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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB101C43219 for ; Fri, 4 Nov 2022 03:27:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229708AbiKDD1V (ORCPT ); Thu, 3 Nov 2022 23:27:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230504AbiKDDZ4 (ORCPT ); Thu, 3 Nov 2022 23:25:56 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4438E64ED for ; Thu, 3 Nov 2022 20:25:36 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id u18-20020a627912000000b0056d93d8b8bdso1686999pfc.16 for ; Thu, 03 Nov 2022 20:25:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=YbRm3I0sewWtsZIHwhErDFMz3x0ncMPhKVqkK3e/Kzk=; b=F/j+r+DQWgWU+H64J7k+Tlw9APbvQO6yhhwJkgncOiWnKlmmd7ff3U0fDMWcrIM6eA Rrc6+HsRPDXVFkN/1Ol4jOSGhYk5Cu9FHGQdp5u2VJzi/qceoBkwLigm8V1aSgsBQSyH t2yGCOTZY8ZguLjd7JLXNalfPBqujqIfzSAqmR9dudUMpphE2D4hoDFPrK6M3xMipjdv kqgjtByufledR5lP2KjsFzIIRNsUFCQbD0UXrW6ZohJ2eQLFOicozTT+r4+rEsHhQ2a5 PDPpXcDvhQeczI4vZMBENr+pBOUlgphRkuSIuEzsnnUi4HLZf13zUZMJMQtvH7HcspTF P9Ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=YbRm3I0sewWtsZIHwhErDFMz3x0ncMPhKVqkK3e/Kzk=; b=W2dN4VAwtVkv4yNtR6ZhPYCVkh1ZuNmTIa/L4mXeSJni+raE+sRxpkT96niN/BByi0 dHRN8MPLp8LgUPs3K67Nib2ywun4xN7Fkc+xryR7as6So4aDVj2FgLv0+7X4kuinBZDe Eua7Dfd7WCaqdHBIHVBwS629Lgn0oqSCrNfsRNl/B1YwnPUwn5lZQAwKZ4K6z+Jb2tF+ vxpN6dAhx7XhA80R9Ioh2IJ4inRLVXLXScekYO13K+O0tcuMBb/WxjYRisbgI9nJO20m FLeTpkrwvErGGYbv44C4POEbfMiqyCot8FpR9EGHYBk+HJsOmq/U6bC9rfVmmOiwGsUx UmyQ== X-Gm-Message-State: ACrzQf2+ZQeuQv+vQqCS1UNm3QZtQLNeTKXYq14NO/PAuRKwot0X1PqN O3uCdD4iHOgZEMgkiAJxlyKFWpDjz6s2Bwgp8akpqtWLmUxXNFMbm2bbQ2PcVy21UUa9jC/A8MT 7ViBLBooUYJxo0LauXel3nCq113vQRkTkoavMd/o8LEaHpJ4V9g== X-Google-Smtp-Source: AMsMyM7Z6bdvew+CNuqL+zRO4xlM9NhZdHxVH3wfWepJiyS61542z1snHXjcv2qO5a2qvaaQV4BBXL8= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:aa7:9421:0:b0:56b:b2a8:6822 with SMTP id y1-20020aa79421000000b0056bb2a86822mr33149365pfo.86.1667532335655; Thu, 03 Nov 2022 20:25:35 -0700 (PDT) Date: Thu, 3 Nov 2022 20:25:19 -0700 In-Reply-To: <20221104032532.1615099-1-sdf@google.com> Mime-Version: 1.0 References: <20221104032532.1615099-1-sdf@google.com> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog Message-ID: <20221104032532.1615099-2-sdf@google.com> Subject: [RFC bpf-next v2 01/14] bpf: Introduce bpf_patch From: Stanislav Fomichev To: bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, David Ahern , Jakub Kicinski , Willem de Bruijn , Jesper Dangaard Brouer , Anatoly Burakov , Alexander Lobakin , Magnus Karlsson , Maryam Tahhan , xdp-hints@xdp-project.net, netdev@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org A simple abstraction around a series of instructions that transparently handles resizing. Currently, we have insn_buf[16] in convert_ctx_accesses which might not be enough for xdp kfuncs. If we find this abstraction helpful, we might convert existing insn_buf[16] to it in the future. Cc: John Fastabend Cc: David Ahern Cc: Martin KaFai Lau Cc: Jakub Kicinski Cc: Willem de Bruijn Cc: Jesper Dangaard Brouer Cc: Anatoly Burakov Cc: Alexander Lobakin Cc: Magnus Karlsson Cc: Maryam Tahhan Cc: xdp-hints@xdp-project.net Cc: netdev@vger.kernel.org Signed-off-by: Stanislav Fomichev --- include/linux/bpf_patch.h | 27 +++++++++++++++++++++ kernel/bpf/Makefile | 2 +- kernel/bpf/bpf_patch.c | 51 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 79 insertions(+), 1 deletion(-) create mode 100644 include/linux/bpf_patch.h create mode 100644 kernel/bpf/bpf_patch.c diff --git a/include/linux/bpf_patch.h b/include/linux/bpf_patch.h new file mode 100644 index 000000000000..81ff738eef8d --- /dev/null +++ b/include/linux/bpf_patch.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _LINUX_BPF_PATCH_H +#define _LINUX_BPF_PATCH_H 1 + +#include + +struct bpf_patch { + struct bpf_insn *insn; + size_t capacity; + size_t len; + int err; +}; + +void bpf_patch_free(struct bpf_patch *patch); +size_t bpf_patch_len(const struct bpf_patch *patch); +int bpf_patch_err(const struct bpf_patch *patch); +void __bpf_patch_append(struct bpf_patch *patch, struct bpf_insn insn); +struct bpf_insn *bpf_patch_data(const struct bpf_patch *patch); + +#define bpf_patch_append(patch, ...) ({ \ + struct bpf_insn insn[] = { __VA_ARGS__ }; \ + int i; \ + for (i = 0; i < ARRAY_SIZE(insn); i++) \ + __bpf_patch_append(patch, insn[i]); \ +}) + +#endif diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 3a12e6b400a2..5724f36292a5 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -13,7 +13,7 @@ obj-$(CONFIG_BPF_SYSCALL) += bpf_local_storage.o bpf_task_storage.o obj-${CONFIG_BPF_LSM} += bpf_inode_storage.o obj-$(CONFIG_BPF_SYSCALL) += disasm.o obj-$(CONFIG_BPF_JIT) += trampoline.o -obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o +obj-$(CONFIG_BPF_SYSCALL) += btf.o memalloc.o bpf_patch.o obj-$(CONFIG_BPF_JIT) += dispatcher.o ifeq ($(CONFIG_NET),y) obj-$(CONFIG_BPF_SYSCALL) += devmap.o diff --git a/kernel/bpf/bpf_patch.c b/kernel/bpf/bpf_patch.c new file mode 100644 index 000000000000..82a10bf5624a --- /dev/null +++ b/kernel/bpf/bpf_patch.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include + +void bpf_patch_free(struct bpf_patch *patch) +{ + kfree(patch->insn); +} + +size_t bpf_patch_len(const struct bpf_patch *patch) +{ + return patch->len; +} + +int bpf_patch_err(const struct bpf_patch *patch) +{ + return patch->err; +} + +void __bpf_patch_append(struct bpf_patch *patch, struct bpf_insn insn) +{ + void *arr; + + if (patch->err) + return; + + if (patch->len + 1 > patch->capacity) { + if (!patch->capacity) + patch->capacity = 16; + else + patch->capacity *= 2; + + arr = krealloc_array(patch->insn, patch->capacity, sizeof(insn), GFP_KERNEL); + if (!arr) { + patch->err = -ENOMEM; + kfree(patch->insn); + return; + } + + patch->insn = arr; + patch->capacity *= 2; + } + + patch->insn[patch->len++] = insn; +} +EXPORT_SYMBOL(__bpf_patch_append); + +struct bpf_insn *bpf_patch_data(const struct bpf_patch *patch) +{ + return patch->insn; +} -- 2.38.1.431.g37b22c650d-goog