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 X-Spam-Level: X-Spam-Status: No, score=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23E71C433E1 for ; Thu, 25 Mar 2021 18:26:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF2F861A3B for ; Thu, 25 Mar 2021 18:26:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230081AbhCYS0C (ORCPT ); Thu, 25 Mar 2021 14:26:02 -0400 Received: from mx2.suse.de ([195.135.220.15]:38430 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbhCYSZ3 (ORCPT ); Thu, 25 Mar 2021 14:25:29 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 50CF6ACFC; Thu, 25 Mar 2021 18:25:27 +0000 (UTC) Message-ID: <9b206c4d00dfe8b7f941260f18909914b2b2eecb.camel@suse.de> Subject: Re: [PATCH] clk: Mark fwnodes when their clock provider is added From: Nicolas Saenz Julienne To: Marek Szyprowski , Tudor Ambarus , corbet@lwn.net, gregkh@linuxfoundation.org, rafael@kernel.org, khilman@kernel.org, ulf.hansson@linaro.org, len.brown@intel.com, lenb@kernel.org, pavel@ucw.cz, mturquette@baylibre.com, sboyd@kernel.org, robh+dt@kernel.org, frowand.list@gmail.com, maz@kernel.org, tglx@linutronix.de, saravanak@google.com Cc: nicolas.ferre@microchip.com, claudiu.beznea@microchip.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-acpi@vger.kernel.org, geert@linux-m68k.org, kernel-team@android.com, linux-rpi-kernel Date: Thu, 25 Mar 2021 19:25:24 +0100 In-Reply-To: References: <20210205222644.2357303-9-saravanak@google.com> <20210210114435.122242-1-tudor.ambarus@microchip.com> <20210210114435.122242-2-tudor.ambarus@microchip.com> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-LP3OfhoAoNoMIlo+oggY" User-Agent: Evolution 3.38.4 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org --=-LP3OfhoAoNoMIlo+oggY Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2021-03-25 at 14:31 +0100, Marek Szyprowski wrote: > Hi >=20 > On 10.02.2021 12:44, Tudor Ambarus wrote: > > This is a follow-up for: > > commit 3c9ea42802a1 ("clk: Mark fwnodes when their clock provider is ad= ded/removed") > >=20 > > The above commit updated the deprecated of_clk_add_provider(), > > but missed to update the preferred of_clk_add_hw_provider(). > > Update it now. > >=20 > > Signed-off-by: Tudor Ambarus >=20 > This patch, which landed in linux-next as commit 6579c8d97ad7 ("clk:=20 > Mark fwnodes when their clock provider is added") causes the following= =20 > NULL pointer dereference on Raspberry Pi 3b+ boards: >=20 > --->8--- >=20 > raspberrypi-firmware soc:firmware: Attached to firmware from=20 > 2020-01-06T13:05:25 > Unable to handle kernel NULL pointer dereference at virtual address=20 > 0000000000000050 > Mem abort info: > =C2=A0=C2=A0 ESR =3D 0x96000004 > =C2=A0=C2=A0 EC =3D 0x25: DABT (current EL), IL =3D 32 bits > =C2=A0=C2=A0 SET =3D 0, FnV =3D 0 > =C2=A0=C2=A0 EA =3D 0, S1PTW =3D 0 > Data abort info: > =C2=A0=C2=A0 ISV =3D 0, ISS =3D 0x00000004 > =C2=A0=C2=A0 CM =3D 0, WnR =3D 0 > [0000000000000050] user address but active_mm is swapper > Internal error: Oops: 96000004 [#1] PREEMPT SMP > Modules linked in: > CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 5.12.0-rc4+ #2764 > Hardware name: Raspberry Pi 3 Model B (DT) > Workqueue: events deferred_probe_work_func > pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=3D--) > pc : of_clk_add_hw_provider+0xac/0xe8 > lr : of_clk_add_hw_provider+0x94/0xe8 > sp : ffff8000130936b0 > x29: ffff8000130936b0 x28: ffff800012494e04 > x27: ffff00003b18cb05 x26: ffff00003aa5c010 > x25: 0000000000000000 x24: 0000000000000000 > x23: ffff00003aa1e380 x22: ffff8000106830d0 > x21: ffff80001233f180 x20: 0000000000000018 > x19: 0000000000000000 x18: ffff8000124d38b0 > x17: 0000000000000013 x16: 0000000000000014 > x15: ffff8000125758b0 x14: 00000000000184e0 > x13: 000000000000292e x12: ffff80001258dd98 > x11: 0000000000000001 x10: 0101010101010101 > x9 : ffff80001233f288 x8 : 7f7f7f7f7f7f7f7f > x7 : fefefefeff6c626f x6 : 5d636d8080808080 > x5 : 00000000006d635d x4 : 0000000000000000 > x3 : 0000000000000000 x2 : 540eb5edae191600 > x1 : 0000000000000000 x0 : 0000000000000000 > Call trace: > =C2=A0=C2=A0of_clk_add_hw_provider+0xac/0xe8 > =C2=A0=C2=A0devm_of_clk_add_hw_provider+0x5c/0xb8 > =C2=A0=C2=A0raspberrypi_clk_probe+0x110/0x210 > =C2=A0=C2=A0platform_probe+0x90/0xd8 > =C2=A0=C2=A0really_probe+0x108/0x3c0 > =C2=A0=C2=A0driver_probe_device+0x60/0xc0 > =C2=A0=C2=A0__device_attach_driver+0x9c/0xd0 > =C2=A0=C2=A0bus_for_each_drv+0x70/0xc8 > =C2=A0=C2=A0__device_attach+0xec/0x150 > =C2=A0=C2=A0device_initial_probe+0x10/0x18 > =C2=A0=C2=A0bus_probe_device+0x94/0xa0 > =C2=A0=C2=A0device_add+0x47c/0x780 > =C2=A0=C2=A0platform_device_add+0x110/0x248 > =C2=A0=C2=A0platform_device_register_full+0x120/0x150 > =C2=A0=C2=A0rpi_firmware_probe+0x158/0x1f8 > =C2=A0=C2=A0platform_probe+0x90/0xd8 > =C2=A0=C2=A0really_probe+0x108/0x3c0 > =C2=A0=C2=A0driver_probe_device+0x60/0xc0 > =C2=A0=C2=A0__device_attach_driver+0x9c/0xd0 > =C2=A0=C2=A0bus_for_each_drv+0x70/0xc8 > =C2=A0=C2=A0__device_attach+0xec/0x150 > =C2=A0=C2=A0device_initial_probe+0x10/0x18 > =C2=A0=C2=A0bus_probe_device+0x94/0xa0 > =C2=A0=C2=A0deferred_probe_work_func+0x70/0xa8 > =C2=A0=C2=A0process_one_work+0x2a8/0x718 > =C2=A0=C2=A0worker_thread+0x48/0x460 > =C2=A0=C2=A0kthread+0x134/0x160 > =C2=A0=C2=A0ret_from_fork+0x10/0x18 > Code: b1006294 540000c0 b140069f 54000088 (3940e280) > ---[ end trace 7ead5ec2f0c51cfe ]--- >=20 > This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls= =20 > devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL= =20 > dev->of_node. I'm not sure if adding a check for a NULL np in=20 > of_clk_add_hw_provider() is a right fix, though. I believe the right fix is not to call 'devm_of_clk_add_hw_provider()' if 'pdev->dev.of_node =3D=3D NULL'. In such case, which is RPi3's, only the CP= U clock is used, and it's defined and queried later through devm_clk_hw_register_clkdev(). @Marek, I don't mind taking care of it if it's OK with you. Regards, Nicolas --=-LP3OfhoAoNoMIlo+oggY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAmBc1ZQACgkQlfZmHno8 x/4/cwgApx9UVDHRcpZ+rQEOKxGZTTXSUbWvYW7ZZOKlx/kyViTeiN1O4oP8+r43 gh0xAJOqyscnNko26PhVXwnnbqSHoybYK+M+fr8dXWmEanEPoCAjaRXCua+IOIS5 v8I7LCfC0IEz7hvIl9MHh5Z7o9uemr4gKj4p7KiYDnU2ksZD0/1sCaw2fVq4uS5Z 4yao5SnyTjXcJ3mjmQayPUkh3jGrZkSCC5r7GamGibFq49WLJawONbhscimpFtAn xylSgcgnkUDiP5X2WM3lYLOfG2rYifXdkUSqahSfw7lmL3YmNlYvUvTk5CZEKc88 wQikLex04QNJMnySXNu/djsgI2v1aA== =QlQJ -----END PGP SIGNATURE----- --=-LP3OfhoAoNoMIlo+oggY--