[PATCH bpf-next 6/6] selftests/bpf: add BPF_CORE_READ and BPF_CORE_READ_STR_INTO macro tests
From: Andrii Nakryiko <hidden>
Date: 2019-09-30 20:45:25
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [selftests] (test runners & infrastructure), kernel selftest framework, the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Shuah Khan, Linus Torvalds
Validate BPF_CORE_READ correctness and handling of up to 9 levels of nestedness using cyclic task->(group_leader->)*->tgid chains. Also add a test of maximum-dpeth BPF_CORE_READ_STR_INTO() macro. Signed-off-by: Andrii Nakryiko <redacted> --- .../selftests/bpf/prog_tests/core_reloc.c | 8 ++- .../selftests/bpf/progs/core_reloc_types.h | 9 ++++ .../bpf/progs/test_core_reloc_kernel.c | 54 ++++++++++++++++++- 3 files changed, 68 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/core_reloc.c b/tools/testing/selftests/bpf/prog_tests/core_reloc.c
index f3863f976a48..21a0dff66241 100644
--- a/tools/testing/selftests/bpf/prog_tests/core_reloc.c
+++ b/tools/testing/selftests/bpf/prog_tests/core_reloc.c@@ -193,8 +193,12 @@ static struct core_reloc_test_case test_cases[] = { .btf_src_file = NULL, /* load from /lib/modules/$(uname -r) */ .input = "", .input_len = 0, - .output = "\1", /* true */ - .output_len = 1, + .output = STRUCT_TO_CHAR_PTR(core_reloc_kernel_output) { + .valid = { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, }, + .comm = "test_progs\0\0\0\0\0", + .comm_len = 11, + }, + .output_len = sizeof(struct core_reloc_kernel_output), }, /* validate BPF program can use multiple flavors to match against
diff --git a/tools/testing/selftests/bpf/progs/core_reloc_types.h b/tools/testing/selftests/bpf/progs/core_reloc_types.h
index f686a8138d90..9a6bdeb4894c 100644
--- a/tools/testing/selftests/bpf/progs/core_reloc_types.h
+++ b/tools/testing/selftests/bpf/progs/core_reloc_types.h@@ -1,5 +1,14 @@ #include <stdint.h> #include <stdbool.h> +/* + * KERNEL + */ + +struct core_reloc_kernel_output { + int valid[10]; + char comm[16]; + int comm_len; +}; /* * FLAVORS
diff --git a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c
index e5308026cfda..f318d39623b5 100644
--- a/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c
+++ b/tools/testing/selftests/bpf/progs/test_core_reloc_kernel.c@@ -12,9 +12,17 @@ static volatile struct data { char out[256]; } data; +struct core_reloc_kernel_output { + int valid[10]; + char comm[16]; + int comm_len; +}; + struct task_struct { int pid; int tgid; + char comm[16]; + struct task_struct *group_leader; }; #define CORE_READ(dst, src) bpf_core_read(dst, sizeof(*dst), src)
@@ -23,7 +31,9 @@ SEC("raw_tracepoint/sys_enter") int test_core_kernel(void *ctx) { struct task_struct *task = (void *)bpf_get_current_task(); + struct core_reloc_kernel_output *out = (void *)&data.out; uint64_t pid_tgid = bpf_get_current_pid_tgid(); + uint32_t real_tgid = (uint32_t)pid_tgid; int pid, tgid; if (CORE_READ(&pid, &task->pid) ||
@@ -31,7 +41,49 @@ int test_core_kernel(void *ctx) return 1; /* validate pid + tgid matches */ - data.out[0] = (((uint64_t)pid << 32) | tgid) == pid_tgid; + out->valid[0] = (((uint64_t)pid << 32) | tgid) == pid_tgid; + + /* test variadic BPF_CORE_READ macros */ + out->valid[1] = BPF_CORE_READ(task, + tgid) == real_tgid; + out->valid[2] = BPF_CORE_READ(task, + group_leader, + tgid) == real_tgid; + out->valid[3] = BPF_CORE_READ(task, + group_leader, group_leader, + tgid) == real_tgid; + out->valid[4] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + tgid) == real_tgid; + out->valid[5] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + group_leader, + tgid) == real_tgid; + out->valid[6] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + group_leader, group_leader, + tgid) == real_tgid; + out->valid[7] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + group_leader, group_leader, group_leader, + tgid) == real_tgid; + out->valid[8] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + group_leader, group_leader, group_leader, + group_leader, + tgid) == real_tgid; + out->valid[9] = BPF_CORE_READ(task, + group_leader, group_leader, group_leader, + group_leader, group_leader, group_leader, + group_leader, group_leader, + tgid) == real_tgid; + + /* test BPF_CORE_READ_STR_INTO() returns correct code and contents */ + out->comm_len = BPF_CORE_READ_STR_INTO( + &out->comm, task, + group_leader, group_leader, group_leader, group_leader, + group_leader, group_leader, group_leader, group_leader, + comm); return 0; }
--
2.17.1