From: Vitaliy Makkoveev <mvs@openbsd.org>
Subject: sysctl: unlock KERN_CPTIME{,2}
To: David Gwynne <david@gwynne.id.au>, tech@openbsd.org
Cc: sysctl: unlockKERN_CPTIME{@openbsd.org, 2}@openbsd.org;
Date: Wed, 4 Jun 2025 22:26:32 +0300

Fixed subject: Subject: sysctl: unlock KERN_CPTIME{,2}

On Wed, Jun 04, 2025 at 10:08:27PM +0300, Vitaliy Makkoveev wrote:
> dlg@ made the CPU state statistics mp-safe, but forgot to move sysctl(2)
> cases out of locks.
> 
> Index: sys/kern/kern_sysctl.c
> ===================================================================
> RCS file: /cvs/src/sys/kern/kern_sysctl.c,v
> retrieving revision 1.475
> diff -u -p -r1.475 kern_sysctl.c
> --- sys/kern/kern_sysctl.c	4 Jun 2025 13:29:11 -0000	1.475
> +++ sys/kern/kern_sysctl.c	4 Jun 2025 19:05:07 -0000
> @@ -410,6 +410,9 @@ kern_sysctl_dirs(int top_name, int *name
>  	case KERN_MALLOCSTATS:
>  		return (sysctl_malloc(name, namelen, oldp, oldlenp,
>  		    newp, newlen, p));
> +	case KERN_CPTIME2:
> +		return (sysctl_cptime2(name, namelen, oldp, oldlenp,
> +		    newp, newlen));
>  	case KERN_POOL:
>  		return (sysctl_dopool(name, namelen, oldp, oldlenp));
>  #if NAUDIO > 0
> @@ -490,9 +493,6 @@ kern_sysctl_dirs_locked(int top_name, in
>  #endif
>  	case KERN_TIMECOUNTER:
>  		return (sysctl_tc(name, namelen, oldp, oldlenp, newp, newlen));
> -	case KERN_CPTIME2:
> -		return (sysctl_cptime2(name, namelen, oldp, oldlenp,
> -		    newp, newlen));
>  #ifdef WITNESS
>  	case KERN_WITNESSWATCH:
>  		return witness_sysctl_watch(oldp, oldlenp, newp, newlen);
> @@ -632,6 +632,33 @@ kern_sysctl(int *name, u_int namelen, vo
>  			return (ENXIO);
>  		return (sysctl_rdint(oldp, oldlenp, newp, mp->msg_bufs));
>  	}
> +	case KERN_CPTIME:
> +	{
> +		CPU_INFO_ITERATOR cii;
> +		struct cpu_info *ci;
> +		long cp_time[CPUSTATES];
> +		int i, n = 0;
> +
> +		memset(cp_time, 0, sizeof(cp_time));
> +
> +		CPU_INFO_FOREACH(cii, ci) {
> +			uint64_t ci_cp_time[CPUSTATES];
> +
> +			if (!cpu_is_online(ci))
> +				continue;
> +
> +			n++;
> +			sysctl_ci_cp_time(ci, ci_cp_time);
> +			for (i = 0; i < CPUSTATES; i++)
> +				cp_time[i] += ci_cp_time[i];
> +		}
> +
> +		for (i = 0; i < CPUSTATES; i++)
> +			cp_time[i] /= n;
> +
> +		return (sysctl_rdstruct(oldp, oldlenp, newp, &cp_time,
> +		    sizeof(cp_time)));
> +	}
>  	case KERN_POOL_DEBUG: {
>  		extern int pool_debug;
>  		int oldval, newval;
> @@ -714,33 +741,6 @@ kern_sysctl_locked(int *name, u_int name
>  		if (newp && !error)
>  			domainnamelen = newlen;
>  		return (error);
> -	case KERN_CPTIME:
> -	{
> -		CPU_INFO_ITERATOR cii;
> -		struct cpu_info *ci;
> -		long cp_time[CPUSTATES];
> -		int i, n = 0;
> -
> -		memset(cp_time, 0, sizeof(cp_time));
> -
> -		CPU_INFO_FOREACH(cii, ci) {
> -			uint64_t ci_cp_time[CPUSTATES];
> -
> -			if (!cpu_is_online(ci))
> -				continue;
> -
> -			n++;
> -			sysctl_ci_cp_time(ci, ci_cp_time);
> -			for (i = 0; i < CPUSTATES; i++)
> -				cp_time[i] += ci_cp_time[i];
> -		}
> -
> -		for (i = 0; i < CPUSTATES; i++)
> -			cp_time[i] /= n;
> -
> -		return (sysctl_rdstruct(oldp, oldlenp, newp, &cp_time,
> -		    sizeof(cp_time)));
> -	}
>  	case KERN_NCHSTATS:
>  		return (sysctl_rdstruct(oldp, oldlenp, newp, &nchstats,
>  		    sizeof(struct nchstats)));
>