Re: [PATCH sysctl-next] kernel/kexec_core: move kexec_core sysctls into its own file

[Baoquan He]

On 02/23/22 at 11:03am, yingelin wrote:
> This move the kernel/kexec_core.c respective sysctls to its own file.

Hmm, why is the move needed? 

With my understanding, sysctls are all put in kernel/sysctl.c,
why is kexec special?

> 
> Signed-off-by: yingelin <yingelin@xxxxxxxxxx>
> ---
>  kernel/kexec_core.c | 20 ++++++++++++++++++++
>  kernel/sysctl.c     | 13 -------------
>  2 files changed, 20 insertions(+), 13 deletions(-)
> 
> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
> index 68480f731192..e57339d49439 100644
> --- a/kernel/kexec_core.c
> +++ b/kernel/kexec_core.c
> @@ -936,6 +936,26 @@ int kimage_load_segment(struct kimage *image,
>  struct kimage *kexec_image;
>  struct kimage *kexec_crash_image;
>  int kexec_load_disabled;
> +static struct ctl_table kexec_core_sysctls[] = {
> +	{
> +		.procname	= "kexec_load_disabled",
> +		.data		= &kexec_load_disabled,
> +		.maxlen		= sizeof(int),
> +		.mode		= 0644,
> +		/* only handle a transition from default "0" to "1" */
> +		.proc_handler	= proc_dointvec_minmax,
> +		.extra1		= SYSCTL_ONE,
> +		.extra2		= SYSCTL_ONE,
> +	},
> +	{ }
> +};
> +
> +static int __init kexec_core_sysctl_init(void)
> +{
> +	register_sysctl_init("kernel", kexec_core_sysctls);
> +	return 0;
> +}
> +late_initcall(kexec_core_sysctl_init);
>  
>  /*
>   * No panic_cpu check version of crash_kexec().  This function is called
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index ae5e59396b5d..00e97c6d6576 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -61,7 +61,6 @@
>  #include <linux/capability.h>
>  #include <linux/binfmts.h>
>  #include <linux/sched/sysctl.h>
> -#include <linux/kexec.h>
>  #include <linux/bpf.h>
>  #include <linux/mount.h>
>  #include <linux/userfaultfd_k.h>
> @@ -1839,18 +1838,6 @@ static struct ctl_table kern_table[] = {
>  		.proc_handler	= tracepoint_printk_sysctl,
>  	},
>  #endif
> -#ifdef CONFIG_KEXEC_CORE
> -	{
> -		.procname	= "kexec_load_disabled",
> -		.data		= &kexec_load_disabled,
> -		.maxlen		= sizeof(int),
> -		.mode		= 0644,
> -		/* only handle a transition from default "0" to "1" */
> -		.proc_handler	= proc_dointvec_minmax,
> -		.extra1		= SYSCTL_ONE,
> -		.extra2		= SYSCTL_ONE,
> -	},
> -#endif
>  #ifdef CONFIG_MODULES
>  	{
>  		.procname	= "modprobe",
> -- 
> 2.26.2
>