmod in following change,
so it's convenient to have declarations in single place.

The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf
programs that use test kfuncs.

As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h
and bpf/bpf_helpers.h for bpf programs build, so the declarations
have proper __ksym attribute and we can resolve all the structs.

Note in kfunc_call_test_subprog.c we can no longer use the sk_state
define from bpf_tcp_helpers.h (because it clashed with vmlinux.h)
and we need to address __sk_common.skc_state field directly.

Acked-by: David Vernet 
Signed-off-by: Jiri Olsa 
Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov

selftests/bpf: Add test to access integer type of variable array

2023-04-20T04:29:39+00:00

Add prog test for accessing integer type of variable array in tracing
program.
In addition, hook load_balance function to access sd->span[0], only
to confirm whether the load is successful. Because there is no direct
way to trigger load_balance call.

Co-developed-by: Chengming Zhou 
Signed-off-by: Chengming Zhou 
Signed-off-by: Feng Zhou 
Link: https://lore.kernel.org/r/20230420032735.27760-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov

selftests/bpf: Fix compiler warnings in bpf_testmod for kfuncs

2023-04-13T12:54:45+00:00

Add -Wmissing-prototypes ignore in bpf_testmod.c, similarly to what we
do in kernel code proper.

Reported-by: kernel test robot 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/oe-kbuild-all/202304080951.l14IDv3n-lkp@intel.com/
Link: https://lore.kernel.org/bpf/20230412034647.3968143-1-andrii@kernel.org

selftests/bpf: Keep the loop in bpf_testmod_loop_test

2023-04-13T12:32:05+00:00

Some compilers (for example clang-15) optimize bpf_testmod_loop_test and
remove the loop:

gcc version
(gdb) disassemble bpf_testmod_loop_test
Dump of assembler code for function bpf_testmod_loop_test:
   0x0000000000000570 <+0>:     callq  0x575 
   0x0000000000000575 <+5>:     xor    %eax,%eax
   0x0000000000000577 <+7>:     test   %edi,%edi
   0x0000000000000579 <+9>:     jle    0x587 
   0x000000000000057b <+11>:    xor    %edx,%edx
   0x000000000000057d <+13>:    add    %edx,%eax
   0x000000000000057f <+15>:    add    $0x1,%edx
   0x0000000000000582 <+18>:    cmp    %edx,%edi
   0x0000000000000584 <+20>:    jne    0x57d 
   0x0000000000000586 <+22>:    retq
   0x0000000000000587 <+23>:    retq

clang-15 version
(gdb) disassemble bpf_testmod_loop_test
Dump of assembler code for function bpf_testmod_loop_test:
   0x0000000000000450 <+0>:     nopl   0x0(%rax,%rax,1)
   0x0000000000000455 <+5>:     test   %edi,%edi
   0x0000000000000457 <+7>:     jle    0x46b 
   0x0000000000000459 <+9>:     lea    -0x1(%rdi),%eax
   0x000000000000045c <+12>:    lea    -0x2(%rdi),%ecx
   0x000000000000045f <+15>:    imul   %rax,%rcx
   0x0000000000000463 <+19>:    shr    %rcx
   0x0000000000000466 <+22>:    lea    -0x1(%rdi,%rcx,1),%eax
   0x000000000000046a <+26>:    retq
   0x000000000000046b <+27>:    xor    %eax,%eax
   0x000000000000046d <+29>:    retq

Note: The jne instruction is removed in clang-15 version.

Force the compile to keep the loop by making sum volatile.

Signed-off-by: Song Liu 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20230412210423.900851-4-song@kernel.org

bpf/selftests: Test fentry attachment to shadowed functions

2023-03-16T01:38:30+00:00

Adds a new test that tries to attach a program to fentry of two
functions of the same name, one located in vmlinux and the other in
bpf_testmod.

To avoid conflicts with existing tests, a new function
"bpf_fentry_shadow_test" was created both in vmlinux and in bpf_testmod.

The previous commit fixed a bug which caused this test to fail. The
verifier would always use the vmlinux function's address as the target
trampoline address, hence trying to create two trampolines for a single
address, which is forbidden.

The test (similarly to other fentry/fexit tests) is not working on arm64
at the moment.

Signed-off-by: Viktor Malik 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/r/5fe2f364190b6f79b085066ed7c5989c5bc475fa.1678432753.git.vmalik@redhat.com
Signed-off-by: Alexei Starovoitov

selftests/bpf: implement and test custom testmod_seq iterator

2023-03-09T00:19:51+00:00

Implement a trivial iterator returning same specified integer value
N times as part of bpf_testmod kernel module. Add selftests to validate
everything works end to end.

We also reuse these tests as "verification-only" tests to validate that
kernel prints the state of custom kernel module-defined iterator correctly:

  fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)

"testmod_seq" part is an iterator type, and is coming from module's BTF
data dynamically at runtime.

Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/r/20230308184121.1165081-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov

bpf: Add __bpf_kfunc tag to all kfuncs

2023-02-01T23:25:14+00:00

Now that we have the __bpf_kfunc tag, we should use add it to all
existing kfuncs to ensure that they'll never be elided in LTO builds.

Signed-off-by: David Vernet 
Signed-off-by: Daniel Borkmann 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/bpf/20230201173016.342758-4-void@manifault.com