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 andriin@fb.com Signed-off-by: Hao Luo haoluo@google.com --- .../selftests/bpf/prog_tests/ksyms_btf.c | 10 +++++++ .../selftests/bpf/progs/test_ksyms_btf.c | 26 +++++++++++++++++++ 2 files changed, 36 insertions(+)
diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c index 7b6846342449..22cc642dbc0e 100644 --- a/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_btf.c @@ -58,6 +58,16 @@ void test_ksyms_btf(void) CHECK(data->out__bpf_prog_active != bpf_prog_active_addr, "bpf_prog_active", "got %llu, exp %llu\n", data->out__bpf_prog_active, bpf_prog_active_addr);
+ CHECK(data->out__rq_cpu == -1, "rq_cpu", + "got %u, exp != -1\n", data->out__rq_cpu); + CHECK(data->out__percpu_bpf_prog_active == -1, "percpu_bpf_prog_active", + "got %d, exp != -1\n", data->out__percpu_bpf_prog_active); + + CHECK(data->out__this_rq_cpu == -1, "this_rq_cpu", + "got %u, exp != -1\n", data->out__this_rq_cpu); + CHECK(data->out__this_bpf_prog_active == -1, "this_bpf_prog_active", + "got %d, exp != -1\n", data->out__this_bpf_prog_active); + cleanup: 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 e04e31117f84..02d564349892 100644 --- a/tools/testing/selftests/bpf/progs/test_ksyms_btf.c +++ b/tools/testing/selftests/bpf/progs/test_ksyms_btf.c @@ -8,15 +8,41 @@ __u64 out__runqueues = -1; __u64 out__bpf_prog_active = -1;
+__u32 out__rq_cpu = -1; /* percpu struct fields */ +int out__percpu_bpf_prog_active = -1; /* percpu int */ + +__u32 out__this_rq_cpu = -1; +int out__this_bpf_prog_active = -1; + 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 = (__u64)&runqueues; out__bpf_prog_active = (__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__percpu_bpf_prog_active = *active; + + /* 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; }