From patchwork Tue Mar 21 20:38:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 13183259 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 357F2C6FD1D for ; Tue, 21 Mar 2023 20:39:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229508AbjCUUjN (ORCPT ); Tue, 21 Mar 2023 16:39:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230115AbjCUUjK (ORCPT ); Tue, 21 Mar 2023 16:39:10 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E1E23B862; Tue, 21 Mar 2023 13:39:09 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id kq3so4945166plb.13; Tue, 21 Mar 2023 13:39:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1679431149; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Hlp+Ui1dMfarlEBa998LNtp9z3tMlr+TDoifOg7iOB0=; b=ZKA+LjZP7Qd0izBYnfaud7ZiAZAxTuO07Cbi8bLClSyVmrffdKJRpQYh8kTydZzZ+z qyLXMP17NmKMUcJY9+ISRULrYJIaLzBnRGS9Vd4oLw1qpVfhHSc2NLzBpNV/4EqmobM7 BT4jlCMdpTItjhZshpiPmKSeqdwmk+qpo0otRmG5U45RdBSgp6svpY4Do+QyaiHER4mI Sw7byk4QLK1IRSCrCdmDGad+BVJQSkzbLVT5f9Nb4Dq8WDMeCmadtjLqQcMP3/BpBnL+ v25T+e69crpXrI42iortoQ0mZCcWbI3Zp5RztmfWHmbtgocTBww7lXdJ0ZegTM0m+cs0 ZWiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679431149; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Hlp+Ui1dMfarlEBa998LNtp9z3tMlr+TDoifOg7iOB0=; b=NnYWZ8Hj02xYcsIpZxXe+uINgmhbNEygSD8nrhBUbIeg3PHQfBZG3vWN0Vn7d3Rqm3 7QSYQvIrlxpHKsLSlBgaIJG7mmbXTbUCN7H9gLWd0oWifEDXfUV28zDSctXf0hNdE28J JS93+FxlHtFaBtgWi47hGHhP2QGjx6d6u3MhsgCTac+HSe5TVo/DQO2lvhj1tTI+hqV6 l0woPTG36cbQGFdKVCoB5YOChMCP9q3lDqJ+9AyE6B70qUlGifZMs9iLdzWw8LMB5ykY iCPe9su/V5YxoMv9c4ClZcPDw7GZEIoZBgcJUd9Drg5DdUsqtsqAKDCLl0KABzRqtWrY uj/A== X-Gm-Message-State: AO0yUKVxNObpj/u6txjdxYOF1U1T14K7gVvfSpHi9OcWNIW+IQdiVGog rFEpVmDGXZAeM4vWE7xeyrI= X-Google-Smtp-Source: AK7set87Le+EgWstCpX+zsRd8jFVB2e2cCpMhTRgS+zPB+fhpz3WDCgi6i+g3u65B7puybVv5292fA== X-Received: by 2002:a17:90b:3b46:b0:23b:50ff:59ba with SMTP id ot6-20020a17090b3b4600b0023b50ff59bamr1018463pjb.21.1679431148654; Tue, 21 Mar 2023 13:39:08 -0700 (PDT) Received: from macbook-pro-6.dhcp.thefacebook.com ([2620:10d:c090:500::5:34cf]) by smtp.gmail.com with ESMTPSA id i5-20020a17090aa90500b002311c4596f6sm10549938pjq.54.2023.03.21.13.39.07 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 21 Mar 2023 13:39:08 -0700 (PDT) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, void@manifault.com, davemarchevsky@meta.com, tj@kernel.org, memxor@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH v2 bpf-next 3/4] libbpf: Support kfunc detection in light skeleton. Date: Tue, 21 Mar 2023 13:38:53 -0700 Message-Id: <20230321203854.3035-4-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.37.1 (Apple Git-137.1) In-Reply-To: <20230321203854.3035-1-alexei.starovoitov@gmail.com> References: <20230321203854.3035-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Alexei Starovoitov Teach gen_loader to find {btf_id, btf_obj_fd} of kernel variables and kfuncs and populate corresponding ld_imm64 and bpf_call insns. Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf_gen_internal.h | 4 +++- tools/lib/bpf/gen_loader.c | 38 ++++++++++++++++---------------- tools/lib/bpf/libbpf.c | 7 ++++-- 3 files changed, 27 insertions(+), 22 deletions(-) diff --git a/tools/lib/bpf/bpf_gen_internal.h b/tools/lib/bpf/bpf_gen_internal.h index 223308931d55..fdf44403ff36 100644 --- a/tools/lib/bpf/bpf_gen_internal.h +++ b/tools/lib/bpf/bpf_gen_internal.h @@ -11,6 +11,7 @@ struct ksym_relo_desc { int insn_idx; bool is_weak; bool is_typeless; + bool is_ld64; }; struct ksym_desc { @@ -24,6 +25,7 @@ struct ksym_desc { bool typeless; }; int insn; + bool is_ld64; }; struct bpf_gen { @@ -65,7 +67,7 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx); void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum bpf_attach_type type); void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, - bool is_typeless, int kind, int insn_idx); + bool is_typeless, bool is_ld64, int kind, int insn_idx); void bpf_gen__record_relo_core(struct bpf_gen *gen, const struct bpf_core_relo *core_relo); void bpf_gen__populate_outer_map(struct bpf_gen *gen, int outer_map_idx, int key, int inner_map_idx); diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c index b74c82bb831e..83e8e3bfd8ff 100644 --- a/tools/lib/bpf/gen_loader.c +++ b/tools/lib/bpf/gen_loader.c @@ -560,7 +560,7 @@ static void emit_find_attach_target(struct bpf_gen *gen) } void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, - bool is_typeless, int kind, int insn_idx) + bool is_typeless, bool is_ld64, int kind, int insn_idx) { struct ksym_relo_desc *relo; @@ -574,6 +574,7 @@ void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, relo->name = name; relo->is_weak = is_weak; relo->is_typeless = is_typeless; + relo->is_ld64 = is_ld64; relo->kind = kind; relo->insn_idx = insn_idx; gen->relo_cnt++; @@ -586,9 +587,11 @@ static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_des int i; for (i = 0; i < gen->nr_ksyms; i++) { - if (!strcmp(gen->ksyms[i].name, relo->name)) { - gen->ksyms[i].ref++; - return &gen->ksyms[i]; + kdesc = &gen->ksyms[i]; + if (kdesc->kind == relo->kind && kdesc->is_ld64 == relo->is_ld64 && + !strcmp(kdesc->name, relo->name)) { + kdesc->ref++; + return kdesc; } } kdesc = libbpf_reallocarray(gen->ksyms, gen->nr_ksyms + 1, sizeof(*kdesc)); @@ -603,6 +606,7 @@ static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_des kdesc->ref = 1; kdesc->off = 0; kdesc->insn = 0; + kdesc->is_ld64 = relo->is_ld64; return kdesc; } @@ -864,23 +868,17 @@ static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn { int insn; - pr_debug("gen: emit_relo (%d): %s at %d\n", relo->kind, relo->name, relo->insn_idx); + pr_debug("gen: emit_relo (%d): %s at %d %s\n", + relo->kind, relo->name, relo->insn_idx, relo->is_ld64 ? "ld64" : "call"); insn = insns + sizeof(struct bpf_insn) * relo->insn_idx; emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn)); - switch (relo->kind) { - case BTF_KIND_VAR: + if (relo->is_ld64) { if (relo->is_typeless) emit_relo_ksym_typeless(gen, relo, insn); else emit_relo_ksym_btf(gen, relo, insn); - break; - case BTF_KIND_FUNC: + } else { emit_relo_kfunc_btf(gen, relo, insn); - break; - default: - pr_warn("Unknown relocation kind '%d'\n", relo->kind); - gen->error = -EDOM; - return; } } @@ -903,18 +901,20 @@ static void cleanup_core_relo(struct bpf_gen *gen) static void cleanup_relos(struct bpf_gen *gen, int insns) { + struct ksym_desc *kdesc; int i, insn; for (i = 0; i < gen->nr_ksyms; i++) { + kdesc = &gen->ksyms[i]; /* only close fds for typed ksyms and kfuncs */ - if (gen->ksyms[i].kind == BTF_KIND_VAR && !gen->ksyms[i].typeless) { + if (kdesc->is_ld64 && !kdesc->typeless) { /* close fd recorded in insn[insn_idx + 1].imm */ - insn = gen->ksyms[i].insn; + insn = kdesc->insn; insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm); emit_sys_close_blob(gen, insn); - } else if (gen->ksyms[i].kind == BTF_KIND_FUNC) { - emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off)); - if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ) + } else if (!kdesc->is_ld64) { + emit_sys_close_blob(gen, blob_fd_array_off(gen, kdesc->off)); + if (kdesc->off < MAX_FD_ARRAY_SZ) gen->nr_fd_array--; } } diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f8131f963803..5d32aa8ea38a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7070,18 +7070,21 @@ static int bpf_program_record_relos(struct bpf_program *prog) for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct extern_desc *ext = &obj->externs[relo->sym_off]; + int kind; switch (relo->type) { case RELO_EXTERN_LD64: if (ext->type != EXT_KSYM) continue; + kind = btf_is_var(btf__type_by_id(obj->btf, ext->btf_id)) ? + BTF_KIND_VAR : BTF_KIND_FUNC; bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak, !ext->ksym.type_id, - BTF_KIND_VAR, relo->insn_idx); + true, kind, relo->insn_idx); break; case RELO_EXTERN_CALL: bpf_gen__record_extern(obj->gen_loader, ext->name, - ext->is_weak, false, BTF_KIND_FUNC, + ext->is_weak, false, false, BTF_KIND_FUNC, relo->insn_idx); break; case RELO_CORE: {