From patchwork Tue Jul 12 14:58:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 589916 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 30E3BC43334 for ; Tue, 12 Jul 2022 15:06:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233305AbiGLPGK (ORCPT ); Tue, 12 Jul 2022 11:06:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233426AbiGLPFn (ORCPT ); Tue, 12 Jul 2022 11:05:43 -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 2E216C3AC6 for ; Tue, 12 Jul 2022 08:00:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1657638015; 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=Ft4K/Gttu2oB4xR+UD3eEqkW6z/fkcD3zck7/fdZ/0M=; b=gvV7ByuH0sli4wYK/RVuVJudS0qnfaqTkXzVupLhqxTfpq+GorvGr8tUIdjOudHstlidfk 5H8HpGKDB24uiClWwLTNyVp0ip83RL1HsG4RK8/WO9/UQv/7xWKDvMW2+8yMDNL7/SWNQr fvSZuiBj7wjJEPT2xm6vvbmj9oxIhhg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-443-kEFUa479Ndiqvwfx-ivFWw-1; Tue, 12 Jul 2022 11:00:10 -0400 X-MC-Unique: kEFUa479Ndiqvwfx-ivFWw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A89DE2803031; Tue, 12 Jul 2022 15:00:07 +0000 (UTC) Received: from plouf.redhat.com (unknown [10.39.195.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 156E32166B26; Tue, 12 Jul 2022 15:00:03 +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 , Shuah Khan , Dave Marchevsky , Joe Stringer , Jonathan Corbet Cc: Tero Kristo , linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, Benjamin Tissoires Subject: [PATCH bpf-next v6 16/23] HID: bpf: introduce hid_hw_request() Date: Tue, 12 Jul 2022 16:58:43 +0200 Message-Id: <20220712145850.599666-17-benjamin.tissoires@redhat.com> In-Reply-To: <20220712145850.599666-1-benjamin.tissoires@redhat.com> References: <20220712145850.599666-1-benjamin.tissoires@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-input@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. Signed-off-by: Benjamin Tissoires --- 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 | 148 +++++++++++++++++++++++++++++ drivers/hid/hid-core.c | 2 + include/linux/hid_bpf.h | 13 ++- 3 files changed, 162 insertions(+), 1 deletion(-) diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index 87fd11539213..8348f5ae17f8 100644 --- a/drivers/hid/bpf/hid_bpf_dispatch.c +++ b/drivers/hid/bpf/hid_bpf_dispatch.c @@ -232,14 +232,162 @@ 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; + int err; + + 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) + 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_SET_START(hid_bpf_syscall_kfunc_ids) BTF_ID(func, hid_bpf_attach_prog) +BTF_ID(func, hid_bpf_allocate_context) +BTF_ID(func, hid_bpf_release_context) +BTF_ID(func, hid_bpf_hw_request) BTF_SET_END(hid_bpf_syscall_kfunc_ids) +BTF_SET_START(hid_bpf_syscall_kfunc_ret_null_ids) +BTF_ID(func, hid_bpf_allocate_context) +BTF_SET_END(hid_bpf_syscall_kfunc_ret_null_ids) + +BTF_SET_START(hid_bpf_syscall_kfunc_alloc_ids) +BTF_ID(func, hid_bpf_allocate_context) +BTF_SET_END(hid_bpf_syscall_kfunc_alloc_ids) + +BTF_SET_START(hid_bpf_syscall_kfunc_release_ids) +BTF_ID(func, hid_bpf_release_context) +BTF_SET_END(hid_bpf_syscall_kfunc_release_ids) + static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = { .owner = THIS_MODULE, .check_set = &hid_bpf_syscall_kfunc_ids, + .ret_null_set = &hid_bpf_syscall_kfunc_ret_null_ids, + .acquire_set = &hid_bpf_syscall_kfunc_alloc_ids, + .release_set = &hid_bpf_syscall_kfunc_release_ids, }; int hid_bpf_connect_device(struct hid_device *hdev) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index c2589106ea4b..356d3822f17d 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2917,6 +2917,8 @@ 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 c9684de18f3f..ade0def154b6 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 @@ -81,7 +85,14 @@ 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; };