[src/trunk]: src/lib/libc/gen add more locking (when we read and write fields)

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

details:   https://anonhg.NetBSD.org/src/rev/d8f6ea09e76c
branches:  trunk
changeset: 781981:d8f6ea09e76c
user:      christos <christos%NetBSD.org@localhost>
date:      Wed Oct 10 23:53:43 2012 +0000

description:
add more locking (when we read and write fields)

diffstat:

 lib/libc/gen/syslog.c |  20 +++++++++++++++-----
 1 files changed, 15 insertions(+), 5 deletions(-)

diffs (52 lines):

diff -r 9153b7590043 -r d8f6ea09e76c lib/libc/gen/syslog.c
--- a/lib/libc/gen/syslog.c     Wed Oct 10 22:52:26 2012 +0000
+++ b/lib/libc/gen/syslog.c     Wed Oct 10 23:53:43 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: syslog.c,v 1.51 2012/10/10 22:50:51 christos Exp $     */
+/*     $NetBSD: syslog.c,v 1.52 2012/10/10 23:53:43 christos Exp $     */
 
 /*
  * Copyright (c) 1983, 1988, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)syslog.c   8.5 (Berkeley) 4/29/95";
 #else
-__RCSID("$NetBSD: syslog.c,v 1.51 2012/10/10 22:50:51 christos Exp $");
+__RCSID("$NetBSD: syslog.c,v 1.52 2012/10/10 23:53:43 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -289,13 +289,19 @@
                }
        } else {
                prlen = snprintf_ss(p, tbuf_left, "-");
-
-               /* if gmtime_r() was signal-safe we could output the UTC-time:
+#if 0
+               /*
+                * if gmtime_r() was signal-safe we could output
+                * the UTC-time:
+                */
                gmtime_r(&now, &tmnow);
                prlen = strftime(p, tbuf_left, "%FT%TZ", &tmnow);
-               */
+#endif
        }
 
+       if (data == &sdata)
+               mutex_lock(&syslog_mutex);
+
        if (data->log_hostname[0] == '\0' && gethostname(data->log_hostname,
            sizeof(data->log_hostname)) == -1) {
                /* can this really happen? */
@@ -312,6 +318,10 @@
        DEC();
        prlen = snprintf_ss(p, tbuf_left, "%s ",
            data->log_tag ? data->log_tag : "-");
+
+       if (data == &sdata)
+               mutex_unlock(&syslog_mutex);
+
        if (data->log_stat & (LOG_PERROR|LOG_CONS)) {
                iovcnt = 0;
                iov[iovcnt].iov_base = p;