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-rw-r--r--tools/lib/bpf/btf.c197
-rw-r--r--tools/lib/bpf/btf.h8
-rw-r--r--tools/lib/bpf/libbpf.map9
3 files changed, 169 insertions, 45 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index fa1b147c63c6..0258cf108c0a 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -78,10 +78,32 @@ struct btf {
void *types_data;
size_t types_data_cap; /* used size stored in hdr->type_len */
- /* type ID to `struct btf_type *` lookup index */
+ /* type ID to `struct btf_type *` lookup index
+ * type_offs[0] corresponds to the first non-VOID type:
+ * - for base BTF it's type [1];
+ * - for split BTF it's the first non-base BTF type.
+ */
__u32 *type_offs;
size_t type_offs_cap;
+ /* number of types in this BTF instance:
+ * - doesn't include special [0] void type;
+ * - for split BTF counts number of types added on top of base BTF.
+ */
__u32 nr_types;
+ /* if not NULL, points to the base BTF on top of which the current
+ * split BTF is based
+ */
+ struct btf *base_btf;
+ /* BTF type ID of the first type in this BTF instance:
+ * - for base BTF it's equal to 1;
+ * - for split BTF it's equal to biggest type ID of base BTF plus 1.
+ */
+ int start_id;
+ /* logical string offset of this BTF instance:
+ * - for base BTF it's equal to 0;
+ * - for split BTF it's equal to total size of base BTF's string section size.
+ */
+ int start_str_off;
void *strs_data;
size_t strs_data_cap; /* used size stored in hdr->str_len */
@@ -176,7 +198,7 @@ static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off)
__u32 *p;
p = btf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32),
- btf->nr_types + 1, BTF_MAX_NR_TYPES, 1);
+ btf->nr_types, BTF_MAX_NR_TYPES, 1);
if (!p)
return -ENOMEM;
@@ -252,12 +274,16 @@ static int btf_parse_str_sec(struct btf *btf)
const char *start = btf->strs_data;
const char *end = start + btf->hdr->str_len;
- if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET ||
- start[0] || end[-1]) {
+ if (btf->base_btf && hdr->str_len == 0)
+ return 0;
+ if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || end[-1]) {
+ pr_debug("Invalid BTF string section\n");
+ return -EINVAL;
+ }
+ if (!btf->base_btf && start[0]) {
pr_debug("Invalid BTF string section\n");
return -EINVAL;
}
-
return 0;
}
@@ -372,19 +398,9 @@ static int btf_parse_type_sec(struct btf *btf)
struct btf_header *hdr = btf->hdr;
void *next_type = btf->types_data;
void *end_type = next_type + hdr->type_len;
- int err, i = 0, type_size;
-
- /* VOID (type_id == 0) is specially handled by btf__get_type_by_id(),
- * so ensure we can never properly use its offset from index by
- * setting it to a large value
- */
- err = btf_add_type_idx_entry(btf, UINT_MAX);
- if (err)
- return err;
+ int err, type_size;
while (next_type + sizeof(struct btf_type) <= end_type) {
- i++;
-
if (btf->swapped_endian)
btf_bswap_type_base(next_type);
@@ -392,7 +408,7 @@ static int btf_parse_type_sec(struct btf *btf)
if (type_size < 0)
return type_size;
if (next_type + type_size > end_type) {
- pr_warn("BTF type [%d] is malformed\n", i);
+ pr_warn("BTF type [%d] is malformed\n", btf->start_id + btf->nr_types);
return -EINVAL;
}
@@ -417,7 +433,7 @@ static int btf_parse_type_sec(struct btf *btf)
__u32 btf__get_nr_types(const struct btf *btf)
{
- return btf->nr_types;
+ return btf->start_id + btf->nr_types - 1;
}
/* internal helper returning non-const pointer to a type */
@@ -425,13 +441,14 @@ static struct btf_type *btf_type_by_id(struct btf *btf, __u32 type_id)
{
if (type_id == 0)
return &btf_void;
-
- return btf->types_data + btf->type_offs[type_id];
+ if (type_id < btf->start_id)
+ return btf_type_by_id(btf->base_btf, type_id);
+ return btf->types_data + btf->type_offs[type_id - btf->start_id];
}
const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
{
- if (type_id > btf->nr_types)
+ if (type_id >= btf->start_id + btf->nr_types)
return NULL;
return btf_type_by_id((struct btf *)btf, type_id);
}
@@ -440,9 +457,13 @@ static int determine_ptr_size(const struct btf *btf)
{
const struct btf_type *t;
const char *name;
- int i;
+ int i, n;
- for (i = 1; i <= btf->nr_types; i++) {
+ if (btf->base_btf && btf->base_btf->ptr_sz > 0)
+ return btf->base_btf->ptr_sz;
+
+ n = btf__get_nr_types(btf);
+ for (i = 1; i <= n; i++) {
t = btf__type_by_id(btf, i);
if (!btf_is_int(t))
continue;
@@ -725,7 +746,7 @@ void btf__free(struct btf *btf)
free(btf);
}
-struct btf *btf__new_empty(void)
+static struct btf *btf_new_empty(struct btf *base_btf)
{
struct btf *btf;
@@ -733,12 +754,21 @@ struct btf *btf__new_empty(void)
if (!btf)
return ERR_PTR(-ENOMEM);
+ btf->nr_types = 0;
+ btf->start_id = 1;
+ btf->start_str_off = 0;
btf->fd = -1;
btf->ptr_sz = sizeof(void *);
btf->swapped_endian = false;
+ if (base_btf) {
+ btf->base_btf = base_btf;
+ btf->start_id = btf__get_nr_types(base_btf) + 1;
+ btf->start_str_off = base_btf->hdr->str_len;
+ }
+
/* +1 for empty string at offset 0 */
- btf->raw_size = sizeof(struct btf_header) + 1;
+ btf->raw_size = sizeof(struct btf_header) + (base_btf ? 0 : 1);
btf->raw_data = calloc(1, btf->raw_size);
if (!btf->raw_data) {
free(btf);
@@ -752,12 +782,22 @@ struct btf *btf__new_empty(void)
btf->types_data = btf->raw_data + btf->hdr->hdr_len;
btf->strs_data = btf->raw_data + btf->hdr->hdr_len;
- btf->hdr->str_len = 1; /* empty string at offset 0 */
+ btf->hdr->str_len = base_btf ? 0 : 1; /* empty string at offset 0 */
return btf;
}
-struct btf *btf__new(const void *data, __u32 size)
+struct btf *btf__new_empty(void)
+{
+ return btf_new_empty(NULL);
+}
+
+struct btf *btf__new_empty_split(struct btf *base_btf)
+{
+ return btf_new_empty(base_btf);
+}
+
+static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf)
{
struct btf *btf;
int err;
@@ -766,6 +806,16 @@ struct btf *btf__new(const void *data, __u32 size)
if (!btf)
return ERR_PTR(-ENOMEM);
+ btf->nr_types = 0;
+ btf->start_id = 1;
+ btf->start_str_off = 0;
+
+ if (base_btf) {
+ btf->base_btf = base_btf;
+ btf->start_id = btf__get_nr_types(base_btf) + 1;
+ btf->start_str_off = base_btf->hdr->str_len;
+ }
+
btf->raw_data = malloc(size);
if (!btf->raw_data) {
err = -ENOMEM;
@@ -798,7 +848,13 @@ done:
return btf;
}
-struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
+struct btf *btf__new(const void *data, __u32 size)
+{
+ return btf_new(data, size, NULL);
+}
+
+static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
+ struct btf_ext **btf_ext)
{
Elf_Data *btf_data = NULL, *btf_ext_data = NULL;
int err = 0, fd = -1, idx = 0;
@@ -876,7 +932,7 @@ struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
err = -ENOENT;
goto done;
}
- btf = btf__new(btf_data->d_buf, btf_data->d_size);
+ btf = btf_new(btf_data->d_buf, btf_data->d_size, base_btf);
if (IS_ERR(btf))
goto done;
@@ -921,7 +977,17 @@ done:
return btf;
}
-struct btf *btf__parse_raw(const char *path)
+struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext)
+{
+ return btf_parse_elf(path, NULL, btf_ext);
+}
+
+struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf)
+{
+ return btf_parse_elf(path, base_btf, NULL);
+}
+
+static struct btf *btf_parse_raw(const char *path, struct btf *base_btf)
{
struct btf *btf = NULL;
void *data = NULL;
@@ -975,7 +1041,7 @@ struct btf *btf__parse_raw(const char *path)
}
/* finally parse BTF data */
- btf = btf__new(data, sz);
+ btf = btf_new(data, sz, base_btf);
err_out:
free(data);
@@ -984,18 +1050,38 @@ err_out:
return err ? ERR_PTR(err) : btf;
}
-struct btf *btf__parse(const char *path, struct btf_ext **btf_ext)
+struct btf *btf__parse_raw(const char *path)
+{
+ return btf_parse_raw(path, NULL);
+}
+
+struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf)
+{
+ return btf_parse_raw(path, base_btf);
+}
+
+static struct btf *btf_parse(const char *path, struct btf *base_btf, struct btf_ext **btf_ext)
{
struct btf *btf;
if (btf_ext)
*btf_ext = NULL;
- btf = btf__parse_raw(path);
+ btf = btf_parse_raw(path, base_btf);
if (!IS_ERR(btf) || PTR_ERR(btf) != -EPROTO)
return btf;
- return btf__parse_elf(path, btf_ext);
+ return btf_parse_elf(path, base_btf, btf_ext);
+}
+
+struct btf *btf__parse(const char *path, struct btf_ext **btf_ext)
+{
+ return btf_parse(path, NULL, btf_ext);
+}
+
+struct btf *btf__parse_split(const char *path, struct btf *base_btf)
+{
+ return btf_parse(path, base_btf, NULL);
}
static int compare_vsi_off(const void *_a, const void *_b)
@@ -1179,8 +1265,8 @@ static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endi
memcpy(p, btf->types_data, hdr->type_len);
if (swap_endian) {
- for (i = 1; i <= btf->nr_types; i++) {
- t = p + btf->type_offs[i];
+ for (i = 0; i < btf->nr_types; i++) {
+ t = p + btf->type_offs[i];
/* btf_bswap_type_rest() relies on native t->info, so
* we swap base type info after we swapped all the
* additional information
@@ -1223,8 +1309,10 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
const char *btf__str_by_offset(const struct btf *btf, __u32 offset)
{
- if (offset < btf->hdr->str_len)
- return btf->strs_data + offset;
+ if (offset < btf->start_str_off)
+ return btf__str_by_offset(btf->base_btf, offset);
+ else if (offset - btf->start_str_off < btf->hdr->str_len)
+ return btf->strs_data + (offset - btf->start_str_off);
else
return NULL;
}
@@ -1461,7 +1549,10 @@ static int btf_ensure_modifiable(struct btf *btf)
/* if BTF was created from scratch, all strings are guaranteed to be
* unique and deduplicated
*/
- btf->strs_deduped = btf->hdr->str_len <= 1;
+ if (btf->hdr->str_len == 0)
+ btf->strs_deduped = true;
+ if (!btf->base_btf && btf->hdr->str_len == 1)
+ btf->strs_deduped = true;
/* invalidate raw_data representation */
btf_invalidate_raw_data(btf);
@@ -1493,6 +1584,14 @@ int btf__find_str(struct btf *btf, const char *s)
long old_off, new_off, len;
void *p;
+ if (btf->base_btf) {
+ int ret;
+
+ ret = btf__find_str(btf->base_btf, s);
+ if (ret != -ENOENT)
+ return ret;
+ }
+
/* BTF needs to be in a modifiable state to build string lookup index */
if (btf_ensure_modifiable(btf))
return -ENOMEM;
@@ -1507,7 +1606,7 @@ int btf__find_str(struct btf *btf, const char *s)
memcpy(p, s, len);
if (hashmap__find(btf->strs_hash, (void *)new_off, (void **)&old_off))
- return old_off;
+ return btf->start_str_off + old_off;
return -ENOENT;
}
@@ -1523,6 +1622,14 @@ int btf__add_str(struct btf *btf, const char *s)
void *p;
int err;
+ if (btf->base_btf) {
+ int ret;
+
+ ret = btf__find_str(btf->base_btf, s);
+ if (ret != -ENOENT)
+ return ret;
+ }
+
if (btf_ensure_modifiable(btf))
return -ENOMEM;
@@ -1549,12 +1656,12 @@ int btf__add_str(struct btf *btf, const char *s)
err = hashmap__insert(btf->strs_hash, (void *)new_off, (void *)new_off,
HASHMAP_ADD, (const void **)&old_off, NULL);
if (err == -EEXIST)
- return old_off; /* duplicated string, return existing offset */
+ return btf->start_str_off + old_off; /* duplicated string, return existing offset */
if (err)
return err;
btf->hdr->str_len += len; /* new unique string, adjust data length */
- return new_off;
+ return btf->start_str_off + new_off;
}
static void *btf_add_type_mem(struct btf *btf, size_t add_sz)
@@ -1584,7 +1691,7 @@ static int btf_commit_type(struct btf *btf, int data_sz)
btf->hdr->type_len += data_sz;
btf->hdr->str_off += data_sz;
btf->nr_types++;
- return btf->nr_types;
+ return btf->start_id + btf->nr_types - 1;
}
/*
@@ -4167,14 +4274,14 @@ static int btf_dedup_compact_types(struct btf_dedup *d)
memmove(p, btf__type_by_id(d->btf, i), len);
d->hypot_map[i] = next_type_id;
- d->btf->type_offs[next_type_id] = p - d->btf->types_data;
+ d->btf->type_offs[next_type_id - 1] = p - d->btf->types_data;
p += len;
next_type_id++;
}
/* shrink struct btf's internal types index and update btf_header */
d->btf->nr_types = next_type_id - 1;
- d->btf->type_offs_cap = d->btf->nr_types + 1;
+ d->btf->type_offs_cap = d->btf->nr_types;
d->btf->hdr->type_len = p - d->btf->types_data;
new_offs = libbpf_reallocarray(d->btf->type_offs, d->btf->type_offs_cap,
sizeof(*new_offs));
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 57247240a20a..1093f6fe6800 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -31,11 +31,19 @@ enum btf_endianness {
};
LIBBPF_API void btf__free(struct btf *btf);
+
LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
+LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
LIBBPF_API struct btf *btf__new_empty(void);
+LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
+
LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
+LIBBPF_API struct btf *btf__parse_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__parse_elf(const char *path, struct btf_ext **btf_ext);
+LIBBPF_API struct btf *btf__parse_elf_split(const char *path, struct btf *base_btf);
LIBBPF_API struct btf *btf__parse_raw(const char *path);
+LIBBPF_API struct btf *btf__parse_raw_split(const char *path, struct btf *base_btf);
+
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 4ebfadf45b47..29ff4807b909 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -337,3 +337,12 @@ LIBBPF_0.2.0 {
perf_buffer__consume_buffer;
xsk_socket__create_shared;
} LIBBPF_0.1.0;
+
+LIBBPF_0.3.0 {
+ global:
+ btf__parse_elf_split;
+ btf__parse_raw_split;
+ btf__parse_split;
+ btf__new_empty_split;
+ btf__new_split;
+} LIBBPF_0.2.0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 13:44:16 +0000