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x86/percpu: Use __force to cast from __percpu address space

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[ Upstream commit a55c1fdad5f61b4bfe42319694b23671a758cb28 ]

Fix Sparse warning when casting from __percpu address space by using
__force in the cast. x86 named address spaces are not considered to
be subspaces of the generic (flat) address space, so explicit casts
are required to convert pointers between these address spaces and the
generic address space (the application should cast to uintptr_t and
apply the segment base offset). The cast to uintptr_t removes
__percpu address space tag and Sparse reports:

  warning: cast removes address space '__percpu' of expression

Use __force to inform Sparse that the cast is intentional.

Fixes: 9a462b9eafa6 ("x86/percpu: Use compiler segment prefix qualifier")
Reported-by: Charlemagne Lasse <charlemagnelasse@gmail.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20240402175058.52649-1-ubizjak@gmail.com

Closes: https://lore.kernel.org/lkml/CAFGhKbzev7W4aHwhFPWwMZQEHenVgZUj7=aunFieVqZg3mt14A@mail.gmail.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Uros Bizjak 2024-04-02 19:50:38 +02:00 committed by Greg Kroah-Hartman
parent ac751e2327
commit 6229529507
1 changed files with 1 additions and 1 deletions
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2
arch/x86/include/asm/percpu.h
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@ -77,7 +77,7 @@
#define arch_raw_cpu_ptr(_ptr) \
({ \
unsigned long tcp_ptr__ = __raw_my_cpu_offset; \
tcp_ptr__ += (unsigned long)(_ptr); \
tcp_ptr__ += (__force unsigned long)(_ptr); \
(typeof(*(_ptr)) __kernel __force *)tcp_ptr__; \
})
#else