[src/trunk]: src/sys/kern Remove unused code branch in the signa...

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

details:   https://anonhg.NetBSD.org/src/rev/c0acf446a60c
branches:  trunk
changeset: 318456:c0acf446a60c
user:      kamil <kamil%NetBSD.org@localhost>
date:      Tue Apr 24 18:34:46 2018 +0000
description:
Remove unused code branch in the signal code

Remove the ppsig argument from proc_stop_done() and from sigswitch().

This functionality was used in now gone filesystem tracing feature (/proc).
It prevented emitting signal child signals to a debugging program, namely
with the SIGCHLD signal.

The modern solution to perform tracing without signals in a debugger is
to spawn a debugging server and outsource the tracing functionality to it.
This is done in software like gdb-server, lldb-server etc.

No functional change intended.

Sponsored by <The NetBSD Foundation>

diffstat:

 sys/kern/kern_sig.c |  30 ++++++++++++++----------------
 1 files changed, 14 insertions(+), 16 deletions(-)

diffs (121 lines):

diff -r e863109c4a58 -r c0acf446a60c sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c       Tue Apr 24 18:34:30 2018 +0000
+++ b/sys/kern/kern_sig.c       Tue Apr 24 18:34:46 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sig.c,v 1.339 2017/12/07 19:49:43 christos Exp $  */
+/*     $NetBSD: kern_sig.c,v 1.340 2018/04/24 18:34:46 kamil Exp $     */
 
 /*-
  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.339 2017/12/07 19:49:43 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.340 2018/04/24 18:34:46 kamil Exp $");
 
 #include "opt_ptrace.h"
 #include "opt_dtrace.h"
@@ -123,7 +123,7 @@
 static int     sigpost(struct lwp *, sig_t, int, int);
 static int     sigput(sigpend_t *, struct proc *, ksiginfo_t *);
 static int     sigunwait(struct proc *, const ksiginfo_t *);
-static void    sigswitch(bool, int, int);
+static void    sigswitch(int, int);
 
 static void    sigacts_poolpage_free(struct pool *, void *);
 static void    *sigacts_poolpage_alloc(struct pool *, int);
@@ -1506,7 +1506,7 @@
  * Drop p_lock briefly if PS_NOTIFYSTOP is set and ppsig is true.
  */
 static void
-proc_stop_done(struct proc *p, bool ppsig, int ppmask)
+proc_stop_done(struct proc *p, int ppmask)
 {
 
        KASSERT(mutex_owned(proc_lock));
@@ -1519,10 +1519,8 @@
        p->p_waited = 0;
        p->p_pptr->p_nstopchild++;
        if ((p->p_sflag & PS_NOTIFYSTOP) != 0) {
-               if (ppsig) {
-                       /* child_psignal drops p_lock briefly. */
-                       child_psignal(p, ppmask);
-               }
+               /* child_psignal drops p_lock briefly. */
+               child_psignal(p, ppmask);
                cv_broadcast(&p->p_pptr->p_waitcv);
        }
 }
@@ -1531,7 +1529,7 @@
  * Stop the current process and switch away when being stopped or traced.
  */
 static void
-sigswitch(bool ppsig, int ppmask, int signo)
+sigswitch(int ppmask, int signo)
 {
        struct lwp *l = curlwp;
        struct proc *p = l->l_proc;
@@ -1568,7 +1566,7 @@
                         * Note that proc_stop_done() can drop
                         * p->p_lock briefly.
                         */
-                       proc_stop_done(p, ppsig, ppmask);
+                       proc_stop_done(p, ppmask);
                }
 
                mutex_exit(proc_lock);
@@ -1667,7 +1665,7 @@
                 * we awaken, check for a signal from the debugger.
                 */
                if (p->p_stat == SSTOP || (p->p_sflag & PS_STOPPING) != 0) {
-                       sigswitch(true, PS_NOCLDSTOP, 0);
+                       sigswitch(PS_NOCLDSTOP, 0);
                        signo = sigchecktrace();
                } else
                        signo = 0;
@@ -1737,7 +1735,7 @@
                        /* Emulation-specific handling of signal trace */
                        if (p->p_emul->e_tracesig == NULL ||
                            (*p->p_emul->e_tracesig)(p, signo) == 0)
-                               sigswitch(1, 0, signo);
+                               sigswitch(0, signo);
 
                        /* Check for a signal from the debugger. */
                        if ((signo = sigchecktrace()) == 0)
@@ -1791,7 +1789,7 @@
                                p->p_xsig = signo;
                                p->p_sflag &= ~PS_CONTINUED;
                                signo = 0;
-                               sigswitch(true, PS_NOCLDSTOP, p->p_xsig);
+                               sigswitch(PS_NOCLDSTOP, p->p_xsig);
                        } else if (prop & SA_IGNORE) {
                                /*
                                 * Except for SIGCONT, shouldn't get here.
@@ -2134,7 +2132,7 @@
         */
 
        if (p->p_nrlwps == 0) {
-               proc_stop_done(p, true, PS_NOCLDSTOP);
+               proc_stop_done(p, PS_NOCLDSTOP);
        } else {
                /*
                 * Have the remaining LWPs come to a halt, and trigger
@@ -2206,7 +2204,7 @@
                                         */
                                        restart = true;
                                }
-                               proc_stop_done(p, true, PS_NOCLDSTOP);
+                               proc_stop_done(p, PS_NOCLDSTOP);
                        } else
                                more = true;
 
@@ -2283,7 +2281,7 @@
        p->p_xsig = SIGTRAP;
        p->p_sigctx.ps_info._signo = p->p_xsig;
        p->p_sigctx.ps_info._code = trapno;
-       sigswitch(true, 0, p->p_xsig);
+       sigswitch(0, p->p_xsig);
        mutex_exit(p->p_lock);
 }