[src/trunk]: src/sys Pull signal actions out of struct user, make them a sepa...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/929c8b8d06d1
branches:  trunk
changeset: 472508:929c8b8d06d1
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Apr 30 21:23:49 1999 +0000

description:
Pull signal actions out of struct user, make them a separate proc
substructure, and allow them to be shared.

Required for clone(2).

diffstat:

 sys/kern/init_main.c |  15 ++++++---
 sys/kern/kern_exit.c |   7 +++-
 sys/kern/kern_fork.c |   8 ++++-
 sys/kern/kern_sig.c  |  83 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 sys/sys/signalvar.h  |  10 +++++-
 sys/sys/user.h       |   3 +-
 sys/uvm/uvm_glue.c   |   9 +---
 7 files changed, 118 insertions(+), 17 deletions(-)

diffs (286 lines):

diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/kern/init_main.c
--- a/sys/kern/init_main.c      Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/kern/init_main.c      Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: init_main.c,v 1.148 1999/04/30 18:42:59 thorpej Exp $  */
+/*     $NetBSD: init_main.c,v 1.149 1999/04/30 21:23:49 thorpej Exp $  */
 
 /*
  * Copyright (c) 1995 Christopher G. Demetriou.  All rights reserved.
@@ -118,6 +118,7 @@
 struct cwdinfo cwdi0;
 struct plimit limit0;
 struct vmspace vmspace0;
+struct sigacts sigacts0;
 #ifndef curproc
 struct proc *curproc = &proc0;
 #endif
@@ -294,11 +295,10 @@
        p->p_addr = proc0paddr;                         /* XXX */
 
        /*
-        * We continue to place resource usage info and signal
-        * actions in the user struct so they're pageable.
+        * We continue to place resource usage info in the
+        * user struct so they're pageable.
         */
        p->p_stats = &p->p_addr->u_stats;
-       p->p_sigacts = &p->p_addr->u_sigacts;
 
        /*
         * Charge root for one process.
@@ -395,7 +395,12 @@
        p->p_stats->p_start = runtime = mono_time = boottime = time;
        p->p_rtime.tv_sec = p->p_rtime.tv_usec = 0;
 
-       /* Initialize signal state for process 0. */
+       /*
+        * Initialize signal-related data structures, and signal state
+        * for proc0.
+        */
+       signal_init();
+       p->p_sigacts = &sigacts0;
        siginit(p);
 
        /* Create process 1 (init(8)). */
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/kern/kern_exit.c
--- a/sys/kern/kern_exit.c      Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/kern/kern_exit.c      Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_exit.c,v 1.66 1999/04/30 20:54:04 thorpej Exp $   */
+/*     $NetBSD: kern_exit.c,v 1.67 1999/04/30 21:23:49 thorpej Exp $   */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -301,6 +301,11 @@
        }
 
        /*
+        * Release the process's signal state.
+        */
+       sigactsfree(p);
+
+       /*
         * Clear curproc after we've done all operations
         * that could block, and before tearing down the rest
         * of the process state that might be used from clock, etc.
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/kern/kern_fork.c
--- a/sys/kern/kern_fork.c      Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/kern/kern_fork.c      Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_fork.c,v 1.55 1999/04/30 18:42:59 thorpej Exp $   */
+/*     $NetBSD: kern_fork.c,v 1.56 1999/04/30 21:23:49 thorpej Exp $   */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -58,6 +58,7 @@
 #include <sys/ktrace.h>
 #include <sys/vmmeter.h>
 #include <sys/sched.h>
+#include <sys/signalvar.h>
 
 #include <sys/syscallargs.h>
 
@@ -314,6 +315,11 @@
        scheduler_fork_hook(p1, p2);
 
        /*
+        * Create signal actions for the child process.
+        */
+       p2->p_sigacts = sigactsinit(p1);
+
+       /*
         * This begins the section where we must prevent the parent
         * from being swapped.
         */
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c       Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/kern/kern_sig.c       Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sig.c,v 1.88 1999/04/30 18:43:00 thorpej Exp $    */
+/*     $NetBSD: kern_sig.c,v 1.89 1999/04/30 21:23:49 thorpej Exp $    */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -64,6 +64,8 @@
 #include <sys/core.h>
 #include <sys/ptrace.h>
 #include <sys/filedesc.h>
+#include <sys/malloc.h>
+#include <sys/pool.h>
 
 #include <sys/mount.h>
 #include <sys/syscallargs.h>
@@ -80,6 +82,8 @@
 
 sigset_t contsigmask, stopsigmask, sigcantmask;
 
+struct pool sigacts_pool;      /* memory pool for sigacts structures */
+
 /*
  * Can process p, with pcred pc, send the signal signum to process q?
  */
@@ -91,6 +95,80 @@
            (pc)->pc_ucred->cr_uid == (q)->p_ucred->cr_uid || \
            ((signum) == SIGCONT && (q)->p_session == (p)->p_session))
 
+/*
+ * Initialize signal-related data structures.
+ */
+void
+signal_init()
+{
+
+       pool_init(&sigacts_pool, sizeof(struct sigacts), 0, 0, 0, "sigapl",
+           0, pool_page_alloc_nointr, pool_page_free_nointr, M_SUBPROC);
+}
+
+/*
+ * Create an initial sigacts structure, using the same signal state
+ * as p.
+ */
+struct sigacts *
+sigactsinit(p)
+       struct proc *p;
+{
+       struct sigacts *ps;
+
+       ps = pool_get(&sigacts_pool, PR_WAITOK);
+       memcpy(ps, p->p_sigacts, sizeof(struct sigacts));
+       ps->ps_refcnt = 1;
+       return (ps);
+}
+
+/*
+ * Make p2 share p1's sigacts.
+ */
+void
+sigactsshare(p1, p2)
+       struct proc *p1, *p2;
+{
+
+       p2->p_sigacts = p1->p_sigacts;
+       p1->p_sigacts->ps_refcnt++;
+}
+
+/*
+ * Make this process not share its sigacts, maintaining all
+ * signal state.
+ */
+void
+sigactsunshare(p)
+       struct proc *p;
+{
+       struct sigacts *newps;
+
+       if (p->p_sigacts->ps_refcnt == 1)
+               return;
+
+       newps = sigactsinit(p);
+       sigactsfree(p);
+       p->p_sigacts = newps;
+}
+
+/*
+ * Release a sigacts structure.
+ */
+void
+sigactsfree(p)
+       struct proc *p;
+{
+       struct sigacts *ps = p->p_sigacts;
+
+       if (--ps->ps_refcnt > 0)
+               return;
+
+       p->p_sigacts = NULL;
+
+       pool_put(&sigacts_pool, ps);
+}
+
 int
 sigaction1(p, signum, nsa, osa)
        struct proc *p;
@@ -238,6 +316,9 @@
        ps->ps_sigstk.ss_flags = SS_DISABLE;
        ps->ps_sigstk.ss_size = 0;
        ps->ps_sigstk.ss_sp = 0;
+
+       /* One reference. */
+       ps->ps_refcnt = 1;
 }
 
 /*
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/sys/signalvar.h
--- a/sys/sys/signalvar.h       Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/sys/signalvar.h       Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: signalvar.h,v 1.21 1998/10/03 14:29:02 drochner Exp $  */
+/*     $NetBSD: signalvar.h,v 1.22 1999/04/30 21:23:50 thorpej Exp $   */
 
 /*
  * Copyright (c) 1991, 1993
@@ -55,6 +55,7 @@
        int     ps_sig;                 /* for core dump/debugger XXX */
        long    ps_code;                /* for core dump/debugger XXX */
        void    *ps_sigcode;            /* address of signal trampoline */
+       int     ps_refcnt;              /* reference count */
 };
 
 /* signal flags */
@@ -162,6 +163,13 @@
 int    sigaltstack1 __P((struct proc *p, \
            const struct sigaltstack *nss, struct sigaltstack *oss));
 
+void   signal_init __P((void));
+
+struct sigacts *sigactsinit __P((struct proc *));
+void   sigactsshare __P((struct proc *, struct proc *));
+void   sigactsunshare __P((struct proc *));
+void   sigactsfree __P((struct proc *));
+
 /*
  * Machine-dependent functions:
  */
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/sys/user.h
--- a/sys/sys/user.h    Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/sys/user.h    Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: user.h,v 1.12 1997/10/16 02:32:55 mycroft Exp $        */
+/*     $NetBSD: user.h,v 1.13 1999/04/30 21:23:50 thorpej Exp $        */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -61,7 +61,6 @@
 struct user {
        struct  pcb u_pcb;
 
-       struct  sigacts u_sigacts;      /* p_sigacts points here (use it!) */
        struct  pstats u_stats;         /* p_stats points here (use it!) */
 };
 
diff -r 4f76aacf91c3 -r 929c8b8d06d1 sys/uvm/uvm_glue.c
--- a/sys/uvm/uvm_glue.c        Fri Apr 30 21:09:50 1999 +0000
+++ b/sys/uvm/uvm_glue.c        Fri Apr 30 21:23:49 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_glue.c,v 1.18 1999/03/26 21:58:39 mycroft Exp $    */
+/*     $NetBSD: uvm_glue.c,v 1.19 1999/04/30 21:23:50 thorpej Exp $    */
 
 /* 
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -288,13 +288,10 @@
                panic("uvm_fork: uvm_fault_wire failed: %d", rv);
 
        /*
-        * p_stats and p_sigacts currently point at fields in the user
-        * struct but not at &u, instead at p_addr.  Copy p_sigacts and
-        * parts of p_stats; zero the rest of p_stats (statistics).
+        * p_stats currently points at a field in the user struct.  Copy
+        * parts of p_stats, and zero out the rest.
         */
        p2->p_stats = &up->u_stats;
-       p2->p_sigacts = &up->u_sigacts;
-       up->u_sigacts = *p1->p_sigacts;
        memset(&up->u_stats.pstat_startzero, 0,
        (unsigned) ((caddr_t)&up->u_stats.pstat_endzero -
                    (caddr_t)&up->u_stats.pstat_startzero));