Re: [PATCH] riscv: hwprobe: use _BITULL() rather than BIT() in MIPS vendor uapi header

[Jesse Taube]

On Thu, Sep 17, 2026 at 3:54 AM Zongmin Zhou <min_halo@xxxxxxx> wrote:
>
> From: Zongmin Zhou <zhouzongmin@xxxxxxxxxx>
>
> BIT() is a kernel-internal macro that is not available to userspace, but
> the MIPS vendor extension uapi header uses it without defining or
> including it. Any userspace program that includes this header and uses
> RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL fails to build.

Maybe CC stable?

>
> Use _BITULL(0) from linux/const.h instead, which keeps the value at 1,
> so there is no ABI change.
>
> Fixes: bb4b0f8a1bcb ("riscv: hwprobe: Add MIPS vendor extension probing")
> Signed-off-by: Zongmin Zhou <zhouzongmin@xxxxxxxxxx>

Reviewed-by: Jesse Taube <jtaubepe@xxxxxxxxxx>

> ---
>  arch/riscv/include/uapi/asm/vendor/mips.h | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/uapi/asm/vendor/mips.h b/arch/riscv/include/uapi/asm/vendor/mips.h
> index e65ab268b265..a31c23afe74f 100644
> --- a/arch/riscv/include/uapi/asm/vendor/mips.h
> +++ b/arch/riscv/include/uapi/asm/vendor/mips.h
> @@ -1,3 +1,5 @@
>  /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
>
> -#define RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL   BIT(0)
> +#include <linux/const.h>
> +
> +#define RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL   _BITULL(0)

This changes the type from `unsigned long` to `unsigned long long`, though the
type when passed to `hwprobe` is `unsigned long long` so it doesn't
break anything.

Thanks,
Jesse Taube

> --
> 2.34.1
>
>
> No virus found
>                 Checked by Hillstone Network AntiVirus
>
>
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