From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 E0CA9C433E9 for ; Wed, 3 Mar 2021 03:56:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B07F364E6F for ; Wed, 3 Mar 2021 03:56:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352515AbhCCDui (ORCPT ); Tue, 2 Mar 2021 22:50:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240792AbhCBRiu (ORCPT ); Tue, 2 Mar 2021 12:38:50 -0500 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1564C061A2B for ; Tue, 2 Mar 2021 09:20:34 -0800 (PST) Received: by mail-pj1-x1029.google.com with SMTP id jx13so2376154pjb.1 for ; Tue, 02 Mar 2021 09:20:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cilium-io.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cZPyA9m3sp7GWzupY4xnewRoMydoMiMPf4WFOI3CF9w=; b=sJ2OJLwmwqDDPUf35eKDe6NU8HZy6R5/C9TvVUeRumZ9EyXhSA8h8QolBQYVIGEN3+ sjISVk5hmKpVotMoC6UygTqdDwxXci49TMiDryrojQJTntTO6DIwRbfX2NFNfItree7x C7BAyAFlxavkRwkLf7sxBHmaw3ED/rv53Y6tRW/1IhShcs2ltLS5YQ6FgsbBqIROgkYA fM+Ix6srOLtyQ0/iwdookdICuoar/FA9pgawiIFa0X/QW/HYWNqQw5w9g+srowA9OM/V YYbJprgQcsn0hJflHr828zG+XIi0BAjXSo/wbl8mQ1w9yYi50Sht7if7badDtS4JC388 2lSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cZPyA9m3sp7GWzupY4xnewRoMydoMiMPf4WFOI3CF9w=; b=S2Zqd0U81U6HsbnGSyBlpblwimeUcr/JFZDY2FcHIWB78S9qdpBz86wM0dIADsx1NP 6rizR1kWGjR9zoDPU+Zbwq4N/dgqnp7ryqpX95W40KFk07il8RPTeevJs8H16LWPZp7f kO6Yxkq/Z6LToQ25+eKVLeHk5kgFem8CY0x9J1dJPKSn/4WNgDKFOzrBPzSwEQKPKsGg OGuW3bRQiBITD2fEayjLDuOAiZ1QJjOW5T/alBeaboQjVgBJhLYmBz03/zCPlIcNJmhX srMAF9BXrCxdRUyjeuOxsyEckLu0jIMsWx4ZBUyCleVgCXjJ3vT0/c2fe+S8GNVRkMga GOWw== X-Gm-Message-State: AOAM531/wrmdH1yb70Av/iJ+NKXURU8E5a/8F/ZUObwahKG8EWhsqOtG OIfIo/SIQH4N8+PwAJoJJkVXIHh6ExMYUakI X-Google-Smtp-Source: ABdhPJz+91huBG/Dlm8J0g83YpRM8aSMTTD4XhyVsTbpSADsoEBemrdz+CbGvbQH2oxc1uXLp/0Zpg== X-Received: by 2002:a17:90b:110c:: with SMTP id gi12mr5436954pjb.48.1614705633830; Tue, 02 Mar 2021 09:20:33 -0800 (PST) Received: from localhost.localdomain (c-73-93-5-123.hsd1.ca.comcast.net. [73.93.5.123]) by smtp.gmail.com with ESMTPSA id b15sm20073923pgg.85.2021.03.02.09.20.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Mar 2021 09:20:33 -0800 (PST) From: Joe Stringer To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, ast@kernel.org, linux-doc@vger.kernel.org, linux-man@vger.kernel.org, =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Quentin Monnet , Michael Kerrisk Subject: [PATCHv2 bpf-next 01/15] bpf: Import syscall arg documentation Date: Tue, 2 Mar 2021 09:19:33 -0800 Message-Id: <20210302171947.2268128-2-joe@cilium.io> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210302171947.2268128-1-joe@cilium.io> References: <20210302171947.2268128-1-joe@cilium.io> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org These descriptions are present in the man-pages project from the original submissions around 2015-2016. Import them so that they can be kept up to date as developers extend the bpf syscall commands. These descriptions follow the pattern used by scripts/bpf_helpers_doc.py so that we can take advantage of the parser to generate more up-to-date man page writing based upon these headers. Some minor wording adjustments were made to make the descriptions more consistent for the description / return format. Acked-by: Toke Høiland-Jørgensen Reviewed-by: Quentin Monnet Co-authored-by: Alexei Starovoitov Co-authored-by: Michael Kerrisk Signed-off-by: Joe Stringer --- include/uapi/linux/bpf.h | 122 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 121 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b89af20cfa19..fb16c590e6d9 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -93,7 +93,127 @@ union bpf_iter_link_info { } map; }; -/* BPF syscall commands, see bpf(2) man-page for details. */ +/* BPF syscall commands, see bpf(2) man-page for more details. */ +/** + * DOC: eBPF Syscall Preamble + * + * The operation to be performed by the **bpf**\ () system call is determined + * by the *cmd* argument. Each operation takes an accompanying argument, + * provided via *attr*, which is a pointer to a union of type *bpf_attr* (see + * below). The size argument is the size of the union pointed to by *attr*. + */ +/** + * DOC: eBPF Syscall Commands + * + * BPF_MAP_CREATE + * Description + * Create a map and return a file descriptor that refers to the + * map. The close-on-exec file descriptor flag (see **fcntl**\ (2)) + * is automatically enabled for the new file descriptor. + * + * Applying **close**\ (2) to the file descriptor returned by + * **BPF_MAP_CREATE** will delete the map (but see NOTES). + * + * Return + * A new file descriptor (a nonnegative integer), or -1 if an + * error occurred (in which case, *errno* is set appropriately). + * + * BPF_MAP_LOOKUP_ELEM + * Description + * Look up an element with a given *key* in the map referred to + * by the file descriptor *map_fd*. + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * + * BPF_MAP_UPDATE_ELEM + * Description + * Create or update an element (key/value pair) in a specified map. + * + * The *flags* argument should be specified as one of the + * following: + * + * **BPF_ANY** + * Create a new element or update an existing element. + * **BPF_NOEXIST** + * Create a new element only if it did not exist. + * **BPF_EXIST** + * Update an existing element. + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * + * May set *errno* to **EINVAL**, **EPERM**, **ENOMEM**, + * **E2BIG**, **EEXIST**, or **ENOENT**. + * + * **E2BIG** + * The number of elements in the map reached the + * *max_entries* limit specified at map creation time. + * **EEXIST** + * If *flags* specifies **BPF_NOEXIST** and the element + * with *key* already exists in the map. + * **ENOENT** + * If *flags* specifies **BPF_EXIST** and the element with + * *key* does not exist in the map. + * + * BPF_MAP_DELETE_ELEM + * Description + * Look up and delete an element by key in a specified map. + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * + * BPF_MAP_GET_NEXT_KEY + * Description + * Look up an element by key in a specified map and return the key + * of the next element. Can be used to iterate over all elements + * in the map. + * + * Return + * Returns zero on success. On error, -1 is returned and *errno* + * is set appropriately. + * + * The following cases can be used to iterate over all elements of + * the map: + * + * * If *key* is not found, the operation returns zero and sets + * the *next_key* pointer to the key of the first element. + * * If *key* is found, the operation returns zero and sets the + * *next_key* pointer to the key of the next element. + * * If *key* is the last element, returns -1 and *errno* is set + * to **ENOENT**. + * + * May set *errno* to **ENOMEM**, **EFAULT**, **EPERM**, or + * **EINVAL** on error. + * + * BPF_PROG_LOAD + * Description + * Verify and load an eBPF program, returning a new file + * descriptor associated with the program. + * + * Applying **close**\ (2) to the file descriptor returned by + * **BPF_PROG_LOAD** will unload the eBPF program (but see NOTES). + * + * The close-on-exec file descriptor flag (see **fcntl**\ (2)) is + * automatically enabled for the new file descriptor. + * + * Return + * A new file descriptor (a nonnegative integer), or -1 if an + * error occurred (in which case, *errno* is set appropriately). + * + * NOTES + * eBPF objects (maps and programs) can be shared between processes. + * For example, after **fork**\ (2), the child inherits file descriptors + * referring to the same eBPF objects. In addition, file descriptors + * referring to eBPF objects can be transferred over UNIX domain sockets. + * File descriptors referring to eBPF objects can be duplicated in the + * usual way, using **dup**\ (2) and similar calls. An eBPF object is + * deallocated only after all file descriptors referring to the object + * have been closed. + */ enum bpf_cmd { BPF_MAP_CREATE, BPF_MAP_LOOKUP_ELEM, -- 2.27.0