Re: [PATCH v2 2/2] drm/syncobj: Use scope-based cleanup for eventfd_ctx

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] cleanup: mixing goto and scope-based cleanup in drm_syncobj_eventfd_ioctl
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commit ff6fd047e86cd28041b0ce12099546c46df110b2
Author: Bence Csokas <bence.csokas@arm.com>

drm/syncobj: Use scope-based cleanup for eventfd_ctx

This patch converts the eventfd context in drm_syncobj_eventfd_ioctl() to
use scope-based cleanup now that eventfd supports it.

> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index c23a5de27effa..efc4e8af220c8 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -1462,9 +1462,9 @@ int
>  drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
>  			  struct drm_file *file_private)
>  {
> +	struct eventfd_ctx *ev_fd_ctx __free(eventfd) = NULL;
>  	struct drm_syncobj_eventfd *args = data;
>  	struct drm_syncobj *syncobj;

[ ... ]

> @@ -1490,10 +1490,10 @@ drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
>  	entry = kzalloc_obj(*entry);
>  	if (!entry) {
>  		ret = -ENOMEM;
> -		goto err_kzalloc;
> +		goto err_fdget;

[Severity: Medium]
Does this mix goto-based error handling and scope-based cleanup within
drm_syncobj_eventfd_ioctl()?

According to include/linux/cleanup.h, the expectation is that usage of
goto and cleanup helpers is never mixed in the same function. All resources
that need cleanup should either be converted to scope-based cleanup, or
none of them.

Leaving the err_fdget label to manually call drm_syncobj_put(syncobj)
while using __free(eventfd) for ev_fd_ctx can lead to confusing resource
ownership and break the expected LIFO teardown ordering.

Could syncobj be converted to use scope-based cleanup as well?

>  	}
>  	entry->syncobj = syncobj;
> -	entry->ev_fd_ctx = ev_fd_ctx;
> +	entry->ev_fd_ctx = no_free_ptr(ev_fd_ctx);
>  	entry->point = args->point;
>  	entry->flags = args->flags;

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Sashiko AI review · https://sashiko.dev/#/patchset/20260915-efd-autofree-v2-0-06d2c9d1547f@arm.com?part=2