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From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
	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 <linux-rpi-kernel@lists.infradead.org>,
	Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Subject: Re: [PATCH] clk: Mark fwnodes when their clock provider is added
Date: Thu, 25 Mar 2021 14:31:57 +0100
Message-ID: <d24bebc5-0f78-021f-293f-e58defa32531@samsung.com> (raw)
In-Reply-To: <20210210114435.122242-2-tudor.ambarus@microchip.com>

Hi

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 added/removed")
>
> The above commit updated the deprecated of_clk_add_provider(),
> but missed to update the preferred of_clk_add_hw_provider().
> Update it now.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

This patch, which landed in linux-next as commit 6579c8d97ad7 ("clk: 
Mark fwnodes when their clock provider is added") causes the following 
NULL pointer dereference on Raspberry Pi 3b+ boards:

--->8---

raspberrypi-firmware soc:firmware: Attached to firmware from 
2020-01-06T13:05:25
Unable to handle kernel NULL pointer dereference at virtual address 
0000000000000050
Mem abort info:
   ESR = 0x96000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
Data abort info:
   ISV = 0, ISS = 0x00000004
   CM = 0, WnR = 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=--)
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:
  of_clk_add_hw_provider+0xac/0xe8
  devm_of_clk_add_hw_provider+0x5c/0xb8
  raspberrypi_clk_probe+0x110/0x210
  platform_probe+0x90/0xd8
  really_probe+0x108/0x3c0
  driver_probe_device+0x60/0xc0
  __device_attach_driver+0x9c/0xd0
  bus_for_each_drv+0x70/0xc8
  __device_attach+0xec/0x150
  device_initial_probe+0x10/0x18
  bus_probe_device+0x94/0xa0
  device_add+0x47c/0x780
  platform_device_add+0x110/0x248
  platform_device_register_full+0x120/0x150
  rpi_firmware_probe+0x158/0x1f8
  platform_probe+0x90/0xd8
  really_probe+0x108/0x3c0
  driver_probe_device+0x60/0xc0
  __device_attach_driver+0x9c/0xd0
  bus_for_each_drv+0x70/0xc8
  __device_attach+0xec/0x150
  device_initial_probe+0x10/0x18
  bus_probe_device+0x94/0xa0
  deferred_probe_work_func+0x70/0xa8
  process_one_work+0x2a8/0x718
  worker_thread+0x48/0x460
  kthread+0x134/0x160
  ret_from_fork+0x10/0x18
Code: b1006294 540000c0 b140069f 54000088 (3940e280)
---[ end trace 7ead5ec2f0c51cfe ]---

This patch mainly revealed that clk/bcm/clk-raspberrypi.c driver calls 
devm_of_clk_add_hw_provider(), with a device pointer, which has a NULL 
dev->of_node. I'm not sure if adding a check for a NULL np in 
of_clk_add_hw_provider() is a right fix, though.

> ---
>   drivers/clk/clk.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 27ff90eacb1f..9370e4dfecae 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -4594,6 +4594,8 @@ int of_clk_add_hw_provider(struct device_node *np,
>   	if (ret < 0)
>   		of_clk_del_provider(np);
>   
> +	fwnode_dev_initialized(&np->fwnode, true);
> +
>   	return ret;
>   }
>   EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


  parent reply index

Thread overview: 59+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20210205222651eucas1p28ef87073dea33c1c5224c14aa203bec5@eucas1p2.samsung.com>
2021-02-05 22:26 ` [PATCH v4 0/8] Make fw_devlink=on more forgiving Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 1/8] driver core: fw_devlink: Detect supplier devices that will never be added Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 2/8] of: property: Don't add links to absent suppliers Saravana Kannan
2021-02-09 21:25     ` Rob Herring
2021-02-05 22:26   ` [PATCH v4 3/8] driver core: Add fw_devlink.strict kernel param Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 4/8] of: property: Add fw_devlink support for optional properties Saravana Kannan
2021-02-09 21:33     ` Rob Herring
2021-02-09 21:54       ` Saravana Kannan
2021-02-10  8:25         ` Geert Uytterhoeven
2021-02-05 22:26   ` [PATCH v4 5/8] driver core: fw_devlink: Handle suppliers that don't use driver core Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 6/8] irqdomain: Mark fwnodes when their irqdomain is added/removed Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 7/8] PM: domains: Mark fwnodes when their powerdomain " Saravana Kannan
2021-02-05 22:26   ` [PATCH v4 8/8] clk: Mark fwnodes when their clock provider " Saravana Kannan
2021-02-08 15:38     ` Rob Herring
2021-02-08 23:34       ` Saravana Kannan
2021-02-10 11:44     ` [PATCH] clk: Mark fwnodes when their clock provider is added Tudor Ambarus
2021-02-10 11:44       ` Tudor Ambarus
2021-02-11 13:00         ` Greg KH
2021-02-13  0:37           ` Stephen Boyd
     [not found]         ` <CGME20210325133159eucas1p297b769beb681743fb32d362a86cc6e3e@eucas1p2.samsung.com>
2021-03-25 13:31           ` Marek Szyprowski [this message]
2021-03-25 15:47             ` Geert Uytterhoeven
2021-03-25 18:25             ` Nicolas Saenz Julienne
2021-03-26 18:13               ` Stephen Boyd
2021-03-26 18:29                 ` Geert Uytterhoeven
     [not found]                   ` <161705310317.3012082.15148238105608149214@swboyd.mtv.corp.google.com>
2021-03-29 23:28                     ` Saravana Kannan
     [not found]                       ` <161706920822.3012082.10047587064612237296@swboyd.mtv.corp.google.com>
2021-03-30  6:58                         ` Geert Uytterhoeven
     [not found]                           ` <161715734080.2260335.881350237641202575@swboyd.mtv.corp.google.com>
2021-03-31  7:05                             ` Geert Uytterhoeven
     [not found]                               ` <161721871083.2260335.2392646934517115770@swboyd.mtv.corp.google.com>
2021-04-05 11:04                                 ` Nicolas Saenz Julienne
2021-04-21  3:26         ` Guenter Roeck
2021-04-21  7:00           ` Saravana Kannan
2021-02-10 19:13       ` Saravana Kannan
2021-03-30 15:42       ` Guenter Roeck
2021-03-30 16:26         ` Saravana Kannan
     [not found]     ` <161317679292.1254594.15797939257637374295@swboyd.mtv.corp.google.com>
2021-02-14 21:15       ` [PATCH v4 8/8] clk: Mark fwnodes when their clock provider is added/removed Saravana Kannan
2021-02-06  2:45   ` [PATCH v4 0/8] Make fw_devlink=on more forgiving Saravana Kannan
2021-02-06 19:41   ` Geert Uytterhoeven
2021-02-06 20:47     ` Saravana Kannan
2021-02-08  8:40   ` Marek Szyprowski
2021-02-08 23:57     ` Saravana Kannan
2021-02-10  8:19   ` Tudor.Ambarus
2021-02-10  8:54     ` Saravana Kannan
2021-02-10 10:02       ` Tudor.Ambarus
2021-02-10 19:14         ` Saravana Kannan
2021-02-11 13:00   ` Geert Uytterhoeven
2021-02-11 13:05     ` Geert Uytterhoeven
2021-02-12  2:59     ` Saravana Kannan
2021-02-12  8:14       ` Geert Uytterhoeven
2021-02-12 20:57         ` Saravana Kannan
2021-02-15 12:38       ` Geert Uytterhoeven
2021-02-15 21:26         ` Saravana Kannan
2021-02-16  8:05           ` Geert Uytterhoeven
2021-02-16 18:48             ` Saravana Kannan
2021-02-16 20:31               ` Geert Uytterhoeven
2021-02-17 23:57                 ` Saravana Kannan
2021-02-25  9:21                   ` Geert Uytterhoeven
2021-02-15 15:16       ` Geert Uytterhoeven
2021-02-15 21:57         ` Saravana Kannan
2021-02-16 12:58           ` Geert Uytterhoeven
2021-02-15 11:19     ` Geert Uytterhoeven

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