Re: [PATCH 01/17] locking/mutex: assert static storage for DEFINE_MUTEX()

[Yury Norov]

On Tue, Sep 15, 2026 at 10:23:00AM +0200, Peter Zijlstra wrote:
> On Mon, Sep 14, 2026 at 11:03:19PM -0400, Yury Norov wrote:
> > DEFINE_MUTEX() uses a static lock initializer whose lockdep class key
> > requires a persistent object address. Reject automatic local declarations
> > with ASSERT_STATIC_STORAGE(), in both the regular and PREEMPT_RT variants.
> > Align the VMA and memblock tools stubs with the kernel declaration.
> > 
> > The two automatic mutexes in the WireGuard allowedips selftests already
> > call mutex_init(). Replace their redundant static initializers with plain
> > struct mutex declarations.
> > 
> > Assisted-by: OpenAI Codex
> > Signed-off-by: Yury Norov <ynorov@xxxxxxxxxx>
> > ---
> >  drivers/net/wireguard/selftest/allowedips.c | 4 ++--
> >  include/linux/mutex.h                       | 7 +++++--
> >  tools/testing/memblock/linux/mutex.h        | 8 ++++++--
> >  tools/testing/vma/include/dup.h             | 5 ++++-
> >  4 files changed, 17 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/net/wireguard/selftest/allowedips.c b/drivers/net/wireguard/selftest/allowedips.c
> > index 3e857e6fb627..ecb2908228e7 100644
> > --- a/drivers/net/wireguard/selftest/allowedips.c
> > +++ b/drivers/net/wireguard/selftest/allowedips.c
> > @@ -257,7 +257,7 @@ static __init bool randomized_test(void)
> >  	u8 ip[16], mutate_mask[16], mutated[16];
> >  	struct wg_peer **peers, *peer;
> >  	struct horrible_allowedips h;
> > -	DEFINE_MUTEX(mutex);
> > +	struct mutex mutex;
> >  	struct allowedips t;
> >  	bool ret = false;
> >  
> > @@ -499,7 +499,7 @@ bool __init wg_allowedips_selftest(void)
> >  	struct allowedips_node *iter_node;
> >  	bool success = false;
> >  	struct allowedips t;
> > -	DEFINE_MUTEX(mutex);
> > +	struct mutex mutex;
> >  	struct in6_addr ip;
> >  	size_t i = 0, count = 0;
> >  	__be64 part;
> 
> This should probably be a separate patch.
> 
> > diff --git a/include/linux/mutex.h b/include/linux/mutex.h
> > index 734048c02f4f..2f2d95f3097c 100644
> > --- a/include/linux/mutex.h
> > +++ b/include/linux/mutex.h
> > @@ -11,6 +11,7 @@
> >  #ifndef __LINUX_MUTEX_H
> >  #define __LINUX_MUTEX_H
> >  
> > +#include <linux/compiler.h>
> >  #include <asm/current.h>
> >  #include <linux/list.h>
> >  #include <linux/spinlock_types.h>
> > @@ -84,7 +85,8 @@ do {									\
> >  		__DEP_MAP_MUTEX_INITIALIZER(lockname) }
> >  
> >  #define DEFINE_MUTEX(mutexname) \
> > -	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname)
> > +	struct mutex mutexname = __MUTEX_INITIALIZER(mutexname);	\
> > +	ASSERT_STATIC_STORAGE(mutexname)
> 
> My tree no has ASSERT_STATIC_STORAGE. Please repost when that lands?

It's on top of:

https://lore.kernel.org/all/20260911221444.1523311-1-ynorov@xxxxxxxxxx/

Check the cover letter for more details.