[src/trunk]: src/sys/kern adjust the change of rev. 1.190 so that trap signal...

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

details:   https://anonhg.NetBSD.org/src/rev/31bda28a6c9e
branches:  trunk
changeset: 570192:31bda28a6c9e
user:      jdolecek <jdolecek%NetBSD.org@localhost>
date:      Tue Sep 28 08:59:20 2004 +0000

description:
adjust the change of rev. 1.190 so that trap signals not matching
the reset condition are processed properly; this fixes PR#26687 by
Jan Schaumann

many thanks to Mark Davies, who tracked the offending change down
and helped test patches

while here, g/c unused sigtrapmask and rearrange some code to pre-r1.190 form
for better readability

diffstat:

 sys/kern/kern_sig.c |  96 +++++++++++++++++++++++-----------------------------
 1 files changed, 43 insertions(+), 53 deletions(-)

diffs (139 lines):

diff -r c143cb56b9ae -r 31bda28a6c9e sys/kern/kern_sig.c
--- a/sys/kern/kern_sig.c       Tue Sep 28 06:51:37 2004 +0000
+++ b/sys/kern/kern_sig.c       Tue Sep 28 08:59:20 2004 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_sig.c,v 1.197 2004/06/08 19:35:30 he Exp $        */
+/*     $NetBSD: kern_sig.c,v 1.198 2004/09/28 08:59:20 jdolecek Exp $  */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.197 2004/06/08 19:35:30 he Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_sig.c,v 1.198 2004/09/28 08:59:20 jdolecek Exp $");
 
 #include "opt_ktrace.h"
 #include "opt_compat_sunos.h"
@@ -88,7 +88,7 @@
 static ksiginfo_t *ksiginfo_get(struct proc *, int);
 static void    kpsignal2(struct proc *, const ksiginfo_t *, int);
 
-sigset_t       contsigmask, stopsigmask, sigcantmask, sigtrapmask;
+sigset_t       contsigmask, stopsigmask, sigcantmask;
 
 struct pool    sigacts_pool;   /* memory pool for sigacts structures */
 
@@ -238,12 +238,6 @@
 
        exithook_establish(ksiginfo_exithook, NULL);
        exechook_establish(ksiginfo_exithook, NULL);
-
-       sigaddset(&sigtrapmask, SIGSEGV);
-       sigaddset(&sigtrapmask, SIGBUS);
-       sigaddset(&sigtrapmask, SIGILL);
-       sigaddset(&sigtrapmask, SIGFPE);
-       sigaddset(&sigtrapmask, SIGTRAP);
 }
 
 /*
@@ -1035,44 +1029,47 @@
        /*
         * If proc is traced, always give parent a chance.
         */
-       action = SIG_DFL;
-       if ((p->p_flag & P_TRACED) == 0) {
-               if (KSI_TRAP_P(ksi)) {
-                       /*
-                        * If the signal was the result of a trap, only catch
-                        * the signal if it isn't masked and there is a
-                        * non-default non-ignore handler installed for it.
-                        * Otherwise take the default action.
-                        */
-                       if (!sigismember(&p->p_sigctx.ps_sigmask, signum) &&
-                           sigismember(&p->p_sigctx.ps_sigcatch, signum))
-                               action = SIG_CATCH;
-                       /*
-                        * If we are to take the default action, reset the
-                        * signal back to its defaults.
-                        */
-                       if (action == SIG_DFL) {
-                               sigdelset(&p->p_sigctx.ps_sigignore, signum);
-                               sigdelset(&p->p_sigctx.ps_sigcatch, signum);
-                               sigdelset(&p->p_sigctx.ps_sigmask, signum);
-                               SIGACTION(p, signum).sa_handler = SIG_DFL;
-                       }
-               } else {
-                       /*
-                        * If the signal is being ignored,
-                        * then we forget about it immediately.
-                        * (Note: we don't set SIGCONT in p_sigctx.ps_sigignore,
-                        * and if it is set to SIG_IGN,
-                        * action will be SIG_DFL here.)
-                        */
-                       if (sigismember(&p->p_sigctx.ps_sigignore, signum))
-                               return;
-                       if (sigismember(&p->p_sigctx.ps_sigmask, signum))
-                               action = SIG_HOLD;
-                       else if (sigismember(&p->p_sigctx.ps_sigcatch, signum))
-                               action = SIG_CATCH;
+       if (p->p_flag & P_TRACED) {
+               action = SIG_DFL;
+
+               /*
+                * If the process is being traced and the signal is being
+                * caught, make sure to save any ksiginfo.
+                */
+               if (sigismember(&p->p_sigctx.ps_sigcatch, signum))
+                       ksiginfo_put(p, ksi);
+       } else {
+               /*
+                * If the signal was the result of a trap, reset it
+                * to default action if it's currently masked, so that it would
+                * coredump immediatelly instead of spinning repeatedly
+                * taking the signal.
+                */
+               if (KSI_TRAP_P(ksi)
+                   && sigismember(&p->p_sigctx.ps_sigmask, signum)
+                   && !sigismember(&p->p_sigctx.ps_sigcatch, signum)) {
+                       sigdelset(&p->p_sigctx.ps_sigignore, signum);
+                       sigdelset(&p->p_sigctx.ps_sigcatch, signum);
+                       sigdelset(&p->p_sigctx.ps_sigmask, signum);
+                       SIGACTION(p, signum).sa_handler = SIG_DFL;
                }
-               if (action == SIG_DFL) {
+
+               /*
+                * If the signal is being ignored,
+                * then we forget about it immediately.
+                * (Note: we don't set SIGCONT in p_sigctx.ps_sigignore,
+                * and if it is set to SIG_IGN,
+                * action will be SIG_DFL here.)
+                */
+               if (sigismember(&p->p_sigctx.ps_sigignore, signum))
+                       return;
+               if (sigismember(&p->p_sigctx.ps_sigmask, signum))
+                       action = SIG_HOLD;
+               else if (sigismember(&p->p_sigctx.ps_sigcatch, signum))
+                       action = SIG_CATCH;
+               else {
+                       action = SIG_DFL;
+
                        if (prop & SA_KILL && p->p_nice > NZERO)
                                p->p_nice = NZERO;
 
@@ -1085,13 +1082,6 @@
                        if (prop & SA_TTYSTOP && p->p_pgrp->pg_jobc == 0)
                                return;
                }
-       } else {
-               /*
-                * If the process is being traced and the signal is being
-                * caught, make sure to save any ksiginfo.
-                */
-               if (sigismember(&p->p_sigctx.ps_sigcatch, signum))
-                       ksiginfo_put(p, ksi);
        }
 
        if (prop & SA_CONT)