From patchwork Wed Jan 25 16:47:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Vernet X-Patchwork-Id: 13115859 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 01671C27C76 for ; Wed, 25 Jan 2023 16:47:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235673AbjAYQrq (ORCPT ); Wed, 25 Jan 2023 11:47:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235644AbjAYQrp (ORCPT ); Wed, 25 Jan 2023 11:47:45 -0500 Received: from mail-yw1-f175.google.com (mail-yw1-f175.google.com [209.85.128.175]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7AEA10D7; Wed, 25 Jan 2023 08:47:43 -0800 (PST) Received: by mail-yw1-f175.google.com with SMTP id 00721157ae682-4fd37a1551cso247167597b3.13; Wed, 25 Jan 2023 08:47:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=GXEvYhVDnMHXNpqr41k3IdTNthtzRVxr3+zGczCqXyE=; b=Vj3mRByIac6HCB6wepeCufmGmkpQgfJ8Ux/SDBiG7mf3mTYoqxZWIUw6OZ0s0Lhfdw 1enWOm8xgxxejiYHxKyJ2lrfp2mrQ0cVM6LbsPJrEZVNVJNZGEvqJ4CoRVzKxu0We2TL qtqVh4yxeRVefvYO+8TAR3h11DrDrH4cLOxdaskojjaDBrtE+x1yko+PGZGoCeKeJ6Xq iBqW8AcyhGE9t0NhLEDv4Oku8mZUfpU1oyjqzbj0h176hjMeWYfYgDua6GIgr8kRbKMw lKMjp2yMCMX6npBqvjFd7zJJOz6Qr3IZ5lRI3Nu/d5UX2XebZHGoJ2+Vc7U17lzWdcR2 YhjA== X-Gm-Message-State: AFqh2krZjlPq0jPkjnL0wFBtSs4J0sYgEux3Ws+Wt0fJfyqCIk0ww3i3 Olu2/XpY1czljoZZBASHCYWhVACWIezYbhgr X-Google-Smtp-Source: AMrXdXsQABazh4tUBPXcOonJJXYR4Y77SU0UHvOs8sVwgi13soYGjLykaX0Cz8B/xhOJcn+Urs/Yaw== X-Received: by 2002:a81:1353:0:b0:502:9f7e:3117 with SMTP id 80-20020a811353000000b005029f7e3117mr13066092ywt.10.1674665262446; Wed, 25 Jan 2023 08:47:42 -0800 (PST) Received: from localhost ([2620:10d:c091:480::1:113e]) by smtp.gmail.com with ESMTPSA id q15-20020a05620a038f00b007090f7a4f2asm3769263qkm.82.2023.01.25.08.47.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Jan 2023 08:47:42 -0800 (PST) From: David Vernet To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@meta.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, tj@kernel.org Subject: [PATCH bpf-next v4 1/4] bpf: Allow BPF_PROG_TYPE_STRUCT_OPS programs to be sleepable Date: Wed, 25 Jan 2023 10:47:32 -0600 Message-Id: <20230125164735.785732-2-void@manifault.com> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230125164735.785732-1-void@manifault.com> References: <20230125164735.785732-1-void@manifault.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net BPF struct_ops programs currently cannot be marked as sleepable. This need not be the case -- struct_ops programs can be sleepable, and e.g. invoke kfuncs that export the KF_SLEEPABLE flag. So as to allow future struct_ops programs to invoke such kfuncs, this patch updates the verifier to allow struct_ops programs to be sleepable. A follow-on patch will add support to libbpf for specifying struct_ops.s as a sleepable struct_ops program, and then another patch will add testcases to the dummy_st_ops selftest suite which test sleepable struct_ops behavior. Signed-off-by: David Vernet --- kernel/bpf/verifier.c | 5 +++-- tools/testing/selftests/bpf/verifier/sleepable.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index bb38b01b738f..c8907df49f81 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -17114,7 +17114,8 @@ static bool can_be_sleepable(struct bpf_prog *prog) } } return prog->type == BPF_PROG_TYPE_LSM || - prog->type == BPF_PROG_TYPE_KPROBE; /* only for uprobes */ + prog->type == BPF_PROG_TYPE_KPROBE /* only for uprobes */ || + prog->type == BPF_PROG_TYPE_STRUCT_OPS; } static int check_attach_btf_id(struct bpf_verifier_env *env) @@ -17136,7 +17137,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) } if (prog->aux->sleepable && !can_be_sleepable(prog)) { - verbose(env, "Only fentry/fexit/fmod_ret, lsm, iter and uprobe programs can be sleepable\n"); + verbose(env, "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable\n"); return -EINVAL; } diff --git a/tools/testing/selftests/bpf/verifier/sleepable.c b/tools/testing/selftests/bpf/verifier/sleepable.c index bea0daef908a..1f0d2bdc673f 100644 --- a/tools/testing/selftests/bpf/verifier/sleepable.c +++ b/tools/testing/selftests/bpf/verifier/sleepable.c @@ -85,7 +85,7 @@ .expected_attach_type = BPF_TRACE_RAW_TP, .kfunc = "sched_switch", .result = REJECT, - .errstr = "Only fentry/fexit/fmod_ret, lsm, iter and uprobe programs can be sleepable", + .errstr = "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable", .flags = BPF_F_SLEEPABLE, .runs = -1, },