[PATCH 0/3] arm64: uapi: Provide correct __BITS_PER_LONG for the compat vDSO

Thomas Weißschuh thomas.weissschuh at linutronix.de
Wed Sep 3 03:49:58 PDT 2025


Hi arm64 folks,

On Thu, Aug 21, 2025 at 09:56:43AM +0200, Thomas Weißschuh wrote:
> The generic vDSO library uses the UAPI headers. On arm64 __BITS_PER_LONG is
> always '64' even when used from the compat vDSO. In that case __GENMASK()
> does an illegal bitshift, invoking undefined behaviour.
> 
> The first patch should go into the 6.17 tree.

Could you take this series?


Thanks,

> Signed-off-by: Thomas Weißschuh <thomas.weissschuh at linutronix.de>
> ---
> Thomas Weißschuh (3):
>       arm64: uapi: Provide correct __BITS_PER_LONG for the compat vDSO
>       arm64: vdso32: Stop suppressing warnings
>       arm64: vdso32: Respect -Werror from kbuild
> 
>  arch/arm64/include/uapi/asm/bitsperlong.h |  5 +++++
>  arch/arm64/kernel/vdso32/Makefile         | 13 +------------
>  2 files changed, 6 insertions(+), 12 deletions(-)
> ---
> base-commit: 8f5ae30d69d7543eee0d70083daf4de8fe15d585
> change-id: 20250820-vdso-arm64-compat-bitsperlong-4f59ae7ef6e7
> 
> Best regards,
> -- 
> Thomas Weißschuh <thomas.weissschuh at linutronix.de>
> 



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