[PATCH bpf-next] tools/libbpf: support bigger BTF data sizes
From: Andrii Nakryiko <hidden>
Date: 2019-02-16 03:52:25
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
While it's understandable why kernel limits number of BTF types to 65535 and size of string section to 64KB, in libbpf as user-space library it's too restrictive. E.g., pahole converting DWARF to BTF type information for Linux kernel generates more than 3 million BTF types and more than 3MB of strings, before deduplication. So to allow btf__dedup() to do its work, we need to be able to load bigger BTF sections using btf__new(). Singed-off-by: Andrii Nakryiko [off-list ref] --- tools/lib/bpf/btf.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index ade1c32fb083..68b50e9bbde1 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c@@ -16,7 +16,8 @@ #define max(a, b) ((a) > (b) ? (a) : (b)) #define min(a, b) ((a) < (b) ? (a) : (b)) -#define BTF_MAX_NR_TYPES 65535 +#define BTF_MAX_NR_TYPES 0x7fffffff +#define BTF_MAX_STR_OFFSET 0x7fffffff #define IS_MODIFIER(k) (((k) == BTF_KIND_TYPEDEF) || \ ((k) == BTF_KIND_VOLATILE) || \
@@ -175,7 +176,7 @@ static int btf_parse_str_sec(struct btf *btf) const char *start = btf->nohdr_data + hdr->str_off; const char *end = start + btf->hdr->str_len; - if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || + if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_STR_OFFSET || start[0] || end[-1]) { pr_debug("Invalid BTF string section\n"); return -EINVAL;
@@ -1882,7 +1883,7 @@ static int btf_dedup_prim_types(struct btf_dedup *d) */ static inline bool is_type_mapped(struct btf_dedup *d, uint32_t type_id) { - return d->map[type_id] <= BTF_MAX_TYPE; + return d->map[type_id] <= BTF_MAX_NR_TYPES; } /*
@@ -2033,7 +2034,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, canon_id = resolve_fwd_id(d, canon_id); hypot_type_id = d->hypot_map[canon_id]; - if (hypot_type_id <= BTF_MAX_TYPE) + if (hypot_type_id <= BTF_MAX_NR_TYPES) return hypot_type_id == cand_id; if (btf_dedup_hypot_map_add(d, canon_id, cand_id))
@@ -2252,7 +2253,7 @@ static int btf_dedup_struct_type(struct btf_dedup *d, __u32 type_id) __u32 h; /* already deduped or is in process of deduping (loop detected) */ - if (d->map[type_id] <= BTF_MAX_TYPE) + if (d->map[type_id] <= BTF_MAX_NR_TYPES) return 0; t = d->btf->types[type_id];
@@ -2329,7 +2330,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) if (d->map[type_id] == BTF_IN_PROGRESS_ID) return -ELOOP; - if (d->map[type_id] <= BTF_MAX_TYPE) + if (d->map[type_id] <= BTF_MAX_NR_TYPES) return resolve_type_id(d, type_id); t = d->btf->types[type_id];
@@ -2509,7 +2510,7 @@ static int btf_dedup_remap_type_id(struct btf_dedup *d, __u32 type_id) resolved_type_id = resolve_type_id(d, type_id); new_type_id = d->hypot_map[resolved_type_id]; - if (new_type_id > BTF_MAX_TYPE) + if (new_type_id > BTF_MAX_NR_TYPES) return -EINVAL; return new_type_id; }
--
2.17.1