From patchwork Wed May 19 14:13:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12267481 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=-15.7 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,SPF_HELO_NONE,SPF_PASS,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 4F5E3C43600 for ; Wed, 19 May 2021 14:15:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 31E76611AD for ; Wed, 19 May 2021 14:15:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354341AbhESORM (ORCPT ); Wed, 19 May 2021 10:17:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354067AbhESOPx (ORCPT ); Wed, 19 May 2021 10:15:53 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BC7FC061353; Wed, 19 May 2021 07:14:16 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id z130so7387206wmg.2; Wed, 19 May 2021 07:14:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=TgZRck3xYV0eFV5WJ+ErP6x1msBFrX+wPITeA+FZUrM=; b=GuQ5Akj8Ly+gdqTeAq5q22pTqo7tXEPeY6AwdcM/dr9/gL5j8OOLLuHWkolLSAwh8e TZbp9Pl89OiCF2xbGd+50tvoPPMzq6MXiaY0mHUJE6gMBT1rQGQbOHMr4ryvO7zA2yZ7 VnxGiOB1KoDFdgyk0AtfZrGUcYaE/aGEZacSx5ouWMx60eGWLCVe/QJL89T3tElz4E6k iFa5QsVDV29YonGlYcPMhNgbiZvPZdvDrfQWnekENszuBRsgg3iAz41si2GFCyj+UJgc jSNt0BcHHnSKzysHRk1rmQxTLtJpUPrqoIRLwhYjMxh4gFXVI6AaFKTKl31cxtEO+3F5 0U+A== 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=TgZRck3xYV0eFV5WJ+ErP6x1msBFrX+wPITeA+FZUrM=; b=YvirdeUIawYgYvjQoSuYyM/lBrj6mC19l08f0h5EonxpWH5cugG9fnoqW9gNomjEdE v8YyPLyRMgc6MLJJoH4OqfKJlMIdUnoTSd2FSADyYgBt7qKNW5k0l6DY6N/fAkuiNFYt DKQJrDEHUVplCjfyIZE+CQBzXdiayNRz6sqd/iRkVLk9W/x2IskvW51nUWCKUs0NY3wc paVFr6reuiQcInBIGpxXusIEgHwsqCdTDDEpuu77zC9RMqUGczfwkxgpjenrGKRuqc4s /+AUZZP7x8ioO1mkN9cHwUCOzEu/M8mw2yML6YP8YdABCJWul3HxXdMgVBTbzZEokxUK VQqg== X-Gm-Message-State: AOAM531e1r5ZiYqbmiS7E7eK4/8Sez0OoFRFDsxUG6arhFjS4SdF1ioR uEdFZBQLsx5QiasMq3G+nP99SHcZzewyQ0Y3 X-Google-Smtp-Source: ABdhPJw+wd+UozFtpbl+Z/t/uneOgX1/Bte3KlOFMiTkRTMRQj1OIuk8/XQSGR+LbC3/ff7nMycKSQ== X-Received: by 2002:a1c:7e45:: with SMTP id z66mr11790687wmc.126.1621433654771; Wed, 19 May 2021 07:14:14 -0700 (PDT) Received: from localhost.localdomain ([85.255.235.154]) by smtp.gmail.com with ESMTPSA id z3sm6233569wrq.42.2021.05.19.07.14.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 May 2021 07:14:14 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jens Axboe , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Horst Schirmeier , "Franz-B . Tuneke" , Christian Dietrich Subject: [PATCH 20/23] bpf: Add bpf_copy_to_user() helper Date: Wed, 19 May 2021 15:13:31 +0100 Message-Id: X-Mailer: git-send-email 2.31.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Similarly to bpf_copy_from_user(), also allow sleepable BPF programs to write to user memory. Signed-off-by: Pavel Begunkov --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 8 ++++++++ kernel/bpf/helpers.c | 17 +++++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 4 files changed, 33 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 00597b0c719c..9b775e2b2a01 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1899,6 +1899,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto; extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto; extern const struct bpf_func_proto bpf_copy_from_user_proto; +extern const struct bpf_func_proto bpf_copy_to_user_proto; extern const struct bpf_func_proto bpf_snprintf_btf_proto; extern const struct bpf_func_proto bpf_per_cpu_ptr_proto; extern const struct bpf_func_proto bpf_this_cpu_ptr_proto; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7719ec4a33e7..6f19839d2b05 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3648,6 +3648,13 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * + * long bpf_copy_to_user(void *user_ptr, const void *src, u32 size) + * Description + * Read *size* bytes from *src* and store the data in user space + * address *user_ptr*. This is a wrapper of **copy_to_user**\ (). + * Return + * 0 on success, or a negative error in case of failure. + * * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags) * Description * Use BTF to store a string representation of *ptr*->ptr in *str*, @@ -4085,6 +4092,7 @@ union bpf_attr { FN(iouring_queue_sqe), \ FN(iouring_emit_cqe), \ FN(iouring_reap_cqe), \ + FN(copy_to_user), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 308427fe03a3..9d7814c564e5 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -634,6 +634,23 @@ const struct bpf_func_proto bpf_copy_from_user_proto = { .arg3_type = ARG_ANYTHING, }; +BPF_CALL_3(bpf_copy_to_user, void __user *, user_ptr, + const void *, src, u32, size) +{ + int ret = copy_to_user(user_ptr, src, size); + + return ret ? -EFAULT : 0; +} + +const struct bpf_func_proto bpf_copy_to_user_proto = { + .func = bpf_copy_to_user, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_ANYTHING, + .arg2_type = ARG_PTR_TO_MEM, + .arg3_type = ARG_CONST_SIZE_OR_ZERO, +}; + BPF_CALL_2(bpf_per_cpu_ptr, const void *, ptr, u32, cpu) { if (cpu >= nr_cpu_ids) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 79c893310492..18d497247d69 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3647,6 +3647,13 @@ union bpf_attr { * Return * 0 on success, or a negative error in case of failure. * + * long bpf_copy_to_user(void *user_ptr, const void *src, u32 size) + * Description + * Read *size* bytes from *src* and store the data in user space + * address *user_ptr*. This is a wrapper of **copy_to_user**\ (). + * Return + * 0 on success, or a negative error in case of failure. + * * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags) * Description * Use BTF to store a string representation of *ptr*->ptr in *str*,