| Message ID | 20200903223332.881541-7-haoluo@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | bpf: BTF support for ksyms | expand |
On Thu, Sep 3, 2020 at 3:35 PM Hao Luo <haoluo@google.com> wrote: > > 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); see below for few suggestions to make these test more specific out__this_bpf_prog_active it should always be > 0, no? > + > 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; this is equivalent to using bpf_this_cpu_ptr(), so: 1. you can compare value with out__this_xxx in user-space 2. it's interesting to also test that you can read value from some other CPU. Can you add another variable and get value from CPU #0 always? E.g., for out__cpu_0_rq_cpu it should always be zero, right? > + > + /* 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; > } > > -- > 2.28.0.526.ge36021eeef-goog >
Thanks for taking a look! On Fri, Sep 4, 2020 at 1:15 PM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Thu, Sep 3, 2020 at 3:35 PM Hao Luo <haoluo@google.com> wrote: > > > > 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); > > see below for few suggestions to make these test more specific > > out__this_bpf_prog_active it should always be > 0, no? > I could be wrong, but I remember raw_trace_point is not tracked by bpf_prog_active. So I used bpf_prog_active >= 0 to be safe. > > + > > 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; > > this is equivalent to using bpf_this_cpu_ptr(), so: > > 1. you can compare value with out__this_xxx in user-space > > 2. it's interesting to also test that you can read value from some > other CPU. Can you add another variable and get value from CPU #0 > always? E.g., for out__cpu_0_rq_cpu it should always be zero, right? > Ack. That makes sense. You are right, out__cpu_0_rq_cpu is always zero. > > + > > + /* 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; > > } > > > > -- > > 2.28.0.526.ge36021eeef-goog > >
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; }