diff --git a/linker/linker_environ.c b/linker/linker_environ.c
new file mode 100644
index 0000000..6c5b571
--- /dev/null
+++ b/linker/linker_environ.c
@@ -0,0 +1,204 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+#include "linker_environ.h"
+#include <stddef.h>
+
+static char** _envp;
+
+/* Returns 1 if 'str' points to a valid environment variable definition.
+ * For now, we check that:
+ *  - It is smaller than MAX_ENV_LEN (to detect non-zero terminated strings)
+ *  - It contains at least one equal sign that is not the first character
+ */
+static int
+_is_valid_definition(const char*  str)
+{
+    int   pos = 0;
+    int   first_equal_pos = -1;
+
+    /* According to its sources, the kernel uses 32*PAGE_SIZE by default
+     * as the maximum size for an env. variable definition.
+     */
+    const int MAX_ENV_LEN = 32*4096;
+
+    if (str == NULL)
+        return 0;
+
+    /* Parse the string, looking for the first '=' there, and its size */
+    do {
+        if (str[pos] == '\0')
+            break;
+        if (str[pos] == '=' && first_equal_pos < 0)
+            first_equal_pos = pos;
+        pos++;
+    } while (pos < MAX_ENV_LEN);
+
+    if (pos >= MAX_ENV_LEN)  /* Too large */
+        return 0;
+
+    if (first_equal_pos < 1)  /* No equal sign, or it is the first character */
+        return 0;
+
+    return 1;
+}
+
+unsigned*
+linker_env_init(unsigned* vecs)
+{
+    /* Store environment pointer - can't be NULL */
+    _envp = (char**) vecs;
+
+    /* Skip over all definitions */
+    while (vecs[0] != 0)
+        vecs++;
+    /* The end of the environment block is marked by two NULL pointers */
+    vecs++;
+
+    /* As a sanity check, we're going to remove all invalid variable
+     * definitions from the environment array.
+     */
+    {
+        char** readp  = _envp;
+        char** writep = _envp;
+        for ( ; readp[0] != NULL; readp++ ) {
+            if (!_is_valid_definition(readp[0]))
+                continue;
+            writep[0] = readp[0];
+            writep++;
+        }
+        writep[0] = NULL;
+    }
+
+    /* Return the address of the aux vectors table */
+    return vecs;
+}
+
+/* Check if the environment variable definition at 'envstr'
+ * starts with '<name>=', and if so return the address of the
+ * first character after the equal sign. Otherwise return NULL.
+ */
+static char*
+env_match(char* envstr, const char* name)
+{
+    size_t  cnt = 0;
+
+    while (envstr[cnt] == name[cnt] && name[cnt] != '\0')
+        cnt++;
+
+    if (name[cnt] != '\0' && envstr[cnt] == '=')
+        return envstr + cnt + 1;
+
+    return NULL;
+}
+
+#define MAX_ENV_LEN  (16*4096)
+
+const char*
+linker_env_get(const char* name)
+{
+    char** readp = _envp;
+
+    if (name == NULL || name[0] == '\0')
+        return NULL;
+
+    for ( ; readp[0] != NULL; readp++ ) {
+        char* val = env_match(readp[0], name);
+        if (val != NULL) {
+            /* Return NULL for empty strings, or if it is too large */
+            if (val[0] == '\0')
+                val = NULL;
+            return val;
+        }
+    }
+    return NULL;
+}
+
+
+void
+linker_env_unset(const char* name)
+{
+    char**  readp = _envp;
+    char**  writep = readp;
+
+    if (name == NULL || name[0] == '\0')
+        return;
+
+    for ( ; readp[0] != NULL; readp++ ) {
+        if (env_match(readp[0], name))
+            continue;
+        writep[0] = readp[0];
+        writep++;
+    }
+    /* end list with a NULL */
+    writep[0] = NULL;
+}
+
+
+
+/* Remove unsafe environment variables. This should be used when
+ * running setuid programs. */
+void
+linker_env_secure(void)
+{
+    /* The same list than GLibc at this point */
+    static const char* const unsec_vars[] = {
+        "GCONV_PATH",
+        "GETCONF_DIR",
+        "HOSTALIASES",
+        "LD_AUDIT",
+        "LD_DEBUG",
+        "LD_DEBUG_OUTPUT",
+        "LD_DYNAMIC_WEAK",
+        "LD_LIBRARY_PATH",
+        "LD_ORIGIN_PATH",
+        "LD_PRELOAD",
+        "LD_PROFILE",
+        "LD_SHOW_AUXV",
+        "LD_USE_LOAD_BIAS",
+        "LOCALDOMAIN",
+        "LOCPATH",
+        "MALLOC_TRACE",
+        "MALLOC_CHECK_",
+        "NIS_PATH",
+        "NLSPATH",
+        "RESOLV_HOST_CONF",
+        "RES_OPTIONS",
+        "TMPDIR",
+        "TZDIR",
+        "LD_AOUT_LIBRARY_PATH",
+        "LD_AOUT_PRELOAD",
+    };
+
+    const char* const* cp   = unsec_vars;
+    const char* const* endp = cp + sizeof(unsec_vars)/sizeof(unsec_vars[0]);
+
+    while (cp < endp) {
+        linker_env_unset(*cp);
+        cp++;
+    }
+}