Re: [PATCH 2/4] PCI: kirin: Don't put .remove callback in .exit.text section

[Bjorn Helgaas <helgaas@kernel.org>]

On Sun, Oct 01, 2023 at 07:02:52PM +0200, Uwe Kleine-König wrote:
> With CONFIG_PCIE_KIRIN=y and kirin_pcie_remove() marked with __exit, the
> function is discarded from the driver. In this case a bound device can
> still get unbound, e.g via sysfs. Then no cleanup code is run resulting
> in resource leaks or worse.

kirin_pcie_driver sets .suppress_bind_attrs = true.

Doesn't that mean that we can't unbind a device via sysfs in this
case?

I don't expect modpost to know about .suppress_bind_attrs, so maybe we
should remove the __exit annotation even if it would be safe to keep
it in this case.  It's a tiny function anyway.

> The right thing to do is do always have the remove callback available.
> This fixes the following warning by modpost:
> 
> 	drivers/pci/controller/dwc/pcie-kirin: section mismatch in reference: kirin_pcie_driver+0x8 (section: .data) -> kirin_pcie_remove (section: .exit.text)
> 
> (with ARCH=x86_64 W=1 allmodconfig).
> 
> Fixes: 000f60db784b ("PCI: kirin: Add support for a PHY layer")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/pci/controller/dwc/pcie-kirin.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
> index d93bc2906950..2ee146767971 100644
> --- a/drivers/pci/controller/dwc/pcie-kirin.c
> +++ b/drivers/pci/controller/dwc/pcie-kirin.c
> @@ -741,7 +741,7 @@ static int kirin_pcie_power_on(struct platform_device *pdev,
>  	return ret;
>  }
>  
> -static int __exit kirin_pcie_remove(struct platform_device *pdev)
> +static int kirin_pcie_remove(struct platform_device *pdev)
>  {
>  	struct kirin_pcie *kirin_pcie = platform_get_drvdata(pdev);
>  
> @@ -818,7 +818,7 @@ static int kirin_pcie_probe(struct platform_device *pdev)
>  
>  static struct platform_driver kirin_pcie_driver = {
>  	.probe			= kirin_pcie_probe,
> -	.remove	        	= __exit_p(kirin_pcie_remove),
> +	.remove	        	= kirin_pcie_remove,
>  	.driver			= {
>  		.name			= "kirin-pcie",
>  		.of_match_table		= kirin_pcie_match,
> -- 
> 2.40.1
>