mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

bpf/selftests: Test for bpf_per_cpu_ptr() and bpf_this_cpu_ptr() 

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.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200929235049.2533242-7-haoluo@google.com
This commit is contained in:
Hao Luo 2020-09-29 16:50:49 -07:00 committed by Alexei Starovoitov
parent 63d9b80dcf
commit 00dc73e44a
2 changed files with 50 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
tools/testing/selftests/bpf/prog_tests/ksyms_btf.c
View File

@ -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);

32
tools/testing/selftests/bpf/progs/test_ksyms_btf.c
View File

@ -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;
}