Re: [PATCH v2 4/7] fs/binfmt_elf: replace open-coded string copy with get_task_comm

[Steven Rostedt <rostedt@goodmis.org>]

On Sat, 20 Nov 2021 11:27:35 +0000
Yafang Shao <laoar.shao@gmail.com> wrote:

> diff --git a/include/linux/elfcore-compat.h b/include/linux/elfcore-compat.h
> index e272c3d452ce..54feb64e9b5d 100644
> --- a/include/linux/elfcore-compat.h
> +++ b/include/linux/elfcore-compat.h
> @@ -43,6 +43,11 @@ struct compat_elf_prpsinfo
>  	__compat_uid_t			pr_uid;
>  	__compat_gid_t			pr_gid;
>  	compat_pid_t			pr_pid, pr_ppid, pr_pgrp, pr_sid;
> +	/*
> +	 * The hard-coded 16 is derived from TASK_COMM_LEN, but it can't be
> +	 * changed as it is exposed to userspace. We'd better make it hard-coded
> +	 * here.

Didn't I once suggest having a macro called something like:

  TASK_COMM_LEN_16 ?


https://lore.kernel.org/all/20211014221409.5da58a42@oasis.local.home/

-- Steve


> +	 */
>  	char				pr_fname[16];
>  	char				pr_psargs[ELF_PRARGSZ];
>  };
> diff --git a/include/linux/elfcore.h b/include/linux/elfcore.h
> index 957ebec35aad..746e081879a5 100644
> --- a/include/linux/elfcore.h
> +++ b/include/linux/elfcore.h
> @@ -65,6 +65,11 @@ struct elf_prpsinfo
>  	__kernel_gid_t	pr_gid;
>  	pid_t	pr_pid, pr_ppid, pr_pgrp, pr_sid;
>  	/* Lots missing */
> +	/*
> +	 * The hard-coded 16 is derived from TASK_COMM_LEN, but it can't be
> +	 * changed as it is exposed to userspace. We'd better make it hard-coded
> +	 * here.
> +	 */
>  	char	pr_fname[16];	/* filename of executable */
>  	char	pr_psargs[ELF_PRARGSZ];	/* initial part of arg list */
>  };