linux-kernel - [PATCH -tip] cleanup: Remove address space of returned pointer

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Message-ID: <20240819074124.143565-1-ubizjak@gmail.com>
Date: Mon, 19 Aug 2024 09:41:15 +0200
From: Uros Bizjak <ubizjak@...il.com>
To: linux-kernel@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH -tip] cleanup: Remove address space of returned pointer

Guard functions in local_lock.h are defined using DEFINE_GUARD() and
DEFINE_LOCK_GUARD_1() macros having lock type defined as pointer in
the percpu address space. The functions, defined by these macros
return value in generic address space, causing:

cleanup.h:157:18: error: return from pointer to non-enclosed address space

and

cleanup.h:214:18: error: return from pointer to non-enclosed address space

when strict percpu checks are enabled.

Add explicit casts to remove address space of the returned pointer.

Found by GCC's named address space checks.

Fixes: e4ab322fbaaa ("cleanup: Add conditional guard support")
Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
---
 include/linux/cleanup.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index 9c6b4f2c0176..48da01c1c082 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -290,7 +290,7 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \
 #define DEFINE_GUARD(_name, _type, _lock, _unlock) \
 	DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \
 	static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \
-	{ return *_T; }
+	{ return (void *)(__force unsigned long)*_T; }
 
 #define DEFINE_GUARD_COND(_name, _ext, _condlock) \
 	EXTEND_CLASS(_name, _ext, \
@@ -347,7 +347,7 @@ static inline void class_##_name##_destructor(class_##_name##_t *_T)	\
 									\
 static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T)	\
 {									\
-	return _T->lock;						\
+	return (void *)(__force unsigned long)_T->lock;			\
 }
 
 
-- 
2.46.0