From: Yonghong Song yhs@fb.com
mainline inclusion from mainline-5.17-rc1 commit 2dc1e488e5cdfd937554ca81fd46ad874d244b3f category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add libbpf support for BTF_KIND_TYPE_TAG.
Signed-off-by: Yonghong Song yhs@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20211112012614.1505315-1-yhs@fb.com (cherry picked from commit 2dc1e488e5cdfd937554ca81fd46ad874d244b3f) Signed-off-by: Wang Yufen wangyufen@huawei.com
Conflicts: tools/lib/bpf/libbpf.map
Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/btf.c | 23 +++++++++++++++++++++++ tools/lib/bpf/btf.h | 9 ++++++++- tools/lib/bpf/btf_dump.c | 9 +++++++++ tools/lib/bpf/libbpf.c | 31 ++++++++++++++++++++++++++++++- tools/lib/bpf/libbpf.map | 1 + tools/lib/bpf/libbpf_internal.h | 2 ++ 6 files changed, 73 insertions(+), 2 deletions(-)
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 2a9de5855029..5a55c473c3d6 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -299,6 +299,7 @@ static int btf_type_size(const struct btf_type *t) case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: case BTF_KIND_FLOAT: + case BTF_KIND_TYPE_TAG: return base_size; case BTF_KIND_INT: return base_size + sizeof(__u32); @@ -349,6 +350,7 @@ static int btf_bswap_type_rest(struct btf_type *t) case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: case BTF_KIND_FLOAT: + case BTF_KIND_TYPE_TAG: return 0; case BTF_KIND_INT: *(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1)); @@ -644,6 +646,7 @@ int btf__align_of(const struct btf *btf, __u32 id) case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: + case BTF_KIND_TYPE_TAG: return btf__align_of(btf, t->type); case BTF_KIND_ARRAY: return btf__align_of(btf, btf_array(t)->type); @@ -2227,6 +2230,22 @@ int btf__add_restrict(struct btf *btf, int ref_type_id) return btf_add_ref_kind(btf, BTF_KIND_RESTRICT, NULL, ref_type_id); }
+/* + * Append new BTF_KIND_TYPE_TAG type with: + * - *value*, non-empty/non-NULL tag value; + * - *ref_type_id* - referenced type ID, it might not exist yet; + * Returns: + * - >0, type ID of newly added BTF type; + * - <0, on error. + */ +int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id) +{ + if (!value|| !value[0]) + return libbpf_err(-EINVAL); + + return btf_add_ref_kind(btf, BTF_KIND_TYPE_TAG, value, ref_type_id); +} + /* * Append new BTF_KIND_FUNC type with: * - *name*, non-empty/non-NULL name; @@ -3617,6 +3636,7 @@ static int btf_dedup_prep(struct btf_dedup *d) case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: case BTF_KIND_FLOAT: + case BTF_KIND_TYPE_TAG: h = btf_hash_common(t); break; case BTF_KIND_INT: @@ -3677,6 +3697,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) case BTF_KIND_VAR: case BTF_KIND_DATASEC: case BTF_KIND_DECL_TAG: + case BTF_KIND_TYPE_TAG: return 0;
case BTF_KIND_INT: @@ -4281,6 +4302,7 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_TYPE_TAG: ref_type_id = btf_dedup_ref_type(d, t->type); if (ref_type_id < 0) return ref_type_id; @@ -4587,6 +4609,7 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct case BTF_KIND_FUNC: case BTF_KIND_VAR: case BTF_KIND_DECL_TAG: + case BTF_KIND_TYPE_TAG: return visit(&t->type, ctx);
case BTF_KIND_ARRAY: { diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index f91a91b4f0d2..b436a4f6ae2e 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -153,6 +153,7 @@ LIBBPF_API int btf__add_typedef(struct btf *btf, const char *name, int ref_type_ LIBBPF_API int btf__add_volatile(struct btf *btf, int ref_type_id); LIBBPF_API int btf__add_const(struct btf *btf, int ref_type_id); LIBBPF_API int btf__add_restrict(struct btf *btf, int ref_type_id); +LIBBPF_API int btf__add_type_tag(struct btf *btf, const char *value, int ref_type_id);
/* func and func_proto construction APIs */ LIBBPF_API int btf__add_func(struct btf *btf, const char *name, @@ -329,7 +330,8 @@ static inline bool btf_is_mod(const struct btf_type *t)
return kind == BTF_KIND_VOLATILE || kind == BTF_KIND_CONST || - kind == BTF_KIND_RESTRICT; + kind == BTF_KIND_RESTRICT || + kind == BTF_KIND_TYPE_TAG; }
static inline bool btf_is_func(const struct btf_type *t) @@ -362,6 +364,11 @@ static inline bool btf_is_decl_tag(const struct btf_type *t) return btf_kind(t) == BTF_KIND_DECL_TAG; }
+static inline bool btf_is_type_tag(const struct btf_type *t) +{ + return btf_kind(t) == BTF_KIND_TYPE_TAG; +} + static inline __u8 btf_int_encoding(const struct btf_type *t) { return BTF_INT_ENCODING(*(__u32 *)(t + 1)); diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c index 508a3e3af14a..161c14ab9f3d 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -317,6 +317,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d) case BTF_KIND_FUNC: case BTF_KIND_VAR: case BTF_KIND_DECL_TAG: + case BTF_KIND_TYPE_TAG: d->type_states[t->type].referenced = 1; break;
@@ -560,6 +561,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr) case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: + case BTF_KIND_TYPE_TAG: return btf_dump_order_type(d, t->type, through_ptr);
case BTF_KIND_FUNC_PROTO: { @@ -734,6 +736,7 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id) case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: + case BTF_KIND_TYPE_TAG: btf_dump_emit_type(d, t->type, cont_id); break; case BTF_KIND_ARRAY: @@ -1154,6 +1157,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, case BTF_KIND_CONST: case BTF_KIND_RESTRICT: case BTF_KIND_FUNC_PROTO: + case BTF_KIND_TYPE_TAG: id = t->type; break; case BTF_KIND_ARRAY: @@ -1322,6 +1326,11 @@ static void btf_dump_emit_type_chain(struct btf_dump *d, case BTF_KIND_RESTRICT: btf_dump_printf(d, " restrict"); break; + case BTF_KIND_TYPE_TAG: + btf_dump_emit_mods(d, decls); + name = btf_name_of(d, t->name_off); + btf_dump_printf(d, " __attribute__((btf_type_tag("%s")))", name); + break; case BTF_KIND_ARRAY: { const struct btf_array *a = btf_array(t); const struct btf_type *next_t; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 99af3d9f7859..238c7472250e 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -195,6 +195,8 @@ enum kern_feature_id { FEAT_BTF_FLOAT, /* BTF_KIND_DECL_TAG support */ FEAT_BTF_DECL_TAG, + /* BTF_KIND_TYPE_TAG support */ + FEAT_BTF_TYPE_TAG, __FEAT_CNT, };
@@ -2044,6 +2046,7 @@ static const char *__btf_kind_str(__u16 kind) case BTF_KIND_DATASEC: return "datasec"; case BTF_KIND_FLOAT: return "float"; case BTF_KIND_DECL_TAG: return "decl_tag"; + case BTF_KIND_TYPE_TAG: return "type_tag"; default: return "unknown"; } } @@ -2545,8 +2548,10 @@ static bool btf_needs_sanitization(struct bpf_object *obj) bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT); bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); + bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG);
- return !has_func || !has_datasec || !has_func_global || !has_float || !has_decl_tag; + return !has_func || !has_datasec || !has_func_global || !has_float || + !has_decl_tag || !has_type_tag; }
static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) @@ -2556,6 +2561,7 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT); bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); + bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG); struct btf_type *t; int i, j, vlen;
@@ -2614,6 +2620,10 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) */ t->name_off = 0; t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 0); + } else if (!has_type_tag && btf_is_type_tag(t)) { + /* replace TYPE_TAG with a CONST */ + t->name_off = 0; + t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0); } } } @@ -4442,6 +4452,22 @@ static int probe_kern_btf_decl_tag(void) strs, sizeof(strs))); }
+static int probe_kern_btf_type_tag(void) +{ + static const char strs[] = "\0tag"; + __u32 types[] = { + /* int */ + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + /* attr */ + BTF_TYPE_TYPE_TAG_ENC(1, 1), /* [2] */ + /* ptr */ + BTF_TYPE_ENC(0, BTF_INFO_ENC(BTF_KIND_PTR, 0, 0), 2), /* [3] */ + }; + + return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs))); +} + static int probe_kern_array_mmap(void) { struct bpf_create_map_attr attr = { @@ -4627,6 +4653,9 @@ static struct kern_feature_desc { [FEAT_BTF_DECL_TAG] = { "BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag, }, + [FEAT_BTF_TYPE_TAG] = { + "BTF_KIND_TYPE_TAG support", probe_kern_btf_type_tag, + }, };
static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 29585c815545..2b55dc2e7684 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -388,4 +388,5 @@ LIBBPF_0.6.0 { bpf_program__insns; btf__add_btf; btf__add_decl_tag; + btf__add_type_tag; } LIBBPF_0.5.0; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index d64cc72e453c..5835c34c8b4f 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -71,6 +71,8 @@ BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) #define BTF_TYPE_DECL_TAG_ENC(value, type, component_idx) \ BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), type), (component_idx) +#define BTF_TYPE_TYPE_TAG_ENC(value, type) \ + BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TYPE_TAG, 0, 0), type)
#ifndef likely #define likely(x) __builtin_expect(!!(x), 1)