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

Source file repositories/reference/linux-study-clean/tools/testing/selftests/bpf/prog_tests/btf_permute.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/bpf/prog_tests/btf_permute.c
Extension
.c
Size
7602 bytes
Lines
245
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2026 Xiaomi */

#include <test_progs.h>
#include <bpf/btf.h>
#include "btf_helpers.h"

static void permute_base_check(struct btf *btf)
{
	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");
}

/* Ensure btf__permute works as expected in the base-BTF scenario */
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; /* [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;
	permute_base_check(btf);

	/* ids[0] must be 0 for base BTF */
	permute_ids[0] = 4; /* [0] -> [0] */
	permute_ids[1] = 0; /* [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_ERR(err, "btf__permute_base"))
		goto done;
	/* BTF is not modified */
	permute_base_check(btf);

	/* id_map_cnt is invalid */
	permute_ids[0] = 0; /* [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] */

Annotation

Implementation Notes