[PATCH bpf-next v3 6/6] bpf/selftests: Test for bpf_per_cpu_ptr() and bpf_this_cpu_ptr()
From: Hao Luo <hidden>
Date: 2020-09-16 22:38:35
Also in:
bpf, linux-kselftest, lkml
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, Shuah Khan, Linus Torvalds
Test bpf_per_cpu_ptr() and bpf_this_cpu_ptr(). Test two paths in the kernel. If the base pointer points to a struct, the returned reg is of type PTR_TO_BTF_ID. Direct pointer dereference can be applied on the returned variable. If the base pointer isn't a struct, the returned reg is of type PTR_TO_MEM, which also supports direct pointer dereference. Acked-by: Andrii Nakryiko <redacted> Signed-off-by: Hao Luo <redacted> --- .../selftests/bpf/prog_tests/ksyms_btf.c | 18 +++++++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 32 +++++++++++++++++++ 2 files changed, 50 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
index c6ef06c0629a..28e26bd3e0ca 100644
--- a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c@@ -11,6 +11,8 @@ static int duration; void test_ksyms_btf(void) { __u64 runqueues_addr, bpf_prog_active_addr; + __u32 this_rq_cpu; + int this_bpf_prog_active; struct test_ksyms_btf *skel = NULL; struct test_ksyms_btf__data *data; struct btf *btf;
@@ -64,6 +66,22 @@ void test_ksyms_btf(void) (unsigned long long)data->out__bpf_prog_active_addr, (unsigned long long)bpf_prog_active_addr); + CHECK(data->out__rq_cpu == -1, "rq_cpu", + "got %u, exp != -1\n", data->out__rq_cpu); + CHECK(data->out__bpf_prog_active < 0, "bpf_prog_active", + "got %d, exp >= 0\n", data->out__bpf_prog_active); + CHECK(data->out__cpu_0_rq_cpu != 0, "cpu_rq(0)->cpu", + "got %u, exp 0\n", data->out__cpu_0_rq_cpu); + + this_rq_cpu = data->out__this_rq_cpu; + CHECK(this_rq_cpu != data->out__rq_cpu, "this_rq_cpu", + "got %u, exp %u\n", this_rq_cpu, data->out__rq_cpu); + + this_bpf_prog_active = data->out__this_bpf_prog_active; + CHECK(this_bpf_prog_active != data->out__bpf_prog_active, "this_bpf_prog_active", + "got %d, exp %d\n", this_bpf_prog_active, + data->out__bpf_prog_active); + cleanup: btf__free(btf); test_ksyms_btf__destroy(skel);
diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_btf.c b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c
index 7dde2082131d..bb8ea9270f29 100644
--- a/tools/testing/selftests/bpf/progs/test_ksyms_btf.c
+++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c@@ -8,15 +8,47 @@ __u64 out__runqueues_addr = -1; __u64 out__bpf_prog_active_addr = -1; +__u32 out__rq_cpu = -1; /* percpu struct fields */ +int out__bpf_prog_active = -1; /* percpu int */ + +__u32 out__this_rq_cpu = -1; +int out__this_bpf_prog_active = -1; + +__u32 out__cpu_0_rq_cpu = -1; /* cpu_rq(0)->cpu */ + extern const struct rq runqueues __ksym; /* struct type global var. */ extern const int bpf_prog_active __ksym; /* int type global var. */ SEC("raw_tp/sys_enter") int handler(const void *ctx) { + struct rq *rq; + int *active; + __u32 cpu; + out__runqueues_addr = (__u64)&runqueues; out__bpf_prog_active_addr = (__u64)&bpf_prog_active; + cpu = bpf_get_smp_processor_id(); + + /* test bpf_per_cpu_ptr() */ + rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, cpu); + if (rq) + out__rq_cpu = rq->cpu; + active = (int *)bpf_per_cpu_ptr(&bpf_prog_active, cpu); + if (active) + out__bpf_prog_active = *active; + + rq = (struct rq *)bpf_per_cpu_ptr(&runqueues, 0); + if (rq) /* should always be valid, but we can't spare the check. */ + out__cpu_0_rq_cpu = rq->cpu; + + /* test bpf_this_cpu_ptr */ + rq = (struct rq *)bpf_this_cpu_ptr(&runqueues); + out__this_rq_cpu = rq->cpu; + active = (int *)bpf_this_cpu_ptr(&bpf_prog_active); + out__this_bpf_prog_active = *active; + return 0; }
--
2.28.0.618.gf4bc123cb7-goog