From patchwork Wed Sep 8 15:35:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hengqi Chen X-Patchwork-Id: 12481385 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=-20.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 98E2EC433EF for ; Wed, 8 Sep 2021 15:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 761086103E for ; Wed, 8 Sep 2021 15:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235992AbhIHPhH (ORCPT ); Wed, 8 Sep 2021 11:37:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235441AbhIHPhG (ORCPT ); Wed, 8 Sep 2021 11:37:06 -0400 Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 268BAC061575 for ; Wed, 8 Sep 2021 08:35:59 -0700 (PDT) Received: by mail-pg1-x52e.google.com with SMTP id w7so2980364pgk.13 for ; Wed, 08 Sep 2021 08:35:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5THeVPjlz5mHu6wptsoRq2zUg/vecY8txoTSBglnhfU=; b=EH3WvulbuyG8a2BaItgcUVwF+cQvpmLZfNdTAzAJZ2nq/pmy3mh5BRd+DLJfm9Ngcv 3GlH9dqwExSUFLrC6SZlS4OI4ITUX0m9SxBCsfsAVB7dZ8CA48/FWFr2WLvZJH9TgpEv yKhEEvmNuZQrVqZKz9qAcvilr0NH15ePz5q4RzrW7yPNUrP4yxIiFOkrGmG7Y/+eVa0O qcoWp9Ik6tViRdAqbWA4tVX3rI3C1gW9fjdsJi0q/sKvwJTXKDIllyAESh3zenjUeuRV HW2OJsFdvWhDiz71TGiEsR5g67uLVBGAo3u9+Trlouu2bS7gx9nE9cR7B852idY+yK6E 8ptg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=5THeVPjlz5mHu6wptsoRq2zUg/vecY8txoTSBglnhfU=; b=bwRp0KXKQ347jV5MjKYyA8AdWiDqjA/uW9D6we8EcIuOroL6BUwH/+WH+Dcgo1UXWu 0rkz8X1CA62BMCJxQ0HTnFF6yMQJ/dSvbDcsoS/Xmm+W/ryjNxYaFwPCE/+c1JR2k0tb 0xiC8uGjs6b6m6PAwHBCo8lt0fvjRFwNhOrqbj1mxLbEHW2As3h7pP1DroSDx3c3Ex8d PJ0puWiJFL9U66V1JYhADUG+y3AeWiWyB+CIVfpJnDZguRueu+xH8gbE+wTlYkeWnsvI /JooXkPM7lRyywds18tHEo2eaEAUerZztho+ltD1HIBNnz0xyrG9qUNed/LVEJsTWoI6 PqRA== X-Gm-Message-State: AOAM5302YIQnEuGmqqItVpB5kwN3cUgVHBPLjFPusdUmT0pcN0NJr3m5 +BKwAJZD/xwGFOLtzMwb31ia5vapDSdLUA== X-Google-Smtp-Source: ABdhPJwFVY9/wIRB783leYX0/BKmDkHnRz/HWGoFVfMU4/dfoQZd+ykzzfxXr+ttB5/+1/kEdFYTPw== X-Received: by 2002:aa7:8893:0:b0:416:4ed7:e4c4 with SMTP id z19-20020aa78893000000b004164ed7e4c4mr4292801pfe.83.1631115358527; Wed, 08 Sep 2021 08:35:58 -0700 (PDT) Received: from localhost.localdomain ([119.28.83.143]) by smtp.gmail.com with ESMTPSA id l23sm2588245pji.45.2021.09.08.08.35.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Sep 2021 08:35:58 -0700 (PDT) From: Hengqi Chen To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, yhs@fb.com, john.fastabend@gmail.com, hengqi.chen@gmail.com Subject: [PATCH bpf-next] libbpf: deprecate bpf_object__unload() API Date: Wed, 8 Sep 2021 23:35:44 +0800 Message-Id: <20210908153544.749101-1-hengqi.chen@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net BPF objects are not re-loadable after unload. User are expected to use bpf_object__close() to unload and free up resources in one operation. No need to expose bpf_object__unload() as a public API, deprecate it.[0] Remove bpf_object__unload() inside bpf_object__load_xattr(), it is the caller's responsibility to free up resources, otherwise, the following code path will cause double-free problem when loading failed: bpf_prog_load bpf_prog_load_xattr bpf_object__load bpf_object__load_xattr Replace bpf_object__unload() inside bpf_object__close() with the necessary cleanup operations to avoid compilation error. [0] Closes: https://github.com/libbpf/libbpf/issues/290 Signed-off-by: Hengqi Chen --- tools/lib/bpf/libbpf.c | 8 +++++--- tools/lib/bpf/libbpf.h | 3 ++- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 8f579c6666b2..c56b466c5461 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -6931,7 +6931,6 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr) if (obj->maps[i].pinned && !obj->maps[i].reused) bpf_map__unpin(&obj->maps[i], NULL); - bpf_object__unload(obj); pr_warn("failed to load object '%s'\n", obj->path); return libbpf_err(err); } @@ -7540,12 +7539,15 @@ void bpf_object__close(struct bpf_object *obj) bpf_gen__free(obj->gen_loader); bpf_object__elf_finish(obj); - bpf_object__unload(obj); btf__free(obj->btf); btf_ext__free(obj->btf_ext); - for (i = 0; i < obj->nr_maps; i++) + for (i = 0; i < obj->nr_maps; i++) { + zclose(obj->maps[i].fd); + if (obj->maps[i].st_ops) + zfree(&obj->maps[i].st_ops->kern_vdata); bpf_map__destroy(&obj->maps[i]); + } zfree(&obj->btf_custom_path); zfree(&obj->kconfig); diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 2f6f0e15d1e7..748f7dabe4c7 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -147,7 +147,8 @@ struct bpf_object_load_attr { /* Load/unload object into/from kernel */ LIBBPF_API int bpf_object__load(struct bpf_object *obj); LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr); -LIBBPF_API int bpf_object__unload(struct bpf_object *obj); +LIBBPF_API LIBBPF_DEPRECATED("bpf_object__unload() is deprecated, use bpf_object__close() instead") +int bpf_object__unload(struct bpf_object *obj); LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);