Add PS_SYSTEM, the process-level mirror of the thread-level P_SYSTEM,

and FORK_SYSTEM as a flag to set them.  This eliminates needing to
peek into other processes threads in various places.  Inspired by NetBSD

ok miod@ matthew@

diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index eaea6e4..92481c3 100644 (file)
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: init_main.c,v 1.211 2014/04/18 11:51:17 guenther Exp $        */
+/*     $OpenBSD: init_main.c,v 1.212 2014/05/04 05:03:26 guenther Exp $        */
 /*     $NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $   */
 
 /*
@@ -266,6 +266,7 @@ main(void *framep)
        process0.ps_refcnt = 1;
        p->p_p = pr = &process0;
        LIST_INSERT_HEAD(&allprocess, pr, ps_list);
+       atomic_setbits_int(&pr->ps_flags, PS_SYSTEM);
 
        /* Set the default routing table/domain. */
        process0.ps_rtableid = 0;

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index da052e8..b2ff555 100644 (file)
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_fork.c,v 1.164 2014/05/03 22:44:36 guenther Exp $        */
+/*     $OpenBSD: kern_fork.c,v 1.165 2014/05/04 05:03:26 guenther Exp $        */
 /*     $NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $  */
 
 /*
@@ -208,6 +208,8 @@ process_new(struct proc *p, struct process *parent, int flags)
                atomic_setbits_int(&pr->ps_flags, PS_TRACED);
        if (flags & FORK_NOZOMBIE)
                atomic_setbits_int(&pr->ps_flags, PS_NOZOMBIE);
+       if (flags & FORK_SYSTEM)
+               atomic_setbits_int(&pr->ps_flags, PS_SYSTEM);
 
        /* it's sufficiently inited to be globally visible */
        LIST_INSERT_HEAD(&allprocess, pr, ps_list);
@@ -236,7 +238,7 @@ fork1(struct proc *curp, int flags, void *stack, pid_t *tidptr,
 
        /* sanity check some flag combinations */
        if (flags & FORK_THREAD) {
-               if ((flags & FORK_SIGHAND) == 0)
+               if ((flags & FORK_SIGHAND) == 0 || (flags & FORK_SYSTEM) != 0)
                        return (EINVAL);
        }
        if (flags & FORK_SIGHAND && (flags & FORK_SHAREVM) == 0)
@@ -331,6 +333,8 @@ fork1(struct proc *curp, int flags, void *stack, pid_t *tidptr,
                process_new(p, curpr, flags);
                pr = p->p_p;
        }
+       if (pr->ps_flags & PS_SYSTEM)
+               atomic_setbits_int(&p->p_flag, P_SYSTEM);
 
        /*
         * Duplicate sub-structures as needed.

diff --git a/sys/kern/kern_kthread.c b/sys/kern/kern_kthread.c
index 39b7689..8733f82 100644 (file)
--- a/sys/kern/kern_kthread.c
+++ b/sys/kern/kern_kthread.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_kthread.c,v 1.34 2014/02/12 05:47:36 guenther Exp $      */
+/*     $OpenBSD: kern_kthread.c,v 1.35 2014/05/04 05:03:26 guenther Exp $      */
 /*     $NetBSD: kern_kthread.c,v 1.3 1998/12/22 21:21:36 kleink Exp $  */
 
 /*-
@@ -67,15 +67,10 @@ kthread_create(void (*func)(void *), void *arg,
         * parent to wait for.
         */
        error = fork1(&proc0, FORK_SHAREVM|FORK_SHAREFILES|FORK_NOZOMBIE|
-           FORK_SIGHAND, NULL, 0, func, arg, NULL, &p);
+           FORK_SYSTEM|FORK_SIGHAND, NULL, 0, func, arg, NULL, &p);
        if (error)
                return (error);
 
-       /*
-        * Mark it as a system process.
-        */
-       atomic_setbits_int(&p->p_flag, P_SYSTEM);
-
        /* Name it as specified. */
        strlcpy(p->p_comm, name, sizeof p->p_comm);
 

diff --git a/sys/kern/kern_sched.c b/sys/kern/kern_sched.c
index 1482a31..32e8527 100644 (file)
--- a/sys/kern/kern_sched.c
+++ b/sys/kern/kern_sched.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sched.c,v 1.31 2014/02/12 05:47:36 guenther Exp $        */
+/*     $OpenBSD: kern_sched.c,v 1.32 2014/05/04 05:03:26 guenther Exp $        */
 /*
  * Copyright (c) 2007, 2008 Artur Grabowski <art@openbsd.org>
  *
@@ -106,15 +106,10 @@ sched_kthreads_create(void *v)
        static int num;
 
        if (fork1(&proc0, FORK_SHAREVM|FORK_SHAREFILES|FORK_NOZOMBIE|
-           FORK_SIGHAND|FORK_IDLE, NULL, 0, sched_idle, ci, NULL,
+           FORK_SYSTEM|FORK_SIGHAND|FORK_IDLE, NULL, 0, sched_idle, ci, NULL,
            &spc->spc_idleproc))
                panic("fork idle");
 
-       /*
-        * Mark it as a system process.
-        */
-       atomic_setbits_int(&spc->spc_idleproc->p_flag, P_SYSTEM);
-
        /* Name it as specified. */
        snprintf(spc->spc_idleproc->p_comm, sizeof(spc->spc_idleproc->p_comm),
            "idle%d", num);

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index dd42647..0c15c8e 100644 (file)
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sig.c,v 1.165 2014/05/04 03:53:37 deraadt Exp $  */
+/*     $OpenBSD: kern_sig.c,v 1.166 2014/05/04 05:03:26 guenther Exp $ */
 /*     $NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $   */
 
 /*
@@ -618,7 +618,6 @@ sys_kill(struct proc *cp, void *v, register_t *retval)
 int
 killpg1(struct proc *cp, int signum, int pgid, int all)
 {
-       struct proc *p;
        struct process *pr;
        struct pgrp *pgrp;
        int nfound = 0;
@@ -628,13 +627,12 @@ killpg1(struct proc *cp, int signum, int pgid, int all)
                 * broadcast
                 */
                LIST_FOREACH(pr, &allprocess, ps_list) {
-                       p = pr->ps_mainproc;
-                       if (pr->ps_pid <= 1 || p->p_flag & P_SYSTEM ||
+                       if (pr->ps_pid <= 1 || pr->ps_flags & PS_SYSTEM ||
                            pr == cp->p_p || !cansignal(cp, pr, signum))
                                continue;
                        nfound++;
                        if (signum)
-                               psignal(p, signum);
+                               prsignal(pr, signum);
                }
        else {
                if (pgid == 0)
@@ -648,13 +646,12 @@ killpg1(struct proc *cp, int signum, int pgid, int all)
                                return (ESRCH);
                }
                LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
-                       p = pr->ps_mainproc;
-                       if (pr->ps_pid <= 1 || p->p_flag & P_SYSTEM ||
+                       if (pr->ps_pid <= 1 || pr->ps_flags & PS_SYSTEM ||
                            !cansignal(cp, pr, signum))
                                continue;
                        nfound++;
-                       if (signum && P_ZOMBIE(p) == 0)
-                               psignal(p, signum);
+                       if (signum)
+                               prsignal(pr, signum);
                }
        }
        return (nfound ? 0 : ESRCH);

diff --git a/sys/kern/kern_sysctl.c b/sys/kern/kern_sysctl.c
index 2d07834..e1950f3 100644 (file)
--- a/sys/kern/kern_sysctl.c
+++ b/sys/kern/kern_sysctl.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sysctl.c,v 1.247 2014/05/03 23:30:04 guenther Exp $      */
+/*     $OpenBSD: kern_sysctl.c,v 1.248 2014/05/04 05:03:26 guenther Exp $      */
 /*     $NetBSD: kern_sysctl.c,v 1.17 1996/05/20 17:49:05 mrg Exp $     */
 
 /*-
@@ -1252,7 +1252,7 @@ sysctl_file(int *name, u_int namelen, char *where, size_t *sizep,
                         * processes
                         */
                        pp = pr->ps_mainproc;
-                       if ((pp->p_flag & P_SYSTEM) || (pr->ps_flags & PS_EXITING)
+                       if ((pr->ps_flags & (PS_SYSTEM | PS_EXITING))
                            || pp->p_stat == SIDL || pp->p_stat == SZOMB)
                                continue;
                        if (arg > 0 && pp->p_pid != (pid_t)arg) {
@@ -1284,7 +1284,7 @@ sysctl_file(int *name, u_int namelen, char *where, size_t *sizep,
                         * skip system, exiting, embryonic and undead
                         * processes
                         */
-                       if ((pp->p_flag & P_SYSTEM) || (pr->ps_flags & PS_EXITING)
+                       if ((pr->ps_flags & (PS_SYSTEM | PS_EXITING))
                            || pp->p_stat == SIDL || pp->p_stat == SZOMB)
                                continue;
                        if (arg >= 0 && pp->p_ucred->cr_uid != (uid_t)arg) {
@@ -1418,7 +1418,7 @@ again:
                        break;
 
                case KERN_PROC_ALL:
-                       if (p->p_flag & P_SYSTEM)
+                       if (pr->ps_flags & PS_SYSTEM)
                                continue;
                        break;
 
@@ -1584,11 +1584,8 @@ sysctl_proc_args(int *name, u_int namelen, void *oldp, size_t *oldlenp,
                return (0);
        }
 
-       if (vp->p_flag & P_SYSTEM)
-               return (EINVAL);
-
-       /* Exiting - don't bother, it will be gone soon anyway */
-       if (vp->p_p->ps_flags & PS_EXITING)
+       /* Either system process or exiting/zombie */
+       if (vp->p_p->ps_flags & (PS_SYSTEM | PS_EXITING))
                return (EINVAL);
 
        /* Execing - danger. */
@@ -1774,15 +1771,12 @@ sysctl_proc_cwd(int *name, u_int namelen, void *oldp, size_t *oldlenp,
                return (0);
        }
 
-       if (findp->p_flag & P_SYSTEM)
-               return (EINVAL);
-
-       /* Exiting - don't bother, it will be gone soon anyway */
-       if (findp->p_p->ps_flags & PS_EXITING)
+       /* Either system process or exiting/zombie */
+       if (findp->p_p->ps_flags & (PS_SYSTEM | PS_EXITING))
                return (EINVAL);
 
        /* Only owner or root can get cwd */
-       if (findp->p_ucred->cr_uid != cp->p_ucred->cr_uid &&
+       if (findp->p_p->ps_ucred->cr_uid != cp->p_ucred->cr_uid &&
            (error = suser(cp, 0)) != 0)
                return (error);
 

diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index 2500fef..088d4f3 100644 (file)
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: sys_process.c,v 1.60 2014/03/30 21:54:48 guenther Exp $       */
+/*     $OpenBSD: sys_process.c,v 1.61 2014/05/04 05:03:26 guenther Exp $       */
 /*     $NetBSD: sys_process.c,v 1.55 1996/05/15 06:17:47 tls Exp $     */
 
 /*-
@@ -185,7 +185,7 @@ sys_ptrace(struct proc *p, void *v, register_t *retval)
                /*
                 *      (2) it's a system process
                 */
-               if (ISSET(t->p_flag, P_SYSTEM))
+               if (ISSET(tr->ps_flags, PS_SYSTEM))
                        return (EPERM);
 
                /*

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 33ec6d8..cf4170a 100644 (file)
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: proc.h,v 1.184 2014/04/18 11:51:17 guenther Exp $     */
+/*     $OpenBSD: proc.h,v 1.185 2014/05/04 05:03:26 guenther Exp $     */
 /*     $NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $       */
 
 /*-
@@ -242,12 +242,13 @@ struct process {
 #define        PS_SINGLEUNWIND 0x00002000      /* Other threads must unwind. */
 #define        PS_NOZOMBIE     0x00004000      /* No signal or zombie at exit. */
 #define        PS_STOPPED      0x00008000      /* Just stopped, need sig to parent. */
+#define        PS_SYSTEM       0x00010000      /* No sigs, stats or swapping. */
 
 #define        PS_BITS \
     ("\20\01CONTROLT\02EXEC\03INEXEC\04EXITING\05SUGID" \
      "\06SUGIDEXEC\07PPWAIT\010ISPWAIT\011PROFIL\012TRACED" \
      "\013WAITED\014COREDUMP\015SINGLEEXIT\016SINGLEUNWIND" \
-     "\017NOZOMBIE\020STOPPED")
+     "\017NOZOMBIE\020STOPPED\021SYSTEM")
 
 
 struct proc {
@@ -415,6 +416,7 @@ struct uidinfo *uid_find(uid_t);
 #define FORK_IDLE      0x00000004
 #define FORK_PPWAIT    0x00000008
 #define FORK_SHAREFILES        0x00000010
+#define FORK_SYSTEM    0x00000020
 #define FORK_NOZOMBIE  0x00000040
 #define FORK_SHAREVM   0x00000080
 #define FORK_TFORK     0x00000100