svn commit: r316070 - stable/10/lib/libkvm

[Ngie Cooper]

Author: ngie
Date: Tue Mar 28 05:57:20 2017
New Revision: 316070
URL: https://svnweb.freebsd.org/changeset/base/316070

Log:
  MFC r315647:
  
  Handle kd == NULL gracefully with kvm_close(3)
  
  Don't segfault in kvm_close(3) if provided a NULL pointer. Instead, return
  -1 and set errno to EINVAL.
  
  Document this new behavior explicitly.

Modified:
  stable/10/lib/libkvm/kvm.c
  stable/10/lib/libkvm/kvm_open.3
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/lib/libkvm/kvm.c
==============================================================================
--- stable/10/lib/libkvm/kvm.c	Tue Mar 28 04:48:55 2017	(r316069)
+++ stable/10/lib/libkvm/kvm.c	Tue Mar 28 05:57:20 2017	(r316070)
@@ -262,6 +262,10 @@ kvm_close(kvm_t *kd)
 {
 	int error = 0;
 
+	if (kd == NULL) {
+		errno = EINVAL;
+		return (-1);
+	}
 	if (kd->pmfd >= 0)
 		error |= close(kd->pmfd);
 	if (kd->vmfd >= 0)

Modified: stable/10/lib/libkvm/kvm_open.3
==============================================================================
--- stable/10/lib/libkvm/kvm_open.3	Tue Mar 28 04:48:55 2017	(r316069)
+++ stable/10/lib/libkvm/kvm_open.3	Tue Mar 28 05:57:20 2017	(r316070)
@@ -32,7 +32,7 @@
 .\"     @(#)kvm_open.3	8.3 (Berkeley) 4/19/94
 .\" $FreeBSD$
 .\"
-.Dd January 29, 2004
+.Dd March 20, 2017
 .Dt KVM_OPEN 3
 .Os
 .Sh NAME
@@ -181,10 +181,29 @@ is returned, in which case
 writes the error message into
 .Fa errbuf .
 .Pp
+.Rv -std kvm_close
+.Sh ERRORS
 The
 .Fn kvm_close
-function returns 0 on success and -1 on failure.
+function may fail and set the global variable
+.Va errno
+for any of the errors specified for
+.Xr close 2 .
+.Pp
+The
+.Fn kvm_close
+function may also fail and set
+.Va errno
+if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value passed via
+.Fa kd
+was
+.Dv NULL .
+.El
 .Sh SEE ALSO
+.Xr close 2 ,
 .Xr open 2 ,
 .Xr kvm 3 ,
 .Xr kvm_getargv 3 ,