From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail11.truemail.it (mail11.truemail.it [217.194.8.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB22A198A3F for ; Wed, 18 Dec 2024 10:38:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.194.8.81 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734518286; cv=none; b=qnZTfAPvUOPRw9CDMDBGV0Rd1DIMCxq8xioEnwxmlaxztunI3R3zB0jI1VHeydJ0hhtln6eN4FQmubPaFBBGEcE1DQkvtR32NYlbRHlYkQ7SxLJR0+jJrULKeqdRBn4cNhX9jkJeX8Y46UmcZX+xf0w0jsKqorfMklaLhSH6L1o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734518286; c=relaxed/simple; bh=bYLDD8/8TM76bmYy74XFWSp63b13S4DU4o5bbP/qsUY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=t48ouSq6qkmoFD5+uJ1SqXmEIJET6ypniZPjnSkyr3VrIhqEndfbQj1YoH1C70Y6USFmhzZ/BiNgcK17B88kCwNGJq6MFpLps6iPs3EL45K8qXjshMslC1jDtqcVk/PYJzBE6vR1nXdDu4uiH6XOA2OS3Wl54petTaveGMh1daE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it; spf=pass smtp.mailfrom=dolcini.it; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b=SDRKzOHT; arc=none smtp.client-ip=217.194.8.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=dolcini.it Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=dolcini.it Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=dolcini.it header.i=@dolcini.it header.b="SDRKzOHT" Received: from francesco-nb (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 82C801FCF7; Wed, 18 Dec 2024 11:37:52 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dolcini.it; s=default; t=1734518273; bh=w1v0QHKNQOz/R/miGVNt6KYUwMYCc0ptPv/vzKqwCq0=; h=From:To:Subject; b=SDRKzOHT/1TjkV5y/uanoyFxmfPB9kdqyxQr2r2kslxgv6kPjP1ZTmq64KyhQHiNB kiN3S6y3/7Odz6/e7n/jaiShZxhnZD+WgDbQLOw24wDanyd68DKtJfinbfK0QRm5y/ EukjeJoWGfMarfmaiwOm5l5lDr9HrxWqUe48b0eN+wtsgc7KiVW8h7nDet26oLYGyC J8PNYqBNOBrIZspL2tEO9AqViPS3K45ARiRNW45usKwlBw23KSAR5/O9Qv/zG6GsXJ UI1dpM2SFo0dt97lQv5o5XK7tpuOVz2hO2PnIa4YMxaG/kU19moRSRdEE6PkT6LTh2 60wXEfp/T4m7Q== Date: Wed, 18 Dec 2024 11:37:47 +0100 From: Francesco Dolcini To: Xu Yang Cc: heikki.krogerus@linux.intel.com, gregkh@linuxfoundation.org, andre.draszik@linaro.org, rdbabiera@google.com, m.felsch@pengutronix.de, dan.carpenter@linaro.org, emanuele.ghidoli@toradex.com, parth.pancholi@toradex.com, francesco.dolcini@toradex.com, u.kleine-koenig@baylibre.com, linux-usb@vger.kernel.org, imx@lists.linux.dev, jun.li@nxp.com Subject: Re: [PATCH v4] usb: typec: tcpci: fix NULL pointer issue on shared irq case Message-ID: <20241218103747.GA4500@francesco-nb> References: <20241218095328.2604607-1-xu.yang_2@nxp.com> Precedence: bulk X-Mailing-List: imx@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241218095328.2604607-1-xu.yang_2@nxp.com> On Wed, Dec 18, 2024 at 05:53:28PM +0800, Xu Yang wrote: > The tcpci_irq() may meet below NULL pointer dereference issue: > > [ 2.641851] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 > [ 2.641951] status 0x1, 0x37f > [ 2.650659] Mem abort info: > [ 2.656490] ESR = 0x0000000096000004 > [ 2.660230] EC = 0x25: DABT (current EL), IL = 32 bits > [ 2.665532] SET = 0, FnV = 0 > [ 2.668579] EA = 0, S1PTW = 0 > [ 2.671715] FSC = 0x04: level 0 translation fault > [ 2.676584] Data abort info: > [ 2.679459] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 > [ 2.684936] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > [ 2.689980] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > [ 2.695284] [0000000000000010] user address but active_mm is swapper > [ 2.701632] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP > [ 2.707883] Modules linked in: > [ 2.710936] CPU: 1 UID: 0 PID: 87 Comm: irq/111-2-0051 Not tainted 6.12.0-rc6-06316-g7f63786ad3d1-dirty #4 > [ 2.720570] Hardware name: NXP i.MX93 11X11 EVK board (DT) > [ 2.726040] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) > [ 2.732989] pc : tcpci_irq+0x38/0x318 > [ 2.736647] lr : _tcpci_irq+0x14/0x20 > [ 2.740295] sp : ffff80008324bd30 > [ 2.743597] x29: ffff80008324bd70 x28: ffff800080107894 x27: ffff800082198f70 > [ 2.750721] x26: ffff0000050e6680 x25: ffff000004d172ac x24: ffff0000050f0000 > [ 2.757845] x23: ffff000004d17200 x22: 0000000000000001 x21: ffff0000050f0000 > [ 2.764969] x20: ffff000004d17200 x19: 0000000000000000 x18: 0000000000000001 > [ 2.772093] x17: 0000000000000000 x16: ffff80008183d8a0 x15: ffff00007fbab040 > [ 2.779217] x14: ffff00007fb918c0 x13: 0000000000000000 x12: 000000000000017a > [ 2.786341] x11: 0000000000000001 x10: 0000000000000a90 x9 : ffff80008324bd00 > [ 2.793465] x8 : ffff0000050f0af0 x7 : ffff00007fbaa840 x6 : 0000000000000031 > [ 2.800589] x5 : 000000000000017a x4 : 0000000000000002 x3 : 0000000000000002 > [ 2.807713] x2 : ffff80008324bd3a x1 : 0000000000000010 x0 : 0000000000000000 > [ 2.814838] Call trace: > [ 2.817273] tcpci_irq+0x38/0x318 > [ 2.820583] _tcpci_irq+0x14/0x20 > [ 2.823885] irq_thread_fn+0x2c/0xa8 > [ 2.827456] irq_thread+0x16c/0x2f4 > [ 2.830940] kthread+0x110/0x114 > [ 2.834164] ret_from_fork+0x10/0x20 > [ 2.837738] Code: f9426420 f9001fe0 d2800000 52800201 (f9400a60) > > This may happen on shared irq case. Such as two Type-C ports share one > irq. After the first port finished tcpci_register_port(), it may trigger > interrupt. However, if the interrupt comes by chance the 2nd port finishes > devm_request_threaded_irq(), the 2nd port interrupt handler will run at > first. Then the above issue happens due to tcpci is still a NULL pointer > in tcpci_irq() when dereference to regmap. > > devm_request_threaded_irq() > <-- port1 irq comes > disable_irq(client->irq); > tcpci_register_port() > > This will restore the logic to the state before commit (77e85107a771 "usb: > typec: tcpci: support edge irq"). > > However, moving tcpci_register_port() earlier creates a problem when use > edge irq because tcpci_init() will be called before > devm_request_threaded_irq(). The tcpci_init() writes the ALERT_MASK to > the hardware to tell it to start generating interrupts but we're not ready > to deal with them yet, then the ALERT events may be missed and ALERT line > will not recover to high level forever. To avoid the issue, this will also > set ALERT_MASK register after devm_request_threaded_irq() return. > > Fixes: 77e85107a771 ("usb: typec: tcpci: support edge irq") > Cc: stable@vger.kernel.org > Tested-by: Emanuele Ghidoli > Signed-off-by: Xu Yang Reviewed-by: Francesco Dolcini