svn commit: r197194 - in stable/8/sys: . amd64/include/xen cddl/contrib/opensolaris contrib/dev/acpica contrib/pf dev/coretemp dev/syscons/daemon dev/xen/xenpci

[John Baldwin]

Author: jhb
Date: Mon Sep 14 16:13:12 2009
New Revision: 197194
URL: http://svn.freebsd.org/changeset/base/197194

Log:
  MFC 197062:
  Don't malloc a buffer while holding the prison0 mutex.  Instead, use a loop
  where we figure out the hostname length under the lock, malloc the buffer
  with the lock dropped, then recheck the length under the lock and loop again
  if the buffer is now too small.
  
  Approved by:	re (kib)

Modified:
  stable/8/sys/   (props changed)
  stable/8/sys/amd64/include/xen/   (props changed)
  stable/8/sys/cddl/contrib/opensolaris/   (props changed)
  stable/8/sys/contrib/dev/acpica/   (props changed)
  stable/8/sys/contrib/pf/   (props changed)
  stable/8/sys/dev/coretemp/coretemp.c   (props changed)
  stable/8/sys/dev/syscons/daemon/daemon_saver.c
  stable/8/sys/dev/xen/xenpci/   (props changed)

Modified: stable/8/sys/dev/syscons/daemon/daemon_saver.c
==============================================================================
--- stable/8/sys/dev/syscons/daemon/daemon_saver.c	Mon Sep 14 15:53:30 2009	(r197193)
+++ stable/8/sys/dev/syscons/daemon/daemon_saver.c	Mon Sep 14 16:13:12 2009	(r197194)
@@ -351,11 +351,23 @@ daemon_saver(video_adapter_t *adp, int b
 static int
 daemon_init(video_adapter_t *adp)
 {
+	size_t hostlen;
 
 	mtx_lock(&prison0.pr_mtx);
-	messagelen = strlen(prison0.pr_hostname) + 3 + strlen(ostype) + 1 + 
-	    strlen(osrelease);
-	message = malloc(messagelen + 1, M_DEVBUF, M_WAITOK);
+	for (;;) {
+		hostlen = strlen(prison0.pr_hostname);
+		mtx_unlock(&prison0.pr_mtx);
+	
+		messagelen = hostlen + 3 + strlen(ostype) + 1 +
+		    strlen(osrelease);
+		message = malloc(messagelen + 1, M_DEVBUF, M_WAITOK);
+		mtx_lock(&prison0.pr_mtx);
+		if (hostlen < strlen(prison0.pr_hostname)) {
+			free(message, M_DEVBUF);
+			continue;
+		}
+		break;
+	}
 	sprintf(message, "%s - %s %s", prison0.pr_hostname, ostype, osrelease);
 	mtx_unlock(&prison0.pr_mtx);
 	blanked = 0;