[src/trunk]: src/lib/libc Use a bit array to keep track of malloced environme...

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

details:   https://anonhg.NetBSD.org/src/rev/9d9e66dc2ab4
branches:  trunk
changeset: 757796:9d9e66dc2ab4
user:      christos <christos%NetBSD.org@localhost>
date:      Thu Sep 23 17:30:49 2010 +0000

description:
Use a bit array to keep track of malloced environment entries so we can
free them.

diffstat:

 lib/libc/compat/stdlib/compat_unsetenv.c |   7 +++--
 lib/libc/stdlib/getenv.c                 |  39 ++++++++++++++++++++++++++++---
 lib/libc/stdlib/local.h                  |  12 ++++++++-
 lib/libc/stdlib/setenv.c                 |  21 ++++++++++++----
 lib/libc/stdlib/unsetenv.c               |  28 +++++++++++++---------
 5 files changed, 81 insertions(+), 26 deletions(-)

diffs (251 lines):

diff -r 9ab7b9b99c50 -r 9d9e66dc2ab4 lib/libc/compat/stdlib/compat_unsetenv.c
--- a/lib/libc/compat/stdlib/compat_unsetenv.c  Thu Sep 23 16:02:41 2010 +0000
+++ b/lib/libc/compat/stdlib/compat_unsetenv.c  Thu Sep 23 17:30:49 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: compat_unsetenv.c,v 1.1 2005/09/13 01:44:09 christos Exp $     */
+/*     $NetBSD: compat_unsetenv.c,v 1.2 2010/09/23 17:30:49 christos Exp $     */
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "from: @(#)setenv.c     8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: compat_unsetenv.c,v 1.1 2005/09/13 01:44:09 christos Exp $");
+__RCSID("$NetBSD: compat_unsetenv.c,v 1.2 2010/09/23 17:30:49 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -46,8 +46,9 @@
 #include <stdlib.h>
 #include <compat/include/stdlib.h>
 #include <string.h>
+#include <bitstring.h>
+#include "reentrant.h"
 #include "local.h"
-#include "reentrant.h"
 
 #ifdef __weak_alias
 __weak_alias(unsetenv,_unsetenv)
diff -r 9ab7b9b99c50 -r 9d9e66dc2ab4 lib/libc/stdlib/getenv.c
--- a/lib/libc/stdlib/getenv.c  Thu Sep 23 16:02:41 2010 +0000
+++ b/lib/libc/stdlib/getenv.c  Thu Sep 23 17:30:49 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: getenv.c,v 1.19 2008/10/31 17:46:04 christos Exp $     */
+/*     $NetBSD: getenv.c,v 1.20 2010/09/23 17:30:49 christos Exp $     */
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)getenv.c   8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: getenv.c,v 1.19 2008/10/31 17:46:04 christos Exp $");
+__RCSID("$NetBSD: getenv.c,v 1.20 2010/09/23 17:30:49 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -43,13 +43,15 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <bitstring.h>
+#include "reentrant.h"
 #include "local.h"
-#include "reentrant.h"
 
 #ifdef _REENTRANT
 rwlock_t __environ_lock = RWLOCK_INITIALIZER;
 #endif
-extern char **environ;
+bitstr_t *__environ_malloced;
+static size_t environ_bitlen;
 
 __weak_alias(getenv_r, _getenv_r)
 
@@ -99,6 +101,35 @@
        return rv;
 }
 
+int
+__allocenv(int offset)
+{
+       bitstr_t *s;
+       size_t nl;
+
+       if (offset == -1) {
+               char **ptr;
+               for (ptr = environ, offset = 0; *ptr; ptr++)
+                       offset++;
+       }
+       nl = bitstr_size(offset + 2);
+       if (__environ_malloced == NULL) {
+               s = malloc(nl);
+       } else if (environ_bitlen < nl)
+               s = realloc(__environ_malloced, nl);
+       else
+               return 0;
+
+       if (s == NULL)
+               return -1;
+
+       (void)memset(&s[environ_bitlen], 0, nl - environ_bitlen);
+       environ_bitlen = nl;
+       __environ_malloced = s;
+
+       return 0;
+}
+
 /*
  * __findenv --
  *     Returns pointer to value associated with name, if any, else NULL.
diff -r 9ab7b9b99c50 -r 9d9e66dc2ab4 lib/libc/stdlib/local.h
--- a/lib/libc/stdlib/local.h   Thu Sep 23 16:02:41 2010 +0000
+++ b/lib/libc/stdlib/local.h   Thu Sep 23 17:30:49 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: local.h,v 1.2 2009/10/21 01:07:45 snj Exp $    */
+/*     $NetBSD: local.h,v 1.3 2010/09/23 17:30:49 christos Exp $       */
 
 /*
  * Copyright (c) 1997 Christos Zoulas.  All rights reserved.
@@ -24,4 +24,12 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-char *__findenv __P((const char *, int *));
+char *__findenv(const char *, int *);
+int __allocenv(int);
+
+#ifdef _REENTRANT
+extern rwlock_t __environ_lock;
+#endif
+
+extern char **environ;
+extern bitstr_t *__environ_malloced;
diff -r 9ab7b9b99c50 -r 9d9e66dc2ab4 lib/libc/stdlib/setenv.c
--- a/lib/libc/stdlib/setenv.c  Thu Sep 23 16:02:41 2010 +0000
+++ b/lib/libc/stdlib/setenv.c  Thu Sep 23 17:30:49 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: setenv.c,v 1.33 2010/09/23 16:02:41 christos Exp $     */
+/*     $NetBSD: setenv.c,v 1.34 2010/09/23 17:30:49 christos Exp $     */
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)setenv.c   8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: setenv.c,v 1.33 2010/09/23 16:02:41 christos Exp $");
+__RCSID("$NetBSD: setenv.c,v 1.34 2010/09/23 17:30:49 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -44,8 +44,9 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <bitstring.h>
+#include "reentrant.h"
 #include "local.h"
-#include "reentrant.h"
 
 #ifdef __weak_alias
 __weak_alias(setenv,_setenv)
@@ -56,6 +57,7 @@
 #endif
 
 extern char **environ;
+extern bitstr_t *__environ_malloced;
 
 /*
  * setenv --
@@ -74,12 +76,18 @@
        _DIAGASSERT(name != NULL);
        _DIAGASSERT(value != NULL);
 
+       rwlock_wrlock(&__environ_lock);
+       /* find if already exists */
+       c = __findenv(name, &offset);
+
+       if (__allocenv(offset) == -1)
+               return -1;
+
        if (*value == '=')                      /* no `=' in value */
                ++value;
        l_value = strlen(value);
-       rwlock_wrlock(&__environ_lock);
-       /* find if already exists */
-       if ((c = __findenv(name, &offset)) != NULL) {
+
+       if (c != NULL) {
                if (!rewrite)
                        goto good;
                if (strlen(c) > l_value)        /* old larger; copy over */
@@ -109,6 +117,7 @@
        (void)memcpy(c, name, size);
        c += size;
        *c++ = '=';
+       bit_set(__environ_malloced, offset);
 copy:
        (void)memcpy(c, value, l_value + 1);
 good:
diff -r 9ab7b9b99c50 -r 9d9e66dc2ab4 lib/libc/stdlib/unsetenv.c
--- a/lib/libc/stdlib/unsetenv.c        Thu Sep 23 16:02:41 2010 +0000
+++ b/lib/libc/stdlib/unsetenv.c        Thu Sep 23 17:30:49 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: unsetenv.c,v 1.3 2005/09/13 01:44:10 christos Exp $    */
+/*     $NetBSD: unsetenv.c,v 1.4 2010/09/23 17:30:49 christos Exp $    */
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "from: @(#)setenv.c     8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: unsetenv.c,v 1.3 2005/09/13 01:44:10 christos Exp $");
+__RCSID("$NetBSD: unsetenv.c,v 1.4 2010/09/23 17:30:49 christos Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -44,14 +44,9 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
-#include "local.h"
+#include <bitstring.h>
 #include "reentrant.h"
-
-#ifdef _REENTRANT
-extern rwlock_t __environ_lock;
-#endif
-
-extern char **environ;
+#include "local.h"
 
 /*
  * unsetenv(name) --
@@ -71,11 +66,22 @@
                return -1;
        }
 
+       if (__allocenv(-1) == -1)
+               return -1;
+
        rwlock_wrlock(&__environ_lock);
-       while (__findenv(name, &offset))        /* if set multiple times */
-               for (p = &environ[offset];; ++p)
+       while (__findenv(name, &offset)) {      /* if set multiple times */
+               if (bit_test(__environ_malloced, offset))
+                       free(environ[offset]);
+               for (p = &environ[offset];; ++p, ++offset) {
+                       if (bit_test(__environ_malloced, offset + 1))
+                               bit_set(__environ_malloced, offset);
+                       else
+                               bit_clear(__environ_malloced, offset);
                        if (!(*p = *(p + 1)))
                                break;
+               }
+       }
        rwlock_unlock(&__environ_lock);
 
        return 0;