From patchwork Tue Oct 25 09:34:51 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 618520 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 8DA4BC04A95 for ; Tue, 25 Oct 2022 09:36:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231723AbiJYJge (ORCPT ); Tue, 25 Oct 2022 05:36:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231867AbiJYJgB (ORCPT ); Tue, 25 Oct 2022 05:36:01 -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 ESMTPS id 92E36101E2B for ; Tue, 25 Oct 2022 02:35:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1666690526; 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=RHcambJWvEK/XhdAms9KGjFabN2WVNwXlubD1rms2qI=; b=OlW6UNhg4Ikm7vqe22EI5kMKUKJb63iuk45qxfLGrR+Uiiq+m7YZ9pRK1BQos7NgMmg5aB YbyyYMgIe99B95h01rotxFVHLOArQGbGb0BZhwgTK/9QksEYuZ/LEe9V4dYxGr68s73lPq uekMOB+QGoWj5sr1a3r6JM/BfGHRiU0= 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-437-BKG1aKn1NPK3xGiyz-x09g-1; Tue, 25 Oct 2022 05:35:18 -0400 X-MC-Unique: BKG1aKn1NPK3xGiyz-x09g-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EFBEF800B23; Tue, 25 Oct 2022 09:35:17 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.195.44]) by smtp.corp.redhat.com (Postfix) with ESMTP id 35B9A492CA2; Tue, 25 Oct 2022 09:35:16 +0000 (UTC) From: Benjamin Tissoires To: Greg KH , Jiri Kosina , Jonathan Corbet , Shuah Khan Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, Benjamin Tissoires Subject: [PATCH hid v11 07/14] HID: bpf: introduce hid_hw_request() Date: Tue, 25 Oct 2022 11:34:51 +0200 Message-Id: <20221025093458.457089-8-benjamin.tissoires@redhat.com> In-Reply-To: <20221025093458.457089-1-benjamin.tissoires@redhat.com> References: <20221025093458.457089-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This function can not be called under IRQ, thus it is only available while in SEC("syscall"). For consistency, this function requires a HID-BPF context to work with, and so we also provide a helper to create one based on the HID unique ID. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Benjamin Tissoires --- no changes in v11 no changes in v10 changes in v9: - fixed kfunc declaration aaccording to latest upstream changes no changes in v8 changes in v7: - hid_bpf_allocate_context: remove unused variable - ensures buf is not NULL changes in v6: - rename parameter size into buf__sz to teach the verifier about the actual buffer size used by the call - remove the allocated data in the user created context, it's not used new-ish in v5 --- drivers/hid/bpf/hid_bpf_dispatch.c | 132 +++++++++++++++++++++++++++++ drivers/hid/hid-core.c | 2 + include/linux/hid_bpf.h | 13 ++- 3 files changed, 146 insertions(+), 1 deletion(-) diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index efd4e4b4a615..c657222f914d 100644 --- a/drivers/hid/bpf/hid_bpf_dispatch.c +++ b/drivers/hid/bpf/hid_bpf_dispatch.c @@ -220,9 +220,141 @@ hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags) return __hid_bpf_attach_prog(hdev, prog_type, prog_fd, flags); } +/** + * hid_bpf_allocate_context - Allocate a context to the given HID device + * + * @hid_id: the system unique identifier of the HID device + * + * @returns A pointer to &struct hid_bpf_ctx on success, %NULL on error. + */ +noinline struct hid_bpf_ctx * +hid_bpf_allocate_context(unsigned int hid_id) +{ + struct hid_device *hdev; + struct hid_bpf_ctx_kern *ctx_kern = NULL; + struct device *dev; + + if (!hid_bpf_ops) + return NULL; + + dev = bus_find_device(hid_bpf_ops->bus_type, NULL, &hid_id, device_match_id); + if (!dev) + return NULL; + + hdev = to_hid_device(dev); + + ctx_kern = kzalloc(sizeof(*ctx_kern), GFP_KERNEL); + if (!ctx_kern) + return NULL; + + ctx_kern->ctx.hid = hdev; + + return &ctx_kern->ctx; +} + +/** + * hid_bpf_release_context - Release the previously allocated context @ctx + * + * @ctx: the HID-BPF context to release + * + */ +noinline void +hid_bpf_release_context(struct hid_bpf_ctx *ctx) +{ + struct hid_bpf_ctx_kern *ctx_kern; + + if (!ctx) + return; + + ctx_kern = container_of(ctx, struct hid_bpf_ctx_kern, ctx); + + kfree(ctx_kern); +} + +/** + * hid_bpf_hw_request - Communicate with a HID device + * + * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context() + * @buf: a %PTR_TO_MEM buffer + * @buf__sz: the size of the data to transfer + * @rtype: the type of the report (%HID_INPUT_REPORT, %HID_FEATURE_REPORT, %HID_OUTPUT_REPORT) + * @reqtype: the type of the request (%HID_REQ_GET_REPORT, %HID_REQ_SET_REPORT, ...) + * + * @returns %0 on success, a negative error code otherwise. + */ +noinline int +hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz, + enum hid_report_type rtype, enum hid_class_request reqtype) +{ + struct hid_device *hdev = (struct hid_device *)ctx->hid; /* discard const */ + struct hid_report *report; + struct hid_report_enum *report_enum; + u8 *dma_data; + u32 report_len; + int ret; + + /* check arguments */ + if (!ctx || !hid_bpf_ops || !buf) + return -EINVAL; + + switch (rtype) { + case HID_INPUT_REPORT: + case HID_OUTPUT_REPORT: + case HID_FEATURE_REPORT: + break; + default: + return -EINVAL; + } + + switch (reqtype) { + case HID_REQ_GET_REPORT: + case HID_REQ_GET_IDLE: + case HID_REQ_GET_PROTOCOL: + case HID_REQ_SET_REPORT: + case HID_REQ_SET_IDLE: + case HID_REQ_SET_PROTOCOL: + break; + default: + return -EINVAL; + } + + if (buf__sz < 1) + return -EINVAL; + + report_enum = hdev->report_enum + rtype; + report = hid_bpf_ops->hid_get_report(report_enum, buf); + if (!report) + return -EINVAL; + + report_len = hid_report_len(report); + + if (buf__sz > report_len) + buf__sz = report_len; + + dma_data = kmemdup(buf, buf__sz, GFP_KERNEL); + if (!dma_data) + return -ENOMEM; + + ret = hid_bpf_ops->hid_hw_raw_request(hdev, + dma_data[0], + dma_data, + buf__sz, + rtype, + reqtype); + + if (ret > 0) + memcpy(buf, dma_data, ret); + + kfree(dma_data); + return ret; +} + /* for syscall HID-BPF */ BTF_SET8_START(hid_bpf_syscall_kfunc_ids) BTF_ID_FLAGS(func, hid_bpf_attach_prog) +BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE) +BTF_ID_FLAGS(func, hid_bpf_hw_request) BTF_SET8_END(hid_bpf_syscall_kfunc_ids) static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = { diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 6bee65624551..5dac2a1cc205 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2918,6 +2918,8 @@ int hid_check_keys_pressed(struct hid_device *hid) EXPORT_SYMBOL_GPL(hid_check_keys_pressed); static struct hid_bpf_ops hid_ops = { + .hid_get_report = hid_get_report, + .hid_hw_raw_request = hid_hw_raw_request, .owner = THIS_MODULE, .bus_type = &hid_bus_type, }; diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h index 277afae784ec..bf83d5811c51 100644 --- a/include/linux/hid_bpf.h +++ b/include/linux/hid_bpf.h @@ -61,11 +61,15 @@ struct hid_bpf_ctx { int hid_bpf_device_event(struct hid_bpf_ctx *ctx); /* Following functions are kfunc that we export to BPF programs */ -/* only available in tracing */ +/* available everywhere in HID-BPF */ __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx, unsigned int offset, const size_t __sz); /* only available in syscall */ int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, __u32 flags); +int hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz, + enum hid_report_type rtype, enum hid_class_request reqtype); +struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id); +void hid_bpf_release_context(struct hid_bpf_ctx *ctx); /* * Below is HID internal @@ -84,7 +88,14 @@ enum hid_bpf_prog_type { HID_BPF_PROG_TYPE_MAX, }; +struct hid_report_enum; + struct hid_bpf_ops { + struct hid_report *(*hid_get_report)(struct hid_report_enum *report_enum, const u8 *data); + int (*hid_hw_raw_request)(struct hid_device *hdev, + unsigned char reportnum, __u8 *buf, + size_t len, enum hid_report_type rtype, + enum hid_class_request reqtype); struct module *owner; struct bus_type *bus_type; };