[src/trunk]: src/sys/kern sigtimedwait: fix a memory leak (which happens sinc...

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

details:   https://anonhg.NetBSD.org/src/rev/dcecef5e2a86
branches:  trunk
changeset: 750185:dcecef5e2a86
user:      rmind <rmind%NetBSD.org@localhost>
date:      Sat Dec 19 18:25:54 2009 +0000

description:
sigtimedwait: fix a memory leak (which happens since newlock2 times).
Allocate ksiginfo on stack since it is safe and sigget() assumes that it is
not allocated from pool (pending signals via sigput()/sigget() "mill" should
be dynamically allocated, however).  Might be useful to revisit later.

Likely the cause of PR/40750 and indirect cause of PR/39283.

diffstat:

 sys/kern/sys_sig.c |  25 ++++++++-----------------
 1 files changed, 8 insertions(+), 17 deletions(-)

diffs (74 lines):

diff -r c65e0abe0f15 -r dcecef5e2a86 sys/kern/sys_sig.c
--- a/sys/kern/sys_sig.c        Sat Dec 19 18:06:51 2009 +0000
+++ b/sys/kern/sys_sig.c        Sat Dec 19 18:25:54 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_sig.c,v 1.23 2009/03/29 17:54:12 christos Exp $    */
+/*     $NetBSD: sys_sig.c,v 1.24 2009/12/19 18:25:54 rmind 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 1.23 2009/03/29 17:54:12 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.24 2009/12/19 18:25:54 rmind Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -636,7 +636,7 @@
        int error, signum;
        int timo = 0;
        struct timespec ts, tsstart, tsnow;
-       ksiginfo_t *ksi;
+       ksiginfo_t ksi;
 
        memset(&tsstart, 0, sizeof tsstart);     /* XXX gcc */
 
@@ -674,13 +674,6 @@
         */
        sigminusset(&sigcantmask, &l->l_sigwaitset);
 
-       /*
-        * Allocate a ksi up front.  We can't sleep with the mutex held.
-        */
-       ksi = ksiginfo_alloc(p, NULL, PR_WAITOK);
-       if (ksi == NULL)
-               return (ENOMEM);
-
        mutex_enter(p->p_lock);
 
        /*
@@ -692,8 +685,8 @@
                goto out;
        }
 
-       if ((signum = sigget(&p->p_sigpend, ksi, 0, &l->l_sigwaitset)) == 0)
-               signum = sigget(&l->l_sigpend, ksi, 0, &l->l_sigwaitset);
+       if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0)
+               signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset);
 
        if (signum != 0) {
                /*
@@ -706,7 +699,7 @@
        /*
         * Set up the sigwait list.
         */
-       l->l_sigwaited = ksi;
+       l->l_sigwaited = &ksi;
        LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter);
 
        /*
@@ -761,10 +754,8 @@
         */
  out:
        if (error == 0)
-               error = (*put_info)(&ksi->ksi_info, SCARG(uap, info),
-                   sizeof(ksi->ksi_info));
-
-       ksiginfo_free(ksi);
+               error = (*put_info)(&ksi.ksi_info, SCARG(uap, info),
+                   sizeof(ksi.ksi_info));
 
        return error;
 }