Re: [PATCH 0/2] driver core: platform: avoid use-after-free on device name

[Thomas Petazzoni <thomas.petazzoni@bootlin.com>]

On Thu, 20 Feb 2025 19:26:41 +0100
Théo Lebrun <theo.lebrun@bootlin.com> wrote:

> That used to exist! I cannot see how it could be a good idea to
> reintroduce the distinction though.
> 
> commit eca3930163ba8884060ce9d9ff5ef0d9b7c7b00f
> Author: Grant Likely <grant.likely@secretlab.ca>
> Date:   Tue Jun 8 07:48:21 2010 -0600
> 
>     of: Merge of_platform_bus_type with platform_bus_type

I don't really see how an of_platform bus would make sense. OF is not a
bus at all, it's a way of providing HW description to an operating
system.

What would IMO make a lot more sense is mmio_bus, for Memory-Mapped I/O
peripherals. mmio_device can be described through OF, through old-style
board.c, possibly through ACPI, or other means.

But in my eyes, the current platform bus is exactly this: the bus for
MMIO devices. It would have be clearer to name it mmio_bus, and that
would have probably prevented abuses of the platform bus for things
that aren't memory-mapped peripherals.

But clearly any bus that has "OF" in its name is wrong, as OF cannot be
a bus. Keep in mind that OF allows to describe not only MMIO devices,
but also I2C devices, SPI devices, MMC/SDIO devices, PCI devices, USB
devices, etc. OF is a description of the HW, not a bus.

Best regards,

Thomas
-- 
Thomas Petazzoni, co-owner and CEO, Bootlin
Embedded Linux and Kernel engineering and training
https://bootlin.com