From: Donglin Peng <pengdonglin@xiaomi.com>
This patch introduces test cases for the btf__permute function to ensure
it works correctly with both base BTF and split BTF scenarios.
The test suite includes:
- test_permute_base: Validates permutation on base BTF
- test_permute_split: Tests permutation on split BTF
- test_permute_drop_base: Validates type dropping on base BTF
- test_permute_drop_split: Tests type dropping on split BTF
- test_permute_drop_dedup: Tests type dropping and deduping
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Song Liu <song@kernel.org>
Cc: Xiaoqin Zhang <zhangxiaoqin@xiaomi.com>
Signed-off-by: Donglin Peng <pengdonglin@xiaomi.com>
---
.../selftests/bpf/prog_tests/btf_permute.c | 626 ++++++++++++++++++
1 file changed, 626 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/btf_permute.c
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_permute.c b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
new file mode 100644
index 000000000000..c1a47b8461ee
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2025 Xiaomi */
+
+#include <test_progs.h>
+#include <bpf/btf.h>
+#include "btf_helpers.h"
+
+/* Ensure btf__permute work as expected with base BTF */
+static void test_permute_base(void)
+{
+ struct btf *btf;
+ __u32 permute_ids[7];
+ int err;
+
+ btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
+ return;
+
+ btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
+ btf__add_ptr(btf, 1); /* [2] ptr to int */
+ btf__add_struct(btf, "s1", 4); /* [3] struct s1 { */
+ btf__add_field(btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_struct(btf, "s2", 4); /* [4] struct s2 { */
+ btf__add_field(btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_func_proto(btf, 1); /* [5] int (*)(int *p); */
+ btf__add_func_param(btf, "p", 2);
+ btf__add_func(btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] FUNC 'f' type_id=5 linkage=static");
+
+ permute_ids[0] = 0;
+ permute_ids[1] = 4; /* [1] -> [4] */
+ permute_ids[2] = 3; /* [2] -> [3] */
+ permute_ids[3] = 5; /* [3] -> [5] */
+ permute_ids[4] = 1; /* [4] -> [1] */
+ permute_ids[5] = 6; /* [5] -> [6] */
+ permute_ids[6] = 2; /* [6] -> [2] */
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_OK(err, "btf__permute_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[2] FUNC 'f' type_id=6 linkage=static",
+ "[3] PTR '(anon)' type_id=4",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=3");
+
+ /* For base BTF, id_map[0] must be 0 */
+ permute_ids[0] = 4;
+ permute_ids[1] = 0;
+ permute_ids[2] = 3;
+ permute_ids[3] = 5;
+ permute_ids[4] = 1;
+ permute_ids[5] = 6;
+ permute_ids[6] = 2;
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_ERR(err, "btf__permute_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[2] FUNC 'f' type_id=6 linkage=static",
+ "[3] PTR '(anon)' type_id=4",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=3");
+
+ /*
+ * For base BTF, id_map_cnt must equal to the number of types
+ * include VOID type
+ */
+ permute_ids[0] = 4;
+ permute_ids[1] = 0;
+ permute_ids[2] = 3;
+ permute_ids[3] = 5;
+ permute_ids[4] = 1;
+ permute_ids[5] = 6;
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids) - 1, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[2] FUNC 'f' type_id=6 linkage=static",
+ "[3] PTR '(anon)' type_id=4",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=3");
+
+ /* Multiple types can not be mapped to the same ID */
+ permute_ids[0] = 0;
+ permute_ids[1] = 4;
+ permute_ids[2] = 4;
+ permute_ids[3] = 5;
+ permute_ids[4] = 1;
+ permute_ids[5] = 6;
+ permute_ids[6] = 2;
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_ERR(err, "btf__permute_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[2] FUNC 'f' type_id=6 linkage=static",
+ "[3] PTR '(anon)' type_id=4",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=3");
+
+ /* Type ID must be valid */
+ permute_ids[0] = 0;
+ permute_ids[1] = 4;
+ permute_ids[2] = 3;
+ permute_ids[3] = 5;
+ permute_ids[4] = 1;
+ permute_ids[5] = 7;
+ permute_ids[6] = 2;
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_ERR(err, "btf__permute_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[2] FUNC 'f' type_id=6 linkage=static",
+ "[3] PTR '(anon)' type_id=4",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[6] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=3");
+
+done:
+ btf__free(btf);
+}
+
+/* Ensure btf__permute work as expected with split BTF */
+static void test_permute_split(void)
+{
+ struct btf *split_btf = NULL, *base_btf = NULL;
+ __u32 permute_ids[4];
+ int err;
+
+ base_btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(base_btf, "empty_main_btf"))
+ return;
+
+ btf__add_int(base_btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
+ btf__add_ptr(base_btf, 1); /* [2] ptr to int */
+ VALIDATE_RAW_BTF(
+ base_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1");
+ split_btf = btf__new_empty_split(base_btf);
+ if (!ASSERT_OK_PTR(split_btf, "empty_split_btf"))
+ goto cleanup;
+ btf__add_struct(split_btf, "s1", 4); /* [3] struct s1 { */
+ btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_struct(split_btf, "s2", 4); /* [4] struct s2 { */
+ btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_func_proto(split_btf, 1); /* [5] int (*)(int p); */
+ btf__add_func_param(split_btf, "p", 2);
+ btf__add_func(split_btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] FUNC 'f' type_id=5 linkage=static");
+
+ permute_ids[0] = 6; /* [3] -> [6] */
+ permute_ids[1] = 3; /* [4] -> [3] */
+ permute_ids[2] = 5; /* [5] -> [5] */
+ permute_ids[3] = 4; /* [6] -> [4] */
+ err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_OK(err, "btf__permute_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] FUNC 'f' type_id=5 linkage=static",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /*
+ * For split BTF, id_map_cnt must equal to the number of types
+ * added on top of base BTF
+ */
+ permute_ids[0] = 4;
+ permute_ids[1] = 3;
+ permute_ids[2] = 5;
+ permute_ids[3] = 6;
+ err = btf__permute(split_btf, permute_ids, 3, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] FUNC 'f' type_id=5 linkage=static",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /* Multiple types can not be mapped to the same ID */
+ permute_ids[0] = 4;
+ permute_ids[1] = 3;
+ permute_ids[2] = 3;
+ permute_ids[3] = 6;
+ err = btf__permute(split_btf, permute_ids, 4, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] FUNC 'f' type_id=5 linkage=static",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /* Can not map to base ID */
+ permute_ids[0] = 4;
+ permute_ids[1] = 2;
+ permute_ids[2] = 5;
+ permute_ids[3] = 6;
+ err = btf__permute(split_btf, permute_ids, 4, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] FUNC 'f' type_id=5 linkage=static",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+cleanup:
+ btf__free(split_btf);
+ btf__free(base_btf);
+}
+
+/* Verify btf__permute function drops types correctly with base_btf */
+static void test_permute_drop_base(void)
+{
+ struct btf *btf;
+ __u32 permute_ids[7];
+ int err;
+
+ btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
+ return;
+
+ btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
+ btf__add_ptr(btf, 1); /* [2] ptr to int */
+ btf__add_struct(btf, "s1", 4); /* [3] struct s1 { */
+ btf__add_field(btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_struct(btf, "s2", 4); /* [4] struct s2 { */
+ btf__add_field(btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_func_proto(btf, 1); /* [5] int (*)(int *p); */
+ btf__add_func_param(btf, "p", 2);
+ btf__add_func(btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] FUNC 'f' type_id=5 linkage=static");
+
+ /* Drop ID 4 */
+ permute_ids[0] = 0;
+ permute_ids[1] = 5; /* [1] -> [5] */
+ permute_ids[2] = 1; /* [2] -> [1] */
+ permute_ids[3] = 2; /* [3] -> [2] */
+ permute_ids[4] = 0; /* Drop [4] */
+ permute_ids[5] = 3; /* [5] -> [3] */
+ permute_ids[6] = 4; /* [6] -> [4] */
+ err = btf__permute(btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_base"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] PTR '(anon)' type_id=5",
+ "[2] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=5 bits_offset=0",
+ "[3] FUNC_PROTO '(anon)' ret_type_id=5 vlen=1\n"
+ "\t'p' type_id=1",
+ "[4] FUNC 'f' type_id=3 linkage=static",
+ "[5] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
+
+ /* Continue dropping */
+ permute_ids[0] = 0;
+ permute_ids[1] = 1; /* [1] -> [1] */
+ permute_ids[2] = 2; /* [2] -> [2] */
+ permute_ids[3] = 3; /* [3] -> [3] */
+ permute_ids[4] = 0; /* Drop [4] */
+ permute_ids[5] = 4; /* [5] -> [4] */
+ err = btf__permute(btf, permute_ids, 6, NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_base_fail"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] PTR '(anon)' type_id=4",
+ "[2] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[3] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=1",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
+
+ /* Cannot drop the ID referenced by others */
+ permute_ids[0] = 0;
+ permute_ids[1] = 2;
+ permute_ids[2] = 3;
+ permute_ids[3] = 1;
+ permute_ids[4] = 0; /* [4] is referenced by others */
+ err = btf__permute(btf, permute_ids, 5, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_drop_base_fail"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] PTR '(anon)' type_id=4",
+ "[2] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=4 bits_offset=0",
+ "[3] FUNC_PROTO '(anon)' ret_type_id=4 vlen=1\n"
+ "\t'p' type_id=1",
+ "[4] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
+
+ /* Drop 2 IDs at once */
+ permute_ids[0] = 0;
+ permute_ids[1] = 2; /* [1] -> [2] */
+ permute_ids[2] = 0; /* Drop [2] */
+ permute_ids[3] = 0; /* Drop [3] */
+ permute_ids[4] = 1; /* [4] -> [1] */
+ err = btf__permute(btf, permute_ids, 5, NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_base_fail"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1");
+
+ /* Drop all IDs */
+ permute_ids[0] = 0;
+ permute_ids[1] = 0; /* Drop [1] */
+ permute_ids[2] = 0; /* Drop [2] */
+ err = btf__permute(btf, permute_ids, 3, NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_base_fail"))
+ goto done;
+ if (!ASSERT_EQ(btf__type_cnt(btf), 0, "btf__permute_drop_split all"))
+ goto done;
+
+done:
+ btf__free(btf);
+}
+
+/* Verify btf__permute function drops types correctly with split BTF */
+static void test_permute_drop_split(void)
+{
+ struct btf *split_btf = NULL, *base_btf = NULL;
+ __u32 permute_ids[4];
+ int err;
+
+ base_btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(base_btf, "empty_main_btf"))
+ return;
+
+ btf__add_int(base_btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
+ btf__add_ptr(base_btf, 1); /* [2] ptr to int */
+ VALIDATE_RAW_BTF(
+ base_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1");
+ split_btf = btf__new_empty_split(base_btf);
+ if (!ASSERT_OK_PTR(split_btf, "empty_split_btf"))
+ goto cleanup;
+ btf__add_struct(split_btf, "s1", 4); /* [3] struct s1 { */
+ btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_struct(split_btf, "s2", 4); /* [4] struct s2 { */
+ btf__add_field(split_btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_func_proto(split_btf, 1); /* [5] int (*)(int p); */
+ btf__add_func_param(split_btf, "p", 2);
+ btf__add_func(split_btf, "f", BTF_FUNC_STATIC, 5); /* [6] int f(int *p); */
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[4] STRUCT 's2' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[5] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[6] FUNC 'f' type_id=5 linkage=static");
+
+ /* Drop ID 4 */
+ permute_ids[0] = 5; /* [3] -> [5] */
+ permute_ids[1] = 0; /* Drop [4] */
+ permute_ids[2] = 3; /* [5] -> [3] */
+ permute_ids[3] = 4; /* [6] -> [4] */
+ err = btf__permute(split_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[4] FUNC 'f' type_id=3 linkage=static",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /* Can not drop the type referenced by others */
+ permute_ids[0] = 0; /* [3] is referenced by [4] */
+ permute_ids[1] = 4;
+ permute_ids[2] = 3;
+ err = btf__permute(split_btf, permute_ids, 3, NULL);
+ if (!ASSERT_ERR(err, "btf__permute_drop_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
+ "\t'p' type_id=2",
+ "[4] FUNC 'f' type_id=3 linkage=static",
+ "[5] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /* Continue dropping */
+ permute_ids[0] = 0; /* Drop [3] */
+ permute_ids[1] = 0; /* Drop [4] */
+ permute_ids[2] = 3; /* [5] -> [3] */
+ err = btf__permute(split_btf, permute_ids, 3, NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1",
+ "[3] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0");
+
+ /* Continue dropping */
+ permute_ids[0] = 0; /* Drop [3] */
+ err = btf__permute(split_btf, permute_ids, 1, NULL);
+ if (!ASSERT_OK(err, "btf__permute_drop_split"))
+ goto cleanup;
+
+ VALIDATE_RAW_BTF(
+ split_btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] PTR '(anon)' type_id=1");
+
+cleanup:
+ btf__free(split_btf);
+ btf__free(base_btf);
+}
+
+/* Verify btf__permute then btf__dedup work correctly */
+static void test_permute_drop_dedup(void)
+{
+ struct btf *btf, *new_btf;
+ const struct btf_header *hdr;
+ const void *btf_data;
+ char expect_strs[] = "\0int\0s1\0m\0tag1\0tag2\0tag3";
+ char expect_strs_dedupped[] = "\0int\0s1\0m\0tag1";
+ __u32 permute_ids[6], btf_size;
+ int err;
+
+ btf = btf__new_empty();
+ if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
+ return;
+
+ btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
+ btf__add_struct(btf, "s1", 4); /* [2] struct s1 { */
+ btf__add_field(btf, "m", 1, 0, 0); /* int m; */
+ /* } */
+ btf__add_decl_tag(btf, "tag1", 2, -1); /* [3] tag -> s1: tag1 */
+ btf__add_decl_tag(btf, "tag2", 2, 1); /* [4] tag -> s1/m: tag2 */
+ btf__add_decl_tag(btf, "tag3", 2, 1); /* [5] tag -> s1/m: tag3 */
+
+ VALIDATE_RAW_BTF(
+ btf,
+ "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+ "[2] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=1 bits_offset=0",
+ "[3] DECL_TAG 'tag1' type_id=2 component_idx=-1",
+ "[4] DECL_TAG 'tag2' type_id=2 component_idx=1",
+ "[5] DECL_TAG 'tag3' type_id=2 component_idx=1");
+
+ btf_data = btf__raw_data(btf, &btf_size);
+ hdr = btf_data;
+ if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
+ goto done;
+
+ new_btf = btf__new(btf_data, btf_size);
+ if (!ASSERT_OK_PTR(new_btf, "btf__new"))
+ goto done;
+
+ /* Drop 2 IDs result in unreferenced strings */
+ permute_ids[0] = 0;
+ permute_ids[1] = 3; /* [1] -> [3] */
+ permute_ids[2] = 1; /* [2] -> [1] */
+ permute_ids[3] = 2; /* [3] -> [2] */
+ permute_ids[4] = 0; /* Drop result in unreferenced "tag2" */
+ permute_ids[5] = 0; /* Drop result in unreferenced "tag3" */
+ err = btf__permute(new_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
+ if (!ASSERT_OK(err, "btf__permute"))
+ goto done;
+
+ VALIDATE_RAW_BTF(
+ new_btf,
+ "[1] STRUCT 's1' size=4 vlen=1\n"
+ "\t'm' type_id=3 bits_offset=0",
+ "[2] DECL_TAG 'tag1' type_id=1 component_idx=-1",
+ "[3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
+
+ btf_data = btf__raw_data(new_btf, &btf_size);
+ hdr = btf_data;
+ if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
+ goto done;
+
+ err = btf__dedup(new_btf, NULL);
+ if (!ASSERT_OK(err, "btf__dedup"))
+ goto done;
+
+ btf_data = btf__raw_data(new_btf, &btf_size);
+ hdr = btf_data;
+ if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs_dedupped), "expect_strs_dedupped"))
+ goto done;
+
+done:
+ btf__free(btf);
+ btf__free(new_btf);
+}
+
+void test_btf_permute(void)
+{
+ if (test__start_subtest("permute_base"))
+ test_permute_base();
+ if (test__start_subtest("permute_split"))
+ test_permute_split();
+ if (test__start_subtest("permute_drop_base"))
+ test_permute_drop_base();
+ if (test__start_subtest("permute_drop_split"))
+ test_permute_drop_split();
+ if (test__start_subtest("permute_drop_dedup"))
+ test_permute_drop_dedup();
+}
--
2.34.1> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_permute.c b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
> new file mode 100644
> index 000000000..c1a47b846
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
[ ... ]
> @@ -0,0 +1,626 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Copyright (c) 2025 Xiaomi */
> +
> +#include <test_progs.h>
> +#include <bpf/btf.h>
> +#include "btf_helpers.h"
[ ... ]
> +/* Verify btf__permute then btf__dedup work correctly */
> +static void test_permute_drop_dedup(void)
> +{
> + struct btf *btf, *new_btf;
^^^^^^^^
Can this crash if the test fails before new_btf is initialized? Looking
at the declaration above, new_btf is uninitialized, and if ASSERT_EQ()
fails at line 570 before new_btf is assigned, the code jumps to the done
label which calls btf__free(new_btf). While btf__free() checks for NULL,
it doesn't protect against uninitialized garbage values and may
dereference an invalid pointer.
> + const struct btf_header *hdr;
> + const void *btf_data;
> + char expect_strs[] = "\0int\0s1\0m\0tag1\0tag2\0tag3";
> + char expect_strs_dedupped[] = "\0int\0s1\0m\0tag1";
> + __u32 permute_ids[6], btf_size;
> + int err;
> +
> + btf = btf__new_empty();
> + if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
> + return;
> +
> + btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
> + btf__add_struct(btf, "s1", 4); /* [2] struct s1 { */
> + btf__add_field(btf, "m", 1, 0, 0); /* int m; */
> + /* } */
> + btf__add_decl_tag(btf, "tag1", 2, -1); /* [3] tag -> s1: tag1 */
> + btf__add_decl_tag(btf, "tag2", 2, 1); /* [4] tag -> s1/m: tag2 */
> + btf__add_decl_tag(btf, "tag3", 2, 1); /* [5] tag -> s1/m: tag3 */
> +
> + VALIDATE_RAW_BTF(
> + btf,
> + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
> + "[2] STRUCT 's1' size=4 vlen=1\n"
> + "\t'm' type_id=1 bits_offset=0",
> + "[3] DECL_TAG 'tag1' type_id=2 component_idx=-1",
> + "[4] DECL_TAG 'tag2' type_id=2 component_idx=1",
> + "[5] DECL_TAG 'tag3' type_id=2 component_idx=1");
> +
> + btf_data = btf__raw_data(btf, &btf_size);
> + hdr = btf_data;
> + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
^^^^^^^^^^^^^^
Does this need a NULL check for btf_data? The btf__raw_data() function
can return NULL on allocation failure (returns NULL at btf.c:1596), and
dereferencing hdr->str_len without checking would cause a segfault and
crash the test program.
> + goto done;
> +
> + new_btf = btf__new(btf_data, btf_size);
> + if (!ASSERT_OK_PTR(new_btf, "btf__new"))
> + goto done;
> +
> + /* Drop 2 IDs result in unreferenced strings */
> + permute_ids[0] = 0;
> + permute_ids[1] = 3; /* [1] -> [3] */
> + permute_ids[2] = 1; /* [2] -> [1] */
> + permute_ids[3] = 2; /* [3] -> [2] */
> + permute_ids[4] = 0; /* Drop result in unreferenced "tag2" */
> + permute_ids[5] = 0; /* Drop result in unreferenced "tag3" */
> + err = btf__permute(new_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
> + if (!ASSERT_OK(err, "btf__permute"))
> + goto done;
> +
> + VALIDATE_RAW_BTF(
> + new_btf,
> + "[1] STRUCT 's1' size=4 vlen=1\n"
> + "\t'm' type_id=3 bits_offset=0",
> + "[2] DECL_TAG 'tag1' type_id=1 component_idx=-1",
> + "[3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
> +
> + btf_data = btf__raw_data(new_btf, &btf_size);
> + hdr = btf_data;
> + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
^^^^^^^^^^^^^^
Same NULL check issue here with btf__raw_data().
> + goto done;
> +
> + err = btf__dedup(new_btf, NULL);
> + if (!ASSERT_OK(err, "btf__dedup"))
> + goto done;
> +
> + btf_data = btf__raw_data(new_btf, &btf_size);
> + hdr = btf_data;
> + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs_dedupped), "expect_strs_dedupped"))
^^^^^^^^^^^^^^
And again here.
> + goto done;
> +
> +done:
> + btf__free(btf);
> + btf__free(new_btf);
> +}
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19359945665
On Fri, Nov 14, 2025 at 5:39 PM <bot+bpf-ci@kernel.org> wrote:
>
> > diff --git a/tools/testing/selftests/bpf/prog_tests/btf_permute.c b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
> > new file mode 100644
> > index 000000000..c1a47b846
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/prog_tests/btf_permute.c
>
> [ ... ]
>
> > @@ -0,0 +1,626 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright (c) 2025 Xiaomi */
> > +
> > +#include <test_progs.h>
> > +#include <bpf/btf.h>
> > +#include "btf_helpers.h"
>
> [ ... ]
>
> > +/* Verify btf__permute then btf__dedup work correctly */
> > +static void test_permute_drop_dedup(void)
> > +{
> > + struct btf *btf, *new_btf;
> ^^^^^^^^
> Can this crash if the test fails before new_btf is initialized? Looking
> at the declaration above, new_btf is uninitialized, and if ASSERT_EQ()
> fails at line 570 before new_btf is assigned, the code jumps to the done
> label which calls btf__free(new_btf). While btf__free() checks for NULL,
> it doesn't protect against uninitialized garbage values and may
> dereference an invalid pointer.
Thanks, I will fix it.
>
> > + const struct btf_header *hdr;
> > + const void *btf_data;
> > + char expect_strs[] = "\0int\0s1\0m\0tag1\0tag2\0tag3";
> > + char expect_strs_dedupped[] = "\0int\0s1\0m\0tag1";
> > + __u32 permute_ids[6], btf_size;
> > + int err;
> > +
> > + btf = btf__new_empty();
> > + if (!ASSERT_OK_PTR(btf, "empty_main_btf"))
> > + return;
> > +
> > + btf__add_int(btf, "int", 4, BTF_INT_SIGNED); /* [1] int */
> > + btf__add_struct(btf, "s1", 4); /* [2] struct s1 { */
> > + btf__add_field(btf, "m", 1, 0, 0); /* int m; */
> > + /* } */
> > + btf__add_decl_tag(btf, "tag1", 2, -1); /* [3] tag -> s1: tag1 */
> > + btf__add_decl_tag(btf, "tag2", 2, 1); /* [4] tag -> s1/m: tag2 */
> > + btf__add_decl_tag(btf, "tag3", 2, 1); /* [5] tag -> s1/m: tag3 */
> > +
> > + VALIDATE_RAW_BTF(
> > + btf,
> > + "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
> > + "[2] STRUCT 's1' size=4 vlen=1\n"
> > + "\t'm' type_id=1 bits_offset=0",
> > + "[3] DECL_TAG 'tag1' type_id=2 component_idx=-1",
> > + "[4] DECL_TAG 'tag2' type_id=2 component_idx=1",
> > + "[5] DECL_TAG 'tag3' type_id=2 component_idx=1");
> > +
> > + btf_data = btf__raw_data(btf, &btf_size);
> > + hdr = btf_data;
> > + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
> ^^^^^^^^^^^^^^
> Does this need a NULL check for btf_data? The btf__raw_data() function
> can return NULL on allocation failure (returns NULL at btf.c:1596), and
> dereferencing hdr->str_len without checking would cause a segfault and
> crash the test program.
Thanks, I will fix it.
>
> > + goto done;
> > +
> > + new_btf = btf__new(btf_data, btf_size);
> > + if (!ASSERT_OK_PTR(new_btf, "btf__new"))
> > + goto done;
> > +
> > + /* Drop 2 IDs result in unreferenced strings */
> > + permute_ids[0] = 0;
> > + permute_ids[1] = 3; /* [1] -> [3] */
> > + permute_ids[2] = 1; /* [2] -> [1] */
> > + permute_ids[3] = 2; /* [3] -> [2] */
> > + permute_ids[4] = 0; /* Drop result in unreferenced "tag2" */
> > + permute_ids[5] = 0; /* Drop result in unreferenced "tag3" */
> > + err = btf__permute(new_btf, permute_ids, ARRAY_SIZE(permute_ids), NULL);
> > + if (!ASSERT_OK(err, "btf__permute"))
> > + goto done;
> > +
> > + VALIDATE_RAW_BTF(
> > + new_btf,
> > + "[1] STRUCT 's1' size=4 vlen=1\n"
> > + "\t'm' type_id=3 bits_offset=0",
> > + "[2] DECL_TAG 'tag1' type_id=1 component_idx=-1",
> > + "[3] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
> > +
> > + btf_data = btf__raw_data(new_btf, &btf_size);
> > + hdr = btf_data;
> > + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs), "expect_strs"))
> ^^^^^^^^^^^^^^
> Same NULL check issue here with btf__raw_data().
Thanks, I will fix it.
>
> > + goto done;
> > +
> > + err = btf__dedup(new_btf, NULL);
> > + if (!ASSERT_OK(err, "btf__dedup"))
> > + goto done;
> > +
> > + btf_data = btf__raw_data(new_btf, &btf_size);
> > + hdr = btf_data;
> > + if (!ASSERT_EQ(hdr->str_len, ARRAY_SIZE(expect_strs_dedupped), "expect_strs_dedupped"))
> ^^^^^^^^^^^^^^
> And again here.
Thanks, I will fix it.
>
> > + goto done;
> > +
> > +done:
> > + btf__free(btf);
> > + btf__free(new_btf);
> > +}
>
>
> ---
> AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
> See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
>
> CI run summary: https://github.com/kernel-patches/bpf/actions/runs/19359945665
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