[src/trunk]: src/lib/libc/stdlib Remember memory used by allocated environmen...

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

details:   https://anonhg.NetBSD.org/src/rev/d3aa5942fa2c
branches:  trunk
changeset: 757832:d3aa5942fa2c
user:      tron <tron%NetBSD.org@localhost>
date:      Sat Sep 25 18:11:40 2010 +0000

description:
Remember memory used by allocated environment variables instead of
using a bitmap. This deals with the case where a variable is first
set via setenv(3) or putenv(3), then overwritten by changing
"environ" directory and afterwards overwritten with setenv(3) again.

This stops "zsh" from crashing under NetBSD-current.

Code reviewed by Christos Zoulas.

diffstat:

 lib/libc/stdlib/getenv.c   |  32 +++++++++++++++-----------------
 lib/libc/stdlib/local.h    |   4 ++--
 lib/libc/stdlib/setenv.c   |  20 ++++++++++----------
 lib/libc/stdlib/unsetenv.c |  30 ++++++++++++++----------------
 4 files changed, 41 insertions(+), 45 deletions(-)

diffs (221 lines):

diff -r 44ae5a1bd041 -r d3aa5942fa2c lib/libc/stdlib/getenv.c
--- a/lib/libc/stdlib/getenv.c  Sat Sep 25 15:30:30 2010 +0000
+++ b/lib/libc/stdlib/getenv.c  Sat Sep 25 18:11:40 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: getenv.c,v 1.20 2010/09/23 17:30:49 christos Exp $     */
+/*     $NetBSD: getenv.c,v 1.21 2010/09/25 18:11:40 tron 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 1.20 2010/09/23 17:30:49 christos Exp $");
+__RCSID("$NetBSD: getenv.c,v 1.21 2010/09/25 18:11:40 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -43,15 +43,14 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
-#include <bitstring.h>
 #include "reentrant.h"
 #include "local.h"
 
 #ifdef _REENTRANT
 rwlock_t __environ_lock = RWLOCK_INITIALIZER;
 #endif
-bitstr_t *__environ_malloced;
-static size_t environ_bitlen;
+char **__environ_malloced;
+static size_t environ_malloced_len;
 
 __weak_alias(getenv_r, _getenv_r)
 
@@ -104,28 +103,27 @@
 int
 __allocenv(int offset)
 {
-       bitstr_t *s;
+       char **p;
        size_t nl;
 
        if (offset == -1) {
                char **ptr;
-               for (ptr = environ, offset = 0; *ptr; ptr++)
+               for (ptr = environ, offset = 0; *ptr != NULL; 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
+
+       if ((size_t)offset < environ_malloced_len)
                return 0;
 
-       if (s == NULL)
+       nl = offset + 2;
+       p = realloc(__environ_malloced, nl * sizeof(char *));
+       if (p == NULL)
                return -1;
 
-       (void)memset(&s[environ_bitlen], 0, nl - environ_bitlen);
-       environ_bitlen = nl;
-       __environ_malloced = s;
+       (void)memset(&p[environ_malloced_len], 0,
+           (nl - environ_malloced_len) * sizeof(char *));
+       environ_malloced_len = nl;
+       __environ_malloced = p;
 
        return 0;
 }
diff -r 44ae5a1bd041 -r d3aa5942fa2c lib/libc/stdlib/local.h
--- a/lib/libc/stdlib/local.h   Sat Sep 25 15:30:30 2010 +0000
+++ b/lib/libc/stdlib/local.h   Sat Sep 25 18:11:40 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: local.h,v 1.3 2010/09/23 17:30:49 christos Exp $       */
+/*     $NetBSD: local.h,v 1.4 2010/09/25 18:11:40 tron Exp $   */
 
 /*
  * Copyright (c) 1997 Christos Zoulas.  All rights reserved.
@@ -32,4 +32,4 @@
 #endif
 
 extern char **environ;
-extern bitstr_t *__environ_malloced;
+extern char **__environ_malloced;
diff -r 44ae5a1bd041 -r d3aa5942fa2c lib/libc/stdlib/setenv.c
--- a/lib/libc/stdlib/setenv.c  Sat Sep 25 15:30:30 2010 +0000
+++ b/lib/libc/stdlib/setenv.c  Sat Sep 25 18:11:40 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: setenv.c,v 1.35 2010/09/24 14:31:15 christos Exp $     */
+/*     $NetBSD: setenv.c,v 1.36 2010/09/25 18:11:40 tron 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 1.35 2010/09/24 14:31:15 christos Exp $");
+__RCSID("$NetBSD: setenv.c,v 1.36 2010/09/25 18:11:40 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -44,7 +44,6 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
-#include <bitstring.h>
 #include "reentrant.h"
 #include "local.h"
 
@@ -56,9 +55,6 @@
 extern rwlock_t __environ_lock;
 #endif
 
-extern char **environ;
-extern bitstr_t *__environ_malloced;
-
 /*
  * setenv --
  *     Set the value of the environmental variable "name" to be
@@ -76,7 +72,9 @@
        _DIAGASSERT(name != NULL);
        _DIAGASSERT(value != NULL);
 
-       rwlock_wrlock(&__environ_lock);
+       if (rwlock_wrlock(&__environ_lock) != 0)
+               return -1;
+
        /* find if already exists */
        c = __findenv(name, &offset);
 
@@ -113,13 +111,15 @@
        /* name + `=' + value */
        if ((c = malloc(size + l_value + 2)) == NULL)
                goto bad;
-       if (bit_test(__environ_malloced, offset))
-               free(environ[offset]);
+
        environ[offset] = c;
        (void)memcpy(c, name, size);
        c += size;
        *c++ = '=';
-       bit_set(__environ_malloced, offset);
+
+       free(__environ_malloced[offset]);
+       __environ_malloced[offset] = c;
+
 copy:
        (void)memcpy(c, value, l_value + 1);
 good:
diff -r 44ae5a1bd041 -r d3aa5942fa2c lib/libc/stdlib/unsetenv.c
--- a/lib/libc/stdlib/unsetenv.c        Sat Sep 25 15:30:30 2010 +0000
+++ b/lib/libc/stdlib/unsetenv.c        Sat Sep 25 18:11:40 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: unsetenv.c,v 1.5 2010/09/24 14:34:44 christos Exp $    */
+/*     $NetBSD: unsetenv.c,v 1.6 2010/09/25 18:11:40 tron 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 1.5 2010/09/24 14:34:44 christos Exp $");
+__RCSID("$NetBSD: unsetenv.c,v 1.6 2010/09/25 18:11:40 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -53,10 +53,8 @@
  *     Delete environmental variable "name".
  */
 int
-unsetenv(name)
-       const char *name;
+unsetenv(const char *name)
 {
-       char **p;
        int offset;
 
        _DIAGASSERT(name != NULL);
@@ -66,22 +64,22 @@
                return -1;
        }
 
-       rwlock_wrlock(&__environ_lock);
+       if (rwlock_wrlock(&__environ_lock) != 0)
+               return -1;
 
        if (__allocenv(-1) == -1)
                return -1;
 
-       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;
+       while (__findenv(name, &offset) != NULL ) { /* if set multiple times */
+               free(__environ_malloced[offset]);
+
+               while (environ[offset] != NULL) {
+                       environ[offset] = environ[offset + 1];
+                       __environ_malloced[offset] =
+                           __environ_malloced[offset + 1];
+                       offset++;
                }
+               __environ_malloced[offset] = NULL;
        }
        rwlock_unlock(&__environ_lock);