From patchwork Sat Oct 7 12:45:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuyi Zhou X-Patchwork-Id: 13412328 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AC8F1EEA9 for ; Sat, 7 Oct 2023 12:45:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="eQIb15HR" Received: from mail-il1-x12e.google.com (mail-il1-x12e.google.com [IPv6:2607:f8b0:4864:20::12e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07784CA for ; Sat, 7 Oct 2023 05:45:43 -0700 (PDT) Received: by mail-il1-x12e.google.com with SMTP id e9e14a558f8ab-35135b79b6aso12171405ab.0 for ; Sat, 07 Oct 2023 05:45:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1696682742; x=1697287542; darn=vger.kernel.org; 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=1fHKbB55ASWON/deExPD4dUQ5zDEYtrEPvSSX1RWcvI=; b=eQIb15HRAUl/E+/1CDSW96CjqWTit2i8IEuMZZ6lnRinibB26rPdHCbkN9t5i/rBbL +MzZZ3uBBwBpaCLZxWJ2Ee99O24DO1MGTwXBrjPKJhlMIzymN7NUihQ+asoKBCgPD8if 6ezggLKJvTYWdNRTBPsGpOgqbtVHwJYxAsvcjpKhgx+YoaIC6qV+ZI6FEjdy7MvOmkns V9cJl5Lzsm3walRoHEa609CujJD1xPpYaYqAH1klUCBAOjHuFESrIegIX/RyNK4JtDbL /RrIuZjM41J8wd8QpRXQzTWuSnrYnnyZEPNzCXD5TQW6Rfk4ytzVp9UbtbKy22L3FE7x CB0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696682742; x=1697287542; 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=1fHKbB55ASWON/deExPD4dUQ5zDEYtrEPvSSX1RWcvI=; b=fDXjWLVi/kr8+HdfTM2r6gbj6UP1uGsj5Mi2RmDg1Y/O3CTGsUkFli5Hg3nneiosMr sI2miO80CFPtVC3SDogmfQh4RxdAqXozFxdotI9cuNiIVZhriQ6Rnf82gJz1dugs79TC CgwSUj1sMgp/Pr4hz6/74Gwp72gLjc0/+r1nLp6ErOepC1FpkftJLtIyKSGnCVukuReN XimtfSai/gC4GBik/Z1tz6Bo7mfZpunXYr0RlnM2hfBRW/9OrWxprgQb4nwZSYVhlbqv ZIo/3G8a8w/Set2px4dEzOg656RY6pthZsrga3MjcZ2hqp5T9pcKTEE56St1Eo8b0IQE 36Vw== X-Gm-Message-State: AOJu0Yy3AJHqXougxmQJYl4nHBHGldS/taYpSqqdwwWz/e4wbOD8o5yh jLX/FVS46cqq7YcTY+TqZ5Lif0hz70MDt1FldG4= X-Google-Smtp-Source: AGHT+IEesn1Ojrp3/Ky7Vcr39Ol3hiQGhi8DUzoEoqPxCGvShIC2KFZjb2b5NyK3iS/7swfHi+0FRw== X-Received: by 2002:a05:6e02:11a7:b0:34f:70ec:d4cf with SMTP id 7-20020a056e0211a700b0034f70ecd4cfmr9114932ilj.8.1696682742110; Sat, 07 Oct 2023 05:45:42 -0700 (PDT) Received: from n37-019-243.byted.org ([180.184.51.134]) by smtp.gmail.com with ESMTPSA id d6-20020a17090ad3c600b00256799877ffsm5095388pjw.47.2023.10.07.05.45.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Oct 2023 05:45:41 -0700 (PDT) From: Chuyi Zhou To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, tj@kernel.org, linux-kernel@vger.kernel.org, Chuyi Zhou Subject: [PATCH bpf-next v4 3/8] bpf: Introduce task open coded iterator kfuncs Date: Sat, 7 Oct 2023 20:45:17 +0800 Message-Id: <20231007124522.34834-4-zhouchuyi@bytedance.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20231007124522.34834-1-zhouchuyi@bytedance.com> References: <20231007124522.34834-1-zhouchuyi@bytedance.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net This patch adds kfuncs bpf_iter_task_{new,next,destroy} which allow creation and manipulation of struct bpf_iter_task in open-coded iterator style. BPF programs can use these kfuncs or through bpf_for_each macro to iterate all processes in the system. The API design keep consistent with SEC("iter/task"). bpf_iter_task_new() accepts a specific task and iterating type which allows: 1. iterating all process in the system(BPF_TASK_ITER_ALL_PROCS) 2. iterating all threads in the system(BPF_TASK_ITER_ALL_THREADS) 3. iterating all threads of a specific task(BPF_TASK_ITER_PROC_THREADS) Signed-off-by: Chuyi Zhou --- kernel/bpf/helpers.c | 3 + kernel/bpf/task_iter.c | 82 +++++++++++++++++++ .../testing/selftests/bpf/bpf_experimental.h | 5 ++ 3 files changed, 90 insertions(+) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 8699cabb52b2..8111437a999e 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2552,6 +2552,9 @@ BTF_ID_FLAGS(func, bpf_iter_num_destroy, KF_ITER_DESTROY) BTF_ID_FLAGS(func, bpf_iter_css_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS) BTF_ID_FLAGS(func, bpf_iter_css_task_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_css_task_destroy, KF_ITER_DESTROY) +BTF_ID_FLAGS(func, bpf_iter_task_new, KF_ITER_NEW | KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_iter_task_next, KF_ITER_NEXT | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_iter_task_destroy, KF_ITER_DESTROY) BTF_ID_FLAGS(func, bpf_dynptr_adjust) BTF_ID_FLAGS(func, bpf_dynptr_is_null) BTF_ID_FLAGS(func, bpf_dynptr_is_rdonly) diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c index 2cfcb4dd8a37..c2e1c3cbffea 100644 --- a/kernel/bpf/task_iter.c +++ b/kernel/bpf/task_iter.c @@ -856,6 +856,88 @@ __bpf_kfunc void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it) bpf_mem_free(&bpf_global_ma, kit->css_it); } +struct bpf_iter_task { + __u64 __opaque[3]; +} __attribute__((aligned(8))); + +struct bpf_iter_task_kern { + struct task_struct *task; + struct task_struct *pos; + unsigned int flags; +} __attribute__((aligned(8))); + +enum { + BPF_TASK_ITER_ALL_PROCS, + BPF_TASK_ITER_ALL_THREADS, + BPF_TASK_ITER_PROC_THREADS +}; + +__bpf_kfunc int bpf_iter_task_new(struct bpf_iter_task *it, + struct task_struct *task, unsigned int flags) +{ + struct bpf_iter_task_kern *kit = (void *)it; + + BUILD_BUG_ON(sizeof(struct bpf_iter_task_kern) != sizeof(struct bpf_iter_task)); + BUILD_BUG_ON(__alignof__(struct bpf_iter_task_kern) != + __alignof__(struct bpf_iter_task)); + + kit->task = kit->pos = NULL; + switch (flags) { + case BPF_TASK_ITER_ALL_THREADS: + case BPF_TASK_ITER_ALL_PROCS: + case BPF_TASK_ITER_PROC_THREADS: + break; + default: + return -EINVAL; + } + + if (flags == BPF_TASK_ITER_PROC_THREADS) + kit->task = task; + else + kit->task = &init_task; + kit->pos = kit->task; + kit->flags = flags; + return 0; +} + +__bpf_kfunc struct task_struct *bpf_iter_task_next(struct bpf_iter_task *it) +{ + struct bpf_iter_task_kern *kit = (void *)it; + struct task_struct *pos; + unsigned int flags; + + flags = kit->flags; + pos = kit->pos; + + if (!pos) + goto out; + + if (flags == BPF_TASK_ITER_ALL_PROCS) + goto get_next_task; + + kit->pos = next_thread(kit->pos); + if (kit->pos == kit->task) { + if (flags == BPF_TASK_ITER_PROC_THREADS) { + kit->pos = NULL; + goto out; + } + } else + goto out; + +get_next_task: + kit->pos = next_task(kit->pos); + kit->task = kit->pos; + if (kit->pos == &init_task) + kit->pos = NULL; + +out: + return pos; +} + +__bpf_kfunc void bpf_iter_task_destroy(struct bpf_iter_task *it) +{ +} + DEFINE_PER_CPU(struct mmap_unlock_irq_work, mmap_unlock_work); static void do_mmap_read_unlock(struct irq_work *entry) diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h index 8b53537e0f27..1ec82997cce7 100644 --- a/tools/testing/selftests/bpf/bpf_experimental.h +++ b/tools/testing/selftests/bpf/bpf_experimental.h @@ -457,5 +457,10 @@ extern int bpf_iter_css_task_new(struct bpf_iter_css_task *it, extern struct task_struct *bpf_iter_css_task_next(struct bpf_iter_css_task *it) __weak __ksym; extern void bpf_iter_css_task_destroy(struct bpf_iter_css_task *it) __weak __ksym; +struct bpf_iter_task; +extern int bpf_iter_task_new(struct bpf_iter_task *it, + struct task_struct *task, unsigned int flags) __weak __ksym; +extern struct task_struct *bpf_iter_task_next(struct bpf_iter_task *it) __weak __ksym; +extern void bpf_iter_task_destroy(struct bpf_iter_task *it) __weak __ksym; #endif