On Mon, Mar 02, 2026 at 01:25:24PM +0100, Thomas Weißschuh wrote:
> There is nothing userspace can do with this value. In the kernel is
> always combined with AT_VECTOR_SIZE_BASE, which is not exposed to
> userspace and also changes from time to time.
>
> Move the symbol to kernel-internal headers.
>
> Meant to be applied through the asm-generic tree.
> The default recipient list was huge. I trimmed it to only the
> architecture lists.
I don't see anything in Debian Code Search that actually uses this
symbol, so that seems fine. Userspace already parses auxvec looking for
AT_NULL, so length isn't useful.
Reviewed-by: Kees Cook <kees@kernel.org>
>
> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
> ---
> Thomas Weißschuh (15):
> MAINTAINERS: exec: Add more auxvec.h variants
> auxvec.h: Move AT_VECTOR_SIZE definitions to linux/auxvec.h
> asm-generic: add an in-kernel auxvec.h header
> ARM: drop custom asm/auxvec.h
> x86: Remove AT_VECTOR_SIZE_ARCH from UAPI
> arm64: Remove AT_VECTOR_SIZE_ARCH from UAPI
> RISC-V: Remove AT_VECTOR_SIZE_ARCH from UAPI
> LoongArch: Remove AT_VECTOR_SIZE_ARCH from UAPI
> s390: Remove AT_VECTOR_SIZE_ARCH from UAPI
> powerpc: Remove AT_VECTOR_SIZE_ARCH from UAPI
> MIPS: Remove AT_VECTOR_SIZE_ARCH from UAPI
> sparc: Remove AT_VECTOR_SIZE_ARCH from UAPI
> sh: Remove AT_VECTOR_SIZE_ARCH from UAPI
> alpha: remove AT_VECTOR_SIZE_ARCH from UAPI
> auxvec.h: Drop fallback AT_VECTOR_SIZE_ARCH
>
> MAINTAINERS | 5 +++++
> arch/alpha/include/asm/auxvec.h | 7 +++++++
> arch/alpha/include/uapi/asm/auxvec.h | 8 +++-----
> arch/arm/include/asm/auxvec.h | 1 -
> arch/arm64/include/asm/auxvec.h | 7 +++++++
> arch/arm64/include/uapi/asm/auxvec.h | 6 ++----
> arch/loongarch/include/asm/auxvec.h | 14 ++++++++++++++
> arch/loongarch/include/uapi/asm/auxvec.h | 8 +++-----
> arch/mips/include/asm/auxvec.h | 17 +++++++++++++++++
> arch/mips/include/uapi/asm/auxvec.h | 8 +++-----
> arch/powerpc/include/asm/auxvec.h | 7 +++++++
> arch/powerpc/include/uapi/asm/auxvec.h | 6 ++----
> arch/riscv/include/asm/auxvec.h | 13 +++++++++++++
> arch/riscv/include/uapi/asm/auxvec.h | 2 --
> arch/s390/include/asm/auxvec.h | 7 +++++++
> arch/s390/include/uapi/asm/auxvec.h | 6 ++----
> arch/sh/include/asm/auxvec.h | 7 +++++++
> arch/sh/include/uapi/asm/auxvec.h | 8 +++-----
> arch/sparc/include/asm/auxvec.h | 6 ++++++
> arch/sparc/include/uapi/asm/auxvec.h | 8 +++-----
> arch/x86/include/asm/auxvec.h | 12 ++++++++++++
> arch/x86/include/uapi/asm/auxvec.h | 13 +++----------
> include/asm-generic/Kbuild | 1 +
> include/asm-generic/auxvec.h | 7 +++++++
> include/linux/auxvec.h | 5 +++++
> include/linux/mm_types.h | 6 ------
> 26 files changed, 139 insertions(+), 56 deletions(-)
> ---
> base-commit: f6b3b0a4c85882ad75bce3b093173203e3f39f28
> change-id: 20260109-at-vector-size-arch-6e0f2e9ff8b6
>
> Best regards,
> --
> Thomas Weißschuh <thomas.weissschuh@linutronix.de>
>
--
Kees Cook