diff --git a/libc/Android.bp b/libc/Android.bp
index 4cf31bc..51a7bf0 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -343,10 +343,6 @@
         "upstream-netbsd/lib/libc/stdlib/reallocarr.c",
         "upstream-netbsd/lib/libc/stdlib/seed48.c",
         "upstream-netbsd/lib/libc/stdlib/srand48.c",
-        "upstream-netbsd/lib/libc/string/memccpy.c",
-        "upstream-netbsd/lib/libc/string/strcasestr.c",
-        "upstream-netbsd/lib/libc/string/strcoll.c",
-        "upstream-netbsd/lib/libc/string/strxfrm.c",
     ],
     multilib: {
         lib32: {
@@ -468,7 +464,10 @@
         "upstream-openbsd/lib/libc/stdlib/setenv.c",
         "upstream-openbsd/lib/libc/stdlib/tfind.c",
         "upstream-openbsd/lib/libc/stdlib/tsearch.c",
+        "upstream-openbsd/lib/libc/string/memccpy.c",
         "upstream-openbsd/lib/libc/string/strcasecmp.c",
+        "upstream-openbsd/lib/libc/string/strcasestr.c",
+        "upstream-openbsd/lib/libc/string/strcoll.c",
         "upstream-openbsd/lib/libc/string/strcspn.c",
         "upstream-openbsd/lib/libc/string/strdup.c",
         "upstream-openbsd/lib/libc/string/strndup.c",
@@ -477,6 +476,7 @@
         "upstream-openbsd/lib/libc/string/strspn.c",
         "upstream-openbsd/lib/libc/string/strstr.c",
         "upstream-openbsd/lib/libc/string/strtok.c",
+        "upstream-openbsd/lib/libc/string/strxfrm.c",
         "upstream-openbsd/lib/libc/string/wcslcpy.c",
         "upstream-openbsd/lib/libc/string/wcswidth.c",
     ],
diff --git a/libc/upstream-netbsd/lib/libc/string/memccpy.c b/libc/upstream-openbsd/lib/libc/string/memccpy.c
similarity index 83%
rename from libc/upstream-netbsd/lib/libc/string/memccpy.c
rename to libc/upstream-openbsd/lib/libc/string/memccpy.c
index c086241..635061b 100644
--- a/libc/upstream-netbsd/lib/libc/string/memccpy.c
+++ b/libc/upstream-openbsd/lib/libc/string/memccpy.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: memccpy.c,v 1.13 2012/06/25 22:32:46 abs Exp $	*/
+/*	$OpenBSD: memccpy.c,v 1.7 2015/08/31 02:53:57 guenther Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -29,25 +29,12 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-#if defined(LIBC_SCCS) && !defined(lint)
-#if 0
-static char sccsid[] = "@(#)memccpy.c	8.1 (Berkeley) 6/4/93";
-#else
-__RCSID("$NetBSD: memccpy.c,v 1.13 2012/06/25 22:32:46 abs Exp $");
-#endif
-#endif /* LIBC_SCCS and not lint */
-
-#include <assert.h>
 #include <string.h>
 
 void *
 memccpy(void *t, const void *f, int c, size_t n)
 {
 
-	_DIAGASSERT(t != 0);
-	_DIAGASSERT(f != 0);
-
 	if (n) {
 		unsigned char *tp = t;
 		const unsigned char *fp = f;
@@ -59,3 +46,4 @@
 	}
 	return (0);
 }
+DEF_WEAK(memccpy);
diff --git a/libc/upstream-netbsd/lib/libc/string/strcasestr.c b/libc/upstream-openbsd/lib/libc/string/strcasestr.c
similarity index 83%
rename from libc/upstream-netbsd/lib/libc/string/strcasestr.c
rename to libc/upstream-openbsd/lib/libc/string/strcasestr.c
index f8a9444..abb3e15 100644
--- a/libc/upstream-netbsd/lib/libc/string/strcasestr.c
+++ b/libc/upstream-openbsd/lib/libc/string/strcasestr.c
@@ -1,4 +1,5 @@
-/*	$NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp $	*/
+/*	$OpenBSD: strcasestr.c,v 1.4 2015/08/31 02:53:57 guenther Exp $	*/
+/*	$NetBSD: strcasestr.c,v 1.2 2005/02/09 21:35:47 kleink Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -32,13 +33,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-#if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: strcasestr.c,v 1.3 2005/11/29 03:12:00 christos Exp $");
-#endif /* LIBC_SCCS and not lint */
-
-#include "namespace.h"
-#include <assert.h>
 #include <ctype.h>
 #include <string.h>
 
@@ -51,11 +45,8 @@
 	char c, sc;
 	size_t len;
 
-	_DIAGASSERT(s != NULL);
-	_DIAGASSERT(find != NULL);
-
 	if ((c = *find++) != 0) {
-		c = tolower((unsigned char)c);
+		c = (char)tolower((unsigned char)c);
 		len = strlen(find);
 		do {
 			do {
@@ -65,5 +56,6 @@
 		} while (strncasecmp(s, find, len) != 0);
 		s--;
 	}
-	return __UNCONST(s);
+	return ((char *)s);
 }
+DEF_WEAK(strcasestr);
diff --git a/libc/upstream-netbsd/lib/libc/string/strcoll.c b/libc/upstream-openbsd/lib/libc/string/strcoll.c
similarity index 78%
rename from libc/upstream-netbsd/lib/libc/string/strcoll.c
rename to libc/upstream-openbsd/lib/libc/string/strcoll.c
index 77a0942..47a6ea4 100644
--- a/libc/upstream-netbsd/lib/libc/string/strcoll.c
+++ b/libc/upstream-openbsd/lib/libc/string/strcoll.c
@@ -1,8 +1,7 @@
-/*	$NetBSD: strcoll.c,v 1.10 2012/06/25 22:32:46 abs Exp $	*/
-
+/*	$OpenBSD: strcoll.c,v 1.6 2015/08/31 02:53:57 guenther Exp $ */
 /*-
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Chris Torek.
@@ -32,16 +31,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-#if defined(LIBC_SCCS) && !defined(lint)
-#if 0
-static char sccsid[] = "@(#)strcoll.c	8.1 (Berkeley) 6/4/93";
-#else
-__RCSID("$NetBSD: strcoll.c,v 1.10 2012/06/25 22:32:46 abs Exp $");
-#endif
-#endif /* LIBC_SCCS and not lint */
-
-#include <assert.h>
 #include <string.h>
 
 /*
@@ -50,10 +39,7 @@
 int
 strcoll(const char *s1, const char *s2)
 {
-
-	_DIAGASSERT(s1 != NULL);
-	_DIAGASSERT(s2 != NULL);
-
 	/* LC_COLLATE is unimplemented, hence always "C" */
 	return (strcmp(s1, s2));
 }
+DEF_STRONG(strcoll);
diff --git a/libc/upstream-netbsd/lib/libc/string/strxfrm.c b/libc/upstream-openbsd/lib/libc/string/strxfrm.c
similarity index 73%
rename from libc/upstream-netbsd/lib/libc/string/strxfrm.c
rename to libc/upstream-openbsd/lib/libc/string/strxfrm.c
index 42c2a24..97df097 100644
--- a/libc/upstream-netbsd/lib/libc/string/strxfrm.c
+++ b/libc/upstream-openbsd/lib/libc/string/strxfrm.c
@@ -1,8 +1,7 @@
-/*	$NetBSD: strxfrm.c,v 1.12 2012/06/25 22:32:46 abs Exp $	*/
-
+/*	$OpenBSD: strxfrm.c,v 1.7 2015/08/31 02:53:57 guenther Exp $ */
 /*-
- * Copyright (c) 1990, 1993
- *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1990 The Regents of the University of California.
+ * All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Chris Torek.
@@ -32,16 +31,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-#if defined(LIBC_SCCS) && !defined(lint)
-#if 0
-static char sccsid[] = "@(#)strxfrm.c	8.1 (Berkeley) 6/4/93";
-#else
-__RCSID("$NetBSD: strxfrm.c,v 1.12 2012/06/25 22:32:46 abs Exp $");
-#endif
-#endif /* LIBC_SCCS and not lint */
-
-#include <assert.h>
 #include <string.h>
 
 /*
@@ -52,19 +41,12 @@
 size_t
 strxfrm(char *dst, const char *src, size_t n)
 {
-	size_t srclen, copysize;
-
-	_DIAGASSERT(src != NULL);
 
 	/*
 	 * Since locales are unimplemented, this is just a copy.
 	 */
-	srclen = strlen(src);
-	if (n != 0) {
-		_DIAGASSERT(dst != NULL);
-		copysize = srclen < n ? srclen : n - 1;
-		(void)memcpy(dst, src, copysize);
-		dst[copysize] = 0;
-	}
-	return (srclen);
+	if (n == 0)
+		return (strlen(src));
+	return (strlcpy(dst, src, n));
 }
+DEF_STRONG(strxfrm);
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 428dd25..e759d76 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -91,19 +91,21 @@
 static const char* const kLdConfigVndkLiteFilePath = "/system/etc/ld.config.vndk_lite.txt";
 
 #if defined(__LP64__)
-static const char* const kSystemLibDir     = "/system/lib64";
-static const char* const kOdmLibDir        = "/odm/lib64";
-static const char* const kVendorLibDir     = "/vendor/lib64";
-static const char* const kAsanSystemLibDir = "/data/asan/system/lib64";
-static const char* const kAsanOdmLibDir    = "/data/asan/odm/lib64";
-static const char* const kAsanVendorLibDir = "/data/asan/vendor/lib64";
+static const char* const kSystemLibDir        = "/system/lib64";
+static const char* const kOdmLibDir           = "/odm/lib64";
+static const char* const kVendorLibDir        = "/vendor/lib64";
+static const char* const kAsanSystemLibDir    = "/data/asan/system/lib64";
+static const char* const kAsanOdmLibDir       = "/data/asan/odm/lib64";
+static const char* const kAsanVendorLibDir    = "/data/asan/vendor/lib64";
+static const char* const kRuntimeApexLibDir   = "/apex/com.android.runtime/lib64";
 #else
-static const char* const kSystemLibDir     = "/system/lib";
-static const char* const kOdmLibDir        = "/odm/lib";
-static const char* const kVendorLibDir     = "/vendor/lib";
-static const char* const kAsanSystemLibDir = "/data/asan/system/lib";
-static const char* const kAsanOdmLibDir    = "/data/asan/odm/lib";
-static const char* const kAsanVendorLibDir = "/data/asan/vendor/lib";
+static const char* const kSystemLibDir        = "/system/lib";
+static const char* const kOdmLibDir           = "/odm/lib";
+static const char* const kVendorLibDir        = "/vendor/lib";
+static const char* const kAsanSystemLibDir    = "/data/asan/system/lib";
+static const char* const kAsanOdmLibDir       = "/data/asan/odm/lib";
+static const char* const kAsanVendorLibDir    = "/data/asan/vendor/lib";
+static const char* const kRuntimeApexLibDir   = "/apex/com.android.runtime/lib";
 #endif
 
 static const char* const kAsanLibDirPrefix = "/data/asan";
@@ -228,6 +230,44 @@
 }
 // END OF WORKAROUND
 
+// Workaround for dlopen(/system/lib(64)/<soname>) when .so is in /apex. http://b/121248172
+/**
+ * Translate /system path to /apex path if needed
+ * The workaround should work only when targetSdkVersion < Q.
+ *
+ * param out_name_to_apex pointing to /apex path
+ * return true if translation is needed
+ */
+static bool translateSystemPathToApexPath(const char* name, std::string* out_name_to_apex) {
+  static const char* const kSystemToRuntimeApexLibs[] = {
+    "libicuuc.so",
+    "libicui18n.so",
+  };
+  // New mapping for new apex should be added below
+
+  // Nothing to do if target sdk version is Q or above
+  if (get_application_target_sdk_version() >= __ANDROID_API_Q__) {
+    return false;
+  }
+
+  // If the path is not absolute, or isn't /system/lib, there's nothing to do.
+  if (name[0] != '/' || dirname(name).compare(kSystemLibDir) != 0) {
+    return false;
+  }
+
+  const char* base_name = basename(name);
+
+  for (const char* soname : kSystemToRuntimeApexLibs) {
+    if (strcmp(base_name, soname) == 0) {
+      *out_name_to_apex = std::string(kRuntimeApexLibDir) + "/" + base_name;
+      return true;
+    }
+  }
+
+  return false;
+}
+// End Workaround for dlopen(/system/lib/<soname>) when .so is in /apex.
+
 static std::vector<std::string> g_ld_preload_names;
 
 static bool g_anonymous_namespace_initialized;
@@ -2074,13 +2114,14 @@
   android_namespace_t* ns = get_caller_namespace(caller);
 
   LD_LOG(kLogDlopen,
-         "dlopen(name=\"%s\", flags=0x%x, extinfo=%s, caller=\"%s\", caller_ns=%s@%p) ...",
+         "dlopen(name=\"%s\", flags=0x%x, extinfo=%s, caller=\"%s\", caller_ns=%s@%p, targetSdkVersion=%i) ...",
          name,
          flags,
          android_dlextinfo_to_string(extinfo).c_str(),
          caller == nullptr ? "(null)" : caller->get_realpath(),
          ns == nullptr ? "(null)" : ns->get_name(),
-         ns);
+         ns,
+         get_application_target_sdk_version());
 
   auto purge_guard = android::base::make_scope_guard([&]() { purge_unused_memory(); });
 
@@ -2114,6 +2155,28 @@
     }
   }
 
+  // Workaround for dlopen(/system/lib/<soname>) when .so is in /apex. http://b/121248172
+  // The workaround works only when targetSdkVersion < Q.
+  std::string name_to_apex;
+  if (translateSystemPathToApexPath(name, &name_to_apex)) {
+    const char* new_name = name_to_apex.c_str();
+    LD_LOG(kLogDlopen, "dlopen translating path to /apex: name=%s newName=%s",
+           name,
+           new_name);
+    // Some APEXs could be optionally disabled. Only translate the path
+    // when the old file is absent and the new file exists.
+    if (file_exists(name)) {
+      LD_LOG(kLogDlopen, "dlopen failed to translate path to /apex: /system file exists. %s", name);
+    } else if (!file_exists(new_name)) {
+      LD_LOG(kLogDlopen, "dlopen failed to translate path to /apex: /apex file does not exist. %s",
+             new_name);
+    } else {
+      LD_LOG(kLogDlopen, "dlopen new path to /apex: newName=%s", new_name);
+      name = new_name;
+    }
+  }
+  // End Workaround for dlopen(/system/lib/<soname>) when .so is in /apex.
+
   std::string asan_name_holder;
 
   const char* translated_name = name;
diff --git a/tests/string_test.cpp b/tests/string_test.cpp
index fd2a787..b27ca87 100644
--- a/tests/string_test.cpp
+++ b/tests/string_test.cpp
@@ -1554,3 +1554,40 @@
   ASSERT_EQ(haystack + 1, strstr(haystack, "i"));
   ASSERT_EQ(haystack + 4, strstr(haystack, "da"));
 }
+
+TEST(STRING_TEST, strcasestr_smoke) {
+  const char* haystack = "bIg dAdDy/gIaNt hAyStAcKs";
+  ASSERT_EQ(haystack, strcasestr(haystack, ""));
+  ASSERT_EQ(haystack + 0, strcasestr(haystack, "B"));
+  ASSERT_EQ(haystack + 1, strcasestr(haystack, "i"));
+  ASSERT_EQ(haystack + 4, strcasestr(haystack, "Da"));
+}
+
+TEST(STRING_TEST, strcoll_smoke) {
+  ASSERT_TRUE(strcoll("aab", "aac") < 0);
+  ASSERT_TRUE(strcoll("aab", "aab") == 0);
+  ASSERT_TRUE(strcoll("aac", "aab") > 0);
+}
+
+TEST(STRING_TEST, strxfrm_smoke) {
+  const char* src1 = "aab";
+  char dst1[16] = {};
+  ASSERT_GT(strxfrm(dst1, src1, sizeof(dst1)), 0U);
+  const char* src2 = "aac";
+  char dst2[16] = {};
+  ASSERT_GT(strxfrm(dst2, src2, sizeof(dst2)), 0U);
+  ASSERT_TRUE(strcmp(dst1, dst2) < 0);
+}
+
+TEST(STRING_TEST, memccpy_smoke) {
+  char dst[32];
+
+  memset(dst, 0, sizeof(dst));
+  char* p = static_cast<char*>(memccpy(dst, "hello world", ' ', 32));
+  ASSERT_STREQ("hello ", dst);
+  ASSERT_EQ(ptrdiff_t(6), p - dst);
+
+  memset(dst, 0, sizeof(dst));
+  ASSERT_EQ(nullptr, memccpy(dst, "hello world", ' ', 4));
+  ASSERT_STREQ("hell", dst);
+}