From patchwork Mon Feb 22 21:49:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ilya Leoshkevich X-Patchwork-Id: 12099563 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 011EBC433DB for ; Mon, 22 Feb 2021 21:51:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDB8164E05 for ; Mon, 22 Feb 2021 21:51:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230235AbhBVVvj (ORCPT ); Mon, 22 Feb 2021 16:51:39 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57102 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230036AbhBVVvg (ORCPT ); Mon, 22 Feb 2021 16:51:36 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 11MLWinv169696; Mon, 22 Feb 2021 16:50:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=6rmpCKDZimLq3usXEGvqqQrv0uxcw8o6FDY0JXm6qYs=; b=E+V3gJ9bkkJSAaYS3lLQFcvnAq0AYPJdza9j5rMGeDdslI6HZQkuWvTS9lhQW7QU2EVc kvfl0DlOPkmTcilv3yimo2iIdLszVvB4K+nyEjVuODdMPli7FZzo+oeo2ECaZVXUsZ/u omBGQgo2fteWoSispxAK2KJhZsX46wZRFJ8R7TU4Nv9gFLO55IgPlatmQEvcWGsAw+Ru 4Z10p4Q53PxbbP4XDmKsc03bHNnOFObZuYRY2q+ch1eexmOu4It93C0SRlnRCtHGVYA5 719bXsXjJ0rUY7ptgrPpLv1mDp/kwZL/7kzKbeFznskowv5/0MoEWYVtKJR6dMw7Lzwu Bw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 36vkm9jm28-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Feb 2021 16:50:41 -0500 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 11MLXgDw172937; Mon, 22 Feb 2021 16:50:41 -0500 Received: from ppma06ams.nl.ibm.com (66.31.33a9.ip4.static.sl-reverse.com [169.51.49.102]) by mx0a-001b2d01.pphosted.com with ESMTP id 36vkm9jm1c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Feb 2021 16:50:40 -0500 Received: from pps.filterd (ppma06ams.nl.ibm.com [127.0.0.1]) by ppma06ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 11MLm1gB018396; Mon, 22 Feb 2021 21:50:39 GMT Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by ppma06ams.nl.ibm.com with ESMTP id 36tsph21h6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Feb 2021 21:50:39 +0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 11MLoa6i42795418 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 22 Feb 2021 21:50:36 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2CFE5A4051; Mon, 22 Feb 2021 21:50:36 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9886BA4053; Mon, 22 Feb 2021 21:50:35 +0000 (GMT) Received: from vm.lan (unknown [9.145.151.190]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 22 Feb 2021 21:50:35 +0000 (GMT) From: Ilya Leoshkevich To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Yonghong Song , Arnaldo Carvalho de Melo , John Fastabend Cc: bpf@vger.kernel.org, Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich Subject: [PATCH v4 bpf-next 2/7] libbpf: Add BTF_KIND_FLOAT support Date: Mon, 22 Feb 2021 22:49:12 +0100 Message-Id: <20210222214917.83629-3-iii@linux.ibm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210222214917.83629-1-iii@linux.ibm.com> References: <20210222214917.83629-1-iii@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-02-22_07:2021-02-22,2021-02-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 suspectscore=0 phishscore=0 priorityscore=1501 adultscore=0 malwarescore=0 lowpriorityscore=0 mlxscore=0 clxscore=1015 mlxlogscore=999 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2102220187 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The logic follows that of BTF_KIND_INT most of the time. Sanitization replaces BTF_KIND_FLOATs with BTF_KIND_CONSTs pointing to equally-sized BTF_KIND_ARRAYs on older kernels, for example, the following: [4] FLOAT 'float' size=4 becomes the following: [4] CONST '(anon)' type_id=10 ... [8] INT 'unsigned int' size=4 bits_offset=0 nr_bits=32 encoding=(none) [9] INT 'unsigned char' size=1 bits_offset=0 nr_bits=8 encoding=(none) [10] ARRAY '(anon)' type_id=9 index_type_id=8 nr_elems=4 Signed-off-by: Ilya Leoshkevich --- tools/lib/bpf/btf.c | 44 +++++++++++++++++ tools/lib/bpf/btf.h | 8 ++++ tools/lib/bpf/btf_dump.c | 4 ++ tools/lib/bpf/libbpf.c | 84 +++++++++++++++++++++++++++++++-- tools/lib/bpf/libbpf.map | 5 ++ tools/lib/bpf/libbpf_internal.h | 2 + 6 files changed, 142 insertions(+), 5 deletions(-) diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index fdfff544f59a..1ebfcc687dab 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -292,6 +292,7 @@ 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); @@ -339,6 +340,7 @@ 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)); @@ -579,6 +581,7 @@ __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: @@ -622,6 +625,7 @@ 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); @@ -2400,6 +2404,42 @@ int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz) 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; + + 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); +} + /* * Append new data section variable information entry for current DATASEC type: * - *var_type_id* - type ID, describing type of the variable; @@ -3653,6 +3693,7 @@ 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: @@ -3749,6 +3790,7 @@ 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; @@ -4010,6 +4052,7 @@ 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: @@ -4506,6 +4549,7 @@ 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 1237bcd1dd17..c3b11bcebeda 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -132,6 +132,9 @@ LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __u32 byte_sz); +/* float construction APIs */ +LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz); + struct btf_dedup_opts { unsigned int dedup_table_size; bool dont_resolve_fwds; @@ -294,6 +297,11 @@ 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 2f9d685bd522..5e957fcceee6 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 d43cc3f29dae..45682820a6e8 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, }; @@ -1935,6 +1937,7 @@ 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"; } } @@ -2384,18 +2387,37 @@ 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) +static int btf_ensure_int(struct btf *btf, int *id, const char *name, + size_t byte_sz, int encoding) +{ + if (*id) + return 0; + + *id = btf__add_int(btf, name, byte_sz, encoding); + if (*id < 0) { + pr_warn("Error adding %s BTF type: %d.\n", name, *id); + return *id; + } + + return 0; +} + +static int 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); + int err, i, j, vlen; struct btf_type *t; - int i, j, vlen; + int uchar_id = 0; + int uint_id = 0; for (i = 1; i <= btf__get_nr_types(btf); i++) { t = (struct btf_type *)btf__type_by_id(btf, i); @@ -2445,8 +2467,35 @@ 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 CONST(u8[]) */ + int array_id; + __u32 size; + + size = t->size; + err = btf_ensure_int(btf, &uint_id, "unsigned int", 4, 0); + if (err) + return err; + err = btf_ensure_int(btf, &uchar_id, "unsigned char", 1, 0); + if (err) + return err; + array_id = btf__add_array(btf, uint_id, uchar_id, size); + if (array_id < 0) { + pr_warn("Error adding unsigned char[%" PRIu32 "] BTF type: %d.\n", + t->size, array_id); + return array_id; + } + + /* adding new types may have invalidated t */ + t = (struct btf_type *)btf__type_by_id(btf, i); + + t->name_off = 0; + t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0); + t->type = array_id; } } + + return 0; } static bool libbpf_needs_btf(const struct bpf_object *obj) @@ -2585,6 +2634,7 @@ static int bpf_object__load_vmlinux_btf(struct bpf_object *obj, bool force) static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) { + const char *action = "loading .BTF into kernel"; struct btf *kern_btf = obj->btf; bool btf_mandatory, sanitize; int err = 0; @@ -2614,7 +2664,12 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) /* enforce 8-byte pointers for BPF-targeted BTFs */ btf__set_pointer_size(obj->btf, 8); - bpf_object__sanitize_btf(obj, kern_btf); + err = bpf_object__sanitize_btf(obj, kern_btf); + if (err) { + btf__free(kern_btf); + action = "sanitizing .BTF"; + goto report; + } } err = btf__load(kern_btf); @@ -2629,7 +2684,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) report: if (err) { btf_mandatory = kernel_needs_btf(obj); - pr_warn("Error loading .BTF into kernel: %d. %s\n", err, + pr_warn("Error %s: %d. %s\n", action, err, btf_mandatory ? "BTF is mandatory, can't proceed." : "BTF is optional, ignoring."); if (!btf_mandatory) @@ -3882,6 +3937,18 @@ 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 = { @@ -4061,6 +4128,9 @@ 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) @@ -4940,6 +5010,8 @@ static int bpf_core_fields_are_compat(const struct btf *local_btf, local_id = btf_array(local_type)->type; targ_id = btf_array(targ_type)->type; goto recur; + case BTF_KIND_FLOAT: + return local_type->size == targ_type->size; default: pr_warn("unexpected kind %d relocated, local [%d], target [%d]\n", btf_kind(local_type), local_id, targ_id); @@ -5122,6 +5194,8 @@ static int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id); goto recur; } + case BTF_KIND_FLOAT: + return local_type->size == targ_type->size; default: pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n", btf_kind_str(local_type), local_id, targ_id); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 1c0fd2dd233a..ec898f464ab9 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 969d0ac592ba..343f6eb05637 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)