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-rw-r--r--tools/lib/bpf/btf.c139
1 files changed, 75 insertions, 64 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index a3d259e614b0..7c9957893ef2 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -31,11 +31,12 @@ struct btf {
struct btf_header *hdr;
void *data;
};
- struct btf_type **types;
+ __u32 *type_offs;
+ __u32 type_offs_cap;
const char *strings;
void *nohdr_data;
+ void *types_data;
__u32 nr_types;
- __u32 types_size;
__u32 data_size;
int fd;
int ptr_sz;
@@ -46,30 +47,30 @@ static inline __u64 ptr_to_u64(const void *ptr)
return (__u64) (unsigned long) ptr;
}
-static int btf_add_type(struct btf *btf, struct btf_type *t)
+static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off)
{
- if (btf->types_size - btf->nr_types < 2) {
- struct btf_type **new_types;
+ /* nr_types is 1-based, so N types means we need N+1-sized array */
+ if (btf->nr_types + 2 > btf->type_offs_cap) {
+ __u32 *new_offs;
__u32 expand_by, new_size;
- if (btf->types_size == BTF_MAX_NR_TYPES)
+ if (btf->type_offs_cap == BTF_MAX_NR_TYPES)
return -E2BIG;
- expand_by = max(btf->types_size >> 2, 16U);
- new_size = min(BTF_MAX_NR_TYPES, btf->types_size + expand_by);
+ expand_by = max(btf->type_offs_cap / 4, 16U);
+ new_size = min(BTF_MAX_NR_TYPES, btf->type_offs_cap + expand_by);
- new_types = libbpf_reallocarray(btf->types, new_size, sizeof(*new_types));
- if (!new_types)
+ new_offs = libbpf_reallocarray(btf->type_offs, new_size, sizeof(*new_offs));
+ if (!new_offs)
return -ENOMEM;
- if (btf->nr_types == 0)
- new_types[0] = &btf_void;
+ new_offs[0] = UINT_MAX; /* VOID is specially handled */
- btf->types = new_types;
- btf->types_size = new_size;
+ btf->type_offs = new_offs;
+ btf->type_offs_cap = new_size;
}
- btf->types[++(btf->nr_types)] = t;
+ btf->type_offs[btf->nr_types + 1] = type_off;
return 0;
}
@@ -147,7 +148,7 @@ static int btf_parse_str_sec(struct btf *btf)
return 0;
}
-static int btf_type_size(struct btf_type *t)
+static int btf_type_size(const struct btf_type *t)
{
int base_size = sizeof(struct btf_type);
__u16 vlen = btf_vlen(t);
@@ -185,22 +186,25 @@ static int btf_type_size(struct btf_type *t)
static int btf_parse_type_sec(struct btf *btf)
{
struct btf_header *hdr = btf->hdr;
- void *nohdr_data = btf->nohdr_data;
- void *next_type = nohdr_data + hdr->type_off;
- void *end_type = nohdr_data + hdr->str_off;
+ void *next_type = btf->nohdr_data + hdr->type_off;
+ void *end_type = next_type + hdr->type_len;
+
+ btf->types_data = next_type;
while (next_type < end_type) {
- struct btf_type *t = next_type;
int type_size;
int err;
- type_size = btf_type_size(t);
+ err = btf_add_type_idx_entry(btf, next_type - btf->types_data);
+ if (err)
+ return err;
+
+ type_size = btf_type_size(next_type);
if (type_size < 0)
return type_size;
+
next_type += type_size;
- err = btf_add_type(btf, t);
- if (err)
- return err;
+ btf->nr_types++;
}
return 0;
@@ -211,12 +215,20 @@ __u32 btf__get_nr_types(const struct btf *btf)
return btf->nr_types;
}
+/* internal helper returning non-const pointer to a type */
+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];
+}
+
const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
{
if (type_id > btf->nr_types)
return NULL;
-
- return btf->types[type_id];
+ return btf_type_by_id((struct btf *)btf, type_id);
}
static int determine_ptr_size(const struct btf *btf)
@@ -414,7 +426,7 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name)
return 0;
for (i = 1; i <= btf->nr_types; i++) {
- const struct btf_type *t = btf->types[i];
+ const struct btf_type *t = btf__type_by_id(btf, i);
const char *name = btf__name_by_offset(btf, t->name_off);
if (name && !strcmp(type_name, name))
@@ -433,7 +445,7 @@ __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
return 0;
for (i = 1; i <= btf->nr_types; i++) {
- const struct btf_type *t = btf->types[i];
+ const struct btf_type *t = btf__type_by_id(btf, i);
const char *name;
if (btf_kind(t) != kind)
@@ -455,7 +467,7 @@ void btf__free(struct btf *btf)
close(btf->fd);
free(btf->data);
- free(btf->types);
+ free(btf->type_offs);
free(btf);
}
@@ -789,7 +801,7 @@ int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
__u32 i;
for (i = 1; i <= btf->nr_types; i++) {
- struct btf_type *t = btf->types[i];
+ struct btf_type *t = btf_type_by_id(btf, i);
/* Loader needs to fix up some of the things compiler
* couldn't get its hands on while emitting BTF. This
@@ -1655,7 +1667,7 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
/* special BTF "void" type is made canonical immediately */
d->map[0] = 0;
for (i = 1; i <= btf->nr_types; i++) {
- struct btf_type *t = d->btf->types[i];
+ struct btf_type *t = btf_type_by_id(d->btf, i);
/* VAR and DATASEC are never deduped and are self-canonical */
if (btf_is_var(t) || btf_is_datasec(t))
@@ -1694,7 +1706,7 @@ static int btf_for_each_str_off(struct btf_dedup *d, str_off_fn_t fn, void *ctx)
struct btf_type *t;
for (i = 1; i <= d->btf->nr_types; i++) {
- t = d->btf->types[i];
+ t = btf_type_by_id(d->btf, i);
r = fn(&t->name_off, ctx);
if (r)
return r;
@@ -2229,7 +2241,7 @@ static bool btf_compat_fnproto(struct btf_type *t1, struct btf_type *t2)
*/
static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
{
- struct btf_type *t = d->btf->types[type_id];
+ struct btf_type *t = btf_type_by_id(d->btf, type_id);
struct hashmap_entry *hash_entry;
struct btf_type *cand;
/* if we don't find equivalent type, then we are canonical */
@@ -2256,7 +2268,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_int(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_int(t, cand)) {
new_id = cand_id;
break;
@@ -2268,7 +2280,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_enum(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_enum(t, cand)) {
new_id = cand_id;
break;
@@ -2291,7 +2303,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_common(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_common(t, cand)) {
new_id = cand_id;
break;
@@ -2350,13 +2362,13 @@ static uint32_t resolve_fwd_id(struct btf_dedup *d, uint32_t type_id)
{
__u32 orig_type_id = type_id;
- if (!btf_is_fwd(d->btf->types[type_id]))
+ if (!btf_is_fwd(btf__type_by_id(d->btf, type_id)))
return type_id;
while (is_type_mapped(d, type_id) && d->map[type_id] != type_id)
type_id = d->map[type_id];
- if (!btf_is_fwd(d->btf->types[type_id]))
+ if (!btf_is_fwd(btf__type_by_id(d->btf, type_id)))
return type_id;
return orig_type_id;
@@ -2484,8 +2496,8 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
if (btf_dedup_hypot_map_add(d, canon_id, cand_id))
return -ENOMEM;
- cand_type = d->btf->types[cand_id];
- canon_type = d->btf->types[canon_id];
+ cand_type = btf_type_by_id(d->btf, cand_id);
+ canon_type = btf_type_by_id(d->btf, canon_id);
cand_kind = btf_kind(cand_type);
canon_kind = btf_kind(canon_type);
@@ -2636,8 +2648,8 @@ static void btf_dedup_merge_hypot_map(struct btf_dedup *d)
targ_type_id = d->hypot_map[cand_type_id];
t_id = resolve_type_id(d, targ_type_id);
c_id = resolve_type_id(d, cand_type_id);
- t_kind = btf_kind(d->btf->types[t_id]);
- c_kind = btf_kind(d->btf->types[c_id]);
+ t_kind = btf_kind(btf__type_by_id(d->btf, t_id));
+ c_kind = btf_kind(btf__type_by_id(d->btf, c_id));
/*
* Resolve FWD into STRUCT/UNION.
* It's ok to resolve FWD into STRUCT/UNION that's not yet
@@ -2705,7 +2717,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
if (d->map[type_id] <= BTF_MAX_NR_TYPES)
return 0;
- t = d->btf->types[type_id];
+ t = btf_type_by_id(d->btf, type_id);
kind = btf_kind(t);
if (kind != BTF_KIND_STRUCT && kind != BTF_KIND_UNION)
@@ -2726,7 +2738,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id)
* creating a loop (FWD -> STRUCT and STRUCT -> FWD), because
* FWD and compatible STRUCT/UNION are considered equivalent.
*/
- cand_type = d->btf->types[cand_id];
+ cand_type = btf_type_by_id(d->btf, cand_id);
if (!btf_shallow_equal_struct(t, cand_type))
continue;
@@ -2798,7 +2810,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
if (d->map[type_id] <= BTF_MAX_NR_TYPES)
return resolve_type_id(d, type_id);
- t = d->btf->types[type_id];
+ t = btf_type_by_id(d->btf, type_id);
d->map[type_id] = BTF_IN_PROGRESS_ID;
switch (btf_kind(t)) {
@@ -2816,7 +2828,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_common(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_common(t, cand)) {
new_id = cand_id;
break;
@@ -2840,7 +2852,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_array(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_array(t, cand)) {
new_id = cand_id;
break;
@@ -2872,7 +2884,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
h = btf_hash_fnproto(t);
for_each_dedup_cand(d, hash_entry, h) {
cand_id = (__u32)(long)hash_entry->value;
- cand = d->btf->types[cand_id];
+ cand = btf_type_by_id(d->btf, cand_id);
if (btf_equal_fnproto(t, cand)) {
new_id = cand_id;
break;
@@ -2920,9 +2932,9 @@ static int btf_dedup_ref_types(struct btf_dedup *d)
*/
static int btf_dedup_compact_types(struct btf_dedup *d)
{
- struct btf_type **new_types;
+ __u32 *new_offs;
__u32 next_type_id = 1;
- char *types_start, *p;
+ void *p;
int i, len;
/* we are going to reuse hypot_map to store compaction remapping */
@@ -2930,41 +2942,40 @@ static int btf_dedup_compact_types(struct btf_dedup *d)
for (i = 1; i <= d->btf->nr_types; i++)
d->hypot_map[i] = BTF_UNPROCESSED_ID;
- types_start = d->btf->nohdr_data + d->btf->hdr->type_off;
- p = types_start;
+ p = d->btf->types_data;
for (i = 1; i <= d->btf->nr_types; i++) {
if (d->map[i] != i)
continue;
- len = btf_type_size(d->btf->types[i]);
+ len = btf_type_size(btf__type_by_id(d->btf, i));
if (len < 0)
return len;
- memmove(p, d->btf->types[i], len);
+ memmove(p, btf__type_by_id(d->btf, i), len);
d->hypot_map[i] = next_type_id;
- d->btf->types[next_type_id] = (struct btf_type *)p;
+ d->btf->type_offs[next_type_id] = 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->types_size = d->btf->nr_types;
- d->btf->hdr->type_len = p - types_start;
- new_types = libbpf_reallocarray(d->btf->types, (1 + d->btf->nr_types),
- sizeof(struct btf_type *));
- if (!new_types)
+ d->btf->type_offs_cap = d->btf->nr_types + 1;
+ 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));
+ if (!new_offs)
return -ENOMEM;
- d->btf->types = new_types;
+ d->btf->type_offs = new_offs;
/* make sure string section follows type information without gaps */
- d->btf->hdr->str_off = p - (char *)d->btf->nohdr_data;
+ d->btf->hdr->str_off = p - d->btf->nohdr_data;
memmove(p, d->btf->strings, d->btf->hdr->str_len);
d->btf->strings = p;
p += d->btf->hdr->str_len;
- d->btf->data_size = p - (char *)d->btf->data;
+ d->btf->data_size = p - d->btf->data;
return 0;
}
@@ -2997,7 +3008,7 @@ static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id)
*/
static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id)
{
- struct btf_type *t = d->btf->types[type_id];
+ struct btf_type *t = btf_type_by_id(d->btf, type_id);
int i, r;
switch (btf_kind(t)) {