From 69eaab04c675ef2d0127a80b3395aa90dfd1061f Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 4 Feb 2019 17:29:44 -0800 Subject: btf: extract BTF type size calculation This pre-patch extracts calculation of amount of space taken by BTF type descriptor for later reuse by btf_dedup functionality. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann --- tools/lib/bpf/btf.c | 98 +++++++++++++++++++++++++---------------------------- 1 file changed, 46 insertions(+), 52 deletions(-) (limited to 'tools/lib') diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 7ec0463354db..06bd1a625ff4 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -182,6 +182,37 @@ static int btf_parse_str_sec(struct btf *btf) return 0; } +static int btf_type_size(struct btf_type *t) +{ + int base_size = sizeof(struct btf_type); + __u16 vlen = BTF_INFO_VLEN(t->info); + + switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_FWD: + case BTF_KIND_CONST: + case BTF_KIND_VOLATILE: + case BTF_KIND_RESTRICT: + case BTF_KIND_PTR: + case BTF_KIND_TYPEDEF: + case BTF_KIND_FUNC: + return base_size; + case BTF_KIND_INT: + return base_size + sizeof(__u32); + case BTF_KIND_ENUM: + return base_size + vlen * sizeof(struct btf_enum); + case BTF_KIND_ARRAY: + return base_size + sizeof(struct btf_array); + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + return base_size + vlen * sizeof(struct btf_member); + case BTF_KIND_FUNC_PROTO: + return base_size + vlen * sizeof(struct btf_param); + default: + pr_debug("Unsupported BTF_KIND:%u\n", BTF_INFO_KIND(t->info)); + return -EINVAL; + } +} + static int btf_parse_type_sec(struct btf *btf) { struct btf_header *hdr = btf->hdr; @@ -191,41 +222,13 @@ static int btf_parse_type_sec(struct btf *btf) while (next_type < end_type) { struct btf_type *t = next_type; - __u16 vlen = BTF_INFO_VLEN(t->info); + int type_size; int err; - next_type += sizeof(*t); - switch (BTF_INFO_KIND(t->info)) { - case BTF_KIND_INT: - next_type += sizeof(int); - break; - case BTF_KIND_ARRAY: - next_type += sizeof(struct btf_array); - break; - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: - next_type += vlen * sizeof(struct btf_member); - break; - case BTF_KIND_ENUM: - next_type += vlen * sizeof(struct btf_enum); - break; - case BTF_KIND_FUNC_PROTO: - next_type += vlen * sizeof(struct btf_param); - break; - case BTF_KIND_FUNC: - case BTF_KIND_TYPEDEF: - case BTF_KIND_PTR: - case BTF_KIND_FWD: - case BTF_KIND_VOLATILE: - case BTF_KIND_CONST: - case BTF_KIND_RESTRICT: - break; - default: - pr_debug("Unsupported BTF_KIND:%u\n", - BTF_INFO_KIND(t->info)); - return -EINVAL; - } - + type_size = btf_type_size(t); + if (type_size < 0) + return type_size; + next_type += type_size; err = btf_add_type(btf, t); if (err) return err; @@ -252,21 +255,6 @@ static bool btf_type_is_void_or_null(const struct btf_type *t) return !t || btf_type_is_void(t); } -static __s64 btf_type_size(const struct btf_type *t) -{ - switch (BTF_INFO_KIND(t->info)) { - case BTF_KIND_INT: - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: - case BTF_KIND_ENUM: - return t->size; - case BTF_KIND_PTR: - return sizeof(void *); - default: - return -EINVAL; - } -} - #define MAX_RESOLVE_DEPTH 32 __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) @@ -280,11 +268,16 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) t = btf__type_by_id(btf, type_id); for (i = 0; i < MAX_RESOLVE_DEPTH && !btf_type_is_void_or_null(t); i++) { - size = btf_type_size(t); - if (size >= 0) - break; - switch (BTF_INFO_KIND(t->info)) { + case BTF_KIND_INT: + case BTF_KIND_STRUCT: + case BTF_KIND_UNION: + case BTF_KIND_ENUM: + size = t->size; + goto done; + case BTF_KIND_PTR: + size = sizeof(void *); + goto done; case BTF_KIND_TYPEDEF: case BTF_KIND_VOLATILE: case BTF_KIND_CONST: @@ -308,6 +301,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) if (size < 0) return -EINVAL; +done: if (nelems && size > UINT32_MAX / nelems) return -E2BIG; -- cgit v1.2.3-59-g8ed1b