[PATCH] LoongArch: Increase COMMAND_LINE_SIZE to 4096

[Huacai Chen]

Applied, thanks.

Huacai

On Tue, Aug 12, 2025 at 8:20 PM Ming Wang <wangming01 at loongson.cn> wrote:
>
> The default COMMAND_LINE_SIZE of 512, inherited from asm-generic, is
> too small for modern use cases. For example, kdump configurations or
> extensive debugging parameters can easily exceed this limit.
>
> Therefore, increase the command line size to 4096 bytes, aligning
> LoongArch with the MIPS architecture. This change follows a broader
> trend among architectures to raise this limit to support modern needs;
> for instance, PowerPC increased its value for similar reasons in
> commit a5980d064fe2 ("powerpc: Bump COMMAND_LINE_SIZE to 2048").
>
> Similar to the change made for RISC-V in commit 61fc1ee8be26
> ("riscv: Bump COMMAND_LINE_SIZE value to 1024"), this is considered
> a safe change. The broader kernel community has reached a consensus
> that modifying COMMAND_LINE_SIZE from UAPI headers does not
> constitute a uABI breakage, as well-behaved userspace applications
> should not rely on this macro.
>
> Suggested-by: Huang Cun <cunhuang at tencent.com>
> Signed-off-by: Ming Wang <wangming01 at loongson.cn>
> ---
>  arch/loongarch/include/uapi/asm/setup.h | 8 ++++++++
>  1 file changed, 8 insertions(+)
>  create mode 100644 arch/loongarch/include/uapi/asm/setup.h
>
> diff --git a/arch/loongarch/include/uapi/asm/setup.h b/arch/loongarch/include/uapi/asm/setup.h
> new file mode 100644
> index 000000000000..d46363ce3e02
> --- /dev/null
> +++ b/arch/loongarch/include/uapi/asm/setup.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +
> +#ifndef _UAPI_ASM_LOONGARCH_SETUP_H
> +#define _UAPI_ASM_LOONGARCH_SETUP_H
> +
> +#define COMMAND_LINE_SIZE      4096
> +
> +#endif /* _UAPI_ASM_LOONGARCH_SETUP_H */
> --
> 2.43.0
>
>