From mboxrd@z Thu Jan 1 00:00:00 1970 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 shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CB40FECAAD8 for ; Wed, 21 Sep 2022 11:16:14 +0000 (UTC) Received: from localhost ([::1] helo=shelob.surriel.com) by shelob.surriel.com with esmtp (Exim 4.96) (envelope-from ) id 1oaxi4-0000rt-1Q; Wed, 21 Sep 2022 07:16:08 -0400 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]) by shelob.surriel.com with esmtps (TLS1.2) tls TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1oaxi0-0000rc-2a for kernelnewbies@kernelnewbies.org; Wed, 21 Sep 2022 07:16:05 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id 70EA1320095C; Wed, 21 Sep 2022 07:16:00 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Wed, 21 Sep 2022 07:16:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :cc:content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm2; t=1663758959; x=1663845359; bh=OQruokhchr EakxF8HDNTdtgQzW6jouEUbtXAcVWk/z0=; b=uQKE6RbdLCOSl0VcFYgPjdcKLE 4OB76NP9d7RudzGNM8jgGkbvgLkWSj7blljDe25jnF489Wn8lmmxZqNGZhJ4ADSP 4ujbM+xCD2aTnLPg7pn8vy972MqgjghFd8bogZlTEb3X0bzyzn7wNq0fPFS8WzY1 5P+S35Rvtj3Btcsryhz5HsOP1lOc2rZky60KIMjRdgyqNvUFDR1kJACXppQCvGdR LMMNS7YIIfVY35UJh2f3OArN9qq/p7D+0FO4r/jKAJgSfw4j0rtSldWiUZAL0dSd ZCLXXqUfAmA3KZqDqiruCvdfiY+PNyJ3+b8g3StNPtYJjpDZ06GQC/JyyN6Q== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:in-reply-to:message-id :mime-version:references:reply-to:sender:subject:subject:to:to :x-me-proxy:x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s= fm2; t=1663758959; x=1663845359; bh=OQruokhchrEakxF8HDNTdtgQzW6j ouEUbtXAcVWk/z0=; b=U6p449PdbxvbonnGRn9xg0P/KAkkFEtiY4/UM6mVp5Vs kdCA06WodrDt2qMZ++NIniiMiXFQKIB6gkKessW+3nuluL1Cyr+sewRYn03o7OiQ olHOcetuA7TH2j3xqJ17NuJgL9HcrbNUD5JAukNPpeJeDPkKUIMm78vSvMuQONwX /8Wep7LetFI7PeRi8zN1e0IA0tYwnFzCnVjErBe0dbDcU3rnQtMfMcK/U1SgIW7T 4dZWoBiPWfL5CCsDpq4Si00UldcZceReEqoQbvf29RSl+AnywJtDuz/zYNCwYrzS vRTqHZFc5mJVazvTf1GiuuEMXSE65gv4Z+hFMLOl2w== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvfedrfeefuddgfeelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvfevuffkfhggtggujgesthdtredttddtvdenucfhrhhomhepifhrvghg ucfmjfcuoehgrhgvgheskhhrohgrhhdrtghomheqnecuggftrfgrthhtvghrnhepheegvd evvdeljeeugfdtudduhfekledtiefhveejkeejuefhtdeufefhgfehkeetnecuvehluhhs thgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorg hhrdgtohhm X-ME-Proxy: Feedback-ID: i787e41f1:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 21 Sep 2022 07:15:58 -0400 (EDT) Date: Wed, 21 Sep 2022 13:15:57 +0200 From: Greg KH To: Chan Kim Subject: Re: how to debug... program hangs while downing for write a rwsem Message-ID: References: <0ee901d8cda9$b1056ec0$13104c40$@etri.re.kr> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <0ee901d8cda9$b1056ec0$13104c40$@etri.re.kr> Cc: kernelnewbies@kernelnewbies.org X-BeenThere: kernelnewbies@kernelnewbies.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Learn about the Linux kernel List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kernelnewbies-bounces@kernelnewbies.org On Wed, Sep 21, 2022 at 08:02:50PM +0900, Chan Kim wrote: > Hello kernel experts and users, > > I'm trying to boot linux-5.10.0-rc5 on our arm64 board (using neoverse-v1 > core). 5.10-rc5 is very very very old and obsolete, and not even a real release. Why are you using that specific kernel version? At the very least, use a released and supported 5.10.y tree, but even better, use the latest 5.19.y release. > After the shell comes up, when I press enter key at the prompt, it gives me > another prompt. > But when I press enter key again, it stops responding. > After inspecting where the program hangs, I found it hangs in function > tty_set_termios while downing the rwsem. > Please see below where I marked "<===== this line "". (in file > drivers/tty/tty_ioctl.c) > > int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios) > { > struct ktermios old_termios; > struct tty_ldisc *ld; > > WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY && > tty->driver->subtype == PTY_TYPE_MASTER); > /* > * Perform the actual termios internal changes under lock. > */ > > > /* FIXME: we need to decide on some locking/ordering semantics > for the set_termios notification eventually */ > down_write(&tty->termios_rwsem); <====== this > line What serial driver are you using that is causing this problem? thanks, greg k-h _______________________________________________ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies