Re: [PATCH v3 1/4] rtc: pcf85063: use devm_of_clk_add_hw_provider() for clkout

[sashiko-bot@kernel.org]

> From: Alexander Sverdlin <alexander.sverdlin@siemens.com>
> 
> pcf85063_clkout_register_clk() registered the OF clock provider with the
> deprecated of_clk_add_provider() and never removed it, so the provider
> kept pointing at freed data after unbind, leading to a use-after-free the
> next time the device-tree clock was resolved.
> 
> Switch to devm_clk_hw_register() and devm_of_clk_add_hw_provider(): both
> the clock and its OF provider are managed resources now, and the provider
> is torn down before the clock on unbind.
> 
> Register the clock on the parent i2c device instead of the rtc device.
> devm_of_clk_add_hw_provider() must use the parent, which owns the
> of_node, and the clkout_hw it points at lives in the driver data
> allocated on the parent. Tying both to the parent releases them together
> on unbind, before the driver data is freed, and keeps their teardown
> ordering guaranteed by a single devres list. Registering the clock on the
> rtc device instead could defer its unregistration past unbind (e.g. while
> a /dev/rtcN fd is open), after clkout_hw has already been freed.
> 
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260828164445.3907839-1-alexander.sverdlin@siemens.com?part=1