On Nov 2, 2020, at 10:05 PM, Andrii Nakryiko [off-list ref] wrote:

On Mon, Nov 2, 2020 at 9:35 PM Song Liu [off-list ref] wrote:

quoted

quoted

On Oct 28, 2020, at 5:59 PM, Andrii Nakryiko [off-list ref] wrote:

Add selftests validating BTF deduplication for split BTF case. Add a helper
macro that allows to validate entire BTF with raw BTF dump, not just
type-by-type. This saves tons of code and complexity.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>

Acked-by: Song Liu <redacted>

with a couple nits:

[...]

quoted

int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id);
const char *btf_type_raw_dump(const struct btf *btf, int type_id);
+int btf_validate_raw(struct btf *btf, int nr_types, const char *exp_types[]);

+#define VALIDATE_RAW_BTF(btf, raw_types...)                          \
+     btf_validate_raw(btf,                                           \
+                      sizeof((const char *[]){raw_types})/sizeof(void *),\
+                      (const char *[]){raw_types})
+
+const char *btf_type_c_dump(const struct btf *btf);
#endif

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
new file mode 100644
index 000000000000..097370a41b60
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c

@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+#include <test_progs.h>
+#include <bpf/btf.h>
+#include "btf_helpers.h"
+
+
+static void test_split_simple() {
+     const struct btf_type *t;
+     struct btf *btf1, *btf2 = NULL;
+     int str_off, err;
+
+     btf1 = btf__new_empty();
+     if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
+             return;
+
+     btf__set_pointer_size(btf1, 8); /* enforce 64-bit arch */
+
+     btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
+     btf__add_ptr(btf1, 1);                          /* [2] ptr to int */
+     btf__add_struct(btf1, "s1", 4);                 /* [3] struct s1 { */
+     btf__add_field(btf1, "f1", 1, 0, 0);            /*      int f1; */
+                                                     /* } */
+

nit: two empty lines.

There is a comment on one of them, so I figured it's not an empty line?

Exactly! I missed that one. 

[...]