From patchwork Sat Apr 2 01:58:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joanne Koong X-Patchwork-Id: 12798901 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 95519C433F5 for ; Sat, 2 Apr 2022 02:00:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234809AbiDBCBt (ORCPT ); Fri, 1 Apr 2022 22:01:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229660AbiDBCBs (ORCPT ); Fri, 1 Apr 2022 22:01:48 -0400 Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D0C4103D93 for ; Fri, 1 Apr 2022 18:59:57 -0700 (PDT) Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2320C6Z7031458 for ; Fri, 1 Apr 2022 18:59:56 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=mQ3SVjRfBxe/XRuL3rStLU3p3gqfyKpGj6IOxWyAYrw=; b=JloRv7YhNa5q/ObjPiEcedWAxJtDGQg9BtW2qTLY4rLOQGnSQGu+WGfAOXggCXv3m0Os c9p3+R22V7uvAYn62ZRoj8yy0Xsv9w9jXazctniGq0L/KCVZf6bpT2ARHxQWSnXaCOmi PROfw82xybr5TSg/zYuYCFCN49lffx/bOUU= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3f5gpgaxa5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 01 Apr 2022 18:59:56 -0700 Received: from twshared14141.02.ash7.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Fri, 1 Apr 2022 18:59:55 -0700 Received: by devbig010.atn6.facebook.com (Postfix, from userid 115148) id EA3C8A79067C; Fri, 1 Apr 2022 18:59:43 -0700 (PDT) From: Joanne Koong To: CC: , , , Joanne Koong Subject: [PATCH bpf-next v1 4/7] bpf: Add bpf_dynptr_read and bpf_dynptr_write Date: Fri, 1 Apr 2022 18:58:23 -0700 Message-ID: <20220402015826.3941317-5-joannekoong@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220402015826.3941317-1-joannekoong@fb.com> References: <20220402015826.3941317-1-joannekoong@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: Y5iw4orNgFXp3BYiW4eaebpz8lQLTguv X-Proofpoint-GUID: Y5iw4orNgFXp3BYiW4eaebpz8lQLTguv X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.850,Hydra:6.0.425,FMLib:17.11.64.514 definitions=2022-04-01_08,2022-03-31_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Joanne Koong This patch adds two helper functions, bpf_dynptr_read and bpf_dynptr_write: long bpf_dynptr_read(void *dst, u32 len, struct bpf_dynptr *src, u32 offset); long bpf_dynptr_write(struct bpf_dynptr *dst, u32 offset, void *src, u32 len); The dynptr passed into these functions must be valid dynptrs that have been initialized. Signed-off-by: Joanne Koong --- include/linux/bpf.h | 6 ++++ include/uapi/linux/bpf.h | 18 +++++++++++ kernel/bpf/helpers.c | 56 ++++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 18 +++++++++++ 4 files changed, 98 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index e0fcff9f2aee..cded9753fb7f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2426,6 +2426,12 @@ enum bpf_dynptr_type { #define DYNPTR_MAX_SIZE ((1UL << 28) - 1) #define DYNPTR_SIZE_MASK 0xFFFFFFF #define DYNPTR_TYPE_SHIFT 29 +#define DYNPTR_RDONLY_BIT BIT(28) + +static inline bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr) +{ + return ptr->size & DYNPTR_RDONLY_BIT; +} static inline enum bpf_dynptr_type bpf_dynptr_get_type(struct bpf_dynptr_kern *ptr) { diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6a57d8a1b882..16a35e46be90 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5175,6 +5175,22 @@ union bpf_attr { * After this operation, *ptr* will be an invalidated dynptr. * Return * Void. + * + * long bpf_dynptr_read(void *dst, u32 len, struct bpf_dynptr *src, u32 offset) + * Description + * Read *len* bytes from *src* into *dst*, starting from *offset* + * into *dst*. + * Return + * 0 on success, -EINVAL if *offset* + *len* exceeds the length + * of *src*'s data or if *src* is an invalid dynptr. + * + * long bpf_dynptr_write(struct bpf_dynptr *dst, u32 offset, void *src, u32 len) + * Description + * Write *len* bytes from *src* into *dst*, starting from *offset* + * into *dst*. + * Return + * 0 on success, -EINVAL if *offset* + *len* exceeds the length + * of *dst*'s data or if *dst* is not writeable. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5374,6 +5390,8 @@ union bpf_attr { FN(dynptr_from_mem), \ FN(malloc), \ FN(free), \ + FN(dynptr_read), \ + FN(dynptr_write), \ /* */ /* 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 ed5a7d9d0a18..7ec20e79928e 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1412,6 +1412,58 @@ const struct bpf_func_proto bpf_dynptr_from_mem_proto = { .arg3_type = ARG_PTR_TO_DYNPTR | DYNPTR_TYPE_LOCAL | MEM_UNINIT, }; +BPF_CALL_4(bpf_dynptr_read, void *, dst, u32, len, struct bpf_dynptr_kern *, src, u32, offset) +{ + int err; + + if (!src->data) + return -EINVAL; + + err = bpf_dynptr_check_off_len(src, offset, len); + if (err) + return err; + + memcpy(dst, src->data + src->offset + offset, len); + + return 0; +} + +const struct bpf_func_proto bpf_dynptr_read_proto = { + .func = bpf_dynptr_read, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_MEM_UNINIT, + .arg2_type = ARG_CONST_SIZE_OR_ZERO, + .arg3_type = ARG_PTR_TO_DYNPTR, + .arg4_type = ARG_ANYTHING, +}; + +BPF_CALL_4(bpf_dynptr_write, struct bpf_dynptr_kern *, dst, u32, offset, void *, src, u32, len) +{ + int err; + + if (!dst->data || bpf_dynptr_is_rdonly(dst)) + return -EINVAL; + + err = bpf_dynptr_check_off_len(dst, offset, len); + if (err) + return err; + + memcpy(dst->data + dst->offset + offset, src, len); + + return 0; +} + +const struct bpf_func_proto bpf_dynptr_write_proto = { + .func = bpf_dynptr_write, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_DYNPTR, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_PTR_TO_MEM | MEM_RDONLY, + .arg4_type = ARG_CONST_SIZE_OR_ZERO, +}; + BPF_CALL_2(bpf_malloc, u32, size, struct bpf_dynptr_kern *, ptr) { void *data; @@ -1514,6 +1566,10 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_malloc_proto; case BPF_FUNC_free: return &bpf_free_proto; + case BPF_FUNC_dynptr_read: + return &bpf_dynptr_read_proto; + case BPF_FUNC_dynptr_write: + return &bpf_dynptr_write_proto; default: break; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 6a57d8a1b882..16a35e46be90 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5175,6 +5175,22 @@ union bpf_attr { * After this operation, *ptr* will be an invalidated dynptr. * Return * Void. + * + * long bpf_dynptr_read(void *dst, u32 len, struct bpf_dynptr *src, u32 offset) + * Description + * Read *len* bytes from *src* into *dst*, starting from *offset* + * into *dst*. + * Return + * 0 on success, -EINVAL if *offset* + *len* exceeds the length + * of *src*'s data or if *src* is an invalid dynptr. + * + * long bpf_dynptr_write(struct bpf_dynptr *dst, u32 offset, void *src, u32 len) + * Description + * Write *len* bytes from *src* into *dst*, starting from *offset* + * into *dst*. + * Return + * 0 on success, -EINVAL if *offset* + *len* exceeds the length + * of *dst*'s data or if *dst* is not writeable. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -5374,6 +5390,8 @@ union bpf_attr { FN(dynptr_from_mem), \ FN(malloc), \ FN(free), \ + FN(dynptr_read), \ + FN(dynptr_write), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper