Re: [PATCH v3 4/4] bpf: add tests for ints larger than 128 bits

clang supports arbitrary length ints using the _ExtInt extension. This
can be useful to hold very large values, e.g. 256 bit or 512 bit types.

Larger types (e.g. 1024 bits) are possible but I am unaware of a use
case for these.

This requires the _ExtInt extension enabled in clang, which is under
review.

Link: https://clang.llvm.org/docs/LanguageExtensions.html#extended-integer-types
Link: https://reviews.llvm.org/D93103

Signed-off-by: Sean Young <sean@mess.org>
---
 tools/testing/selftests/bpf/Makefile          |   3 +-
 tools/testing/selftests/bpf/prog_tests/btf.c  |   3 +-
 .../selftests/bpf/progs/test_btf_extint.c     |  50 ++
 tools/testing/selftests/bpf/test_extint.py    | 535 ++++++++++++++++++
 4 files changed, 589 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/test_btf_extint.c
 create mode 100755 tools/testing/selftests/bpf/test_extint.py

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 8c33e999319a..436ad1aed3d9 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile

@@ -70,7 +70,8 @@ TEST_PROGS := test_kmod.sh \
        test_bpftool_build.sh \
        test_bpftool.sh \
        test_bpftool_metadata.sh \
-       test_xsk.sh
+       test_xsk.sh \
+       test_extint.py

 TEST_PROGS_EXTENDED := with_addr.sh \
        with_tunnels.sh \

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 8ae97e2a4b9d..96a93502cf27 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c

@@ -4073,6 +4073,7 @@ struct btf_file_test {
 static struct btf_file_test file_tests[] = {
        { .file = "test_btf_haskv.o", },
        { .file = "test_btf_newkv.o", },
+       { .file = "test_btf_extint.o", },
        { .file = "test_btf_nokv.o", .btf_kv_notfound = true, },
 };

@@ -4414,7 +4415,7 @@ static struct btf_raw_test pprint_test_template[] = {
         * will have both int and enum types.
         */
        .raw_types = {
-               /* unsighed char */                     /* [1] */
+               /* unsigned char */                     /* [1] */

                BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 8, 1),
                /* unsigned short */                    /* [2] */
                BTF_TYPE_INT_ENC(NAME_TBD, 0, 0, 16, 2),

diff --git a/tools/testing/selftests/bpf/progs/test_btf_extint.c b/tools/testing/selftests/bpf/progs/test_btf_extint.c
new file mode 100644
index 000000000000..b0fa9f130dda
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_btf_extint.c

@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct extint {
+       _ExtInt(256) v256;
+       _ExtInt(512) v512;
+};
+
+struct bpf_map_def SEC("maps") btf_map = {
+       .type = BPF_MAP_TYPE_ARRAY,
+       .key_size = sizeof(int),
+       .value_size = sizeof(struct extint),
+       .max_entries = 1,
+};
+
+BPF_ANNOTATE_KV_PAIR(btf_map, int, struct extint);

+
+char _license[] SEC("license") = "GPL";

diff --git a/tools/testing/selftests/bpf/test_extint.py b/tools/testing/selftests/bpf/test_extint.py
new file mode 100755
index 000000000000..86af815a0cf6
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_extint.py

@@ -0,0 +1,535 @@
+#!/usr/bin/python3