From patchwork Tue Mar 18 15:22:07 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Korsgaard X-Patchwork-Id: 874702 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (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 EBD1620DD7B for ; Tue, 18 Mar 2025 15:22:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311355; cv=none; b=IpcunRF9Fr3itpp9veUHEYNYkPb7SpWtvEAE624s5YAyBmo258VsoJUIOsa9lAerelJUt6Slcjuqq7bXKBXHPYA1sSsE4snOpIp8sQrXQBY/tD18foMYzckk53+oVrh1f61/dtwmHpJ4d1UbKRH/MNpa/BNGNLv6dm3uP3hQSl4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742311355; c=relaxed/simple; bh=yftSaW5pqEifSQdDtqgmLKWgEtLSoM4i36ne/OesOl4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=lDY6sA9rqGI2IZS29XvbfxDPNL4JDUcgix+VAEY2VEDLqwzyrfb0ofAM8bHqoooKWPrvBoFEKkZ0zHp9zUVto4Q5nhS7ujUky/KqZZ4B7G713R8coVqf9jz+nt48OuJcggWUbXEExksZ8UMbmDUkd3aEGocXFrHcsAeWePvPwT4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=korsgaard.com; spf=pass smtp.mailfrom=korsgaard.com; arc=none smtp.client-ip=217.70.183.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=korsgaard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=korsgaard.com Received: by mail.gandi.net (Postfix) with ESMTPSA id 0BA56442D2; Tue, 18 Mar 2025 15:22:24 +0000 (UTC) Received: from peko by dell.be.48ers.dk with local (Exim 4.96) (envelope-from ) id 1tuYls-001O81-0B; Tue, 18 Mar 2025 16:22:24 +0100 From: Peter Korsgaard To: gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, john@keeping.me.uk Cc: Peter Korsgaard Subject: [PATCH] usb: gadget: f_hid: wake up readers on disable/unbind Date: Tue, 18 Mar 2025 16:22:07 +0100 Message-Id: <20250318152207.330997-1-peter@korsgaard.com> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-GND-State: clean X-GND-Score: 0 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgddugedvjeelucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuifetpfffkfdpucggtfgfnhhsuhgsshgtrhhisggvnecuuegrihhlohhuthemuceftddunecunecujfgurhephffvvefufffkofgggfestdekredtredttdenucfhrhhomheprfgvthgvrhcumfhorhhsghgrrghrugcuoehpvghtvghrsehkohhrshhgrggrrhgurdgtohhmqeenucggtffrrghtthgvrhhnpeevieevtefhleetleeuledvffeivefgvddtiedvteeugffftddvueffveehgeffudenucfkphepudejkedrudduledruddrudefjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpedujeekrdduudelrddurddufeejpdhhvghlohepuggvlhhlrdgsvgdrgeekvghrshdrughkpdhmrghilhhfrhhomhepphgvkhhosehkohhrshhgrggrrhgurdgtohhmpdhnsggprhgtphhtthhopeegpdhrtghpthhtohepghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhgpdhrtghpthhtoheplhhinhhugidquhhssgesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehjohhhnheskhgvvghpihhnghdrmhgvrdhukhdprhgtphhtthhopehpvghtvghrsehkohhrshhgrggrrhgurdgtohhm X-GND-Sasl: peter@korsgaard.com Similar to how it is done in the write path. Add a disabled flag to track the function state and use it to exit the read loops to ensure no readers get stuck when the function is disabled/unbound, protecting against corruption when the waitq and spinlocks are reinitialized in hidg_bind(). Signed-off-by: Peter Korsgaard --- drivers/usb/gadget/function/f_hid.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/function/f_hid.c index 740311c4fa249..1bc40fc0ccf77 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -75,6 +75,7 @@ struct f_hidg { /* recv report */ spinlock_t read_spinlock; wait_queue_head_t read_queue; + bool disabled; /* recv report - interrupt out only (use_out_ep == 1) */ struct list_head completed_out_req; unsigned int qlen; @@ -329,7 +330,7 @@ static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer, spin_lock_irqsave(&hidg->read_spinlock, flags); -#define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req)) +#define READ_COND_INTOUT (!list_empty(&hidg->completed_out_req) || hidg->disabled) /* wait for at least one buffer to complete */ while (!READ_COND_INTOUT) { @@ -343,6 +344,11 @@ static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer, spin_lock_irqsave(&hidg->read_spinlock, flags); } + if (hidg->disabled) { + spin_unlock_irqrestore(&hidg->read_spinlock, flags); + return -ESHUTDOWN; + } + /* pick the first one */ list = list_first_entry(&hidg->completed_out_req, struct f_hidg_req_list, list); @@ -387,7 +393,7 @@ static ssize_t f_hidg_intout_read(struct file *file, char __user *buffer, return count; } -#define READ_COND_SSREPORT (hidg->set_report_buf != NULL) +#define READ_COND_SSREPORT (hidg->set_report_buf != NULL || hidg->disabled) static ssize_t f_hidg_ssreport_read(struct file *file, char __user *buffer, size_t count, loff_t *ptr) @@ -1012,6 +1018,11 @@ static void hidg_disable(struct usb_function *f) } spin_unlock_irqrestore(&hidg->get_report_spinlock, flags); + spin_lock_irqsave(&hidg->read_spinlock, flags); + hidg->disabled = true; + spin_unlock_irqrestore(&hidg->read_spinlock, flags); + wake_up(&hidg->read_queue); + spin_lock_irqsave(&hidg->write_spinlock, flags); if (!hidg->write_pending) { free_ep_req(hidg->in_ep, hidg->req); @@ -1097,6 +1108,10 @@ static int hidg_set_alt(struct usb_function *f, unsigned intf, unsigned alt) } } + spin_lock_irqsave(&hidg->read_spinlock, flags); + hidg->disabled = false; + spin_unlock_irqrestore(&hidg->read_spinlock, flags); + if (hidg->in_ep != NULL) { spin_lock_irqsave(&hidg->write_spinlock, flags); hidg->req = req_in;