diff --git a/libc/Android.bp b/libc/Android.bp
index cbca35f..de0ac0d 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1286,6 +1286,7 @@
         "bionic/getpid.cpp",
         "bionic/gettid.cpp",
         "bionic/__gnu_basename.cpp",
+        "bionic/grp_pwd.cpp",
         "bionic/ifaddrs.cpp",
         "bionic/inotify_init.cpp",
         "bionic/ioctl.cpp",
diff --git a/libc/Android.mk b/libc/Android.mk
index 0e4dc11..49a8bdb 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -115,6 +115,7 @@
     bionic/getpid.cpp \
     bionic/gettid.cpp \
     bionic/__gnu_basename.cpp \
+    bionic/grp_pwd.cpp \
     bionic/ifaddrs.cpp \
     bionic/inotify_init.cpp \
     bionic/ioctl.cpp \
diff --git a/libc/bionic/grp_pwd.cpp b/libc/bionic/grp_pwd.cpp
new file mode 100644
index 0000000..1cabab4
--- /dev/null
+++ b/libc/bionic/grp_pwd.cpp
@@ -0,0 +1,532 @@
+/*
+ * Copyright (C) 2008 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 <ctype.h>
+#include <errno.h>
+#include <grp.h>
+#include <mntent.h>
+#include <pthread.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "private/android_filesystem_config.h"
+#include "private/bionic_macros.h"
+#include "private/ErrnoRestorer.h"
+#include "private/libc_logging.h"
+#include "private/ThreadLocalBuffer.h"
+
+// POSIX seems to envisage an implementation where the <pwd.h> functions are
+// implemented by brute-force searching with getpwent(3), and the <grp.h>
+// functions are implemented similarly with getgrent(3). This means that it's
+// okay for all the <grp.h> functions to share state, and all the <passwd.h>
+// functions to share state, but <grp.h> functions can't clobber <passwd.h>
+// functions' state and vice versa.
+
+struct group_state_t {
+  group group_;
+  char* group_members_[2];
+  char group_name_buffer_[32];
+};
+
+struct passwd_state_t {
+  passwd passwd_;
+  char name_buffer_[32];
+  char dir_buffer_[32];
+  char sh_buffer_[32];
+};
+
+static ThreadLocalBuffer<group_state_t> g_group_tls_buffer;
+static ThreadLocalBuffer<passwd_state_t> g_passwd_tls_buffer;
+
+static void init_group_state(group_state_t* state) {
+  memset(state, 0, sizeof(group_state_t));
+  state->group_.gr_mem = state->group_members_;
+}
+
+static group_state_t* __group_state() {
+  group_state_t* result = g_group_tls_buffer.get();
+  if (result != nullptr) {
+    init_group_state(result);
+  }
+  return result;
+}
+
+static int do_getpw_r(int by_name, const char* name, uid_t uid,
+                      passwd* dst, char* buf, size_t byte_count,
+                      passwd** result) {
+  // getpwnam_r and getpwuid_r don't modify errno, but library calls we
+  // make might.
+  ErrnoRestorer errno_restorer;
+  *result = NULL;
+
+  // Our implementation of getpwnam(3) and getpwuid(3) use thread-local
+  // storage, so we can call them as long as we copy everything out
+  // before returning.
+  const passwd* src = by_name ? getpwnam(name) : getpwuid(uid); // NOLINT: see above.
+
+  // POSIX allows failure to find a match to be considered a non-error.
+  // Reporting success (0) but with *result NULL is glibc's behavior.
+  if (src == NULL) {
+    return (errno == ENOENT) ? 0 : errno;
+  }
+
+  // Work out where our strings will go in 'buf', and whether we've got
+  // enough space.
+  size_t required_byte_count = 0;
+  dst->pw_name = buf;
+  required_byte_count += strlen(src->pw_name) + 1;
+  dst->pw_dir = buf + required_byte_count;
+  required_byte_count += strlen(src->pw_dir) + 1;
+  dst->pw_shell = buf + required_byte_count;
+  required_byte_count += strlen(src->pw_shell) + 1;
+  if (byte_count < required_byte_count) {
+    return ERANGE;
+  }
+
+  // Copy the strings.
+  snprintf(buf, byte_count, "%s%c%s%c%s", src->pw_name, 0, src->pw_dir, 0, src->pw_shell);
+
+  // pw_passwd and pw_gecos are non-POSIX and unused (always NULL) in bionic.
+  // Note: On LP32, we define pw_gecos to pw_passwd since they're both NULL.
+  dst->pw_passwd = NULL;
+#if defined(__LP64__)
+  dst->pw_gecos = NULL;
+#endif
+
+  // Copy the integral fields.
+  dst->pw_gid = src->pw_gid;
+  dst->pw_uid = src->pw_uid;
+
+  *result = dst;
+  return 0;
+}
+
+int getpwnam_r(const char* name, passwd* pwd,
+               char* buf, size_t byte_count, passwd** result) {
+  return do_getpw_r(1, name, -1, pwd, buf, byte_count, result);
+}
+
+int getpwuid_r(uid_t uid, passwd* pwd,
+               char* buf, size_t byte_count, passwd** result) {
+  return do_getpw_r(0, NULL, uid, pwd, buf, byte_count, result);
+}
+
+static passwd* android_iinfo_to_passwd(passwd_state_t* state,
+                                       const android_id_info* iinfo) {
+  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "%s", iinfo->name);
+  snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
+  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
+
+  passwd* pw = &state->passwd_;
+  pw->pw_name  = state->name_buffer_;
+  pw->pw_uid   = iinfo->aid;
+  pw->pw_gid   = iinfo->aid;
+  pw->pw_dir   = state->dir_buffer_;
+  pw->pw_shell = state->sh_buffer_;
+  return pw;
+}
+
+static group* android_iinfo_to_group(group_state_t* state,
+                                     const android_id_info* iinfo) {
+  snprintf(state->group_name_buffer_, sizeof(state->group_name_buffer_), "%s", iinfo->name);
+
+  group* gr = &state->group_;
+  gr->gr_name   = state->group_name_buffer_;
+  gr->gr_gid    = iinfo->aid;
+  gr->gr_mem[0] = gr->gr_name;
+  return gr;
+}
+
+static passwd* android_id_to_passwd(passwd_state_t* state, unsigned id) {
+  for (size_t n = 0; n < android_id_count; ++n) {
+    if (android_ids[n].aid == id) {
+      return android_iinfo_to_passwd(state, android_ids + n);
+    }
+  }
+  return NULL;
+}
+
+static passwd* android_name_to_passwd(passwd_state_t* state, const char* name) {
+  for (size_t n = 0; n < android_id_count; ++n) {
+    if (!strcmp(android_ids[n].name, name)) {
+      return android_iinfo_to_passwd(state, android_ids + n);
+    }
+  }
+  return NULL;
+}
+
+static group* android_id_to_group(group_state_t* state, unsigned id) {
+  for (size_t n = 0; n < android_id_count; ++n) {
+    if (android_ids[n].aid == id) {
+      return android_iinfo_to_group(state, android_ids + n);
+    }
+  }
+  return NULL;
+}
+
+static group* android_name_to_group(group_state_t* state, const char* name) {
+  for (size_t n = 0; n < android_id_count; ++n) {
+    if (!strcmp(android_ids[n].name, name)) {
+      return android_iinfo_to_group(state, android_ids + n);
+    }
+  }
+  return NULL;
+}
+
+// Translate a user/group name to the corresponding user/group id.
+// all_a1234 -> 0 * AID_USER + AID_SHARED_GID_START + 1234 (group name only)
+// u0_a1234 -> 0 * AID_USER + AID_APP + 1234
+// u2_i1000 -> 2 * AID_USER + AID_ISOLATED_START + 1000
+// u1_system -> 1 * AID_USER + android_ids['system']
+// returns 0 and sets errno to ENOENT in case of error.
+static id_t app_id_from_name(const char* name, bool is_group) {
+  char* end;
+  unsigned long userid;
+  bool is_shared_gid = false;
+
+  if (is_group && name[0] == 'a' && name[1] == 'l' && name[2] == 'l') {
+    end = const_cast<char*>(name+3);
+    userid = 0;
+    is_shared_gid = true;
+  } else if (name[0] == 'u' && isdigit(name[1])) {
+    userid = strtoul(name+1, &end, 10);
+  } else {
+    errno = ENOENT;
+    return 0;
+  }
+
+  if (end[0] != '_' || end[1] == 0) {
+    errno = ENOENT;
+    return 0;
+  }
+
+  unsigned long appid = 0;
+  if (end[1] == 'a' && isdigit(end[2])) {
+    if (is_shared_gid) {
+      // end will point to \0 if the strtoul below succeeds.
+      appid = strtoul(end+2, &end, 10) + AID_SHARED_GID_START;
+      if (appid > AID_SHARED_GID_END) {
+        errno = ENOENT;
+        return 0;
+      }
+    } else {
+      // end will point to \0 if the strtoul below succeeds.
+      appid = strtoul(end+2, &end, 10) + AID_APP;
+    }
+  } else if (end[1] == 'i' && isdigit(end[2])) {
+    // end will point to \0 if the strtoul below succeeds.
+    appid = strtoul(end+2, &end, 10) + AID_ISOLATED_START;
+  } else {
+    for (size_t n = 0; n < android_id_count; n++) {
+      if (!strcmp(android_ids[n].name, end + 1)) {
+        appid = android_ids[n].aid;
+        // Move the end pointer to the null terminator.
+        end += strlen(android_ids[n].name) + 1;
+        break;
+      }
+    }
+  }
+
+  // Check that the entire string was consumed by one of the 3 cases above.
+  if (end[0] != 0) {
+    errno = ENOENT;
+    return 0;
+  }
+
+  // Check that user id won't overflow.
+  if (userid > 1000) {
+    errno = ENOENT;
+    return 0;
+  }
+
+  // Check that app id is within range.
+  if (appid >= AID_USER) {
+    errno = ENOENT;
+    return 0;
+  }
+
+  return (appid + userid*AID_USER);
+}
+
+static void print_app_name_from_uid(const uid_t uid, char* buffer, const int bufferlen) {
+  const uid_t appid = uid % AID_USER;
+  const uid_t userid = uid / AID_USER;
+  if (appid >= AID_ISOLATED_START) {
+    snprintf(buffer, bufferlen, "u%u_i%u", userid, appid - AID_ISOLATED_START);
+  } else if (appid < AID_APP) {
+    for (size_t n = 0; n < android_id_count; n++) {
+      if (android_ids[n].aid == appid) {
+        snprintf(buffer, bufferlen, "u%u_%s", userid, android_ids[n].name);
+        return;
+      }
+    }
+  } else {
+    snprintf(buffer, bufferlen, "u%u_a%u", userid, appid - AID_APP);
+  }
+}
+
+static void print_app_name_from_gid(const gid_t gid, char* buffer, const int bufferlen) {
+  const uid_t appid = gid % AID_USER;
+  const uid_t userid = gid / AID_USER;
+  if (appid >= AID_ISOLATED_START) {
+    snprintf(buffer, bufferlen, "u%u_i%u", userid, appid - AID_ISOLATED_START);
+  } else if (userid == 0 && appid >= AID_SHARED_GID_START && appid <= AID_SHARED_GID_END) {
+    snprintf(buffer, bufferlen, "all_a%u", appid - AID_SHARED_GID_START);
+  } else if (appid < AID_APP) {
+    for (size_t n = 0; n < android_id_count; n++) {
+      if (android_ids[n].aid == appid) {
+        snprintf(buffer, bufferlen, "u%u_%s", userid, android_ids[n].name);
+        return;
+      }
+    }
+  } else {
+    snprintf(buffer, bufferlen, "u%u_a%u", userid, appid - AID_APP);
+  }
+}
+
+// Translate an OEM name to the corresponding user/group id.
+// oem_XXX -> AID_OEM_RESERVED_2_START + XXX, iff XXX is within range.
+static id_t oem_id_from_name(const char* name) {
+  unsigned int id;
+  if (sscanf(name, "oem_%u", &id) != 1) {
+    return 0;
+  }
+  // Check OEM id is within range.
+  if (id > (AID_OEM_RESERVED_2_END - AID_OEM_RESERVED_2_START)) {
+    return 0;
+  }
+  return AID_OEM_RESERVED_2_START + static_cast<id_t>(id);
+}
+
+static passwd* oem_id_to_passwd(uid_t uid, passwd_state_t* state) {
+  if (uid < AID_OEM_RESERVED_2_START || uid > AID_OEM_RESERVED_2_END) {
+    return NULL;
+  }
+
+  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "oem_%u",
+           uid - AID_OEM_RESERVED_2_START);
+  snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
+  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
+
+  passwd* pw = &state->passwd_;
+  pw->pw_name  = state->name_buffer_;
+  pw->pw_dir   = state->dir_buffer_;
+  pw->pw_shell = state->sh_buffer_;
+  pw->pw_uid   = uid;
+  pw->pw_gid   = uid;
+  return pw;
+}
+
+static group* oem_id_to_group(gid_t gid, group_state_t* state) {
+  if (gid < AID_OEM_RESERVED_2_START || gid > AID_OEM_RESERVED_2_END) {
+    return NULL;
+  }
+
+  snprintf(state->group_name_buffer_, sizeof(state->group_name_buffer_),
+           "oem_%u", gid - AID_OEM_RESERVED_2_START);
+
+  group* gr = &state->group_;
+  gr->gr_name   = state->group_name_buffer_;
+  gr->gr_gid    = gid;
+  gr->gr_mem[0] = gr->gr_name;
+  return gr;
+}
+
+// Translate a uid into the corresponding name.
+// 0 to AID_APP-1                   -> "system", "radio", etc.
+// AID_APP to AID_ISOLATED_START-1  -> u0_a1234
+// AID_ISOLATED_START to AID_USER-1 -> u0_i1234
+// AID_USER+                        -> u1_radio, u1_a1234, u2_i1234, etc.
+// returns a passwd structure (sets errno to ENOENT on failure).
+static passwd* app_id_to_passwd(uid_t uid, passwd_state_t* state) {
+  if (uid < AID_APP) {
+    errno = ENOENT;
+    return NULL;
+  }
+
+  print_app_name_from_uid(uid, state->name_buffer_, sizeof(state->name_buffer_));
+
+  const uid_t appid = uid % AID_USER;
+  if (appid < AID_APP) {
+      snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
+  } else {
+      snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/data");
+  }
+
+  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
+
+  passwd* pw = &state->passwd_;
+  pw->pw_name  = state->name_buffer_;
+  pw->pw_dir   = state->dir_buffer_;
+  pw->pw_shell = state->sh_buffer_;
+  pw->pw_uid   = uid;
+  pw->pw_gid   = uid;
+  return pw;
+}
+
+// Translate a gid into the corresponding app_<gid>
+// group structure (sets errno to ENOENT on failure).
+static group* app_id_to_group(gid_t gid, group_state_t* state) {
+  if (gid < AID_APP) {
+    errno = ENOENT;
+    return NULL;
+  }
+
+  print_app_name_from_gid(gid, state->group_name_buffer_, sizeof(state->group_name_buffer_));
+
+  group* gr = &state->group_;
+  gr->gr_name   = state->group_name_buffer_;
+  gr->gr_gid    = gid;
+  gr->gr_mem[0] = gr->gr_name;
+  return gr;
+}
+
+passwd* getpwuid(uid_t uid) { // NOLINT: implementing bad function.
+  passwd_state_t* state = g_passwd_tls_buffer.get();
+  if (state == NULL) {
+    return NULL;
+  }
+
+  passwd* pw = android_id_to_passwd(state, uid);
+  if (pw != NULL) {
+    return pw;
+  }
+  // Handle OEM range.
+  pw = oem_id_to_passwd(uid, state);
+  if (pw != NULL) {
+    return pw;
+  }
+  return app_id_to_passwd(uid, state);
+}
+
+passwd* getpwnam(const char* login) { // NOLINT: implementing bad function.
+  passwd_state_t* state = g_passwd_tls_buffer.get();
+  if (state == NULL) {
+    return NULL;
+  }
+
+  passwd* pw = android_name_to_passwd(state, login);
+  if (pw != NULL) {
+    return pw;
+  }
+  // Handle OEM range.
+  pw = oem_id_to_passwd(oem_id_from_name(login), state);
+  if (pw != NULL) {
+    return pw;
+  }
+  return app_id_to_passwd(app_id_from_name(login, false), state);
+}
+
+// All users are in just one group, the one passed in.
+int getgrouplist(const char* /*user*/, gid_t group, gid_t* groups, int* ngroups) {
+  if (*ngroups < 1) {
+    *ngroups = 1;
+    return -1;
+  }
+  groups[0] = group;
+  return (*ngroups = 1);
+}
+
+char* getlogin() { // NOLINT: implementing bad function.
+  passwd *pw = getpwuid(getuid()); // NOLINT: implementing bad function in terms of bad function.
+  return (pw != NULL) ? pw->pw_name : NULL;
+}
+
+static group* getgrgid_internal(gid_t gid, group_state_t* state) {
+  group* grp = android_id_to_group(state, gid);
+  if (grp != NULL) {
+    return grp;
+  }
+  // Handle OEM range.
+  grp = oem_id_to_group(gid, state);
+  if (grp != NULL) {
+    return grp;
+  }
+  return app_id_to_group(gid, state);
+}
+
+group* getgrgid(gid_t gid) { // NOLINT: implementing bad function.
+  group_state_t* state = __group_state();
+  if (state == NULL) {
+    return NULL;
+  }
+  return getgrgid_internal(gid, state);
+}
+
+static group* getgrnam_internal(const char* name, group_state_t* state) {
+  group* grp = android_name_to_group(state, name);
+  if (grp != NULL) {
+    return grp;
+  }
+  // Handle OEM range.
+  grp = oem_id_to_group(oem_id_from_name(name), state);
+  if (grp != NULL) {
+    return grp;
+  }
+  return app_id_to_group(app_id_from_name(name, true), state);
+}
+
+group* getgrnam(const char* name) { // NOLINT: implementing bad function.
+  group_state_t* state = __group_state();
+  if (state == NULL) {
+    return NULL;
+  }
+  return getgrnam_internal(name, state);
+}
+
+static int getgroup_r(bool by_name, const char* name, gid_t gid, struct group* grp, char* buf,
+                      size_t buflen, struct group** result) {
+  ErrnoRestorer errno_restorer;
+  *result = NULL;
+  char* p = reinterpret_cast<char*>(
+      BIONIC_ALIGN(reinterpret_cast<uintptr_t>(buf), sizeof(uintptr_t)));
+  if (p + sizeof(group_state_t) > buf + buflen) {
+    return ERANGE;
+  }
+  group_state_t* state = reinterpret_cast<group_state_t*>(p);
+  init_group_state(state);
+  group* retval = (by_name ? getgrnam_internal(name, state) : getgrgid_internal(gid, state));
+  if (retval != NULL) {
+    *grp = *retval;
+    *result = grp;
+    return 0;
+  }
+  return errno;
+}
+
+int getgrgid_r(gid_t gid, struct group* grp, char* buf, size_t buflen, struct group** result) {
+  return getgroup_r(false, NULL, gid, grp, buf, buflen, result);
+}
+
+int getgrnam_r(const char* name, struct group* grp, char* buf, size_t buflen,
+               struct group **result) {
+  return getgroup_r(true, name, 0, grp, buf, buflen, result);
+}
diff --git a/libc/bionic/stubs.cpp b/libc/bionic/stubs.cpp
index 374d015..4e65756 100644
--- a/libc/bionic/stubs.cpp
+++ b/libc/bionic/stubs.cpp
@@ -26,512 +26,9 @@
  * SUCH DAMAGE.
  */
 
-#include <ctype.h>
-#include <errno.h>
-#include <grp.h>
-#include <mntent.h>
 #include <netdb.h>
-#include <pthread.h>
-#include <pwd.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 
-#include "private/android_filesystem_config.h"
-#include "private/bionic_macros.h"
-#include "private/ErrnoRestorer.h"
-#include "private/libc_logging.h"
-#include "private/ThreadLocalBuffer.h"
-
-// POSIX seems to envisage an implementation where the <pwd.h> functions are
-// implemented by brute-force searching with getpwent(3), and the <grp.h>
-// functions are implemented similarly with getgrent(3). This means that it's
-// okay for all the <grp.h> functions to share state, and all the <passwd.h>
-// functions to share state, but <grp.h> functions can't clobber <passwd.h>
-// functions' state and vice versa.
-
-struct group_state_t {
-  group group_;
-  char* group_members_[2];
-  char group_name_buffer_[32];
-};
-
-struct passwd_state_t {
-  passwd passwd_;
-  char name_buffer_[32];
-  char dir_buffer_[32];
-  char sh_buffer_[32];
-};
-
-static ThreadLocalBuffer<group_state_t> g_group_tls_buffer;
-static ThreadLocalBuffer<passwd_state_t> g_passwd_tls_buffer;
-
-static void init_group_state(group_state_t* state) {
-  memset(state, 0, sizeof(group_state_t));
-  state->group_.gr_mem = state->group_members_;
-}
-
-static group_state_t* __group_state() {
-  group_state_t* result = g_group_tls_buffer.get();
-  if (result != nullptr) {
-    init_group_state(result);
-  }
-  return result;
-}
-
-static int do_getpw_r(int by_name, const char* name, uid_t uid,
-                      passwd* dst, char* buf, size_t byte_count,
-                      passwd** result) {
-  // getpwnam_r and getpwuid_r don't modify errno, but library calls we
-  // make might.
-  ErrnoRestorer errno_restorer;
-  *result = NULL;
-
-  // Our implementation of getpwnam(3) and getpwuid(3) use thread-local
-  // storage, so we can call them as long as we copy everything out
-  // before returning.
-  const passwd* src = by_name ? getpwnam(name) : getpwuid(uid); // NOLINT: see above.
-
-  // POSIX allows failure to find a match to be considered a non-error.
-  // Reporting success (0) but with *result NULL is glibc's behavior.
-  if (src == NULL) {
-    return (errno == ENOENT) ? 0 : errno;
-  }
-
-  // Work out where our strings will go in 'buf', and whether we've got
-  // enough space.
-  size_t required_byte_count = 0;
-  dst->pw_name = buf;
-  required_byte_count += strlen(src->pw_name) + 1;
-  dst->pw_dir = buf + required_byte_count;
-  required_byte_count += strlen(src->pw_dir) + 1;
-  dst->pw_shell = buf + required_byte_count;
-  required_byte_count += strlen(src->pw_shell) + 1;
-  if (byte_count < required_byte_count) {
-    return ERANGE;
-  }
-
-  // Copy the strings.
-  snprintf(buf, byte_count, "%s%c%s%c%s", src->pw_name, 0, src->pw_dir, 0, src->pw_shell);
-
-  // pw_passwd and pw_gecos are non-POSIX and unused (always NULL) in bionic.
-  // Note: On LP32, we define pw_gecos to pw_passwd since they're both NULL.
-  dst->pw_passwd = NULL;
-#if defined(__LP64__)
-  dst->pw_gecos = NULL;
-#endif
-
-  // Copy the integral fields.
-  dst->pw_gid = src->pw_gid;
-  dst->pw_uid = src->pw_uid;
-
-  *result = dst;
-  return 0;
-}
-
-int getpwnam_r(const char* name, passwd* pwd,
-               char* buf, size_t byte_count, passwd** result) {
-  return do_getpw_r(1, name, -1, pwd, buf, byte_count, result);
-}
-
-int getpwuid_r(uid_t uid, passwd* pwd,
-               char* buf, size_t byte_count, passwd** result) {
-  return do_getpw_r(0, NULL, uid, pwd, buf, byte_count, result);
-}
-
-static passwd* android_iinfo_to_passwd(passwd_state_t* state,
-                                       const android_id_info* iinfo) {
-  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "%s", iinfo->name);
-  snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
-  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
-
-  passwd* pw = &state->passwd_;
-  pw->pw_name  = state->name_buffer_;
-  pw->pw_uid   = iinfo->aid;
-  pw->pw_gid   = iinfo->aid;
-  pw->pw_dir   = state->dir_buffer_;
-  pw->pw_shell = state->sh_buffer_;
-  return pw;
-}
-
-static group* android_iinfo_to_group(group_state_t* state,
-                                     const android_id_info* iinfo) {
-  snprintf(state->group_name_buffer_, sizeof(state->group_name_buffer_), "%s", iinfo->name);
-
-  group* gr = &state->group_;
-  gr->gr_name   = state->group_name_buffer_;
-  gr->gr_gid    = iinfo->aid;
-  gr->gr_mem[0] = gr->gr_name;
-  return gr;
-}
-
-static passwd* android_id_to_passwd(passwd_state_t* state, unsigned id) {
-  for (size_t n = 0; n < android_id_count; ++n) {
-    if (android_ids[n].aid == id) {
-      return android_iinfo_to_passwd(state, android_ids + n);
-    }
-  }
-  return NULL;
-}
-
-static passwd* android_name_to_passwd(passwd_state_t* state, const char* name) {
-  for (size_t n = 0; n < android_id_count; ++n) {
-    if (!strcmp(android_ids[n].name, name)) {
-      return android_iinfo_to_passwd(state, android_ids + n);
-    }
-  }
-  return NULL;
-}
-
-static group* android_id_to_group(group_state_t* state, unsigned id) {
-  for (size_t n = 0; n < android_id_count; ++n) {
-    if (android_ids[n].aid == id) {
-      return android_iinfo_to_group(state, android_ids + n);
-    }
-  }
-  return NULL;
-}
-
-static group* android_name_to_group(group_state_t* state, const char* name) {
-  for (size_t n = 0; n < android_id_count; ++n) {
-    if (!strcmp(android_ids[n].name, name)) {
-      return android_iinfo_to_group(state, android_ids + n);
-    }
-  }
-  return NULL;
-}
-
-// Translate a user/group name to the corresponding user/group id.
-// all_a1234 -> 0 * AID_USER + AID_SHARED_GID_START + 1234 (group name only)
-// u0_a1234 -> 0 * AID_USER + AID_APP + 1234
-// u2_i1000 -> 2 * AID_USER + AID_ISOLATED_START + 1000
-// u1_system -> 1 * AID_USER + android_ids['system']
-// returns 0 and sets errno to ENOENT in case of error.
-static id_t app_id_from_name(const char* name, bool is_group) {
-  char* end;
-  unsigned long userid;
-  bool is_shared_gid = false;
-
-  if (is_group && name[0] == 'a' && name[1] == 'l' && name[2] == 'l') {
-    end = const_cast<char*>(name+3);
-    userid = 0;
-    is_shared_gid = true;
-  } else if (name[0] == 'u' && isdigit(name[1])) {
-    userid = strtoul(name+1, &end, 10);
-  } else {
-    errno = ENOENT;
-    return 0;
-  }
-
-  if (end[0] != '_' || end[1] == 0) {
-    errno = ENOENT;
-    return 0;
-  }
-
-  unsigned long appid = 0;
-  if (end[1] == 'a' && isdigit(end[2])) {
-    if (is_shared_gid) {
-      // end will point to \0 if the strtoul below succeeds.
-      appid = strtoul(end+2, &end, 10) + AID_SHARED_GID_START;
-      if (appid > AID_SHARED_GID_END) {
-        errno = ENOENT;
-        return 0;
-      }
-    } else {
-      // end will point to \0 if the strtoul below succeeds.
-      appid = strtoul(end+2, &end, 10) + AID_APP;
-    }
-  } else if (end[1] == 'i' && isdigit(end[2])) {
-    // end will point to \0 if the strtoul below succeeds.
-    appid = strtoul(end+2, &end, 10) + AID_ISOLATED_START;
-  } else {
-    for (size_t n = 0; n < android_id_count; n++) {
-      if (!strcmp(android_ids[n].name, end + 1)) {
-        appid = android_ids[n].aid;
-        // Move the end pointer to the null terminator.
-        end += strlen(android_ids[n].name) + 1;
-        break;
-      }
-    }
-  }
-
-  // Check that the entire string was consumed by one of the 3 cases above.
-  if (end[0] != 0) {
-    errno = ENOENT;
-    return 0;
-  }
-
-  // Check that user id won't overflow.
-  if (userid > 1000) {
-    errno = ENOENT;
-    return 0;
-  }
-
-  // Check that app id is within range.
-  if (appid >= AID_USER) {
-    errno = ENOENT;
-    return 0;
-  }
-
-  return (appid + userid*AID_USER);
-}
-
-static void print_app_name_from_uid(const uid_t uid, char* buffer, const int bufferlen) {
-  const uid_t appid = uid % AID_USER;
-  const uid_t userid = uid / AID_USER;
-  if (appid >= AID_ISOLATED_START) {
-    snprintf(buffer, bufferlen, "u%u_i%u", userid, appid - AID_ISOLATED_START);
-  } else if (appid < AID_APP) {
-    for (size_t n = 0; n < android_id_count; n++) {
-      if (android_ids[n].aid == appid) {
-        snprintf(buffer, bufferlen, "u%u_%s", userid, android_ids[n].name);
-        return;
-      }
-    }
-  } else {
-    snprintf(buffer, bufferlen, "u%u_a%u", userid, appid - AID_APP);
-  }
-}
-
-static void print_app_name_from_gid(const gid_t gid, char* buffer, const int bufferlen) {
-  const uid_t appid = gid % AID_USER;
-  const uid_t userid = gid / AID_USER;
-  if (appid >= AID_ISOLATED_START) {
-    snprintf(buffer, bufferlen, "u%u_i%u", userid, appid - AID_ISOLATED_START);
-  } else if (userid == 0 && appid >= AID_SHARED_GID_START && appid <= AID_SHARED_GID_END) {
-    snprintf(buffer, bufferlen, "all_a%u", appid - AID_SHARED_GID_START);
-  } else if (appid < AID_APP) {
-    for (size_t n = 0; n < android_id_count; n++) {
-      if (android_ids[n].aid == appid) {
-        snprintf(buffer, bufferlen, "u%u_%s", userid, android_ids[n].name);
-        return;
-      }
-    }
-  } else {
-    snprintf(buffer, bufferlen, "u%u_a%u", userid, appid - AID_APP);
-  }
-}
-
-// Translate an OEM name to the corresponding user/group id.
-// oem_XXX -> AID_OEM_RESERVED_2_START + XXX, iff XXX is within range.
-static id_t oem_id_from_name(const char* name) {
-  unsigned int id;
-  if (sscanf(name, "oem_%u", &id) != 1) {
-    return 0;
-  }
-  // Check OEM id is within range.
-  if (id > (AID_OEM_RESERVED_2_END - AID_OEM_RESERVED_2_START)) {
-    return 0;
-  }
-  return AID_OEM_RESERVED_2_START + static_cast<id_t>(id);
-}
-
-static passwd* oem_id_to_passwd(uid_t uid, passwd_state_t* state) {
-  if (uid < AID_OEM_RESERVED_2_START || uid > AID_OEM_RESERVED_2_END) {
-    return NULL;
-  }
-
-  snprintf(state->name_buffer_, sizeof(state->name_buffer_), "oem_%u",
-           uid - AID_OEM_RESERVED_2_START);
-  snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
-  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
-
-  passwd* pw = &state->passwd_;
-  pw->pw_name  = state->name_buffer_;
-  pw->pw_dir   = state->dir_buffer_;
-  pw->pw_shell = state->sh_buffer_;
-  pw->pw_uid   = uid;
-  pw->pw_gid   = uid;
-  return pw;
-}
-
-static group* oem_id_to_group(gid_t gid, group_state_t* state) {
-  if (gid < AID_OEM_RESERVED_2_START || gid > AID_OEM_RESERVED_2_END) {
-    return NULL;
-  }
-
-  snprintf(state->group_name_buffer_, sizeof(state->group_name_buffer_),
-           "oem_%u", gid - AID_OEM_RESERVED_2_START);
-
-  group* gr = &state->group_;
-  gr->gr_name   = state->group_name_buffer_;
-  gr->gr_gid    = gid;
-  gr->gr_mem[0] = gr->gr_name;
-  return gr;
-}
-
-// Translate a uid into the corresponding name.
-// 0 to AID_APP-1                   -> "system", "radio", etc.
-// AID_APP to AID_ISOLATED_START-1  -> u0_a1234
-// AID_ISOLATED_START to AID_USER-1 -> u0_i1234
-// AID_USER+                        -> u1_radio, u1_a1234, u2_i1234, etc.
-// returns a passwd structure (sets errno to ENOENT on failure).
-static passwd* app_id_to_passwd(uid_t uid, passwd_state_t* state) {
-  if (uid < AID_APP) {
-    errno = ENOENT;
-    return NULL;
-  }
-
-  print_app_name_from_uid(uid, state->name_buffer_, sizeof(state->name_buffer_));
-
-  const uid_t appid = uid % AID_USER;
-  if (appid < AID_APP) {
-      snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/");
-  } else {
-      snprintf(state->dir_buffer_, sizeof(state->dir_buffer_), "/data");
-  }
-
-  snprintf(state->sh_buffer_, sizeof(state->sh_buffer_), "/system/bin/sh");
-
-  passwd* pw = &state->passwd_;
-  pw->pw_name  = state->name_buffer_;
-  pw->pw_dir   = state->dir_buffer_;
-  pw->pw_shell = state->sh_buffer_;
-  pw->pw_uid   = uid;
-  pw->pw_gid   = uid;
-  return pw;
-}
-
-// Translate a gid into the corresponding app_<gid>
-// group structure (sets errno to ENOENT on failure).
-static group* app_id_to_group(gid_t gid, group_state_t* state) {
-  if (gid < AID_APP) {
-    errno = ENOENT;
-    return NULL;
-  }
-
-  print_app_name_from_gid(gid, state->group_name_buffer_, sizeof(state->group_name_buffer_));
-
-  group* gr = &state->group_;
-  gr->gr_name   = state->group_name_buffer_;
-  gr->gr_gid    = gid;
-  gr->gr_mem[0] = gr->gr_name;
-  return gr;
-}
-
-passwd* getpwuid(uid_t uid) { // NOLINT: implementing bad function.
-  passwd_state_t* state = g_passwd_tls_buffer.get();
-  if (state == NULL) {
-    return NULL;
-  }
-
-  passwd* pw = android_id_to_passwd(state, uid);
-  if (pw != NULL) {
-    return pw;
-  }
-  // Handle OEM range.
-  pw = oem_id_to_passwd(uid, state);
-  if (pw != NULL) {
-    return pw;
-  }
-  return app_id_to_passwd(uid, state);
-}
-
-passwd* getpwnam(const char* login) { // NOLINT: implementing bad function.
-  passwd_state_t* state = g_passwd_tls_buffer.get();
-  if (state == NULL) {
-    return NULL;
-  }
-
-  passwd* pw = android_name_to_passwd(state, login);
-  if (pw != NULL) {
-    return pw;
-  }
-  // Handle OEM range.
-  pw = oem_id_to_passwd(oem_id_from_name(login), state);
-  if (pw != NULL) {
-    return pw;
-  }
-  return app_id_to_passwd(app_id_from_name(login, false), state);
-}
-
-// All users are in just one group, the one passed in.
-int getgrouplist(const char* /*user*/, gid_t group, gid_t* groups, int* ngroups) {
-  if (*ngroups < 1) {
-    *ngroups = 1;
-    return -1;
-  }
-  groups[0] = group;
-  return (*ngroups = 1);
-}
-
-char* getlogin() { // NOLINT: implementing bad function.
-  passwd *pw = getpwuid(getuid()); // NOLINT: implementing bad function in terms of bad function.
-  return (pw != NULL) ? pw->pw_name : NULL;
-}
-
-static group* getgrgid_internal(gid_t gid, group_state_t* state) {
-  group* grp = android_id_to_group(state, gid);
-  if (grp != NULL) {
-    return grp;
-  }
-  // Handle OEM range.
-  grp = oem_id_to_group(gid, state);
-  if (grp != NULL) {
-    return grp;
-  }
-  return app_id_to_group(gid, state);
-}
-
-group* getgrgid(gid_t gid) { // NOLINT: implementing bad function.
-  group_state_t* state = __group_state();
-  if (state == NULL) {
-    return NULL;
-  }
-  return getgrgid_internal(gid, state);
-}
-
-static group* getgrnam_internal(const char* name, group_state_t* state) {
-  group* grp = android_name_to_group(state, name);
-  if (grp != NULL) {
-    return grp;
-  }
-  // Handle OEM range.
-  grp = oem_id_to_group(oem_id_from_name(name), state);
-  if (grp != NULL) {
-    return grp;
-  }
-  return app_id_to_group(app_id_from_name(name, true), state);
-}
-
-group* getgrnam(const char* name) { // NOLINT: implementing bad function.
-  group_state_t* state = __group_state();
-  if (state == NULL) {
-    return NULL;
-  }
-  return getgrnam_internal(name, state);
-}
-
-static int getgroup_r(bool by_name, const char* name, gid_t gid, struct group* grp, char* buf,
-                      size_t buflen, struct group** result) {
-  ErrnoRestorer errno_restorer;
-  *result = NULL;
-  char* p = reinterpret_cast<char*>(
-      BIONIC_ALIGN(reinterpret_cast<uintptr_t>(buf), sizeof(uintptr_t)));
-  if (p + sizeof(group_state_t) > buf + buflen) {
-    return ERANGE;
-  }
-  group_state_t* state = reinterpret_cast<group_state_t*>(p);
-  init_group_state(state);
-  group* retval = (by_name ? getgrnam_internal(name, state) : getgrgid_internal(gid, state));
-  if (retval != NULL) {
-    *grp = *retval;
-    *result = grp;
-    return 0;
-  }
-  return errno;
-}
-
-int getgrgid_r(gid_t gid, struct group* grp, char* buf, size_t buflen, struct group** result) {
-  return getgroup_r(false, NULL, gid, grp, buf, buflen, result);
-}
-
-int getgrnam_r(const char* name, struct group* grp, char* buf, size_t buflen,
-               struct group **result) {
-  return getgroup_r(true, name, 0, grp, buf, buflen, result);
-}
-
 // We don't have an /etc/networks, so all inputs return NULL.
 netent* getnetbyname(const char* /*name*/) {
   return NULL;