[src/trunk]: src/sys PR/43625: Mark Davies: Fix pselect(2) to honor the tempo...

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

details:   https://anonhg.NetBSD.org/src/rev/73c0d5ded0f7
branches:  trunk
changeset: 765065:73c0d5ded0f7
user:      christos <christos%NetBSD.org@localhost>
date:      Wed May 18 03:51:41 2011 +0000

description:
PR/43625: Mark Davies: Fix pselect(2) to honor the temporary mask. pselect(2)
(and pollts(2)) are similar to sigsuspend(2) in that they temporarily change
the process signal mask and wait for signal delivery. Factor out and share the
code that does this.

diffstat:

 sys/kern/sys_select.c |  20 ++----------------
 sys/kern/sys_sig.c    |  54 ++++++++++++++++++++++++++++----------------------
 sys/sys/signalvar.h   |   3 +-
 3 files changed, 35 insertions(+), 42 deletions(-)

diffs (154 lines):

diff -r 6f37c7bc0ed5 -r 73c0d5ded0f7 sys/kern/sys_select.c
--- a/sys/kern/sys_select.c     Wed May 18 03:15:12 2011 +0000
+++ b/sys/kern/sys_select.c     Wed May 18 03:51:41 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_select.c,v 1.30 2011/03/06 04:41:58 rmind Exp $    */
+/*     $NetBSD: sys_select.c,v 1.31 2011/05/18 03:51:41 christos Exp $ */
 
 /*-
  * Copyright (c) 2007, 2008, 2009, 2010 The NetBSD Foundation, Inc.
@@ -84,7 +84,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.30 2011/03/06 04:41:58 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_select.c,v 1.31 2011/05/18 03:51:41 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -219,10 +219,8 @@
     struct timespec *ts, sigset_t *mask, register_t *retval)
 {
        lwp_t           * const l = curlwp;
-       proc_t          * const p = l->l_proc;
        selcluster_t    *sc;
        kmutex_t        *lock;
-       sigset_t        oldmask;
        struct timespec sleepts;
        int             error, timo;
 
@@ -233,13 +231,7 @@
 
        if (__predict_false(mask)) {
                sigminusset(&sigcantmask, mask);
-               mutex_enter(p->p_lock);
-               oldmask = l->l_sigmask;
-               l->l_sigmask = *mask;
-               mutex_exit(p->p_lock);
-       } else {
-               /* XXXgcc */
-               oldmask = l->l_sigmask;
+               sigsuspendsetup(l, mask);
        }
 
        sc = curcpu()->ci_data.cpu_selcluster;
@@ -314,12 +306,6 @@
        }
        selclear();
 
-       if (__predict_false(mask)) {
-               mutex_enter(p->p_lock);
-               l->l_sigmask = oldmask;
-               mutex_exit(p->p_lock);
-       }
-
        /* select and poll are not restarted after signals... */
        if (error == ERESTART)
                return EINTR;
diff -r 6f37c7bc0ed5 -r 73c0d5ded0f7 sys/kern/sys_sig.c
--- a/sys/kern/sys_sig.c        Wed May 18 03:15:12 2011 +0000
+++ b/sys/kern/sys_sig.c        Wed May 18 03:51:41 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_sig.c,v 1.32 2011/03/03 20:46:16 martin Exp $      */
+/*     $NetBSD: sys_sig.c,v 1.33 2011/05/18 03:51:41 christos Exp $    */
 
 /*-
  * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.32 2011/03/03 20:46:16 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.33 2011/05/18 03:51:41 christos Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -604,33 +604,39 @@
        mutex_exit(p->p_lock);
 }
 
-int
-sigsuspend1(struct lwp *l, const sigset_t *ss)
+void
+sigsuspendsetup(struct lwp *l, const sigset_t *ss)
 {
        struct proc *p = l->l_proc;
 
-       if (ss) {
-               /*
-                * When returning from sigsuspend, we want
-                * the old mask to be restored after the
-                * signal handler has finished.  Thus, we
-                * save it here and mark the sigctx structure
-                * to indicate this.
-                */
-               mutex_enter(p->p_lock);
-               l->l_sigrestore = 1;
-               l->l_sigoldmask = l->l_sigmask;
-               l->l_sigmask = *ss;
-               sigminusset(&sigcantmask, &l->l_sigmask);
+       /*
+        * When returning from sigsuspend/pselect/pollts, we want
+        * the old mask to be restored after the
+        * signal handler has finished.  Thus, we
+        * save it here and mark the sigctx structure
+        * to indicate this.
+        */
+       mutex_enter(p->p_lock);
+       l->l_sigrestore = 1;
+       l->l_sigoldmask = l->l_sigmask;
+       l->l_sigmask = *ss;
+       sigminusset(&sigcantmask, &l->l_sigmask);
 
-               /* Check for pending signals when sleeping. */
-               if (sigispending(l, 0)) {
-                       lwp_lock(l);
-                       l->l_flag |= LW_PENDSIG;
-                       lwp_unlock(l);
-               }
-               mutex_exit(p->p_lock);
+       /* Check for pending signals when sleeping. */
+       if (sigispending(l, 0)) {
+               lwp_lock(l);
+               l->l_flag |= LW_PENDSIG;
+               lwp_unlock(l);
        }
+       mutex_exit(p->p_lock);
+}
+
+int
+sigsuspend1(struct lwp *l, const sigset_t *ss)
+{
+
+       if (ss)
+               sigsuspendsetup(l, ss);
 
        while (kpause("pause", true, 0, NULL) == 0)
                ;
diff -r 6f37c7bc0ed5 -r 73c0d5ded0f7 sys/sys/signalvar.h
--- a/sys/sys/signalvar.h       Wed May 18 03:15:12 2011 +0000
+++ b/sys/sys/signalvar.h       Wed May 18 03:51:41 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: signalvar.h,v 1.79 2011/04/27 00:38:37 rmind Exp $     */
+/*     $NetBSD: signalvar.h,v 1.80 2011/05/18 03:51:41 christos Exp $  */
 
 /*
  * Copyright (c) 1991, 1993
@@ -148,6 +148,7 @@
            struct sigaction *, const void *, int);
 int    sigprocmask1(struct lwp *, int, const sigset_t *, sigset_t *);
 void   sigpending1(struct lwp *, sigset_t *);
+void   sigsuspendsetup(struct lwp *, const sigset_t *);
 int    sigsuspend1(struct lwp *, const sigset_t *);
 int    sigaltstack1(struct lwp *, const struct sigaltstack *,
            struct sigaltstack *);