selftests/bpf: Fix xdp_pull_data failure with 64K page

If the argument 'pull_len' of run_test() is 'PULL_MAX' or
'PULL_MAX | PULL_PLUS_ONE', the eventual pull_len size
will close to the page size. On arm64 systems with 64K pages,
the pull_len size will be close to 64K. But the existing buffer
will be close to 9000 which is not enough to pull.

For those failed run_tests(), make buff size to
  pg_sz + (pg_sz / 2)
This way, there will be enough buffer space to pull
regardless of page size.

Tested-by: Alan Maguire <[email protected]>
Cc: Amery Hung <[email protected]>
Signed-off-by: Yonghong Song <[email protected]>

Author: Yonghong Song

tools/testing/selftests/bpf/prog_tests/xdp_pull_data.c

@@ -114,12 +114,14 @@ static void test_xdp_pull_data_basic(void)
 {
 	u32 pg_sz, max_meta_len, max_data_len;
 	struct test_xdp_pull_data *skel;
+	int buff_len;
 
 	skel = test_xdp_pull_data__open_and_load();
 	if (!ASSERT_OK_PTR(skel, "test_xdp_pull_data__open_and_load"))
 		return;
 
 	pg_sz = sysconf(_SC_PAGE_SIZE);
+	buff_len = pg_sz + pg_sz / 2;
 
 	if (find_xdp_sizes(skel, pg_sz))
 		goto out;
@@ -140,32 +142,32 @@ static void test_xdp_pull_data_basic(void)
 	run_test(skel, XDP_PASS, pg_sz, 9000, 0, 1025, 1025);
 
 	/* multi-buf pkt, empty linear data area, pull requires memmove */
-	run_test(skel, XDP_PASS, pg_sz, 9000, 0, 0, PULL_MAX);
+	run_test(skel, XDP_PASS, pg_sz, buff_len, 0, 0, PULL_MAX);
 
 	/* multi-buf pkt, no headroom */
-	run_test(skel, XDP_PASS, pg_sz, 9000, max_meta_len, 1024, PULL_MAX);
+	run_test(skel, XDP_PASS, pg_sz, buff_len, max_meta_len, 1024, PULL_MAX);
 
 	/* multi-buf pkt, no tailroom, pull requires memmove */
-	run_test(skel, XDP_PASS, pg_sz, 9000, 0, max_data_len, PULL_MAX);
+	run_test(skel, XDP_PASS, pg_sz, buff_len, 0, max_data_len, PULL_MAX);
 
 	/* Test cases with invalid pull length */
 
 	/* linear xdp pkt, pull more than total data len */
 	run_test(skel, XDP_DROP, pg_sz, 2048, 0, 2048, 2049);
 
 	/* multi-buf pkt with no space left in linear data area */
-	run_test(skel, XDP_DROP, pg_sz, 9000, max_meta_len, max_data_len,
+	run_test(skel, XDP_DROP, pg_sz, buff_len, max_meta_len, max_data_len,
 		 PULL_MAX | PULL_PLUS_ONE);
 
 	/* multi-buf pkt, empty linear data area */
-	run_test(skel, XDP_DROP, pg_sz, 9000, 0, 0, PULL_MAX | PULL_PLUS_ONE);
+	run_test(skel, XDP_DROP, pg_sz, buff_len, 0, 0, PULL_MAX | PULL_PLUS_ONE);
 
 	/* multi-buf pkt, no headroom */
-	run_test(skel, XDP_DROP, pg_sz, 9000, max_meta_len, 1024,
+	run_test(skel, XDP_DROP, pg_sz, buff_len, max_meta_len, 1024,
 		 PULL_MAX | PULL_PLUS_ONE);
 
 	/* multi-buf pkt, no tailroom */
-	run_test(skel, XDP_DROP, pg_sz, 9000, 0, max_data_len,
+	run_test(skel, XDP_DROP, pg_sz, buff_len, 0, max_data_len,
 		 PULL_MAX | PULL_PLUS_ONE);
 
 out: