From patchwork Fri Mar 15 14:44:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 13593555 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 150243D0CA; Fri, 15 Mar 2024 14:44:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710513893; cv=none; b=bNC9HHatI7sGuFvDsTbYpCS1sNdNr+xtGRgu3KpDuWuzerl6lW6yNdxZX/QnUjeARZERQJE/kDhktz+2pNECyoZ2+S885X8PgRg1Inwj0EWoCGpyhOXNgALDy3EL6+C2v2yyf3sDSr2l7+C5fFlK45dIfA0mkjmJA/xEatkC1nY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710513893; c=relaxed/simple; bh=zq66QKtjnXJ4Qer6GMlak1OP/mCYAo+o7m/hoYuei0o=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ss2HjfHokVXmNTpKklr1AxZcUPVWAD2X/6LIYxwneiUI4NSpf8g4kEQAkgcLn3jBhpEv9AQCcP2YblLJ3w5vQIynr7/EUqdeDB4YR93t6oT44f0NpeMH1TnR6mS26JWMYzbMwCyEgiyohPlqOWR4gMfL8aZbIPPGIk3NazhMrbk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J34MSr1p; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="J34MSr1p" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DD460C32784; Fri, 15 Mar 2024 14:44:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710513892; bh=zq66QKtjnXJ4Qer6GMlak1OP/mCYAo+o7m/hoYuei0o=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=J34MSr1pP1mHZVnp9Lcni2ceQKxT/azQc7edzymyCKZWwb+iyL9g/IbNuRZ9cRSTr 4uvW1zWQjyTYBZ45BGwAKxjrfI10xQ3DAxmWzqKMUR62TvZnaKstIBYShyWqfLsQKL sAVdgf5FIhvy9rD/P+4aNl/ch97Qx6uSYJ5YDYUcvmw4d0D0Xwir6i8yXscoo5g+8c 83a54CSetuS7vQEzkGtyDT2/SjdoROVowWQEPFdfV4s2q5CXfjcDtPBnrMfu98p+NK RZDL7gjEtHj0X/napdKvs3rdz2jRuhOUNqQDeOICcPFi96Vk/tplNnchsFPvYYSoCx ZC4mAAUJF8CAQ== From: Benjamin Tissoires Date: Fri, 15 Mar 2024 15:44:39 +0100 Subject: [PATCH v4 2/7] HID: bpf: export hid_hw_output_report as a BPF kfunc Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240315-b4-hid-bpf-new-funcs-v4-2-079c282469d3@kernel.org> References: <20240315-b4-hid-bpf-new-funcs-v4-0-079c282469d3@kernel.org> In-Reply-To: <20240315-b4-hid-bpf-new-funcs-v4-0-079c282469d3@kernel.org> To: Jiri Kosina , Benjamin Tissoires , Jonathan Corbet , Shuah Khan Cc: Benjamin Tissoires , linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1710513885; l=6547; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=zq66QKtjnXJ4Qer6GMlak1OP/mCYAo+o7m/hoYuei0o=; b=cnsXrVOWz3Ti0W+sZSx3G5daPohvB0026JiATxm4hhzvVmUdHLCYCkiOQsBV1hXVie570p1Qs uapkg6Jf4TjCyslK3XpaTmDXttpMnNK9/FnCL6tPmTAiM1Mo7wTjy6p X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= We currently only export hid_hw_raw_request() as a BPF kfunc. However, some devices require an explicit write on the Output Report instead of the use of the control channel. So also export hid_hw_output_report to BPF Signed-off-by: Benjamin Tissoires --- no changes in v4 no changes in v3 no changes in v2 --- Documentation/hid/hid-bpf.rst | 2 +- drivers/hid/bpf/hid_bpf_dispatch.c | 112 +++++++++++++++++++++++++++---------- drivers/hid/hid-core.c | 1 + include/linux/hid_bpf.h | 1 + 4 files changed, 86 insertions(+), 30 deletions(-) diff --git a/Documentation/hid/hid-bpf.rst b/Documentation/hid/hid-bpf.rst index 4fad83a6ebc3..a575004d9025 100644 --- a/Documentation/hid/hid-bpf.rst +++ b/Documentation/hid/hid-bpf.rst @@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs: ----------------------------------------------------------- .. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c - :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_allocate_context hid_bpf_release_context + :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_allocate_context hid_bpf_release_context General overview of a HID-BPF program ===================================== diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index 52abb27426f4..a5b88b491b80 100644 --- a/drivers/hid/bpf/hid_bpf_dispatch.c +++ b/drivers/hid/bpf/hid_bpf_dispatch.c @@ -376,6 +376,46 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx) put_device(&hid->dev); } +static int +__hid_bpf_hw_check_params(struct hid_bpf_ctx *ctx, __u8 *buf, size_t *buf__sz, + enum hid_report_type rtype) +{ + struct hid_report_enum *report_enum; + struct hid_report *report; + struct hid_device *hdev; + u32 report_len; + + /* 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; + } + + if (*buf__sz < 1) + return -EINVAL; + + hdev = (struct hid_device *)ctx->hid; /* discard const */ + + 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; + + return 0; +} + /** * hid_bpf_hw_request - Communicate with a HID device * @@ -392,24 +432,14 @@ 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_report *report; - struct hid_report_enum *report_enum; + size_t size = buf__sz; 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; - } + ret = __hid_bpf_hw_check_params(ctx, buf, &size, rtype); + if (ret) + return ret; switch (reqtype) { case HID_REQ_GET_REPORT: @@ -423,29 +453,16 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz, return -EINVAL; } - if (buf__sz < 1) - return -EINVAL; - hdev = (struct hid_device *)ctx->hid; /* discard const */ - 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); + dma_data = kmemdup(buf, size, GFP_KERNEL); if (!dma_data) return -ENOMEM; ret = hid_bpf_ops->hid_hw_raw_request(hdev, dma_data[0], dma_data, - buf__sz, + size, rtype, reqtype); @@ -455,6 +472,42 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz, kfree(dma_data); return ret; } + +/** + * hid_bpf_hw_output_report - Send an output report to 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 + * + * @returns the number of bytes transferred on success, a negative error code otherwise. + */ +__bpf_kfunc int +hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz) +{ + struct hid_device *hdev; + size_t size = buf__sz; + u8 *dma_data; + int ret; + + /* check arguments */ + ret = __hid_bpf_hw_check_params(ctx, buf, &size, HID_OUTPUT_REPORT); + if (ret) + return ret; + + hdev = (struct hid_device *)ctx->hid; /* discard const */ + + dma_data = kmemdup(buf, size, GFP_KERNEL); + if (!dma_data) + return -ENOMEM; + + ret = hid_bpf_ops->hid_hw_output_report(hdev, + dma_data, + size); + + kfree(dma_data); + return ret; +} __bpf_kfunc_end_defs(); /* @@ -488,6 +541,7 @@ 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_ID_FLAGS(func, hid_bpf_hw_output_report) BTF_KFUNCS_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 de7a477d6665..1243595890ba 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2974,6 +2974,7 @@ 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, + .hid_hw_output_report = hid_hw_output_report, .owner = THIS_MODULE, .bus_type = &hid_bus_type, }; diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h index 7118ac28d468..5c7ff93dc73e 100644 --- a/include/linux/hid_bpf.h +++ b/include/linux/hid_bpf.h @@ -103,6 +103,7 @@ struct hid_bpf_ops { unsigned char reportnum, __u8 *buf, size_t len, enum hid_report_type rtype, enum hid_class_request reqtype); + int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len); struct module *owner; const struct bus_type *bus_type; };