From patchwork Wed Jun 26 13:46:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 13712965 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 EACB2186284; Wed, 26 Jun 2024 13:46:51 +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=1719409612; cv=none; b=Tp++CmDr2qr+vIveRozu8W4ufC2rONq+wxTJszCZikzoEzryDAzvWhvYsftXakD5AFaf/bOfJivxNzOjHlGsSN8ekxjxsWx5EEf8xA6J+UEXIEwQAT6lTneRGo31v+bXk/NL+8/i1v4HswFF7RXFH2HxbXg4IOwW/CHJt+8NqSE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719409612; c=relaxed/simple; bh=hLxv1tQ4ND5CQTyY2sweAPBolNhSrfyuhdyzuv4wmEQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bmdVID6RKLA75IIk3dKQ7fpIxZKpltnuPFe2/YMt78MWXI/F0DqL3J1YfYh9ujSD7wmTrqa6qUhh+RwuNFwqQl+3shUVgewaRmogGVDgydW0tSBMJ/cGF2cMe/eONe1OQy1zeAUqJGP6rUxI1H0SH1zDNp82VnLeWstRSDv403Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E3fBmUvQ; 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="E3fBmUvQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E582EC32782; Wed, 26 Jun 2024 13:46:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719409611; bh=hLxv1tQ4ND5CQTyY2sweAPBolNhSrfyuhdyzuv4wmEQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=E3fBmUvQVBBtJnrFsB8vp3Wx0IQLJ/rpj/nd0NfLfHdPAQS69pBNmecEA4ownvMJ0 KKOl21La9grVtvaJ3l7kf6YHSKc3Et7bgc34qRW6ct08qFzV+MrI2OkK7z8D72rsou GczODF2wC7M04Lk093R6U2ncJilKTpTuDyJzS/s3EvGpO9JLBBAIthcwy+ir1fTULw lPT4ULKcMj8G5cnD4g9EEJ7jU2prjlW2lghncGJxGpLK/dkmhPkt5PAIquyZayDOyY S3ALJv619EXJfNLrzyUexE0Ny+hqk5uCFM0qVU/FpBQA+2koAuEftI+Jf4HnWKYPmi /Nq+Y+PE70GEQ== From: Benjamin Tissoires Date: Wed, 26 Jun 2024 15:46:24 +0200 Subject: [PATCH HID v2 03/13] HID: bpf: protect HID-BPF prog_list access by a SRCU Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240626-hid_hw_req_bpf-v2-3-cfd60fb6c79f@kernel.org> References: <20240626-hid_hw_req_bpf-v2-0-cfd60fb6c79f@kernel.org> In-Reply-To: <20240626-hid_hw_req_bpf-v2-0-cfd60fb6c79f@kernel.org> To: Jiri Kosina , Alexei Starovoitov , Shuah Khan , Jonathan Corbet Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org, Benjamin Tissoires X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=ed25519-sha256; t=1719409602; l=4479; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=hLxv1tQ4ND5CQTyY2sweAPBolNhSrfyuhdyzuv4wmEQ=; b=euocECF82/VA2Yc9x6TuL1sM4rve+X1wAuPOCXC7da15J48DHtEaZKST0aTxrBeZDrc99mjAk u3xTD//3BTrBKmVBwF7DR3V8NHnR8gYVaCb4mc0Zns1ol3tglsSnXjh X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= We want to add sleepable callbacks for hid_hw_raw_request() and hid_hw_output_report(), but we can not use a plain RCU for those. Prepare for a SRCU so we can extend HID-BPF. This changes a little bit how hid_bpf_device_init() behaves, as it may now fail, so there is a tiny hid-core.c change to accommodate for this. Signed-off-by: Benjamin Tissoires --- new in v2 --- drivers/hid/bpf/hid_bpf_dispatch.c | 6 +++++- drivers/hid/bpf/hid_bpf_struct_ops.c | 2 ++ drivers/hid/hid-core.c | 8 +++++++- include/linux/hid_bpf.h | 6 ++++-- 4 files changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/hid/bpf/hid_bpf_dispatch.c b/drivers/hid/bpf/hid_bpf_dispatch.c index 2df31decaac3..c026248e3d73 100644 --- a/drivers/hid/bpf/hid_bpf_dispatch.c +++ b/drivers/hid/bpf/hid_bpf_dispatch.c @@ -506,13 +506,17 @@ void hid_bpf_destroy_device(struct hid_device *hdev) hdev->bpf.destroyed = true; __hid_bpf_ops_destroy_device(hdev); + + synchronize_srcu(&hdev->bpf.srcu); + cleanup_srcu_struct(&hdev->bpf.srcu); } EXPORT_SYMBOL_GPL(hid_bpf_destroy_device); -void hid_bpf_device_init(struct hid_device *hdev) +int hid_bpf_device_init(struct hid_device *hdev) { INIT_LIST_HEAD(&hdev->bpf.prog_list); mutex_init(&hdev->bpf.prog_list_lock); + return init_srcu_struct(&hdev->bpf.srcu); } EXPORT_SYMBOL_GPL(hid_bpf_device_init); diff --git a/drivers/hid/bpf/hid_bpf_struct_ops.c b/drivers/hid/bpf/hid_bpf_struct_ops.c index 8063db1c8d62..d34731a1b457 100644 --- a/drivers/hid/bpf/hid_bpf_struct_ops.c +++ b/drivers/hid/bpf/hid_bpf_struct_ops.c @@ -214,6 +214,7 @@ static int hid_bpf_reg(void *kdata) list_add_rcu(&ops->list, &hdev->bpf.prog_list); else list_add_tail_rcu(&ops->list, &hdev->bpf.prog_list); + synchronize_srcu(&hdev->bpf.srcu); out_unlock: mutex_unlock(&hdev->bpf.prog_list_lock); @@ -244,6 +245,7 @@ static void hid_bpf_unreg(void *kdata) mutex_lock(&hdev->bpf.prog_list_lock); list_del_rcu(&ops->list); + synchronize_srcu(&hdev->bpf.srcu); reconnect = hdev->bpf.rdesc_ops == ops; if (reconnect) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 0775a32f5272..ad08289752da 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2875,9 +2875,15 @@ struct hid_device *hid_allocate_device(void) mutex_init(&hdev->ll_open_lock); kref_init(&hdev->ref); - hid_bpf_device_init(hdev); + ret = hid_bpf_device_init(hdev); + if (ret) + goto out_err; return hdev; + +out_err: + hid_destroy_device(hdev); + return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(hid_allocate_device); diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h index a54741db0415..f93845de5cac 100644 --- a/include/linux/hid_bpf.h +++ b/include/linux/hid_bpf.h @@ -5,6 +5,7 @@ #include #include +#include #include struct hid_device; @@ -145,6 +146,7 @@ struct hid_bpf { struct hid_bpf_ops *rdesc_ops; struct list_head prog_list; struct mutex prog_list_lock; /* protects prog_list update */ + struct srcu_struct srcu; /* protects prog_list read-only access */ }; #ifdef CONFIG_HID_BPF @@ -153,7 +155,7 @@ u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type t int hid_bpf_connect_device(struct hid_device *hdev); void hid_bpf_disconnect_device(struct hid_device *hdev); void hid_bpf_destroy_device(struct hid_device *hid); -void hid_bpf_device_init(struct hid_device *hid); +int hid_bpf_device_init(struct hid_device *hid); u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, u8 *rdesc, unsigned int *size); #else /* CONFIG_HID_BPF */ static inline u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type type, @@ -162,7 +164,7 @@ static inline u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid static inline int hid_bpf_connect_device(struct hid_device *hdev) { return 0; } static inline void hid_bpf_disconnect_device(struct hid_device *hdev) {} static inline void hid_bpf_destroy_device(struct hid_device *hid) {} -static inline void hid_bpf_device_init(struct hid_device *hid) {} +static inline int hid_bpf_device_init(struct hid_device *hid) { return 0; } #define call_hid_bpf_rdesc_fixup(_hdev, _rdesc, _size) \ ((u8 *)kmemdup(_rdesc, *(_size), GFP_KERNEL))