linux-kernel - Re: [PATCH] ACPI: scan: Rearrange code related to acpi_get_device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <d6dcb0cc-ff6a-3b71-55a2-d965cd8a290c@redhat.com>
Date:   Wed, 20 Jan 2021 22:53:30 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Linux ACPI <linux-acpi@...r.kernel.org>
Cc:     LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ACPI: scan: Rearrange code related to
 acpi_get_device_data()

Hi,

On 1/18/21 8:25 PM, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> There are two callers of acpi_get_device_data(), acpi_bus_get_device()
> and acpi_bus_get_acpi_device(), but only one of them takes the int
> return value into account.  Moreover, the latter knows that it passes
> a valid return pointer to acpi_get_device_data() and it properly
> clears that pointer upfront, so it doesn't need acpi_get_device_data()
> to do that.
> 
> For this reason, rearrange acpi_get_device_data() to return a strct
> acpi_device pointer instead of an int and adapt its callers to that.
> 
> While at it, rename acpi_get_device_data() to handle_to_device(),
> because the old name does not really reflect the functionality
> provided by that function.
> 
> No intentional functional impact.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Nice cleanup, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@...hat.com>

Regards,

Hans


> ---
> 
> On top of https://patchwork.kernel.org/project/linux-acpi/patch/20210115215752.389656-1-hdegoede@redhat.com/
> 
> ---
>  drivers/acpi/scan.c |   35 +++++++++++++++++------------------
>  1 file changed, 17 insertions(+), 18 deletions(-)
> 
> Index: linux-pm/drivers/acpi/scan.c
> ===================================================================
> --- linux-pm.orig/drivers/acpi/scan.c
> +++ linux-pm/drivers/acpi/scan.c
> @@ -578,29 +578,31 @@ static void acpi_scan_drop_device(acpi_h
>  	mutex_unlock(&acpi_device_del_lock);
>  }
>  
> -static int acpi_get_device_data(acpi_handle handle, struct acpi_device **device,
> -				void (*callback)(void *))
> +static struct acpi_device *handle_to_device(acpi_handle handle,
> +					    void (*callback)(void *))
>  {
> +	struct acpi_device *adev = NULL;
>  	acpi_status status;
>  
> -	if (!device)
> -		return -EINVAL;
> -
> -	*device = NULL;
> -
>  	status = acpi_get_data_full(handle, acpi_scan_drop_device,
> -				    (void **)device, callback);
> -	if (ACPI_FAILURE(status) || !*device) {
> -		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No context for object [%p]\n",
> -				  handle));
> -		return -ENODEV;
> +				    (void **)&adev, callback);
> +	if (ACPI_FAILURE(status) || !adev) {
> +		acpi_handle_debug(handle, "No context!\n");
> +		return NULL;
>  	}
> -	return 0;
> +	return adev;
>  }
>  
>  int acpi_bus_get_device(acpi_handle handle, struct acpi_device **device)
>  {
> -	return acpi_get_device_data(handle, device, NULL);
> +	if (!device)
> +		return -EINVAL;
> +
> +	*device = handle_to_device(handle, NULL);
> +	if (!*device)
> +		return -ENODEV;
> +
> +	return 0;
>  }
>  EXPORT_SYMBOL(acpi_bus_get_device);
>  
> @@ -612,10 +614,7 @@ static void get_acpi_device(void *dev)
>  
>  struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
>  {
> -	struct acpi_device *adev = NULL;
> -
> -	acpi_get_device_data(handle, &adev, get_acpi_device);
> -	return adev;
> +	return handle_to_device(handle, get_acpi_device);
>  }
>  
>  void acpi_bus_put_acpi_device(struct acpi_device *adev)
> 
> 
>