linux.git/tools/testing/selftests/bpf/bpf_testmod, branch v6.9

selftests/bpf: Test PROBE_MEM of VSYSCALL_ADDR on x86-64

2024-04-26T16:45:18+00:00

The vsyscall is a legacy API for fast execution of system calls. It maps
a page at address VSYSCALL_ADDR into the userspace program. This address
is in the top 10MB of the address space:

ffffffffff600000 - ffffffffff600fff |    4 kB | legacy vsyscall ABI

The last commit fixes the x86-64 BPF JIT to skip accessing addresses in
this memory region. Add this address to bpf_testmod_return_ptr() so we
can make sure that it is fixed.

After this change and without the previous commit, subprogs_extable
selftest will crash the kernel.

Signed-off-by: Puranjay Mohan 
Link: https://lore.kernel.org/r/20240424100210.11982-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov

selftests/bpf: Bad_struct_ops test

2024-03-06T23:18:15+00:00

When loading struct_ops programs kernel requires BTF id of the
struct_ops type and member index for attachment point inside that
type. This makes impossible to use same BPF program in several
struct_ops maps that have different struct_ops type.
Check if libbpf rejects such BPF objects files.

Signed-off-by: Eduard Zingerman 
Signed-off-by: Andrii Nakryiko 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20240306104529.6453-7-eddyz87@gmail.com

selftests/bpf: Test struct_ops map definition with type suffix

2024-03-06T23:18:15+00:00

Extend struct_ops_module test case to check if it is possible to use
'___' suffixes for struct_ops type specification.

Signed-off-by: Eduard Zingerman 
Signed-off-by: Andrii Nakryiko 
Acked-by: David Vernet 
Link: https://lore.kernel.org/bpf/20240306104529.6453-5-eddyz87@gmail.com

selftests/bpf: Test struct_ops maps with a large number of struct_ops program.

2024-03-04T22:09:24+00:00

Create and load a struct_ops map with a large number of struct_ops
programs to generate trampolines taking a size over multiple pages. The
map includes 40 programs. Their trampolines takes 6.6k+, more than 1.5
pages, on x86.

Signed-off-by: Kui-Feng Lee 
Link: https://lore.kernel.org/r/20240224223418.526631-4-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau

selftests/bpf: Test if shadow types work correctly.

2024-02-29T22:23:53+00:00

Change the values of fields, including scalar types and function pointers,
and check if the struct_ops map works as expected.

The test changes the field "test_2" of "testmod_1" from the pointer to
test_2() to pointer to test_3() and the field "data" to 13. The function
test_2() and test_3() both compute a new value for "test_2_result", but in
different way. By checking the value of "test_2_result", it ensures the
struct_ops map works as expected with changes through shadow types.

Signed-off-by: Kui-Feng Lee 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20240229064523.2091270-6-thinker.li@gmail.com

selftests/bpf: Test PTR_MAYBE_NULL arguments of struct_ops operators.

2024-02-13T23:16:44+00:00

Test if the verifier verifies nullable pointer arguments correctly for BPF
struct_ops programs.

"test_maybe_null" in struct bpf_testmod_ops is the operator defined for the
test cases here.

A BPF program should check a pointer for NULL beforehand to access the
value pointed by the nullable pointer arguments, or the verifier should
reject the programs. The test here includes two parts; the programs
checking pointers properly and the programs not checking pointers
beforehand. The test checks if the verifier accepts the programs checking
properly and rejects the programs not checking at all.

Signed-off-by: Kui-Feng Lee 
Link: https://lore.kernel.org/r/20240209023750.1153905-5-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau

selftests/bpf: Suppress warning message of an unused variable.

2024-02-05T18:52:38+00:00

"r" is used to receive the return value of test_2 in bpf_testmod.c, but it
is not actually used. So, we remove "r" and change the return type to
"void".

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202401300557.z5vzn8FM-lkp@intel.com/
Signed-off-by: Kui-Feng Lee 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/r/20240204061204.1864529-1-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau

bpf: treewide: Annotate BPF kfuncs in BTF

2024-02-01T04:40:56+00:00

This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:

1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
   each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
   generate appropriate prototypes for functions with "bpf_kfunc" tag

To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.

Signed-off-by: Daniel Xu 
Acked-by: Benjamin Tissoires 
Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov

selftests/bpf: Drop return in bpf_testmod_exit

2024-01-29T15:41:29+00:00

bpf_testmod_exit() does not need to have a return value (given the void),
so this patch drops this useless 'return' in it.

Signed-off-by: Geliang Tang 
Signed-off-by: Daniel Borkmann 
Acked-by: Jiri Olsa 
Link: https://lore.kernel.org/bpf/5765b287ea088f0c820f2a834faf9b20fb2f8215.1706442113.git.tanggeliang@kylinos.cn

selftests/bpf: test case for register_bpf_struct_ops().

2024-01-24T01:12:52+00:00

Create a new struct_ops type called bpf_testmod_ops within the bpf_testmod
module. When a struct_ops object is registered, the bpf_testmod module will
invoke test_2 from the module.

Signed-off-by: Kui-Feng Lee 
Link: https://lore.kernel.org/r/20240119225005.668602-15-thinker.li@gmail.com
Signed-off-by: Martin KaFai Lau