On Sun, Feb 23, 2025 at 07:34:30PM +0100, Ricardo Ribalda wrote:
On Fri, 21 Feb 2025 at 10:18, Hans Verkuil hverkuil@xs4all.nl wrote:
On 21/02/2025 10:04, Hans Verkuil wrote:
Hi Ricardo,
On 21/01/2025 22:14, Ricardo Ribalda wrote:
When we obtain a reference to of a platform_device, we need to release it via put_device.
Found by cocci: ./platform/nuvoton/npcm-video.c:1677:3-9: ERROR: missing put_device; call of_find_device_by_node on line 1667, but without a corresponding object release within this function. ./platform/nuvoton/npcm-video.c:1684:3-9: ERROR: missing put_device; call of_find_device_by_node on line 1667, but without a corresponding object release within this function. ./platform/nuvoton/npcm-video.c:1690:3-9: ERROR: missing put_device; call of_find_device_by_node on line 1667, but without a corresponding object release within this function. ./platform/nuvoton/npcm-video.c:1694:1-7: ERROR: missing put_device; call of_find_device_by_node on line 1667, but without a corresponding object release within this function.
This driver uses this construct:
struct device *ece_dev __free(put_device) = &ece_pdev->dev;to automatically call put_device. So this patch would 'put' the device twice.
Does cocci understand constructs like this? If I hadn't looked closely at the code first, I would just have merged it.
Oh wait, now that I am reading the following patches I see that it was those later patches that add the __free code.
This is far too confusing. Please post a v2 that just combines the 'fix references' and 'use cleanup.h macros' in a single patch. It makes no sense to have this two-phase approach.
I believe this is discouraged.
cleanup.h macros does not exist in old kernel versions, so makes it impossible to backport the fix to them.
That's not a problem, fix things properly in the main tree and let the stable/lts kernels work it out on their own.
This is an example of other series following this policy: https://lore.kernel.org/lkml/173608125422.1253657.3732758016133408588.stgit@...
They also mention the same here: https://hackerbikepacker.com/kernel-auto-cleanup-1 .... I am pretty sure that I read the policy in a more official location... but I cannot find it right now :)
No, it is NOT official policy at all. Otherwise you would be saying that no one could use these new functions for 6 years just because of really old kernels still living around somewhere. That's not how kernel development works, thankfully.
thanks,
greg k-h