On Tue, 08 Jul 2025 10:42:06 +0100,
Ben Horgan [off-list ref] wrote:
Hi Yury,
On 7/7/25 17:31, Yury Norov wrote:
quoted
Hi Ben,
On Thu, Jul 03, 2025 at 02:57:29PM +0100, Ben Horgan wrote:
quoted
As type##_replace_bits() has no side effects it is only useful if its
return value is checked. Add __must_check to enforce this usage. To have
the bits replaced in-place typep##_replace_bits() can be used instead.
Signed-off-by: Ben Horgan <ben.horgan@arm.com>
---
include/linux/bitfield.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
index 6d9a53db54b6..39333b80d22b 100644
--- a/include/linux/bitfield.h
+++ b/include/linux/bitfield.h
@@ -195,8 +195,8 @@ static __always_inline __##type type##_encode_bits(base v, base field) \
__field_overflow(); \
return to((v & field_mask(field)) * field_multiplier(field)); \
} \
-static __always_inline __##type type##_replace_bits(__##type old, \
- base val, base field) \
+static __always_inline __##type __must_check type##_replace_bits(__##type old, \
+ base val, base field) \
{ \
return (old & ~to(field)) | type##_encode_bits(val, field); \
} \
So, would it make sense to mark _encode_bits() and _get_bits() as
__must_check as well? At least from the point of unification, it
would.
Could do. It seems less important as there are no obvious foot-guns
that these would guards against. Would you like me to add this in a
v2?
quoted
How would we move this - with my bitmap-for next or with arm branch?
I'm not familiar with the branch machinery so can't comment on this.
The first patch will definitely go in via the KVM/arm64 tree, probably
as a fix for 6.16.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.