From ea26899da54fbd1f46ff96be5d190b67ceba1ad8 Mon Sep 17 00:00:00 2001 From: Donglin Peng Date: Fri, 14 Nov 2025 17:02:30 +0800 Subject: [PATCH 1/2] libbpf: Add BTF permutation support for type reordering Introduce btf__permute() API to allow in-place rearrangement of BTF types. This function reorganizes BTF type order according to a provided array of type IDs, updating all type references to maintain consistency. Cc: Eduard Zingerman Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Alan Maguire Cc: Song Liu Cc: Xiaoqin Zhang Signed-off-by: Donglin Peng --- tools/lib/bpf/btf.c | 186 +++++++++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 43 +++++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 230 insertions(+) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 9f141395c074e..de3aa62fd9e57 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -5829,3 +5829,189 @@ int btf__relocate(struct btf *btf, const struct btf *base_btf) btf->owns_base = false; return libbpf_err(err); } + +struct btf_permute { + struct btf *btf; + __u32 *id_map; + __u32 offs; +}; + +/* Callback function to remap individual type ID references */ +static int btf_permute_remap_type_id(__u32 *type_id, void *ctx) +{ + struct btf_permute *p = ctx; + __u32 new_type_id = *type_id; + + /* skip references that point into the base BTF */ + if (new_type_id < p->btf->start_id) + return 0; + + /* invalid reference id */ + if (new_type_id >= btf__type_cnt(p->btf)) + return -EINVAL; + + new_type_id = p->id_map[new_type_id - p->offs]; + /* reference a dropped type is not allowed */ + if (new_type_id == 0) + return -EINVAL; + + *type_id = new_type_id; + return 0; +} + +int btf__permute(struct btf *btf, __u32 *id_map, __u32 id_map_cnt, + const struct btf_permute_opts *opts) +{ + struct btf_permute p; + struct btf_ext *btf_ext; + void *next_type, *end_type; + void *nt, *new_types = NULL; + int err = 0, n, i, new_type_len; + __u32 *order_map = NULL; + __u32 offs, id, new_nr_types = 0; + + if (btf__base_btf(btf)) { + /* + * For split BTF, the number of types added on the + * top of base BTF + */ + n = btf->nr_types; + offs = btf->start_id; + } else if (id_map[0] != 0) { + /* id_map[0] must be 0 for base BTF */ + err = -EINVAL; + goto done; + } else { + /* include VOID type 0 for base BTF */ + n = btf__type_cnt(btf); + offs = 0; + } + + if (!OPTS_VALID(opts, btf_permute_opts) || (id_map_cnt != n)) + return libbpf_err(-EINVAL); + + /* used to record the storage sequence of types */ + order_map = calloc(n, sizeof(*id_map)); + if (!order_map) { + err = -ENOMEM; + goto done; + } + + new_types = calloc(btf->hdr->type_len, 1); + if (!new_types) { + err = -ENOMEM; + goto done; + } + + if (btf_ensure_modifiable(btf)) { + err = -ENOMEM; + goto done; + } + + for (i = 0; i < id_map_cnt; i++) { + id = id_map[i]; + /* + * 0: Drop the specified type (exclude base BTF type 0). + * For base BTF, type 0 is always preserved. + */ + if (id == 0) + continue; + /* Invalid id */ + if (id < btf->start_id || id >= btf__type_cnt(btf)) { + err = -EINVAL; + goto done; + } + id -= offs; + /* Multiple types cannot be mapped to the same ID */ + if (order_map[id]) { + err = -EINVAL; + goto done; + } + order_map[id] = i + offs; + new_nr_types = max(id + 1, new_nr_types); + } + + /* Check for missing IDs */ + for (i = offs ? 0 : 1; i < new_nr_types; i++) { + if (order_map[i] == 0) { + err = -EINVAL; + goto done; + } + } + + p.btf = btf; + p.id_map = id_map; + p.offs = offs; + nt = new_types; + for (i = offs ? 0 : 1; i < new_nr_types; i++) { + struct btf_field_iter it; + const struct btf_type *t; + __u32 *type_id; + int type_size; + + id = order_map[i]; + /* must be a valid type ID */ + t = btf__type_by_id(btf, id); + if (!t) { + err = -EINVAL; + goto done; + } + type_size = btf_type_size(t); + memcpy(nt, t, type_size); + + /* Fix up referenced IDs for BTF */ + err = btf_field_iter_init(&it, nt, BTF_FIELD_ITER_IDS); + if (err) + goto done; + while ((type_id = btf_field_iter_next(&it))) { + err = btf_permute_remap_type_id(type_id, &p); + if (err) + goto done; + } + + nt += type_size; + } + + /* Fix up referenced IDs for btf_ext */ + btf_ext = OPTS_GET(opts, btf_ext, NULL); + if (btf_ext) { + err = btf_ext_visit_type_ids(btf_ext, btf_permute_remap_type_id, &p); + if (err) + goto done; + } + + new_type_len = nt - new_types; + next_type = new_types; + end_type = next_type + new_type_len; + i = 0; + while (next_type + sizeof(struct btf_type) <= end_type) { + btf->type_offs[i++] = next_type - new_types; + next_type += btf_type_size(next_type); + } + + /* Resize */ + if (new_type_len < btf->hdr->type_len) { + void *tmp_types; + + tmp_types = realloc(new_types, new_type_len); + if (new_type_len && !tmp_types) { + err = -ENOMEM; + goto done; + } + new_types = tmp_types; + btf->nr_types = new_nr_types - (offs ? 0 : 1); + btf->type_offs_cap = btf->nr_types; + btf->types_data_cap = new_type_len; + btf->hdr->type_len = new_type_len; + btf->hdr->str_off = new_type_len; + btf->raw_size = btf->hdr->hdr_len + btf->hdr->type_len + btf->hdr->str_len; + } + free(btf->types_data); + btf->types_data = new_types; + return 0; + +done: + free(order_map); + free(new_types); + return libbpf_err(err); +} diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index cc01494d62107..dfe47e9146175 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -281,6 +281,49 @@ LIBBPF_API int btf__dedup(struct btf *btf, const struct btf_dedup_opts *opts); */ LIBBPF_API int btf__relocate(struct btf *btf, const struct btf *base_btf); +struct btf_permute_opts { + size_t sz; + /* optional .BTF.ext info along the main BTF info */ + struct btf_ext *btf_ext; + size_t :0; +}; +#define btf_permute_opts__last_field btf_ext + +/** + * @brief **btf__permute()** performs in-place BTF type rearrangement + * @param btf BTF object to permute + * @param id_map Array mapping original type IDs to new IDs + * @param id_map_cnt Number of elements in @id_map + * @param opts Optional parameters for BTF extension updates + * @return 0 on success, negative error code on failure + * + * **btf__permute()** rearranges BTF types according to the specified ID mapping. + * The @id_map array defines the new type ID for each original type ID. + * + * For **base BTF**: + * - @id_map must include all types from ID 0 to `btf__type_cnt(btf)-1` + * - @id_map_cnt should be `btf__type_cnt(btf)` + * - Mapping uses `id_map[original_id] = new_id` + * + * For **split BTF**: + * - @id_map should cover only split types + * - @id_map_cnt should be `btf__type_cnt(btf) - btf__type_cnt(btf__base_btf(btf))` + * - Mapping uses `id_map[original_id - btf__type_cnt(btf__base_btf(btf))] = new_id` + * + * Setting @id_map element to 0 (except `id_map[0]` for base BTF) drops the corresponding type. + * Dropped types must not be referenced by any retained types. After permutation, + * type references in BTF data and optional extension are updated automatically. + * + * Note: Dropping types may orphan some strings, requiring subsequent **btf__dedup()** + * to clean up unreferenced strings. + * + * On error, returns negative error code and sets errno: + * - `-EINVAL`: Invalid parameters or ID mapping (duplicates, out-of-range) + * - `-ENOMEM`: Memory allocation failure + */ +LIBBPF_API int btf__permute(struct btf *btf, __u32 *id_map, __u32 id_map_cnt, + const struct btf_permute_opts *opts); + struct btf_dump; struct btf_dump_opts { diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 8ed8749907d47..b778e5a5d0a88 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -451,4 +451,5 @@ LIBBPF_1.7.0 { global: bpf_map__set_exclusive_program; bpf_map__exclusive_program; + btf__permute; } LIBBPF_1.6.0; From 3dd8b02ef0a8129d59c6887149d8857ef0ffed9d Mon Sep 17 00:00:00 2001 From: Donglin Peng Date: Fri, 14 Nov 2025 17:02:31 +0800 Subject: [PATCH 2/2] selftests/bpf: Add test cases for btf__permute functionality 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 Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Alan Maguire Cc: Song Liu Cc: Xiaoqin Zhang Signed-off-by: Donglin Peng --- .../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 0000000000000..c1a47b8461ee4 --- /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 +#include +#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(); +}