Re: [PATCH v2 2/2] signal: move show_unhandled_signals sysctl to its own file

[Joel Granados]

On Fri, May 26, 2023 at 03:22:06PM -0700, Luis Chamberlain wrote:
> The show_unhandled_signals sysctl is the only sysctl for debug
> left on kernel/sysctl.c. We've been moving the syctls out from
> kernel/sysctl.c so to help avoid merge conflicts as the shared
> array gets out of hand.
> 
> This change incurs simplifies sysctl registration by localizing
> it where it should go for a penalty in size of increasing the
> kernel by 23 bytes, we accept this given recent cleanups have
> actually already saved us 1465 bytes in the prior commits.
> 
> ./scripts/bloat-o-meter vmlinux.3-remove-dev-table vmlinux.4-remove-debug-table
> add/remove: 3/1 grow/shrink: 0/1 up/down: 177/-154 (23)
> Function                                     old     new   delta
> signal_debug_table                             -     128    +128
> init_signal_sysctls                            -      33     +33
> __pfx_init_signal_sysctls                      -      16     +16
> sysctl_init_bases                             85      59     -26
> debug_table                                  128       -    -128
> Total: Before=21256967, After=21256990, chg +0.00%
> 
> Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> ---
>  kernel/signal.c | 23 +++++++++++++++++++++++
>  kernel/sysctl.c | 14 --------------
>  2 files changed, 23 insertions(+), 14 deletions(-)
> 
> diff --git a/kernel/signal.c b/kernel/signal.c
> index 8f6330f0e9ca..5ba4150c01a7 100644
> --- a/kernel/signal.c
> +++ b/kernel/signal.c
> @@ -45,6 +45,7 @@
>  #include <linux/posix-timers.h>
>  #include <linux/cgroup.h>
>  #include <linux/audit.h>
> +#include <linux/sysctl.h>
>  
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/signal.h>
> @@ -4771,6 +4772,28 @@ static inline void siginfo_buildtime_checks(void)
>  #endif
>  }
>  
> +#if defined(CONFIG_SYSCTL)
> +static struct ctl_table signal_debug_table[] = {
> +#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
> +	{
> +		.procname	= "exception-trace",
> +		.data		= &show_unhandled_signals,
> +		.maxlen		= sizeof(int),
> +		.mode		= 0644,
> +		.proc_handler	= proc_dointvec
> +	},
> +#endif
> +	{ }
> +};
> +
> +static int __init init_signal_sysctls(void)
> +{
> +	register_sysctl_init("debug", signal_debug_table);
> +	return 0;
> +}
> +early_initcall(init_signal_sysctls);
> +#endif /* CONFIG_SYSCTL */
> +
>  void __init signals_init(void)
>  {
>  	siginfo_buildtime_checks();
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index a7fdb828afb6..43240955dcad 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2331,24 +2331,10 @@ static struct ctl_table vm_table[] = {
>  	{ }
>  };
>  
> -static struct ctl_table debug_table[] = {
> -#ifdef CONFIG_SYSCTL_EXCEPTION_TRACE
> -	{
> -		.procname	= "exception-trace",
> -		.data		= &show_unhandled_signals,
> -		.maxlen		= sizeof(int),
> -		.mode		= 0644,
> -		.proc_handler	= proc_dointvec
> -	},
> -#endif
> -	{ }
> -};
> -
>  int __init sysctl_init_bases(void)
>  {
>  	register_sysctl_init("kernel", kern_table);
>  	register_sysctl_init("vm", vm_table);
> -	register_sysctl_init("debug", debug_table);
>  
>  	return 0;
>  }
> -- 
> 2.39.2
> 

LGTM
-- 

Joel Granados

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