Quelle  btf_distill.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2024, Oracle and/or its affiliates. */

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

/* Fabricate base, split BTF with references to base types needed; then create
 * split BTF with distilled base BTF and ensure expectations are met:
 *  - only referenced base types from split BTF are present
 *  - struct/union/enum are represented as empty unless anonymous, when they
 *    are represented in full in split BTF
 */
static void test_distilled_base(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;

 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", 8);   /* [3] struct s1 { */
 btf__add_field(btf1, "f1", 2, 0, 0);  /*      int *f1; */
       /* } */
 btf__add_struct(btf1, "", 12);   /* [4] struct { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
 btf__add_field(btf1, "f2", 3, 32, 0);  /* struct s1 f2; */
       /* } */
 btf__add_int(btf1, "unsigned int", 4, 0); /* [5] unsigned int */
 btf__add_union(btf1, "u1", 12);   /* [6] union u1 { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
 btf__add_field(btf1, "f2", 2, 0, 0);  /* int *f2; */
       /* } */
 btf__add_union(btf1, "", 4);   /* [7] union { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
       /* } */
 btf__add_enum(btf1, "e1", 4);   /* [8] enum e1 { */
 btf__add_enum_value(btf1, "v1", 1);  /* v1 = 1; */
       /* } */
 btf__add_enum(btf1, "", 4);   /* [9] enum { */
 btf__add_enum_value(btf1, "av1", 2);  /* av1 = 2; */
       /* } */
 btf__add_enum64(btf1, "e641", 8, true);  /* [10] enum64 { */
 btf__add_enum64_value(btf1, "v1", 1024); /* v1 = 1024; */
       /* } */
 btf__add_enum64(btf1, "", 8, true);  /* [11] enum64 { */
 btf__add_enum64_value(btf1, "v1", 1025); /* v1 = 1025; */
       /* } */
 btf__add_struct(btf1, "unneeded", 4);  /* [12] struct unneeded { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
       /* } */
 btf__add_struct(btf1, "embedded", 4);  /* [13] struct embedded { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
       /* } */
 btf__add_func_proto(btf1, 1);   /* [14] int (*)(int *p1); */
 btf__add_func_param(btf1, "p1", 1);

 btf__add_array(btf1, 1, 1, 3);   /* [15] int [3]; */

 btf__add_struct(btf1, "from_proto", 4);  /* [16] struct from_proto { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /* int f1; */
       /* } */
 btf__add_union(btf1, "u1", 4);   /* [17] union u1 { */
 btf__add_field(btf1, "f1", 1, 0, 0);  /*  int f1; */
       /* } */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1",
  "[3] STRUCT 's1' size=8 vlen=1\n"
  "\t'f1' type_id=2 bits_offset=0",
  "[4] STRUCT '(anon)' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=3 bits_offset=32",
  "[5] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none)",
  "[6] UNION 'u1' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=2 bits_offset=0",
  "[7] UNION '(anon)' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[8] ENUM 'e1' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'v1' val=1",
  "[9] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'av1' val=2",
  "[10] ENUM64 'e641' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1024",
  "[11] ENUM64 '(anon)' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1025",
  "[12] STRUCT 'unneeded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[13] STRUCT 'embedded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[14] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=1",
  "[15] ARRAY '(anon)' type_id=1 index_type_id=1 nr_elems=3",
  "[16] STRUCT 'from_proto' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[17] UNION 'u1' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0");

 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;

 btf__add_ptr(btf2, 3);    /* [18] ptr to struct s1 */
 /* add ptr to struct anon */
 btf__add_ptr(btf2, 4);    /* [19] ptr to struct (anon) */
 btf__add_const(btf2, 6);   /* [20] const union u1 */
 btf__add_restrict(btf2, 7);   /* [21] restrict union (anon) */
 btf__add_volatile(btf2, 8);   /* [22] volatile enum e1 */
 btf__add_typedef(btf2, "et", 9);  /* [23] typedef enum (anon) */
 btf__add_const(btf2, 10);   /* [24] const enum64 e641 */
 btf__add_ptr(btf2, 11);    /* [25] restrict enum64 (anon) */
 btf__add_struct(btf2, "with_embedded", 4); /* [26] struct with_embedded { */
 btf__add_field(btf2, "f1", 13, 0, 0);  /* struct embedded f1; */
       /* } */
 btf__add_func(btf2, "fn", BTF_FUNC_STATIC, 14); /* [27] int fn(int p1); */
 btf__add_typedef(btf2, "arraytype", 15); /* [28] typedef int[3] foo; */
 btf__add_func_proto(btf2, 1);   /* [29] int (*)(struct from proto p1); */
 btf__add_func_param(btf2, "p1", 16);

 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1",
  "[3] STRUCT 's1' size=8 vlen=1\n"
  "\t'f1' type_id=2 bits_offset=0",
  "[4] STRUCT '(anon)' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=3 bits_offset=32",
  "[5] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none)",
  "[6] UNION 'u1' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=2 bits_offset=0",
  "[7] UNION '(anon)' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[8] ENUM 'e1' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'v1' val=1",
  "[9] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'av1' val=2",
  "[10] ENUM64 'e641' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1024",
  "[11] ENUM64 '(anon)' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1025",
  "[12] STRUCT 'unneeded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[13] STRUCT 'embedded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[14] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=1",
  "[15] ARRAY '(anon)' type_id=1 index_type_id=1 nr_elems=3",
  "[16] STRUCT 'from_proto' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[17] UNION 'u1' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[18] PTR '(anon)' type_id=3",
  "[19] PTR '(anon)' type_id=4",
  "[20] CONST '(anon)' type_id=6",
  "[21] RESTRICT '(anon)' type_id=7",
  "[22] VOLATILE '(anon)' type_id=8",
  "[23] TYPEDEF 'et' type_id=9",
  "[24] CONST '(anon)' type_id=10",
  "[25] PTR '(anon)' type_id=11",
  "[26] STRUCT 'with_embedded' size=4 vlen=1\n"
  "\t'f1' type_id=13 bits_offset=0",
  "[27] FUNC 'fn' type_id=14 linkage=static",
  "[28] TYPEDEF 'arraytype' type_id=15",
  "[29] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=16");

 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(8, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;

 VALIDATE_RAW_BTF(
  btf4,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] STRUCT 's1' size=8 vlen=0",
  "[3] UNION 'u1' size=12 vlen=0",
  "[4] ENUM 'e1' encoding=UNSIGNED size=4 vlen=0",
  "[5] ENUM 'e641' encoding=UNSIGNED size=8 vlen=0",
  "[6] STRUCT 'embedded' size=4 vlen=0",
  "[7] STRUCT 'from_proto' size=4 vlen=0",
  /* split BTF; these types should match split BTF above from 17-28, with
 * updated type id references
 */
  "[8] PTR '(anon)' type_id=2",
  "[9] PTR '(anon)' type_id=20",
  "[10] CONST '(anon)' type_id=3",
  "[11] RESTRICT '(anon)' type_id=21",
  "[12] VOLATILE '(anon)' type_id=4",
  "[13] TYPEDEF 'et' type_id=22",
  "[14] CONST '(anon)' type_id=5",
  "[15] PTR '(anon)' type_id=23",
  "[16] STRUCT 'with_embedded' size=4 vlen=1\n"
  "\t'f1' type_id=6 bits_offset=0",
  "[17] FUNC 'fn' type_id=24 linkage=static",
  "[18] TYPEDEF 'arraytype' type_id=25",
  "[19] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=7",
  /* split BTF types added from original base BTF below */
  "[20] STRUCT '(anon)' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=2 bits_offset=32",
  "[21] UNION '(anon)' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[22] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'av1' val=2",
  "[23] ENUM64 '(anon)' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1025",
  "[24] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=1",
  "[25] ARRAY '(anon)' type_id=1 index_type_id=1 nr_elems=3");

 if (!ASSERT_EQ(btf__relocate(btf4, btf1), 0, "relocate_split"))
  goto cleanup;

 VALIDATE_RAW_BTF(
  btf4,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1",
  "[3] STRUCT 's1' size=8 vlen=1\n"
  "\t'f1' type_id=2 bits_offset=0",
  "[4] STRUCT '(anon)' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=3 bits_offset=32",
  "[5] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none)",
  "[6] UNION 'u1' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=2 bits_offset=0",
  "[7] UNION '(anon)' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[8] ENUM 'e1' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'v1' val=1",
  "[9] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'av1' val=2",
  "[10] ENUM64 'e641' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1024",
  "[11] ENUM64 '(anon)' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1025",
  "[12] STRUCT 'unneeded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[13] STRUCT 'embedded' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[14] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=1",
  "[15] ARRAY '(anon)' type_id=1 index_type_id=1 nr_elems=3",
  "[16] STRUCT 'from_proto' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[17] UNION 'u1' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[18] PTR '(anon)' type_id=3",
  "[19] PTR '(anon)' type_id=30",
  "[20] CONST '(anon)' type_id=6",
  "[21] RESTRICT '(anon)' type_id=31",
  "[22] VOLATILE '(anon)' type_id=8",
  "[23] TYPEDEF 'et' type_id=32",
  "[24] CONST '(anon)' type_id=10",
  "[25] PTR '(anon)' type_id=33",
  "[26] STRUCT 'with_embedded' size=4 vlen=1\n"
  "\t'f1' type_id=13 bits_offset=0",
  "[27] FUNC 'fn' type_id=34 linkage=static",
  "[28] TYPEDEF 'arraytype' type_id=35",
  "[29] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=16",
  /* below here are (duplicate) anon base types added by distill
 * process to split BTF.
 */
  "[30] STRUCT '(anon)' size=12 vlen=2\n"
  "\t'f1' type_id=1 bits_offset=0\n"
  "\t'f2' type_id=3 bits_offset=32",
  "[31] UNION '(anon)' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[32] ENUM '(anon)' encoding=UNSIGNED size=4 vlen=1\n"
  "\t'av1' val=2",
  "[33] ENUM64 '(anon)' encoding=SIGNED size=8 vlen=1\n"
  "\t'v1' val=1025",
  "[34] FUNC_PROTO '(anon)' ret_type_id=1 vlen=1\n"
  "\t'p1' type_id=1",
  "[35] ARRAY '(anon)' type_id=1 index_type_id=1 nr_elems=3");

cleanup:
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

/* ensure we can cope with multiple types with the same name in
 * distilled base BTF.  In this case because sizes are different,
 * we can still disambiguate them.
 */
static void test_distilled_base_multi(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;
 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 btf__add_int(btf1, "int", 8, BTF_INT_SIGNED); /* [2] int */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED");
 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;
 btf__add_ptr(btf2, 1);
 btf__add_const(btf2, 2);
 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED",
  "[3] PTR '(anon)' type_id=1",
  "[4] CONST '(anon)' type_id=2");
 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(3, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  btf3,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED");
 if (!ASSERT_EQ(btf__relocate(btf4, btf1), 0, "relocate_split"))
  goto cleanup;

 VALIDATE_RAW_BTF(
  btf4,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED",
  "[3] PTR '(anon)' type_id=1",
  "[4] CONST '(anon)' type_id=2");

cleanup:
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

/* If a needed type is not present in the base BTF we wish to relocate
 * with, btf__relocate() should error our.
 */
static void test_distilled_base_missing_err(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL, *btf5 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;
 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 btf__add_int(btf1, "int", 8, BTF_INT_SIGNED);   /* [2] int */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED");
 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;
 btf__add_ptr(btf2, 1);
 btf__add_const(btf2, 2);
 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED",
  "[3] PTR '(anon)' type_id=1",
  "[4] CONST '(anon)' type_id=2");
 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(3, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  btf3,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=8 bits_offset=0 nr_bits=64 encoding=SIGNED");
 btf5 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf5, "empty_reloc_btf"))
  goto cleanup;
 btf__add_int(btf5, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 VALIDATE_RAW_BTF(
  btf5,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 ASSERT_EQ(btf__relocate(btf4, btf5), -EINVAL, "relocate_split");

cleanup:
 btf__free(btf5);
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

/* With 2 types of same size in distilled base BTF, relocation should
 * fail as we have no means to choose between them.
 */
static void test_distilled_base_multi_err(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;
 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [2] int */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;
 btf__add_ptr(btf2, 1);
 btf__add_const(btf2, 2);
 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[3] PTR '(anon)' type_id=1",
  "[4] CONST '(anon)' type_id=2");
 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(3, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  btf3,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 ASSERT_EQ(btf__relocate(btf4, btf1), -EINVAL, "relocate_split");
cleanup:
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

/* With 2 types of same size in base BTF, relocation should
 * fail as we have no means to choose between them.
 */
static void test_distilled_base_multi_err2(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL, *btf5 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;
 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;
 btf__add_ptr(btf2, 1);
 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1");
 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(2, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  btf3,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 btf5 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf5, "empty_reloc_btf"))
  goto cleanup;
 btf__add_int(btf5, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 btf__add_int(btf5, "int", 4, BTF_INT_SIGNED);   /* [2] int */
 VALIDATE_RAW_BTF(
  btf5,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 ASSERT_EQ(btf__relocate(btf4, btf5), -EINVAL, "relocate_split");
cleanup:
 btf__free(btf5);
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

/* create split reference BTF from vmlinux + split BTF with a few type references;
 * ensure the resultant split reference BTF is as expected, containing only types
 * needed to disambiguate references from split BTF.
 */
static void test_distilled_base_vmlinux(void)
{
 struct btf *split_btf = NULL, *vmlinux_btf = btf__load_vmlinux_btf();
 struct btf *split_dist = NULL, *base_dist = NULL;
 __s32 int_id, myint_id;

 if (!ASSERT_OK_PTR(vmlinux_btf, "load_vmlinux"))
  return;
 int_id = btf__find_by_name_kind(vmlinux_btf, "int", BTF_KIND_INT);
 if (!ASSERT_GT(int_id, 0, "find_int"))
  goto cleanup;
 split_btf = btf__new_empty_split(vmlinux_btf);
 if (!ASSERT_OK_PTR(split_btf, "new_split"))
  goto cleanup;
 myint_id = btf__add_typedef(split_btf, "myint", int_id);
 btf__add_ptr(split_btf, myint_id);

 if (!ASSERT_EQ(btf__distill_base(split_btf, &base_dist, &split_dist), 0,
         "distill_vmlinux_base"))
  goto cleanup;

 if (!ASSERT_OK_PTR(split_dist, "split_distilled") ||
     !ASSERT_OK_PTR(base_dist, "base_dist"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  split_dist,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] TYPEDEF 'myint' type_id=1",
  "[3] PTR '(anon)' type_id=2");

cleanup:
 btf__free(split_dist);
 btf__free(base_dist);
 btf__free(split_btf);
 btf__free(vmlinux_btf);
}

/* Split and new base BTFs should inherit endianness from source BTF. */
static void test_distilled_endianness(void)
{
 struct btf *base = NULL, *split = NULL, *new_base = NULL, *new_split = NULL;
 struct btf *new_base1 = NULL, *new_split1 = NULL;
 enum btf_endianness inverse_endianness;
 const void *raw_data;
 __u32 size;

 base = btf__new_empty();
 if (!ASSERT_OK_PTR(base, "empty_main_btf"))
  return;
 inverse_endianness = btf__endianness(base) == BTF_LITTLE_ENDIAN ? BTF_BIG_ENDIAN
         : BTF_LITTLE_ENDIAN;
 btf__set_endianness(base, inverse_endianness);
 btf__add_int(base, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 VALIDATE_RAW_BTF(
  base,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED");
 split = btf__new_empty_split(base);
 if (!ASSERT_OK_PTR(split, "empty_split_btf"))
  goto cleanup;
 btf__add_ptr(split, 1);
 VALIDATE_RAW_BTF(
  split,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1");
 if (!ASSERT_EQ(0, btf__distill_base(split, &new_base, &new_split),
         "distilled_base") ||
     !ASSERT_OK_PTR(new_base, "distilled_base") ||
     !ASSERT_OK_PTR(new_split, "distilled_split") ||
     !ASSERT_EQ(2, btf__type_cnt(new_base), "distilled_base_type_cnt"))
  goto cleanup;
 VALIDATE_RAW_BTF(
  new_split,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1");

 raw_data = btf__raw_data(new_base, &size);
 if (!ASSERT_OK_PTR(raw_data, "btf__raw_data #1"))
  goto cleanup;
 new_base1 = btf__new(raw_data, size);
 if (!ASSERT_OK_PTR(new_base1, "new_base1 = btf__new()"))
  goto cleanup;
 raw_data = btf__raw_data(new_split, &size);
 if (!ASSERT_OK_PTR(raw_data, "btf__raw_data #2"))
  goto cleanup;
 new_split1 = btf__new_split(raw_data, size, new_base1);
 if (!ASSERT_OK_PTR(new_split1, "new_split1 = btf__new()"))
  goto cleanup;

 ASSERT_EQ(btf__endianness(new_base1), inverse_endianness, "new_base1 endianness");
 ASSERT_EQ(btf__endianness(new_split1), inverse_endianness, "new_split1 endianness");
 VALIDATE_RAW_BTF(
  new_split1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] PTR '(anon)' type_id=1");
cleanup:
 btf__free(new_split1);
 btf__free(new_base1);
 btf__free(new_split);
 btf__free(new_base);
 btf__free(split);
 btf__free(base);
}

/* If a needed composite type, which is the member of composite type
 * in the split BTF, has a different size in the base BTF we wish to
 * relocate with, btf__relocate() should error out.
 */
static void test_distilled_base_embedded_err(void)
{
 struct btf *btf1 = NULL, *btf2 = NULL, *btf3 = NULL, *btf4 = NULL, *btf5 = NULL;

 btf1 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf1, "empty_main_btf"))
  return;

 btf__add_int(btf1, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 btf__add_struct(btf1, "s1", 4);                 /* [2] struct s1 { */
 btf__add_field(btf1, "f1", 1, 0, 0);            /*      int f1; */
       /* } */
 VALIDATE_RAW_BTF(
  btf1,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] STRUCT 's1' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0");

 btf2 = btf__new_empty_split(btf1);
 if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
  goto cleanup;

 btf__add_struct(btf2, "with_embedded", 8);      /* [3] struct with_embedded { */
 btf__add_field(btf2, "e1", 2, 0, 0);  /*      struct s1 e1; */
       /* } */

 VALIDATE_RAW_BTF(
  btf2,
  "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
  "[2] STRUCT 's1' size=4 vlen=1\n"
  "\t'f1' type_id=1 bits_offset=0",
  "[3] STRUCT 'with_embedded' size=8 vlen=1\n"
  "\t'e1' type_id=2 bits_offset=0");

 if (!ASSERT_EQ(0, btf__distill_base(btf2, &btf3, &btf4),
         "distilled_base") ||
     !ASSERT_OK_PTR(btf3, "distilled_base") ||
     !ASSERT_OK_PTR(btf4, "distilled_split") ||
     !ASSERT_EQ(2, btf__type_cnt(btf3), "distilled_base_type_cnt"))
  goto cleanup;

 VALIDATE_RAW_BTF(
  btf4,
  "[1] STRUCT 's1' size=4 vlen=0",
  "[2] STRUCT 'with_embedded' size=8 vlen=1\n"
  "\t'e1' type_id=1 bits_offset=0");

 btf5 = btf__new_empty();
 if (!ASSERT_OK_PTR(btf5, "empty_reloc_btf"))
  goto cleanup;

 btf__add_int(btf5, "int", 4, BTF_INT_SIGNED);   /* [1] int */
 /* struct with the same name but different size */
 btf__add_struct(btf5, "s1", 8);                 /* [2] struct s1 { */
 btf__add_field(btf5, "f1", 1, 0, 0);            /*      int f1; */
       /* } */

 ASSERT_EQ(btf__relocate(btf4, btf5), -EINVAL, "relocate_split");
cleanup:
 btf__free(btf5);
 btf__free(btf4);
 btf__free(btf3);
 btf__free(btf2);
 btf__free(btf1);
}

void test_btf_distill(void)
{
 if (test__start_subtest("distilled_base"))
  test_distilled_base();
 if (test__start_subtest("distilled_base_multi"))
  test_distilled_base_multi();
 if (test__start_subtest("distilled_base_missing_err"))
  test_distilled_base_missing_err();
 if (test__start_subtest("distilled_base_multi_err"))
  test_distilled_base_multi_err();
 if (test__start_subtest("distilled_base_multi_err2"))
  test_distilled_base_multi_err2();
 if (test__start_subtest("distilled_base_embedded_err"))
  test_distilled_base_embedded_err();
 if (test__start_subtest("distilled_base_vmlinux"))
  test_distilled_base_vmlinux();
 if (test__start_subtest("distilled_endianness"))
  test_distilled_endianness();
}