From 8fd886911a6a99acf4a8facf619a2e7b5225be78 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:47 +0100 Subject: [PATCH 1/9] bpf: Add BTF_KIND_FLOAT to uapi Add a new kind value and expand the kind bitfield. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-2-iii@linux.ibm.com --- include/uapi/linux/btf.h | 5 +++-- tools/include/uapi/linux/btf.h | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h index 5a667107ad2cc..d27b1708efe91 100644 --- a/include/uapi/linux/btf.h +++ b/include/uapi/linux/btf.h @@ -52,7 +52,7 @@ struct btf_type { }; }; -#define BTF_INFO_KIND(info) (((info) >> 24) & 0x0f) +#define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f) #define BTF_INFO_VLEN(info) ((info) & 0xffff) #define BTF_INFO_KFLAG(info) ((info) >> 31) @@ -72,7 +72,8 @@ struct btf_type { #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ #define BTF_KIND_VAR 14 /* Variable */ #define BTF_KIND_DATASEC 15 /* Section */ -#define BTF_KIND_MAX BTF_KIND_DATASEC +#define BTF_KIND_FLOAT 16 /* Floating point */ +#define BTF_KIND_MAX BTF_KIND_FLOAT #define NR_BTF_KINDS (BTF_KIND_MAX + 1) /* For some specific BTF_KIND, "struct btf_type" is immediately diff --git a/tools/include/uapi/linux/btf.h b/tools/include/uapi/linux/btf.h index 5a667107ad2cc..d27b1708efe91 100644 --- a/tools/include/uapi/linux/btf.h +++ b/tools/include/uapi/linux/btf.h @@ -52,7 +52,7 @@ struct btf_type { }; }; -#define BTF_INFO_KIND(info) (((info) >> 24) & 0x0f) +#define BTF_INFO_KIND(info) (((info) >> 24) & 0x1f) #define BTF_INFO_VLEN(info) ((info) & 0xffff) #define BTF_INFO_KFLAG(info) ((info) >> 31) @@ -72,7 +72,8 @@ struct btf_type { #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ #define BTF_KIND_VAR 14 /* Variable */ #define BTF_KIND_DATASEC 15 /* Section */ -#define BTF_KIND_MAX BTF_KIND_DATASEC +#define BTF_KIND_FLOAT 16 /* Floating point */ +#define BTF_KIND_MAX BTF_KIND_FLOAT #define NR_BTF_KINDS (BTF_KIND_MAX + 1) /* For some specific BTF_KIND, "struct btf_type" is immediately From 1b1ce92b24331b569a444858fc487a1ca19dc778 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:48 +0100 Subject: [PATCH 2/9] libbpf: Fix whitespace in btf_add_composite() comment Remove trailing space. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-3-iii@linux.ibm.com --- tools/lib/bpf/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index d9c10830d749f..0797ab714830e 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -1883,7 +1883,7 @@ static int btf_add_composite(struct btf *btf, int kind, const char *name, __u32 * - *byte_sz* - size of the struct, in bytes; * * Struct initially has no fields in it. Fields can be added by - * btf__add_field() right after btf__add_struct() succeeds. + * btf__add_field() right after btf__add_struct() succeeds. * * Returns: * - >0, type ID of newly added BTF type; From 22541a9eeb0d968c133aaebd95fa59da3208e705 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:49 +0100 Subject: [PATCH 3/9] libbpf: Add BTF_KIND_FLOAT support The logic follows that of BTF_KIND_INT most of the time. Sanitization replaces BTF_KIND_FLOATs with equally-sized empty BTF_KIND_STRUCTs on older kernels, for example, the following: [4] FLOAT 'float' size=4 becomes the following: [4] STRUCT '(anon)' size=4 vlen=0 With dwarves patch [1] and this patch, the older kernels, which were failing with the floating-point-related errors, will now start working correctly. [1] https://github.com/iii-i/dwarves/commit/btf-kind-float-v2 Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210226202256.116518-4-iii@linux.ibm.com --- tools/lib/bpf/btf.c | 49 +++++++++++++++++++++++++++++++++ tools/lib/bpf/btf.h | 6 ++++ tools/lib/bpf/btf_dump.c | 4 +++ tools/lib/bpf/libbpf.c | 29 ++++++++++++++++++- tools/lib/bpf/libbpf.map | 5 ++++ tools/lib/bpf/libbpf_internal.h | 2 ++ 6 files changed, 94 insertions(+), 1 deletion(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 0797ab714830e..3aa58f2ac1830 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -291,6 +291,7 @@ static int btf_type_size(const struct btf_type *t) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: return base_size; case BTF_KIND_INT: return base_size + sizeof(__u32); @@ -338,6 +339,7 @@ static int btf_bswap_type_rest(struct btf_type *t) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: return 0; case BTF_KIND_INT: *(__u32 *)(t + 1) = bswap_32(*(__u32 *)(t + 1)); @@ -578,6 +580,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id) case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_DATASEC: + case BTF_KIND_FLOAT: size = t->size; goto done; case BTF_KIND_PTR: @@ -621,6 +624,7 @@ int btf__align_of(const struct btf *btf, __u32 id) switch (kind) { case BTF_KIND_INT: case BTF_KIND_ENUM: + case BTF_KIND_FLOAT: return min(btf_ptr_sz(btf), (size_t)t->size); case BTF_KIND_PTR: return btf_ptr_sz(btf); @@ -1756,6 +1760,47 @@ int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding return btf_commit_type(btf, sz); } +/* + * Append new BTF_KIND_FLOAT type with: + * - *name* - non-empty, non-NULL type name; + * - *sz* - size of the type, in bytes; + * Returns: + * - >0, type ID of newly added BTF type; + * - <0, on error. + */ +int btf__add_float(struct btf *btf, const char *name, size_t byte_sz) +{ + struct btf_type *t; + int sz, name_off; + + /* non-empty name */ + if (!name || !name[0]) + return -EINVAL; + + /* byte_sz must be one of the explicitly allowed values */ + if (byte_sz != 2 && byte_sz != 4 && byte_sz != 8 && byte_sz != 12 && + byte_sz != 16) + return -EINVAL; + + if (btf_ensure_modifiable(btf)) + return -ENOMEM; + + sz = sizeof(struct btf_type); + t = btf_add_type_mem(btf, sz); + if (!t) + return -ENOMEM; + + name_off = btf__add_str(btf, name); + if (name_off < 0) + return name_off; + + t->name_off = name_off; + t->info = btf_type_info(BTF_KIND_FLOAT, 0, 0); + t->size = byte_sz; + + return btf_commit_type(btf, sz); +} + /* it's completely legal to append BTF types with type IDs pointing forward to * types that haven't been appended yet, so we only make sure that id looks * sane, we can't guarantee that ID will always be valid @@ -3626,6 +3671,7 @@ static int btf_dedup_prep(struct btf_dedup *d) case BTF_KIND_FWD: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: h = btf_hash_common(t); break; case BTF_KIND_INT: @@ -3722,6 +3768,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id) break; case BTF_KIND_FWD: + case BTF_KIND_FLOAT: h = btf_hash_common(t); for_each_dedup_cand(d, hash_entry, h) { cand_id = (__u32)(long)hash_entry->value; @@ -3983,6 +4030,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id, return btf_compat_enum(cand_type, canon_type); case BTF_KIND_FWD: + case BTF_KIND_FLOAT: return btf_equal_common(cand_type, canon_type); case BTF_KIND_CONST: @@ -4479,6 +4527,7 @@ static int btf_dedup_remap_type(struct btf_dedup *d, __u32 type_id) switch (btf_kind(t)) { case BTF_KIND_INT: case BTF_KIND_ENUM: + case BTF_KIND_FLOAT: break; case BTF_KIND_FWD: diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 1237bcd1dd17e..029a9cfc8c2d8 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -95,6 +95,7 @@ LIBBPF_API int btf__find_str(struct btf *btf, const char *s); LIBBPF_API int btf__add_str(struct btf *btf, const char *s); LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding); +LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz); LIBBPF_API int btf__add_ptr(struct btf *btf, int ref_type_id); LIBBPF_API int btf__add_array(struct btf *btf, int index_type_id, int elem_type_id, __u32 nr_elems); @@ -294,6 +295,11 @@ static inline bool btf_is_datasec(const struct btf_type *t) return btf_kind(t) == BTF_KIND_DATASEC; } +static inline bool btf_is_float(const struct btf_type *t) +{ + return btf_kind(t) == BTF_KIND_FLOAT; +} + 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 2f9d685bd522c..5e957fcceee66 100644 --- a/tools/lib/bpf/btf_dump.c +++ b/tools/lib/bpf/btf_dump.c @@ -279,6 +279,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d) case BTF_KIND_INT: case BTF_KIND_ENUM: case BTF_KIND_FWD: + case BTF_KIND_FLOAT: break; case BTF_KIND_VOLATILE: @@ -453,6 +454,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr) switch (btf_kind(t)) { case BTF_KIND_INT: + case BTF_KIND_FLOAT: tstate->order_state = ORDERED; return 0; @@ -1133,6 +1135,7 @@ static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id, case BTF_KIND_STRUCT: case BTF_KIND_UNION: case BTF_KIND_TYPEDEF: + case BTF_KIND_FLOAT: goto done; default: pr_warn("unexpected type in decl chain, kind:%u, id:[%u]\n", @@ -1247,6 +1250,7 @@ static void btf_dump_emit_type_chain(struct btf_dump *d, switch (kind) { case BTF_KIND_INT: + case BTF_KIND_FLOAT: btf_dump_emit_mods(d, decls); name = btf_name_of(d, t->name_off); btf_dump_printf(d, "%s", name); diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 62d9ed56b0811..2f351d3ad3e72 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -178,6 +178,8 @@ enum kern_feature_id { FEAT_PROG_BIND_MAP, /* Kernel support for module BTFs */ FEAT_MODULE_BTF, + /* BTF_KIND_FLOAT support */ + FEAT_BTF_FLOAT, __FEAT_CNT, }; @@ -1946,6 +1948,7 @@ static const char *btf_kind_str(const struct btf_type *t) case BTF_KIND_FUNC_PROTO: return "func_proto"; case BTF_KIND_VAR: return "var"; case BTF_KIND_DATASEC: return "datasec"; + case BTF_KIND_FLOAT: return "float"; default: return "unknown"; } } @@ -2395,15 +2398,17 @@ static bool btf_needs_sanitization(struct bpf_object *obj) { bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC); bool has_datasec = kernel_supports(FEAT_BTF_DATASEC); + bool has_float = kernel_supports(FEAT_BTF_FLOAT); bool has_func = kernel_supports(FEAT_BTF_FUNC); - return !has_func || !has_datasec || !has_func_global; + return !has_func || !has_datasec || !has_func_global || !has_float; } static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) { bool has_func_global = kernel_supports(FEAT_BTF_GLOBAL_FUNC); bool has_datasec = kernel_supports(FEAT_BTF_DATASEC); + bool has_float = kernel_supports(FEAT_BTF_FLOAT); bool has_func = kernel_supports(FEAT_BTF_FUNC); struct btf_type *t; int i, j, vlen; @@ -2456,6 +2461,13 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) } else if (!has_func_global && btf_is_func(t)) { /* replace BTF_FUNC_GLOBAL with BTF_FUNC_STATIC */ t->info = BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0); + } else if (!has_float && btf_is_float(t)) { + /* replace FLOAT with an equally-sized empty STRUCT; + * since C compilers do not accept e.g. "float" as a + * valid struct name, make it anonymous + */ + t->name_off = 0; + t->info = BTF_INFO_ENC(BTF_KIND_STRUCT, 0, 0); } } } @@ -3927,6 +3939,18 @@ static int probe_kern_btf_datasec(void) strs, sizeof(strs))); } +static int probe_kern_btf_float(void) +{ + static const char strs[] = "\0float"; + __u32 types[] = { + /* float */ + BTF_TYPE_FLOAT_ENC(1, 4), + }; + + 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 = { @@ -4106,6 +4130,9 @@ static struct kern_feature_desc { [FEAT_MODULE_BTF] = { "module BTF support", probe_module_btf, }, + [FEAT_BTF_FLOAT] = { + "BTF_KIND_FLOAT support", probe_kern_btf_float, + }, }; static bool kernel_supports(enum kern_feature_id feat_id) diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 1c0fd2dd233a6..ec898f464ab90 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -350,3 +350,8 @@ LIBBPF_0.3.0 { xsk_setup_xdp_prog; xsk_socket__update_xskmap; } LIBBPF_0.2.0; + +LIBBPF_0.4.0 { + global: + btf__add_float; +} LIBBPF_0.3.0; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 969d0ac592bad..343f6eb05637c 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -31,6 +31,8 @@ #define BTF_MEMBER_ENC(name, type, bits_offset) (name), (type), (bits_offset) #define BTF_PARAM_ENC(name, type) (name), (type) #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size) +#define BTF_TYPE_FLOAT_ENC(name, sz) \ + BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) #ifndef likely #define likely(x) __builtin_expect(!!(x), 1) From 737e0f919a8d2a313618d8ac67d50e8223bc5d74 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:50 +0100 Subject: [PATCH 4/9] tools/bpftool: Add BTF_KIND_FLOAT support Only dumping support needs to be adjusted, the code structure follows that of BTF_KIND_INT. Example plain and JSON outputs: [4] FLOAT 'float' size=4 {"id":4,"kind":"FLOAT","name":"float","size":4} Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-5-iii@linux.ibm.com --- tools/bpf/bpftool/btf.c | 8 ++++++++ tools/bpf/bpftool/btf_dumper.c | 1 + 2 files changed, 9 insertions(+) diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index fe9e7b3a4b503..985610c3f1933 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -36,6 +36,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", [BTF_KIND_VAR] = "VAR", [BTF_KIND_DATASEC] = "DATASEC", + [BTF_KIND_FLOAT] = "FLOAT", }; struct btf_attach_table { @@ -327,6 +328,13 @@ static int dump_btf_type(const struct btf *btf, __u32 id, jsonw_end_array(w); break; } + case BTF_KIND_FLOAT: { + if (json_output) + jsonw_uint_field(w, "size", t->size); + else + printf(" size=%u", t->size); + break; + } default: break; } diff --git a/tools/bpf/bpftool/btf_dumper.c b/tools/bpf/bpftool/btf_dumper.c index 0e9310727281a..7ca54d046362c 100644 --- a/tools/bpf/bpftool/btf_dumper.c +++ b/tools/bpf/bpftool/btf_dumper.c @@ -596,6 +596,7 @@ static int __btf_dumper_type_only(const struct btf *btf, __u32 type_id, switch (BTF_INFO_KIND(t->info)) { case BTF_KIND_INT: case BTF_KIND_TYPEDEF: + case BTF_KIND_FLOAT: BTF_PRINT_ARG("%s ", btf__name_by_offset(btf, t->name_off)); break; case BTF_KIND_STRUCT: From eea154a852e827c003215f7beed3e10f05471a86 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:51 +0100 Subject: [PATCH 5/9] selftests/bpf: Use the 25th bit in the "invalid BTF_INFO" test The bit being checked by this test is no longer reserved after introducing BTF_KIND_FLOAT, so use the next one instead. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-6-iii@linux.ibm.com --- tools/testing/selftests/bpf/prog_tests/btf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 6a7ee7420701d..c294067361386 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -1903,7 +1903,7 @@ static struct btf_raw_test raw_tests[] = { .raw_types = { /* int */ /* [1] */ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), - BTF_TYPE_ENC(0, 0x10000000, 4), + BTF_TYPE_ENC(0, 0x20000000, 4), BTF_END_RAW, }, .str_sec = "", From b1828f0b04828aa8cccadf00a702f459caefeed9 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:52 +0100 Subject: [PATCH 6/9] bpf: Add BTF_KIND_FLOAT support On the kernel side, introduce a new btf_kind_operations. It is similar to that of BTF_KIND_INT, however, it does not need to handle encodings and bit offsets. Do not implement printing, since the kernel does not know how to format floating-point values. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-7-iii@linux.ibm.com --- kernel/bpf/btf.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 81 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 16e8148a28e29..c914d68f3bf83 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -173,7 +173,7 @@ #define BITS_ROUNDUP_BYTES(bits) \ (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) -#define BTF_INFO_MASK 0x8f00ffff +#define BTF_INFO_MASK 0x9f00ffff #define BTF_INT_MASK 0x0fffffff #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) @@ -280,6 +280,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", [BTF_KIND_VAR] = "VAR", [BTF_KIND_DATASEC] = "DATASEC", + [BTF_KIND_FLOAT] = "FLOAT", }; static const char *btf_type_str(const struct btf_type *t) @@ -574,6 +575,7 @@ static bool btf_type_has_size(const struct btf_type *t) case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_DATASEC: + case BTF_KIND_FLOAT: return true; } @@ -1704,6 +1706,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type, case BTF_KIND_STRUCT: case BTF_KIND_UNION: case BTF_KIND_ENUM: + case BTF_KIND_FLOAT: size = type->size; goto resolved; @@ -1849,7 +1852,7 @@ static int btf_df_check_kflag_member(struct btf_verifier_env *env, return -EINVAL; } -/* Used for ptr, array and struct/union type members. +/* Used for ptr, array struct/union and float type members. * int, enum and modifier types have their specific callback functions. */ static int btf_generic_check_kflag_member(struct btf_verifier_env *env, @@ -3675,6 +3678,81 @@ static const struct btf_kind_operations datasec_ops = { .show = btf_datasec_show, }; +static s32 btf_float_check_meta(struct btf_verifier_env *env, + const struct btf_type *t, + u32 meta_left) +{ + if (btf_type_vlen(t)) { + btf_verifier_log_type(env, t, "vlen != 0"); + return -EINVAL; + } + + if (btf_type_kflag(t)) { + btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); + return -EINVAL; + } + + if (t->size != 2 && t->size != 4 && t->size != 8 && t->size != 12 && + t->size != 16) { + btf_verifier_log_type(env, t, "Invalid type_size"); + return -EINVAL; + } + + btf_verifier_log_type(env, t, NULL); + + return 0; +} + +static int btf_float_check_member(struct btf_verifier_env *env, + const struct btf_type *struct_type, + const struct btf_member *member, + const struct btf_type *member_type) +{ + u64 start_offset_bytes; + u64 end_offset_bytes; + u64 misalign_bits; + u64 align_bytes; + u64 align_bits; + + /* Different architectures have different alignment requirements, so + * here we check only for the reasonable minimum. This way we ensure + * that types after CO-RE can pass the kernel BTF verifier. + */ + align_bytes = min_t(u64, sizeof(void *), member_type->size); + align_bits = align_bytes * BITS_PER_BYTE; + div64_u64_rem(member->offset, align_bits, &misalign_bits); + if (misalign_bits) { + btf_verifier_log_member(env, struct_type, member, + "Member is not properly aligned"); + return -EINVAL; + } + + start_offset_bytes = member->offset / BITS_PER_BYTE; + end_offset_bytes = start_offset_bytes + member_type->size; + if (end_offset_bytes > struct_type->size) { + btf_verifier_log_member(env, struct_type, member, + "Member exceeds struct_size"); + return -EINVAL; + } + + return 0; +} + +static void btf_float_log(struct btf_verifier_env *env, + const struct btf_type *t) +{ + btf_verifier_log(env, "size=%u", t->size); +} + +static const struct btf_kind_operations float_ops = { + .check_meta = btf_float_check_meta, + .resolve = btf_df_resolve, + .check_member = btf_float_check_member, + .check_kflag_member = btf_generic_check_kflag_member, + .log_details = btf_float_log, + .show = btf_df_show, +}; + static int btf_func_proto_check(struct btf_verifier_env *env, const struct btf_type *t) { @@ -3808,6 +3886,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { [BTF_KIND_FUNC_PROTO] = &func_proto_ops, [BTF_KIND_VAR] = &var_ops, [BTF_KIND_DATASEC] = &datasec_ops, + [BTF_KIND_FLOAT] = &float_ops, }; static s32 btf_check_meta(struct btf_verifier_env *env, From 7e72aad3a15c06e40e3ccd2352e5010e978f1acf Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:53 +0100 Subject: [PATCH 7/9] selftest/bpf: Add BTF_KIND_FLOAT tests Test the good variants as well as the potential malformed ones. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210226202256.116518-8-iii@linux.ibm.com --- tools/testing/selftests/bpf/btf_helpers.c | 4 + tools/testing/selftests/bpf/prog_tests/btf.c | 131 +++++++++++++++++++ tools/testing/selftests/bpf/test_btf.h | 3 + 3 files changed, 138 insertions(+) diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c index 48f90490f922b..b692e6ead9b55 100644 --- a/tools/testing/selftests/bpf/btf_helpers.c +++ b/tools/testing/selftests/bpf/btf_helpers.c @@ -23,6 +23,7 @@ static const char * const btf_kind_str_mapping[] = { [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", [BTF_KIND_VAR] = "VAR", [BTF_KIND_DATASEC] = "DATASEC", + [BTF_KIND_FLOAT] = "FLOAT", }; static const char *btf_kind_str(__u16 kind) @@ -173,6 +174,9 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id) } break; } + case BTF_KIND_FLOAT: + fprintf(out, " size=%u", t->size); + break; default: break; } diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index c294067361386..11d98d3cf949f 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -3531,6 +3531,136 @@ static struct btf_raw_test raw_tests[] = { .max_entries = 1, }, +{ + .descr = "float test #1, well-formed", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 2), /* [2] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 4), /* [3] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 8), /* [4] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 12), /* [5] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 16), /* [6] */ + BTF_STRUCT_ENC(NAME_TBD, 5, 48), /* [7] */ + BTF_MEMBER_ENC(NAME_TBD, 2, 0), + BTF_MEMBER_ENC(NAME_TBD, 3, 32), + BTF_MEMBER_ENC(NAME_TBD, 4, 64), + BTF_MEMBER_ENC(NAME_TBD, 5, 128), + BTF_MEMBER_ENC(NAME_TBD, 6, 256), + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0_Float16\0float\0double\0_Float80\0long_double" + "\0floats\0a\0b\0c\0d\0e"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 48, + .key_type_id = 1, + .value_type_id = 7, + .max_entries = 1, +}, +{ + .descr = "float test #2, invalid vlen", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 1), 4), + /* [2] */ + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0float"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 4, + .key_type_id = 1, + .value_type_id = 2, + .max_entries = 1, + .btf_load_err = true, + .err_str = "vlen != 0", +}, +{ + .descr = "float test #3, invalid kind_flag", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_FLOAT, 1, 0), 4), + /* [2] */ + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0float"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 4, + .key_type_id = 1, + .value_type_id = 2, + .max_entries = 1, + .btf_load_err = true, + .err_str = "Invalid btf_info kind_flag", +}, +{ + .descr = "float test #4, member does not fit", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 4), /* [2] */ + BTF_STRUCT_ENC(NAME_TBD, 1, 2), /* [3] */ + BTF_MEMBER_ENC(NAME_TBD, 2, 0), + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0float\0floats\0x"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 4, + .key_type_id = 1, + .value_type_id = 3, + .max_entries = 1, + .btf_load_err = true, + .err_str = "Member exceeds struct_size", +}, +{ + .descr = "float test #5, member is not properly aligned", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 4), /* [2] */ + BTF_STRUCT_ENC(NAME_TBD, 1, 8), /* [3] */ + BTF_MEMBER_ENC(NAME_TBD, 2, 8), + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0float\0floats\0x"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 4, + .key_type_id = 1, + .value_type_id = 3, + .max_entries = 1, + .btf_load_err = true, + .err_str = "Member is not properly aligned", +}, +{ + .descr = "float test #6, invalid size", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), + /* [1] */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 6), /* [2] */ + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0float"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "float_type_check_btf", + .key_size = sizeof(int), + .value_size = 6, + .key_type_id = 1, + .value_type_id = 2, + .max_entries = 1, + .btf_load_err = true, + .err_str = "Invalid type_size", +}, + }; /* struct btf_raw_test raw_tests[] */ static const char *get_next_str(const char *start, const char *end) @@ -6630,6 +6760,7 @@ static int btf_type_size(const struct btf_type *t) case BTF_KIND_PTR: case BTF_KIND_TYPEDEF: case BTF_KIND_FUNC: + case BTF_KIND_FLOAT: return base_size; case BTF_KIND_INT: return base_size + sizeof(__u32); diff --git a/tools/testing/selftests/bpf/test_btf.h b/tools/testing/selftests/bpf/test_btf.h index 2023725f19628..e2394eea4b7f8 100644 --- a/tools/testing/selftests/bpf/test_btf.h +++ b/tools/testing/selftests/bpf/test_btf.h @@ -66,4 +66,7 @@ #define BTF_FUNC_ENC(name, func_proto) \ BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FUNC, 0, 0), func_proto) +#define BTF_TYPE_FLOAT_ENC(name, sz) \ + BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz) + #endif /* _TEST_BTF_H */ From 7999cf7df899caf244236dcc11cce844347dab4a Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:54 +0100 Subject: [PATCH 8/9] selftests/bpf: Add BTF_KIND_FLOAT to the existing deduplication tests Check that floats don't interfere with struct deduplication, that they are not merged with another kinds and that floats of different sizes are not merged with each other. Suggested-by: Andrii Nakryiko Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210226202256.116518-9-iii@linux.ibm.com --- tools/testing/selftests/bpf/prog_tests/btf.c | 43 ++++++++++++++------ 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 11d98d3cf949f..0457ae32b2702 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -6411,11 +6411,12 @@ const struct btf_dedup_test dedup_tests[] = { /* int[16] */ BTF_TYPE_ARRAY_ENC(1, 1, 16), /* [2] */ /* struct s { */ - BTF_STRUCT_ENC(NAME_NTH(2), 4, 84), /* [3] */ + BTF_STRUCT_ENC(NAME_NTH(2), 5, 88), /* [3] */ BTF_MEMBER_ENC(NAME_NTH(3), 4, 0), /* struct s *next; */ BTF_MEMBER_ENC(NAME_NTH(4), 5, 64), /* const int *a; */ BTF_MEMBER_ENC(NAME_NTH(5), 2, 128), /* int b[16]; */ BTF_MEMBER_ENC(NAME_NTH(6), 1, 640), /* int c; */ + BTF_MEMBER_ENC(NAME_NTH(8), 13, 672), /* float d; */ /* ptr -> [3] struct s */ BTF_PTR_ENC(3), /* [4] */ /* ptr -> [6] const int */ @@ -6426,39 +6427,43 @@ const struct btf_dedup_test dedup_tests[] = { /* full copy of the above */ BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 32, 4), /* [7] */ BTF_TYPE_ARRAY_ENC(7, 7, 16), /* [8] */ - BTF_STRUCT_ENC(NAME_NTH(2), 4, 84), /* [9] */ + BTF_STRUCT_ENC(NAME_NTH(2), 5, 88), /* [9] */ BTF_MEMBER_ENC(NAME_NTH(3), 10, 0), BTF_MEMBER_ENC(NAME_NTH(4), 11, 64), BTF_MEMBER_ENC(NAME_NTH(5), 8, 128), BTF_MEMBER_ENC(NAME_NTH(6), 7, 640), + BTF_MEMBER_ENC(NAME_NTH(8), 13, 672), BTF_PTR_ENC(9), /* [10] */ BTF_PTR_ENC(12), /* [11] */ BTF_CONST_ENC(7), /* [12] */ + BTF_TYPE_FLOAT_ENC(NAME_NTH(7), 4), /* [13] */ BTF_END_RAW, }, - BTF_STR_SEC("\0int\0s\0next\0a\0b\0c\0"), + BTF_STR_SEC("\0int\0s\0next\0a\0b\0c\0float\0d"), }, .expect = { .raw_types = { /* int */ - BTF_TYPE_INT_ENC(NAME_NTH(4), BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_TYPE_INT_ENC(NAME_NTH(5), BTF_INT_SIGNED, 0, 32, 4), /* [1] */ /* int[16] */ BTF_TYPE_ARRAY_ENC(1, 1, 16), /* [2] */ /* struct s { */ - BTF_STRUCT_ENC(NAME_NTH(6), 4, 84), /* [3] */ - BTF_MEMBER_ENC(NAME_NTH(5), 4, 0), /* struct s *next; */ + BTF_STRUCT_ENC(NAME_NTH(8), 5, 88), /* [3] */ + BTF_MEMBER_ENC(NAME_NTH(7), 4, 0), /* struct s *next; */ BTF_MEMBER_ENC(NAME_NTH(1), 5, 64), /* const int *a; */ BTF_MEMBER_ENC(NAME_NTH(2), 2, 128), /* int b[16]; */ BTF_MEMBER_ENC(NAME_NTH(3), 1, 640), /* int c; */ + BTF_MEMBER_ENC(NAME_NTH(4), 7, 672), /* float d; */ /* ptr -> [3] struct s */ BTF_PTR_ENC(3), /* [4] */ /* ptr -> [6] const int */ BTF_PTR_ENC(6), /* [5] */ /* const -> [1] int */ BTF_CONST_ENC(1), /* [6] */ + BTF_TYPE_FLOAT_ENC(NAME_NTH(7), 4), /* [7] */ BTF_END_RAW, }, - BTF_STR_SEC("\0a\0b\0c\0int\0next\0s"), + BTF_STR_SEC("\0a\0b\0c\0d\0int\0float\0next\0s"), }, .opts = { .dont_resolve_fwds = false, @@ -6579,9 +6584,10 @@ const struct btf_dedup_test dedup_tests[] = { BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8), BTF_FUNC_ENC(NAME_TBD, 12), /* [13] func */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 2), /* [14] float */ BTF_END_RAW, }, - BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M"), + BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N"), }, .expect = { .raw_types = { @@ -6604,16 +6610,17 @@ const struct btf_dedup_test dedup_tests[] = { BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1), BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8), BTF_FUNC_ENC(NAME_TBD, 12), /* [13] func */ + BTF_TYPE_FLOAT_ENC(NAME_TBD, 2), /* [14] float */ BTF_END_RAW, }, - BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M"), + BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N"), }, .opts = { .dont_resolve_fwds = false, }, }, { - .descr = "dedup: no int duplicates", + .descr = "dedup: no int/float duplicates", .input = { .raw_types = { BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 32, 8), @@ -6628,9 +6635,15 @@ const struct btf_dedup_test dedup_tests[] = { BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 27, 8), /* different byte size */ BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 32, 4), + /* all allowed sizes */ + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 2), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 4), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 8), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 12), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 16), BTF_END_RAW, }, - BTF_STR_SEC("\0int\0some other int"), + BTF_STR_SEC("\0int\0some other int\0float"), }, .expect = { .raw_types = { @@ -6646,9 +6659,15 @@ const struct btf_dedup_test dedup_tests[] = { BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 27, 8), /* different byte size */ BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 32, 4), + /* all allowed sizes */ + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 2), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 4), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 8), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 12), + BTF_TYPE_FLOAT_ENC(NAME_NTH(3), 16), BTF_END_RAW, }, - BTF_STR_SEC("\0int\0some other int"), + BTF_STR_SEC("\0int\0some other int\0float"), }, .opts = { .dont_resolve_fwds = false, From 6be6a0baffc1357b6d2023155753f111624c4fec Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 26 Feb 2021 21:22:56 +0100 Subject: [PATCH 9/9] bpf: Document BTF_KIND_FLOAT in btf.rst Also document the expansion of the kind bitfield. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20210226202256.116518-11-iii@linux.ibm.com --- Documentation/bpf/btf.rst | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst index 44dc789de2b49..846354cd2d69e 100644 --- a/Documentation/bpf/btf.rst +++ b/Documentation/bpf/btf.rst @@ -84,6 +84,7 @@ sequentially and type id is assigned to each recognized type starting from id #define BTF_KIND_FUNC_PROTO 13 /* Function Proto */ #define BTF_KIND_VAR 14 /* Variable */ #define BTF_KIND_DATASEC 15 /* Section */ + #define BTF_KIND_FLOAT 16 /* Floating point */ Note that the type section encodes debug info, not just pure types. ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram. @@ -95,8 +96,8 @@ Each type contains the following common data:: /* "info" bits arrangement * bits 0-15: vlen (e.g. # of struct's members) * bits 16-23: unused - * bits 24-27: kind (e.g. int, ptr, array...etc) - * bits 28-30: unused + * bits 24-28: kind (e.g. int, ptr, array...etc) + * bits 29-30: unused * bit 31: kind_flag, currently used by * struct, union and fwd */ @@ -452,6 +453,18 @@ map definition. * ``offset``: the in-section offset of the variable * ``size``: the size of the variable in bytes +2.2.16 BTF_KIND_FLOAT +~~~~~~~~~~~~~~~~~~~~~ + +``struct btf_type`` encoding requirement: + * ``name_off``: any valid offset + * ``info.kind_flag``: 0 + * ``info.kind``: BTF_KIND_FLOAT + * ``info.vlen``: 0 + * ``size``: the size of the float type in bytes: 2, 4, 8, 12 or 16. + +No additional type data follow ``btf_type``. + 3. BTF Kernel API *****************