Re: [PATCH v5 3/4] cleanup: Annotate guard constructors with nonnull

[Dan Carpenter <error27@gmail.com>]

On Tue, Jun 02, 2026 at 07:12:52AM +0000, Dmitry Ilvokhin wrote:
> Add __nonnull_args() to unconditional guard constructors so the compiler
> warns when NULL is statically known to be passed:
> 
> - DEFINE_GUARD(): re-declare the constructor with __nonnull_args().
> - __DEFINE_LOCK_GUARD_1(): annotate the constructor directly.
> 
> DEFINE_LOCK_GUARD_0() needs no annotation: its constructor takes no
> pointer arguments (.lock is hardcoded to (void *)1).
> 
> Define the __nonnull_args() macro in compiler_attributes.h, following
> the existing convention for attribute wrappers. Deliberately not named
> '__nonnull', to avoid clashing with glibc's __nonnull() when kernel and
> userspace headers are combined (User Mode Linux for example).
> 
> Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
> ---
> Miguel, I dropped your Acked-by due to the rename. Went with
> __nonnull_args() (over __knonnull()). Happy to restore your tag if that
> spelling works for you.
> 

Sparse doesn't like an empty __nonnull_args() at all.

./include/linux/spinlock.h:608:1: error: an expression is expected before ')'
./include/linux/spinlock.h:619:1: error: an expression is expected before ')'
./include/linux/spinlock.h:631:1: error: an expression is expected before ')'

Shouldn't we specify the arguments which are non-NULL?
__nonnull_args(1)?

regards,
dan carpenter