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| author | Eduard Zingerman <eddyz87@gmail.com> | 2023-03-04 04:12:47 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-03-04 08:41:46 +0300 |
| commit | 71cf4d027ad53a1e2847191ac14e50132d35a6a7 (patch) | |
| tree | 8fdcaadb091cc136be7a61a7ee097c0edfa79e47 /tools/testing/selftests/bpf/Makefile | |
| parent | 806f81cd1ee30c66a3d2a4cd18b13c97429397a0 (diff) | |
| download | linux-71cf4d027ad53a1e2847191ac14e50132d35a6a7.tar.xz | |
selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access()
Function verifier.c:convert_ctx_access() applies some rewrites to BPF
instructions that read or write BPF program context. This commit adds
machinery to allow test cases that inspect BPF program after these
rewrites are applied.
An example of a test case:
{
// Shorthand for field offset and size specification
N(CGROUP_SOCKOPT, struct bpf_sockopt, retval),
// Pattern generated for field read
.read = "$dst = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"$dst = *(u64 *)($dst + task_struct::bpf_ctx);"
"$dst = *(u32 *)($dst + bpf_cg_run_ctx::retval);",
// Pattern generated for field write
.write = "*(u64 *)($ctx + bpf_sockopt_kern::tmp_reg) = r9;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"r9 = *(u64 *)(r9 + task_struct::bpf_ctx);"
"*(u32 *)(r9 + bpf_cg_run_ctx::retval) = $src;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::tmp_reg);" ,
},
For each test case, up to three programs are created:
- One that uses BPF_LDX_MEM to read the context field.
- One that uses BPF_STX_MEM to write to the context field.
- One that uses BPF_ST_MEM to write to the context field.
The disassembly of each program is compared with the pattern specified
in the test case.
Kernel code for disassembly is reused (as is in the bpftool).
To keep Makefile changes to the minimum, symbolic links to
`kernel/bpf/disasm.c` and `kernel/bpf/disasm.h ` are added.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/testing/selftests/bpf/Makefile')
| -rw-r--r-- | tools/testing/selftests/bpf/Makefile | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index eab3cf5399f5..16f404aa1b23 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -559,7 +559,7 @@ TRUNNER_BPF_PROGS_DIR := progs TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \ network_helpers.c testing_helpers.c \ btf_helpers.c flow_dissector_load.h \ - cap_helpers.c test_loader.c xsk.c + cap_helpers.c test_loader.c xsk.c disasm.c TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \ $(OUTPUT)/liburandom_read.so \ $(OUTPUT)/xdp_synproxy \ |