The bpf selftest xdp_adjust_tail/xdp_adjust_frags_tail_grow failed on
arm64 with 64KB page:
xdp_adjust_tail/xdp_adjust_frags_tail_grow:FAIL
In bpf_prog_test_run_xdp(), the xdp->frame_sz is set to 4K, but later on
when constructing frags, with 64K page size, the frag data_len could
be more than 4K. This will cause problems in bpf_xdp_frags_increase_tail().
To fix the failure, the xdp->frame_sz is set to be PAGE_SIZE so kernel
can test different page size properly. With the kernel change, the user
space and bpf prog needs adjustment. Currently, the MAX_SKB_FRAGS default
value is 17, so for 4K page, the maximum packet size will be less than 68K.
To test 64K page, a bigger maximum packet size than 68K is desired. So two
different functions are implemented for subtest xdp_adjust_frags_tail_grow.
Depending on different page size, different data input/output sizes are used
to adapt with different page size.
Signed-off-by: Yonghong Song <yonghong.song@xxxxxxxxx>
---
net/bpf/test_run.c | 2 +-
.../bpf/prog_tests/xdp_adjust_tail.c | 96 +++++++++++++++++--
.../bpf/progs/test_xdp_adjust_tail_grow.c | 8 +-
3 files changed, 97 insertions(+), 9 deletions(-)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index aaf13a7d58ed..9728dbd4c66c 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -1255,7 +1255,7 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
headroom -= ctx->data;
}
- max_data_sz = 4096 - headroom - tailroom;
+ max_data_sz = PAGE_SIZE - headroom - tailroom;
if (size > max_data_sz) {
/* disallow live data mode for jumbo frames */
if (do_live)
diff --git a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
index e361129402a1..43264347e7d7 100644
--- a/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
+++ b/tools/testing/selftests/bpf/prog_tests/xdp_adjust_tail.c
@@ -37,21 +37,26 @@ static void test_xdp_adjust_tail_shrink(void)
bpf_object__close(obj);
}
-static void test_xdp_adjust_tail_grow(void)
+static void test_xdp_adjust_tail_grow(bool is_64k_pagesize)
{
const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
struct bpf_object *obj;
- char buf[4096]; /* avoid segfault: large buf to hold grow results */
+ char buf[8192]; /* avoid segfault: large buf to hold grow results */
__u32 expect_sz;
int err, prog_fd;
LIBBPF_OPTS(bpf_test_run_opts, topts,
.data_in = &pkt_v4,
- .data_size_in = sizeof(pkt_v4),
.data_out = buf,
.data_size_out = sizeof(buf),
.repeat = 1,
);
+ /* topts.data_size_in as a special signal to bpf prog */
+ if (is_64k_pagesize)
+ topts.data_size_in = sizeof(pkt_v4) - 1;
+ else
+ topts.data_size_in = sizeof(pkt_v4);
+
err = bpf_prog_test_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd);
if (!ASSERT_OK(err, "test_xdp_adjust_tail_grow"))
return;
@@ -208,7 +213,7 @@ static void test_xdp_adjust_frags_tail_shrink(void)
bpf_object__close(obj);
}
-static void test_xdp_adjust_frags_tail_grow(void)
+static void test_xdp_adjust_frags_tail_grow_4k(void)
{
const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
__u32 exp_size;
@@ -279,16 +284,93 @@ static void test_xdp_adjust_frags_tail_grow(void)
bpf_object__close(obj);
}
+static void test_xdp_adjust_frags_tail_grow_64k(void)
+{
+ const char *file = "./test_xdp_adjust_tail_grow.bpf.o";
+ __u32 exp_size;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ int err, i, prog_fd;
+ __u8 *buf;
+ LIBBPF_OPTS(bpf_test_run_opts, topts);
+
+ obj = bpf_object__open(file);
+ if (libbpf_get_error(obj))
+ return;
+
+ prog = bpf_object__next_program(obj, NULL);
+ if (bpf_object__load(obj))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+
+ buf = malloc(262144);
+ if (!ASSERT_OK_PTR(buf, "alloc buf 256Kb"))
+ goto out;
+
+ /* Test case add 10 bytes to last frag */
+ memset(buf, 1, 262144);
+ exp_size = 90000 + 10;
+
+ topts.data_in = buf;
+ topts.data_out = buf;
+ topts.data_size_in = 90000;
+ topts.data_size_out = 262144;
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+
+ ASSERT_OK(err, "90Kb+10b");
+ ASSERT_EQ(topts.retval, XDP_TX, "90Kb+10b retval");
+ ASSERT_EQ(topts.data_size_out, exp_size, "90Kb+10b size");
+
+ for (i = 0; i < 90000; i++) {
+ if (buf[i] != 1)
+ ASSERT_EQ(buf[i], 1, "90Kb+10b-old");
+ }
+
+ for (i = 90000; i < 90010; i++) {
+ if (buf[i] != 0)
+ ASSERT_EQ(buf[i], 0, "90Kb+10b-new");
+ }
+
+ for (i = 90010; i < 262144; i++) {
+ if (buf[i] != 1)
+ ASSERT_EQ(buf[i], 1, "90Kb+10b-untouched");
+ }
+
+ /* Test a too large grow */
+ memset(buf, 1, 262144);
+ exp_size = 90001;
+
+ topts.data_in = topts.data_out = buf;
+ topts.data_size_in = 90001;
+ topts.data_size_out = 262144;
+ err = bpf_prog_test_run_opts(prog_fd, &topts);
+
+ ASSERT_OK(err, "90Kb+10b");
+ ASSERT_EQ(topts.retval, XDP_DROP, "90Kb+10b retval");
+ ASSERT_EQ(topts.data_size_out, exp_size, "90Kb+10b size");
+
+ free(buf);
+out:
+ bpf_object__close(obj);
+}
+
void test_xdp_adjust_tail(void)
{
+ int page_size = getpagesize();
+
if (test__start_subtest("xdp_adjust_tail_shrink"))
test_xdp_adjust_tail_shrink();
if (test__start_subtest("xdp_adjust_tail_grow"))
- test_xdp_adjust_tail_grow();
+ test_xdp_adjust_tail_grow(page_size == 65536);
if (test__start_subtest("xdp_adjust_tail_grow2"))
test_xdp_adjust_tail_grow2();
if (test__start_subtest("xdp_adjust_frags_tail_shrink"))
test_xdp_adjust_frags_tail_shrink();
- if (test__start_subtest("xdp_adjust_frags_tail_grow"))
- test_xdp_adjust_frags_tail_grow();
+ if (test__start_subtest("xdp_adjust_frags_tail_grow")) {
+ if (page_size == 65536)
+ test_xdp_adjust_frags_tail_grow_64k();
+ else
+ test_xdp_adjust_frags_tail_grow_4k();
+ }
}
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
index dc74d8cf9e3f..5904f45cfbc4 100644
--- a/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
+++ b/tools/testing/selftests/bpf/progs/test_xdp_adjust_tail_grow.c
@@ -19,7 +19,9 @@ int _xdp_adjust_tail_grow(struct xdp_md *xdp)
/* Data length determine test case */
if (data_len == 54) { /* sizeof(pkt_v4) */
- offset = 4096; /* test too large offset */
+ offset = 4096; /* test too large offset, 4k page size */
+ } else if (data_len == 53) { /* sizeof(pkt_v4) - 1 */
+ offset = 65536; /* test too large offset, 64k page size */
} else if (data_len == 74) { /* sizeof(pkt_v6) */
offset = 40;
} else if (data_len == 64) {
@@ -31,6 +33,10 @@ int _xdp_adjust_tail_grow(struct xdp_md *xdp)
offset = 10;
} else if (data_len == 9001) {
offset = 4096;
+ } else if (data_len == 90000) {
+ offset = 10; /* test a small offset, 64k page size */
+ } else if (data_len == 90001) {
+ offset = 65536; /* test too large offset, 64k page size */
} else {
return XDP_ABORTED; /* No matching test */
}
--
2.47.1
