mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-29 05:44:11 +00:00
selftests/bpf: BPF test_prog selftests for bpf_loop inlining
Two new test BPF programs for test_prog selftests checking bpf_loop behavior. Both are corner cases for bpf_loop inlinig transformation: - check that bpf_loop behaves correctly when callback function is not a compile time constant - check that local function variables are not affected by allocating additional stack storage for registers spilled by loop inlining Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/r/20220620235344.569325-6-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
parent
f8acfdd044
commit
0e1bf9ed20
2 changed files with 176 additions and 0 deletions
|
@ -120,6 +120,64 @@ static void check_nested_calls(struct bpf_loop *skel)
|
|||
bpf_link__destroy(link);
|
||||
}
|
||||
|
||||
static void check_non_constant_callback(struct bpf_loop *skel)
|
||||
{
|
||||
struct bpf_link *link =
|
||||
bpf_program__attach(skel->progs.prog_non_constant_callback);
|
||||
|
||||
if (!ASSERT_OK_PTR(link, "link"))
|
||||
return;
|
||||
|
||||
skel->bss->callback_selector = 0x0F;
|
||||
usleep(1);
|
||||
ASSERT_EQ(skel->bss->g_output, 0x0F, "g_output #1");
|
||||
|
||||
skel->bss->callback_selector = 0xF0;
|
||||
usleep(1);
|
||||
ASSERT_EQ(skel->bss->g_output, 0xF0, "g_output #2");
|
||||
|
||||
bpf_link__destroy(link);
|
||||
}
|
||||
|
||||
static void check_stack(struct bpf_loop *skel)
|
||||
{
|
||||
struct bpf_link *link = bpf_program__attach(skel->progs.stack_check);
|
||||
const int max_key = 12;
|
||||
int key;
|
||||
int map_fd;
|
||||
|
||||
if (!ASSERT_OK_PTR(link, "link"))
|
||||
return;
|
||||
|
||||
map_fd = bpf_map__fd(skel->maps.map1);
|
||||
|
||||
if (!ASSERT_GE(map_fd, 0, "bpf_map__fd"))
|
||||
goto out;
|
||||
|
||||
for (key = 1; key <= max_key; ++key) {
|
||||
int val = key;
|
||||
int err = bpf_map_update_elem(map_fd, &key, &val, BPF_NOEXIST);
|
||||
|
||||
if (!ASSERT_OK(err, "bpf_map_update_elem"))
|
||||
goto out;
|
||||
}
|
||||
|
||||
usleep(1);
|
||||
|
||||
for (key = 1; key <= max_key; ++key) {
|
||||
int val;
|
||||
int err = bpf_map_lookup_elem(map_fd, &key, &val);
|
||||
|
||||
if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
|
||||
goto out;
|
||||
if (!ASSERT_EQ(val, key + 1, "bad value in the map"))
|
||||
goto out;
|
||||
}
|
||||
|
||||
out:
|
||||
bpf_link__destroy(link);
|
||||
}
|
||||
|
||||
void test_bpf_loop(void)
|
||||
{
|
||||
struct bpf_loop *skel;
|
||||
|
@ -140,6 +198,10 @@ void test_bpf_loop(void)
|
|||
check_invalid_flags(skel);
|
||||
if (test__start_subtest("check_nested_calls"))
|
||||
check_nested_calls(skel);
|
||||
if (test__start_subtest("check_non_constant_callback"))
|
||||
check_non_constant_callback(skel);
|
||||
if (test__start_subtest("check_stack"))
|
||||
check_stack(skel);
|
||||
|
||||
bpf_loop__destroy(skel);
|
||||
}
|
||||
|
|
|
@ -11,11 +11,19 @@ struct callback_ctx {
|
|||
int output;
|
||||
};
|
||||
|
||||
struct {
|
||||
__uint(type, BPF_MAP_TYPE_HASH);
|
||||
__uint(max_entries, 32);
|
||||
__type(key, int);
|
||||
__type(value, int);
|
||||
} map1 SEC(".maps");
|
||||
|
||||
/* These should be set by the user program */
|
||||
u32 nested_callback_nr_loops;
|
||||
u32 stop_index = -1;
|
||||
u32 nr_loops;
|
||||
int pid;
|
||||
int callback_selector;
|
||||
|
||||
/* Making these global variables so that the userspace program
|
||||
* can verify the output through the skeleton
|
||||
|
@ -111,3 +119,109 @@ int prog_nested_calls(void *ctx)
|
|||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int callback_set_f0(int i, void *ctx)
|
||||
{
|
||||
g_output = 0xF0;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int callback_set_0f(int i, void *ctx)
|
||||
{
|
||||
g_output = 0x0F;
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* non-constant callback is a corner case for bpf_loop inline logic
|
||||
*/
|
||||
SEC("fentry/" SYS_PREFIX "sys_nanosleep")
|
||||
int prog_non_constant_callback(void *ctx)
|
||||
{
|
||||
struct callback_ctx data = {};
|
||||
|
||||
if (bpf_get_current_pid_tgid() >> 32 != pid)
|
||||
return 0;
|
||||
|
||||
int (*callback)(int i, void *ctx);
|
||||
|
||||
g_output = 0;
|
||||
|
||||
if (callback_selector == 0x0F)
|
||||
callback = callback_set_0f;
|
||||
else
|
||||
callback = callback_set_f0;
|
||||
|
||||
bpf_loop(1, callback, NULL, 0);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int stack_check_inner_callback(void *ctx)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int map1_lookup_elem(int key)
|
||||
{
|
||||
int *val = bpf_map_lookup_elem(&map1, &key);
|
||||
|
||||
return val ? *val : -1;
|
||||
}
|
||||
|
||||
static void map1_update_elem(int key, int val)
|
||||
{
|
||||
bpf_map_update_elem(&map1, &key, &val, BPF_ANY);
|
||||
}
|
||||
|
||||
static int stack_check_outer_callback(void *ctx)
|
||||
{
|
||||
int a = map1_lookup_elem(1);
|
||||
int b = map1_lookup_elem(2);
|
||||
int c = map1_lookup_elem(3);
|
||||
int d = map1_lookup_elem(4);
|
||||
int e = map1_lookup_elem(5);
|
||||
int f = map1_lookup_elem(6);
|
||||
|
||||
bpf_loop(1, stack_check_inner_callback, NULL, 0);
|
||||
|
||||
map1_update_elem(1, a + 1);
|
||||
map1_update_elem(2, b + 1);
|
||||
map1_update_elem(3, c + 1);
|
||||
map1_update_elem(4, d + 1);
|
||||
map1_update_elem(5, e + 1);
|
||||
map1_update_elem(6, f + 1);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* Some of the local variables in stack_check and
|
||||
* stack_check_outer_callback would be allocated on stack by
|
||||
* compiler. This test should verify that stack content for these
|
||||
* variables is preserved between calls to bpf_loop (might be an issue
|
||||
* if loop inlining allocates stack slots incorrectly).
|
||||
*/
|
||||
SEC("fentry/" SYS_PREFIX "sys_nanosleep")
|
||||
int stack_check(void *ctx)
|
||||
{
|
||||
if (bpf_get_current_pid_tgid() >> 32 != pid)
|
||||
return 0;
|
||||
|
||||
int a = map1_lookup_elem(7);
|
||||
int b = map1_lookup_elem(8);
|
||||
int c = map1_lookup_elem(9);
|
||||
int d = map1_lookup_elem(10);
|
||||
int e = map1_lookup_elem(11);
|
||||
int f = map1_lookup_elem(12);
|
||||
|
||||
bpf_loop(1, stack_check_outer_callback, NULL, 0);
|
||||
|
||||
map1_update_elem(7, a + 1);
|
||||
map1_update_elem(8, b + 1);
|
||||
map1_update_elem(9, c + 1);
|
||||
map1_update_elem(10, d + 1);
|
||||
map1_update_elem(11, e + 1);
|
||||
map1_update_elem(12, f + 1);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue