From patchwork Thu Apr 21 14:07:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 12821698 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 54782C433F5 for ; Thu, 21 Apr 2022 14:08:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388961AbiDUOLA (ORCPT ); Thu, 21 Apr 2022 10:11:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388960AbiDUOK5 (ORCPT ); Thu, 21 Apr 2022 10:10:57 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4DF3B3A5D8 for ; Thu, 21 Apr 2022 07:08:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1650550084; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qhQ9CmyPF6vnvDSxasy9mn+1Qi+yvX+VfFcFuFqUaJQ=; b=CN5i4ujebb+jc2cutrkCeGYQb0NBZvLx69v2UCWw058emU/jLPfDlpfh6GDNv+4cQvaI9k Sl126Ytn0iBkFE142cNS1U5xB8Qmpjt2U7Jbk5Nm43+PI8Mfo/EvJMOC/OYr+NaChbBCGd 8vxT68j6pG52Ya1vLqipd3Sqtv9aRBk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-673-9jcwQ8XSNcimZGOYl45g0g-1; Thu, 21 Apr 2022 10:07:59 -0400 X-MC-Unique: 9jcwQ8XSNcimZGOYl45g0g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 56DBB85A5BE; Thu, 21 Apr 2022 14:07:57 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.194.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4150440EC002; Thu, 21 Apr 2022 14:07:55 +0000 (UTC) From: Benjamin Tissoires To: Greg KH , Jiri Kosina , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, bpf@vger.kernel.org, Benjamin Tissoires Subject: [RFC bpf-next v4 5/7] HID: initial BPF new way implementation Date: Thu, 21 Apr 2022 16:07:38 +0200 Message-Id: <20220421140740.459558-6-benjamin.tissoires@redhat.com> In-Reply-To: <20220421140740.459558-1-benjamin.tissoires@redhat.com> References: <20220421140740.459558-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Declare an entry point that can use fmod_ret BPF programs, and also an API to access and change the incoming data. Signed-off-by: Benjamin Tissoires --- new-ish in v4: - far from complete, but gives an overview of what we can do now. --- drivers/hid/hid-core.c | 115 ++++++++++++++++++++++++++++++++++++++++ include/linux/hid_bpf.h | 29 ++++++++++ 2 files changed, 144 insertions(+) create mode 100644 include/linux/hid_bpf.h diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index db925794fbe6..ff4e1b47d2fb 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -32,6 +32,9 @@ #include #include #include +#include +#include +#include #include "hid-ids.h" @@ -2008,6 +2011,99 @@ int hid_report_raw_event(struct hid_device *hid, int type, u8 *data, u32 size, } EXPORT_SYMBOL_GPL(hid_report_raw_event); +struct hid_bpf_ctx_kern { + struct hid_device *hdev; + struct hid_bpf_ctx ctx; + u8 *data; + size_t size; +}; + +__weak int hid_bpf_device_event(struct hid_bpf_ctx *ctx, s64 type) +{ + return 0; +} +ALLOW_ERROR_INJECTION(hid_bpf_device_event, NS_ERRNO); + +noinline __u8 * +hid_bpf_kfunc_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t __sz) +{ + struct hid_bpf_ctx_kern *ctx_kern; + + if (!ctx) + return NULL; + + ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx); + + return ctx_kern->data; +} + +noinline void +hid_bpf_kfunc_data_release(__u8 *data) +{ +} + +noinline int +hid_bpf_kfunc_hw_request(struct hid_bpf_ctx *ctx) +{ + if (!ctx) + return -EINVAL; + + pr_err("%s test ctx->bus: %04x %s:%d", __func__, ctx->bus, __FILE__, __LINE__); + + return 0; +} + +/* + * The following set contains all functions we agree BPF programs + * can use. + */ +BTF_SET_START(hid_bpf_kfunc_ids) +BTF_ID(func, hid_bpf_kfunc_get_data) +BTF_ID(func, hid_bpf_kfunc_data_release) +BTF_ID(func, hid_bpf_kfunc_hw_request) +BTF_SET_END(hid_bpf_kfunc_ids) + +/* + * The following set contains all functions to provide a kernel + * resource to the BPF program. + * We need to add a counterpart release function. + */ +BTF_SET_START(hid_bpf_kfunc_acquire_ids) +BTF_ID(func, hid_bpf_kfunc_get_data) +BTF_SET_END(hid_bpf_kfunc_acquire_ids) + +/* + * The following set is the release counterpart of the previous + * function set. + */ +BTF_SET_START(hid_bpf_kfunc_release_ids) +BTF_ID(func, hid_bpf_kfunc_data_release) +BTF_SET_END(hid_bpf_kfunc_release_ids) + +/* + * The following set tells which functions are sleepable. + */ +BTF_SET_START(hid_bpf_kfunc_sleepable_ids) +BTF_ID(func, hid_bpf_kfunc_hw_request) +BTF_SET_END(hid_bpf_kfunc_sleepable_ids) + +static const struct btf_kfunc_id_set hid_bpf_kfunc_set = { + .owner = THIS_MODULE, + .check_set = &hid_bpf_kfunc_ids, + .acquire_set = &hid_bpf_kfunc_acquire_ids, + .release_set = &hid_bpf_kfunc_release_ids, + .ret_null_set = &hid_bpf_kfunc_acquire_ids, /* duplicated to force BPF programs to + * check the validity of the returned pointer + * in acquire function + */ + .sleepable_set = &hid_bpf_kfunc_sleepable_ids, +}; + +static int __init hid_bpf_init(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &hid_bpf_kfunc_set); +} + /** * hid_input_report - report data from lower layer (usb, bt...) * @@ -2025,6 +2121,17 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int i struct hid_driver *hdrv; struct hid_report *report; int ret = 0; + struct hid_bpf_ctx_kern ctx_kern = { + .hdev = hid, + .ctx = { + .bus = hid->bus, + .group = hid->group, + .vendor = hid->vendor, + .product = hid->product, + }, + .data = data, + .size = size, + }; if (!hid) return -ENODEV; @@ -2039,6 +2146,10 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, u32 size, int i report_enum = hid->report_enum + type; hdrv = hid->driver; + ret = hid_bpf_device_event(&ctx_kern.ctx, type); + if (ret) + goto unlock; + if (!size) { dbg_hid("empty report\n"); ret = -1; @@ -2914,6 +3025,10 @@ static int __init hid_init(void) hid_debug_init(); + ret = hid_bpf_init(); + if (ret) + pr_err("%s error in bpf_init: %d %s:%d", __func__, ret, __FILE__, __LINE__); + return 0; err_bus: bus_unregister(&hid_bus_type); diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h new file mode 100644 index 000000000000..100909b27cd8 --- /dev/null +++ b/include/linux/hid_bpf.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ + +#ifndef __HID_BPF_H +#define __HID_BPF_H + +/* + * The following is the HID BPF API. + * + * It should be treated as UAPI, so extra care is required + * when making change to this file. + */ + +struct hid_bpf_ctx { + __u16 bus; /* BUS ID */ + __u16 group; /* Report group */ + __u32 vendor; /* Vendor ID */ + __u32 product; /* Product ID */ + __u32 version; /* HID version */ +}; + +/* Following functions are tracepoints that BPF programs can attach to */ +int hid_bpf_device_event(struct hid_bpf_ctx *ctx, __s64 type); + +/* Following functions are kfunc that we export to BPF programs */ +__u8 *hid_bpf_kfunc_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t __sz); +void hid_bpf_kfunc_data_release(__u8 *data); +int hid_bpf_kfunc_hw_request(struct hid_bpf_ctx *ctx); + +#endif /* __HID_BPF_H */