[PATCH v2] asm-generic: convert __set_fixmap_offset() to static inline

[Min-Hsun Chang]

The current macro implementation of __set_fixmap_offset() uses a
hardcoded identifier `________addr` within a statement expression.
This can lead to variable shadowing and potential naming conflicts.

Furthermore, the macro expands its `idx` and `phys` arguments twice.
This double evaluation is dangerous if arguments with side effects
(e.g., i++) are passed to the macro.

Convert the macro to a static inline function as suggested by David.
This improves type safety, avoids shadowing, and ensures each
argument is evaluated exactly once.

Signed-off-by: Min-Hsun Chang <chmh0624@xxxxxxxxx>
---
Changes in v2:
  - Convert the macro to a static inline function instead of just 
    renaming the local variable (suggested by David Laight).
  - This addresses both variable shadowing and double evaluation 
    issues pointed out during v1 review.
  - Link to v1: https://lore.kernel.org/all/20260307092119.20733-1-chmh0624@xxxxxxxxx/
---
 include/asm-generic/fixmap.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h
index 29cab7947980..541b8db35af2 100644
--- a/include/asm-generic/fixmap.h
+++ b/include/asm-generic/fixmap.h
@@ -71,13 +71,13 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr)
 #endif
 
 /* Return a pointer with offset calculated */
-#define __set_fixmap_offset(idx, phys, flags)				\
-({									\
-	unsigned long ________addr;					\
-	__set_fixmap(idx, phys, flags);					\
-	________addr = fix_to_virt(idx) + ((phys) & (PAGE_SIZE - 1));	\
-	________addr;							\
-})
+static inline unsigned long __set_fixmap_offset(unsigned int idx,
+						phys_addr_t phys,
+						pgprot_t flags)
+{
+	__set_fixmap(idx, phys, flags);
+	return fix_to_virt(idx) + (phys & (PAGE_SIZE - 1));
+}
 
 #define set_fixmap_offset(idx, phys) \
 	__set_fixmap_offset(idx, phys, FIXMAP_PAGE_NORMAL)
-- 
2.43.0