Linux: Implement per-thread file system attributes

Message ID 87o9a6vkl3.fsf@oldenburg.str.redhat.com
State Superseded
Headers

Commit Message

Florian Weimer Nov. 30, 2018, 12:03 p.m. UTC
  This commit adds the functions pthread_attr_setperthreadfs_np and
pthread_attr_getperthreadfs_np.

The implementation is based on suppressing the CLONE_FS clone flag when
creating the new thread.

2018-11-30  Florian Weimer  <fweimer@redhat.com>

	Linux: Implement per-thread file system attributes.
	* nptl/Makefile (routines): Add pthread_attr_setperthreadfs_np,
	pthread_attr_getperthreadfs_np.
	(tests): Add tst-pthread-perthreadfs,
	tst-pthread-perthreadfs-chroot.
	* nptl/Versions (GLIBC_2.29): Export
	pthread_attr_setperthreadfs_np, pthread_attr_getperthreadfs_np.
	* nptl/pthread_attr_setperthreadfs_np.c: New file
	* nptl/pthread_attr_getperthreadfs_np.c: Likewise.
	* nptl/tst-pthread-perthreadfs.c: Likewise.
	* nptl/tst-pthread-perthreadfs-chroot.c: Likewise.
	* sysdeps/nptl/internaltypes.h (ATTR_FLAG_PERTHREADFS): Define.
	* sysdeps/unix/sysv/linux/createthread.c (create_thread): Use it.
	* sysdeps/nptl/pthread.h (pthread_attr_setperthreadfs_np)
	(pthread_attr_getperthreadfs_np): Declare.
	* support/Makefile (libsupport-routines): Add xchdir, xfchdir.
	* support/xunistd.h (xchdir, xfchdir): Declare.
	* support/xchdir.c: New file.
	* support/xfchdir.c: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libc.abilist (GLIBC_2.29): Add
	pthread_attr_setperthreadfs_np, pthread_attr_getperthreadfs_np.
	* sysdeps/unix/sysv/linux/alpha/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/arm/libc.abilist (GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/hppa/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/i386/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/ia64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/nios2/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
	(GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/sh/libc.abilist (GLIBC_2.29): Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist (GLIBC_2.29):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist (GLIBC_2.29):
	Likewise.
  

Comments

Florian Weimer Dec. 5, 2018, 1:21 p.m. UTC | #1
* Florian Weimer:

> This commit adds the functions pthread_attr_setperthreadfs_np and
> pthread_attr_getperthreadfs_np.
>
> The implementation is based on suppressing the CLONE_FS clone flag when
> creating the new thread.

Any comments?  Do we want something like this at all?

Thanks,
Florian
  
Florian Weimer Dec. 13, 2018, 9:06 a.m. UTC | #2
* Florian Weimer:

> This commit adds the functions pthread_attr_setperthreadfs_np and
> pthread_attr_getperthreadfs_np.
>
> The implementation is based on suppressing the CLONE_FS clone flag when
> creating the new thread.
>
> 2018-11-30  Florian Weimer  <fweimer@redhat.com>
>
> 	Linux: Implement per-thread file system attributes.

Original patch:

  <https://sourceware.org/ml/libc-alpha/2018-11/msg00866.html>

It turns out that Samba uses something quite similar today: They call
unshare (CLONE_FS) from certain threads to obtain private file system
attributes.  So there is some demand for this functionality.

The main question is whether the interfaces should stick literally to
other POSIX attribute functions and use this instead:

int pthread_attr_setperthreadfs_np (pthread_attr_t *__attr, int __enabled)
  __THROW __nonnull ((1));
int pthread_attr_getperthreadfs_np (const pthread_attr_t *, int *__enabled)
  __THROW __nonnull ((1, 2));

The patch currently has:

void pthread_attr_setperthreadfs_np (pthread_attr_t *__attr, int __enabled)
  __THROW __nonnull ((1));
int pthread_attr_getperthreadfs_np (const pthread_attr_t *__attr)
  __THROW __nonnull ((1));

I have no strong opinion on this matter.

(I will write documentation once the API is approved for inclusion.)

Thanks,
Florian
  
Florian Weimer Feb. 8, 2019, 12:31 p.m. UTC | #3
* Florian Weimer:

> * Florian Weimer:
>
>> This commit adds the functions pthread_attr_setperthreadfs_np and
>> pthread_attr_getperthreadfs_np.
>>
>> The implementation is based on suppressing the CLONE_FS clone flag when
>> creating the new thread.
>>
>> 2018-11-30  Florian Weimer  <fweimer@redhat.com>
>>
>> 	Linux: Implement per-thread file system attributes.
>
> Original patch:
>
>   <https://sourceware.org/ml/libc-alpha/2018-11/msg00866.html>
>
> It turns out that Samba uses something quite similar today: They call
> unshare (CLONE_FS) from certain threads to obtain private file system
> attributes.  So there is some demand for this functionality.
>
> The main question is whether the interfaces should stick literally to
> other POSIX attribute functions and use this instead:
>
> int pthread_attr_setperthreadfs_np (pthread_attr_t *__attr, int __enabled)
>   __THROW __nonnull ((1));
> int pthread_attr_getperthreadfs_np (const pthread_attr_t *, int *__enabled)
>   __THROW __nonnull ((1, 2));
>
> The patch currently has:
>
> void pthread_attr_setperthreadfs_np (pthread_attr_t *__attr, int __enabled)
>   __THROW __nonnull ((1));
> int pthread_attr_getperthreadfs_np (const pthread_attr_t *__attr)
>   __THROW __nonnull ((1));
>
> I have no strong opinion on this matter.
>
> (I will write documentation once the API is approved for inclusion.)

Ping?

If someone could do a conceptual review of the original patch, I can
rebase it to current master for an actual review.

Thanks,
Florian
  

Patch

diff --git a/NEWS b/NEWS
index 1098be1afb..6acd6e1921 100644
--- a/NEWS
+++ b/NEWS
@@ -35,6 +35,11 @@  Major new features:
   different directory.  This is a GNU extension and similar to the
   Solaris function of the same name.
 
+* On Linux, it is now possible to create threads with per-thread current
+  directory, umask, and file system root.  The functions
+  pthread_attr_setperthreadfs_np and pthread_attr_getperthreadfs_np have
+  been added in support of that.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The glibc.tune tunable namespace has been renamed to glibc.cpu and the
diff --git a/nptl/Makefile b/nptl/Makefile
index 982e43adfa..02346b2f92 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -30,7 +30,8 @@  extra-libs-others := $(extra-libs)
 routines = alloca_cutoff forward libc-lowlevellock libc-cancellation \
 	   libc-cleanup libc_pthread_init libc_multiple_threads \
 	   register-atfork pthread_atfork pthread_self thrd_current \
-	   thrd_equal thrd_sleep thrd_yield
+	   thrd_equal thrd_sleep thrd_yield \
+	   pthread_attr_setperthreadfs_np pthread_attr_getperthreadfs_np
 shared-only-routines = forward
 static-only-routines = pthread_atfork
 
@@ -318,7 +319,8 @@  tests = tst-attr1 tst-attr2 tst-attr3 tst-default-attr \
 	tst-minstack-throw \
 	tst-cnd-basic tst-mtx-trylock tst-cnd-broadcast \
 	tst-cnd-timedwait tst-thrd-detach tst-mtx-basic tst-thrd-sleep \
-	tst-mtx-recursive tst-tss-basic tst-call-once tst-mtx-timedlock
+	tst-mtx-recursive tst-tss-basic tst-call-once tst-mtx-timedlock \
+	tst-pthread-perthreadfs tst-pthread-perthreadfs-chroot
 
 tests-internal := tst-rwlock19 tst-rwlock20 \
 		  tst-sem11 tst-sem12 tst-sem13 \
diff --git a/nptl/Versions b/nptl/Versions
index e7f691da7a..ba71f85411 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -32,6 +32,10 @@  libc {
   GLIBC_2.28 {
     thrd_current; thrd_equal; thrd_sleep; thrd_yield;
   }
+  GLIBC_2.29 {
+    pthread_attr_setperthreadfs_np;
+    pthread_attr_getperthreadfs_np;
+  }
   GLIBC_PRIVATE {
     __libc_alloca_cutoff;
     # Internal libc interface to libpthread
diff --git a/nptl/pthread_attr_getperthreadfs_np.c b/nptl/pthread_attr_getperthreadfs_np.c
new file mode 100644
index 0000000000..f285fe8516
--- /dev/null
+++ b/nptl/pthread_attr_getperthreadfs_np.c
@@ -0,0 +1,27 @@ 
+/* Read the private file system flag in thread attributes.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <internaltypes.h>
+
+int
+pthread_attr_getperthreadfs_np (const pthread_attr_t *attr)
+{
+  struct pthread_attr *iattr = (struct pthread_attr *) attr;
+  return (iattr->flags & ATTR_FLAG_PERTHREADFS) != 0;
+}
diff --git a/nptl/pthread_attr_setperthreadfs_np.c b/nptl/pthread_attr_setperthreadfs_np.c
new file mode 100644
index 0000000000..6ce982a8bb
--- /dev/null
+++ b/nptl/pthread_attr_setperthreadfs_np.c
@@ -0,0 +1,30 @@ 
+/* Change the private file system flag in thread attributes.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <internaltypes.h>
+
+void
+pthread_attr_setperthreadfs_np (pthread_attr_t *attr, int enabled)
+{
+  struct pthread_attr *iattr = (struct pthread_attr *) attr;
+  if (enabled)
+    iattr->flags |= ATTR_FLAG_PERTHREADFS;
+  else
+    iattr->flags &= ~ATTR_FLAG_PERTHREADFS;
+}
diff --git a/nptl/tst-pthread-perthreadfs-chroot.c b/nptl/tst-pthread-perthreadfs-chroot.c
new file mode 100644
index 0000000000..77494c2bcc
--- /dev/null
+++ b/nptl/tst-pthread-perthreadfs-chroot.c
@@ -0,0 +1,256 @@ 
+/* Test per-thread file system attributes, chroot version.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* Paths for chroot operations.  */
+static char *chroot_1;
+static char *chroot_2;
+static char *chroot_3;
+
+/* These paths are used for recognizing chroots.  */
+static const char *const chroot_1_marker = "/chroot-1-marker";
+static const char *const chroot_2_marker = "/chroot-2-marker";
+
+/* Directory available in the chroot for a second chroot call.  */
+static const char *const next_chroot = "/next_chroot";
+
+/* Return 0 for no chroot, 1 for first chroot, 2 for second chroot, or
+   -1 for error.  */
+static int
+which_chroot (void)
+{
+  /* If the full (out-of-chroot) path is present, we are not in a
+     chroot.  */
+  if (access (chroot_1, F_OK) == 0)
+    return 0;
+  if (access (chroot_1_marker, F_OK) == 0)
+    return 1;
+  if (access (chroot_2_marker, F_OK) == 0)
+    return 2;
+  return -1;
+}
+
+/* Thread attribute requesting per-thread file system attributes.  */
+pthread_attr_t attr_perthreadfs;
+
+/* Used to synchronize operations among the threads.  This is needed
+   so that the chroot changes happen in the expected order.  */
+static pthread_barrier_t barrier;
+
+static void *
+thread_which_chroot_helper (void *closure)
+{
+  int *result = closure;
+  *result = which_chroot ();
+  return NULL;
+}
+
+static void *
+thread_which_chroot_helper_perthread (void *closure)
+{
+  int *result = closure;
+  *result = which_chroot ();
+  if (*result == 0)
+    /* No /next-chroot available without a first chroot.  */
+    xchroot (chroot_3);
+  else
+    xchroot (next_chroot);
+  return NULL;
+}
+
+/* Determine the current chroot on another thread.  */
+static int
+thread_which_chroot (void)
+{
+  int result1;
+  pthread_t thr = xpthread_create (NULL, thread_which_chroot_helper, &result1);
+  xpthread_join (thr);
+  /* Same using per-thread attributes.  They are supposed to be equal.
+     Also change the chroot to check isolation.  */
+  int result2;
+  thr = xpthread_create (&attr_perthreadfs,
+                         thread_which_chroot_helper_perthread, &result2);
+  xpthread_join (thr);
+  TEST_COMPARE (result1, result2);
+  return result1;
+}
+
+/* Verify that the file system attributes for the current thread are
+   as expected.  */
+static void
+check_attributes (const char *where, int expected_chroot)
+{
+  printf ("info: reading file attributes in %s\n", where);
+  TEST_COMPARE (which_chroot (), expected_chroot);
+  TEST_COMPARE (thread_which_chroot (), expected_chroot);
+}
+
+/* Thread function launched with per-thread file system
+   attributes.  */
+static void *
+thread_perthreadfs (void *closure)
+{
+  puts ("info: changing file attributes in thread_perthreadfs");
+  xchroot (chroot_1);
+  check_attributes ("thread_perthreadfs", 1);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in thread_sharedfs here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes changed in thread_sharedfs here.  */
+  pthread_barrier_wait (&barrier);
+
+  check_attributes ("thread_perthreadfs", 1);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  return NULL;
+}
+
+/* Thread function launched with shared file system attributes.  */
+static void *
+thread_sharedfs (void *closure)
+{
+  /* Wait for thread_perthreadfs to update chroot.  */
+  pthread_barrier_wait (&barrier);
+
+  check_attributes ("thread_sharedfs", 0);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+
+  puts ("info: changing file attributes in thread_sharedfs");
+  xchroot (chroot_2);
+  check_attributes ("thread_sharedfs", 2);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in thread_perthreadfs here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  support_become_root ();
+  if (!support_can_chroot ())
+    FAIL_UNSUPPORTED ("chroot not supported");
+
+  /* Used to revert the effect of chroot.  */
+  int original_chroot_fd = xopen ("/", O_DIRECTORY | O_RDONLY, 0);
+
+  TEST_COMPARE (access (chroot_1_marker, F_OK), -1);
+  TEST_COMPARE (access (chroot_2_marker, F_OK), -1);
+  TEST_COMPARE (access (next_chroot, F_OK), -1);
+
+  chroot_1 = support_create_temp_directory
+    ("tst-pthread-perthreadfs-chroot-1-");
+  chroot_2 = support_create_temp_directory
+    ("tst-pthread-perthreadfs-chroot-2-");
+  chroot_3 = support_create_temp_directory
+    ("tst-pthread-perthreadfs-chroot-3-");
+  {
+    char *path = xasprintf ("%s%s", chroot_1, chroot_1_marker);
+    xmkdir (path, 0777);
+    add_temp_file (path);
+    free (path);
+
+    path = xasprintf ("%s%s", chroot_1, next_chroot);
+    xmkdir (path, 0777);
+    add_temp_file (path);
+    free (path);
+
+    path = xasprintf ("%s%s", chroot_2, chroot_2_marker);
+    xmkdir (path, 0777);
+    add_temp_file (path);
+    free (path);
+
+    path = xasprintf ("%s%s", chroot_2, next_chroot);
+    xmkdir (path, 0777);
+    add_temp_file (path);
+    free (path);
+  }
+  TEST_COMPARE (which_chroot (), 0);
+
+  xpthread_barrier_init (&barrier, NULL, 3);
+  xpthread_attr_init (&attr_perthreadfs);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 0);
+  pthread_attr_setperthreadfs_np (&attr_perthreadfs, true);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 1);
+  /* The flag is normalized to 1.  */
+  pthread_attr_setperthreadfs_np (&attr_perthreadfs, 2);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 1);
+
+  pthread_t thr1 = xpthread_create (&attr_perthreadfs,
+                                    thread_perthreadfs, NULL);
+  pthread_t thr2 = xpthread_create (NULL, thread_sharedfs, NULL);
+
+  /* Wait for thread_perthreadfs to update chroot.  */
+  xpthread_barrier_wait (&barrier);
+  /* File attributes read thread_sharedfs here.  */
+  xpthread_barrier_wait (&barrier);
+
+  check_attributes ("main thread", 0);
+
+  xpthread_barrier_wait (&barrier);
+  /* File attributes changed thread_sharedfs here.  */
+  xpthread_barrier_wait (&barrier);
+  /* File attributes read in thread_perthreadfs here.  */
+  xpthread_barrier_wait (&barrier);
+
+  check_attributes ("main thread", 2);
+
+  xpthread_barrier_wait (&barrier);
+
+  xpthread_join (thr2);
+  xpthread_join (thr1);
+
+  xpthread_attr_destroy (&attr_perthreadfs);
+  xpthread_barrier_destroy (&barrier);
+
+  free (chroot_3);
+  free (chroot_2);
+  free (chroot_1);
+
+  xfchdir (original_chroot_fd);
+  xclose (original_chroot_fd);
+  xchroot (".");
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/nptl/tst-pthread-perthreadfs.c b/nptl/tst-pthread-perthreadfs.c
new file mode 100644
index 0000000000..d11dc63a1f
--- /dev/null
+++ b/nptl/tst-pthread-perthreadfs.c
@@ -0,0 +1,243 @@ 
+/* Test per-thread file system attributes.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <support/check.h>
+#include <support/temp_file.h>
+#include <support/xthread.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* Original values in the parent process.  */
+static char *original_cwd;
+static mode_t original_umask;
+
+/* New values for the attributes, distinct from the old.  */
+static char *new_cwd_1;
+static char *new_cwd_2;
+static mode_t new_umask_1;
+static mode_t new_umask_2;
+
+/* Thread attribute requesting per-thread file system attributes.  */
+pthread_attr_t attr_perthreadfs;
+
+/* Used to synchronize operations among the threads.  This is needed
+   so that the attribute changes happen in the expected order, and
+   that get_umask_unlocked can be used safely.  */
+static pthread_barrier_t barrier;
+
+/* Linux does not have getumask, so use synchronization and the umask
+   system call to read the value.  */
+static mode_t
+get_umask_unlocked (void)
+{
+  mode_t mask = umask (0);
+  TEST_COMPARE (umask (mask), 0);
+  return mask;
+}
+
+static void *
+thread_get_pwd_helper (void *closure)
+{
+  char *result = get_current_dir_name ();
+  if (closure != NULL)
+    xchdir (closure);
+  return result;
+}
+
+/* Obtain the current directory on another thread.  */
+static char *
+thread_get_pwd (void)
+{
+  pthread_t thr = xpthread_create (NULL, thread_get_pwd_helper, NULL);
+  char *path1 = xpthread_join (thr);
+  /* Same using per-thread attributes.  They are supposed to be equal.
+     Also change the current directory to check isolation.  */
+  thr = xpthread_create (&attr_perthreadfs,
+                         thread_get_pwd_helper, (char *) "/");
+  char *path2 = xpthread_join (thr);
+  TEST_COMPARE_STRING (path1, path2);
+  free (path2);
+  return path1;
+}
+
+static void *
+thread_get_umask_helper (void *closure)
+{
+  mode_t *pmask = closure;
+  *pmask = get_umask_unlocked ();
+  return NULL;
+}
+
+static void *
+thread_get_umask_helper_perthread (void *closure)
+{
+  mode_t *pmask = closure;
+  *pmask = get_umask_unlocked ();
+  /* Check isolation.  This bit pattern is not used anywhere else.  */
+  TEST_COMPARE (umask (*pmask ^ 0101), *pmask);
+  return NULL;
+}
+
+/* Obtain the current umask on another thread.  */
+static mode_t
+thread_get_umask_unlocked (void)
+{
+  mode_t mask1;
+  pthread_t thr = xpthread_create (NULL, thread_get_umask_helper, &mask1);
+  xpthread_join (thr);
+  mode_t mask2;
+  thr = xpthread_create (&attr_perthreadfs,
+                         thread_get_umask_helper_perthread, &mask2);
+  xpthread_join (thr);
+  TEST_COMPARE (mask1, mask2);
+  return mask1;
+}
+
+/* Verify that the file system attributes for the current thread are
+   as expected.  */
+static void
+check_attributes (const char *where, mode_t expected_umask,
+                  const char *expected_cwd)
+{
+  printf ("info: reading file attributes in %s\n", where);
+  TEST_COMPARE (get_umask_unlocked (), expected_umask);
+  TEST_COMPARE (thread_get_umask_unlocked (), expected_umask);
+  char *cwd = get_current_dir_name ();
+  TEST_COMPARE_STRING (cwd, expected_cwd);
+  free (cwd);
+  cwd = thread_get_pwd ();
+  TEST_COMPARE_STRING (cwd, expected_cwd);
+  free (cwd);
+}
+
+/* Thread function launched with per-thread file system
+   attributes.  */
+static void *
+thread_perthreadfs (void *closure)
+{
+  puts ("info: changing file attributes in thread_perthreadfs");
+  xchdir (new_cwd_1);
+  TEST_COMPARE (umask (new_umask_1), original_umask);
+  check_attributes ("thread_perthreadfs", new_umask_1, new_cwd_1);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in thread_sharedfs here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes changed in thread_sharedfs here.  */
+  pthread_barrier_wait (&barrier);
+
+  check_attributes ("thread_perthreadfs", new_umask_1, new_cwd_1);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  return NULL;
+}
+
+/* Thread function launched with shared file system attributes.  */
+static void *
+thread_sharedfs (void *closure)
+{
+  /* Wait for thread_perthreadfs to update current directory and
+     umask.  */
+  pthread_barrier_wait (&barrier);
+
+  check_attributes ("thread_sharedfs", original_umask, original_cwd);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+
+  puts ("info: changing file attributes in thread_sharedfs");
+  TEST_COMPARE (umask (new_umask_2), original_umask);
+  xchdir (new_cwd_2);
+  check_attributes ("thread_sharedfs", new_umask_2, new_cwd_2);
+
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in thread_perthreadfs here.  */
+  pthread_barrier_wait (&barrier);
+  /* File attributes read in main thread here.  */
+  pthread_barrier_wait (&barrier);
+  return NULL;
+}
+
+static int
+do_test (void)
+{
+  original_cwd = get_current_dir_name ();
+  TEST_VERIFY_EXIT (original_cwd != NULL);
+  original_umask = get_umask_unlocked ();
+
+  new_cwd_1 = support_create_temp_directory ("tst-pthread-perthreadfs-1-");
+  new_cwd_2 = support_create_temp_directory ("tst-pthread-perthreadfs-2-");
+  /* Arbitrary bit pattern change to obtain distinct values, so that
+     it is possible to check for actual changes.  */
+  new_umask_1 = original_umask ^ 0111;
+  new_umask_2 = original_umask ^ 0222;
+
+  xpthread_barrier_init (&barrier, NULL, 3);
+  xpthread_attr_init (&attr_perthreadfs);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 0);
+  pthread_attr_setperthreadfs_np (&attr_perthreadfs, true);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 1);
+  /* The flag is normalized to 1.  */
+  pthread_attr_setperthreadfs_np (&attr_perthreadfs, 2);
+  TEST_COMPARE (pthread_attr_getperthreadfs_np (&attr_perthreadfs), 1);
+
+  pthread_t thr1 = xpthread_create (&attr_perthreadfs,
+                                    thread_perthreadfs, NULL);
+  pthread_t thr2 = xpthread_create (NULL, thread_sharedfs, NULL);
+
+  /* Wait for thread_perthreadfs to update current directory and
+     umask.  */
+  xpthread_barrier_wait (&barrier);
+  /* File attributes read thread_sharedfs here.  */
+  xpthread_barrier_wait (&barrier);
+
+  check_attributes ("main thread", original_umask, original_cwd);
+
+  xpthread_barrier_wait (&barrier);
+  /* File attributes changed thread_sharedfs here.  */
+  xpthread_barrier_wait (&barrier);
+  /* File attributes read in thread_perthreadfs here.  */
+  xpthread_barrier_wait (&barrier);
+
+  check_attributes ("main thread", new_umask_2, new_cwd_2);
+
+  xpthread_barrier_wait (&barrier);
+
+  xpthread_join (thr2);
+  xpthread_join (thr1);
+
+  xpthread_attr_destroy (&attr_perthreadfs);
+  xpthread_barrier_destroy (&barrier);
+
+  free (new_cwd_2);
+  free (new_cwd_1);
+  free (original_cwd);
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/support/Makefile b/support/Makefile
index a2536980d1..dd75df5cb8 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -75,12 +75,14 @@  libsupport-routines = \
   xasprintf \
   xbind \
   xcalloc \
+  xchdir \
   xchroot \
   xclose \
   xconnect \
   xcopy_file_range \
   xdlfcn \
   xdup2 \
+  xfchdir \
   xfclose \
   xfopen \
   xfork \
diff --git a/support/xchdir.c b/support/xchdir.c
new file mode 100644
index 0000000000..5f9f001ce0
--- /dev/null
+++ b/support/xchdir.c
@@ -0,0 +1,28 @@ 
+/* chdir with error checking.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+
+void
+xchdir (const char *path)
+{
+  if (chdir (path) != 0)
+    FAIL_EXIT1 ("chdir (\"%s\"): %m", path);
+}
diff --git a/support/xfchdir.c b/support/xfchdir.c
new file mode 100644
index 0000000000..75fadeb865
--- /dev/null
+++ b/support/xfchdir.c
@@ -0,0 +1,28 @@ 
+/* fchdir with error checking.
+   Copyright (C) 2017-2018 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <sys/stat.h>
+
+void
+xfchdir (int fd)
+{
+  if (fchdir (fd) != 0)
+    FAIL_EXIT1 ("fchdir (%d): %m", fd);
+}
diff --git a/support/xunistd.h b/support/xunistd.h
index f99f362cb4..13dfa2c0e5 100644
--- a/support/xunistd.h
+++ b/support/xunistd.h
@@ -38,6 +38,8 @@  int xopen (const char *path, int flags, mode_t);
 void xstat (const char *path, struct stat64 *);
 void xfstat (int fd, struct stat64 *);
 void xmkdir (const char *path, mode_t);
+void xchdir (const char *path);
+void xfchdir (int);
 void xchroot (const char *path);
 void xunlink (const char *path);
 long xsysconf (int name);
diff --git a/sysdeps/nptl/internaltypes.h b/sysdeps/nptl/internaltypes.h
index b78ad99a88..30396cc448 100644
--- a/sysdeps/nptl/internaltypes.h
+++ b/sysdeps/nptl/internaltypes.h
@@ -48,6 +48,7 @@  struct pthread_attr
 #define ATTR_FLAG_OLDATTR		0x0010
 #define ATTR_FLAG_SCHED_SET		0x0020
 #define ATTR_FLAG_POLICY_SET		0x0040
+#define ATTR_FLAG_PERTHREADFS		0x0080
 
 
 /* Mutex attribute data structure.  */
diff --git a/sysdeps/nptl/pthread.h b/sysdeps/nptl/pthread.h
index df049abf74..8efcff278e 100644
--- a/sysdeps/nptl/pthread.h
+++ b/sysdeps/nptl/pthread.h
@@ -406,6 +406,18 @@  extern int pthread_attr_getaffinity_np (const pthread_attr_t *__attr,
 					cpu_set_t *__cpuset)
      __THROW __nonnull ((1, 3));
 
+
+/* Control the flag in ATTR whether the thread has its own current
+   directory, file system root, and umask attribute.  By default, new
+   threads share these attributes with their creating thread.  */
+void pthread_attr_setperthreadfs_np (pthread_attr_t *__attr, int __enabled)
+  __THROW __nonnull ((1));
+
+/* Return 1 if ATTR enables private file system attributes, or 0 if
+   not.  See pthread_attr_setperthreadfs_np.  */
+int pthread_attr_getperthreadfs_np (const pthread_attr_t *__attr)
+  __THROW __nonnull ((1));
+
 /* Get the default attributes used by pthread_create in this process.  */
 extern int pthread_getattr_default_np (pthread_attr_t *__attr)
      __THROW __nonnull ((1));
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index e66c741d04..59e897b59e 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2139,3 +2139,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index 8df162fe99..4ea64a9af9 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2034,6 +2034,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/arm/libc.abilist b/sysdeps/unix/sysv/linux/arm/libc.abilist
index 43c804f9dc..1074323ac7 100644
--- a/sysdeps/unix/sysv/linux/arm/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/libc.abilist
@@ -124,6 +124,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
 GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
diff --git a/sysdeps/unix/sysv/linux/createthread.c b/sysdeps/unix/sysv/linux/createthread.c
index 5879e51bd2..8de97746dc 100644
--- a/sysdeps/unix/sysv/linux/createthread.c
+++ b/sysdeps/unix/sysv/linux/createthread.c
@@ -66,7 +66,9 @@  create_thread (struct pthread *pd, const struct pthread_attr *attr,
 
      CLONE_VM, CLONE_FS, CLONE_FILES
 	These flags select semantics with shared address space and
-	file descriptors according to what POSIX requires.
+	file descriptors according to what POSIX requires.  CLONE_FS
+	is optional; it can be using the function
+	pthread_attr_setperthreadfs_np.
 
      CLONE_SIGHAND, CLONE_THREAD
 	This flag selects the POSIX signal semantics and various
@@ -90,11 +92,13 @@  create_thread (struct pthread *pd, const struct pthread_attr *attr,
 
      The termination signal is chosen to be zero which means no signal
      is sent.  */
-  const int clone_flags = (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SYSVSEM
-			   | CLONE_SIGHAND | CLONE_THREAD
-			   | CLONE_SETTLS | CLONE_PARENT_SETTID
-			   | CLONE_CHILD_CLEARTID
-			   | 0);
+  int clone_flags = (CLONE_VM | CLONE_FILES | CLONE_SYSVSEM
+		     | CLONE_SIGHAND | CLONE_THREAD
+		     | CLONE_SETTLS | CLONE_PARENT_SETTID
+		     | CLONE_CHILD_CLEARTID
+		     | 0);
+  if ((attr->flags & ATTR_FLAG_PERTHREADFS) == 0)
+    clone_flags |= CLONE_FS;
 
   TLS_DEFINE_INIT_TP (tp, pd);
 
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index 88b01c2e75..3a2c85a8d8 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -1881,6 +1881,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index 6d02f31612..9896c9d9f4 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2046,6 +2046,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 4249712611..febdc06b39 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -1915,6 +1915,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index d47b808862..61e077b7fd 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -125,6 +125,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.4 _Exit F
 GLIBC_2.4 _IO_2_1_stderr_ D 0x98
 GLIBC_2.4 _IO_2_1_stdin_ D 0x98
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index d5e38308be..807382fa46 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -1990,6 +1990,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
index 8596b84399..313ec63271 100644
--- a/sysdeps/unix/sysv/linux/microblaze/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/libc.abilist
@@ -2131,3 +2131,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 88e0f896d5..d277f4210e 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -1968,6 +1968,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index aff7462c34..4237bad588 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -1966,6 +1966,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index 71d82444aa..0c200c15f2 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -1974,6 +1974,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index de6c53d293..aceab1b162 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -1969,6 +1969,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index e724bab9fb..e402a05d86 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2172,3 +2172,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index e9ecbccb71..976fa6c45a 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -1994,6 +1994,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index da83ea6028..0837cb981e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -1998,6 +1998,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
index 4535b40d15..0f696145a5 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist
@@ -2229,3 +2229,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
index 65725de4f0..b9a2327410 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist
@@ -124,6 +124,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 _Exit F
 GLIBC_2.3 _IO_2_1_stderr_ D 0xe0
 GLIBC_2.3 _IO_2_1_stdin_ D 0xe0
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index bbb3c4a8e7..56bbeb0572 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2101,3 +2101,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index e85ac2a178..f7a7cc3b7a 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2003,6 +2003,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index d56931022c..5f2bf4126f 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -1909,6 +1909,8 @@  GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 __fentry__ F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sh/libc.abilist b/sysdeps/unix/sysv/linux/sh/libc.abilist
index ff939a15c4..46d4254812 100644
--- a/sysdeps/unix/sysv/linux/sh/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/libc.abilist
@@ -1885,6 +1885,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 64fa9e10a5..be8189851c 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -1997,6 +1997,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index db909d1506..d29252f5b8 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -1938,6 +1938,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index 3b175f104b..a4088c691c 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -1896,6 +1896,8 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F
 GLIBC_2.3 __ctype_b_loc F
 GLIBC_2.3 __ctype_tolower_loc F
 GLIBC_2.3 __ctype_toupper_loc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 1b57710477..e11f54da10 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2147,3 +2147,5 @@  GLIBC_2.28 thrd_equal F
 GLIBC_2.28 thrd_sleep F
 GLIBC_2.28 thrd_yield F
 GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
+GLIBC_2.29 pthread_attr_getperthreadfs_np F
+GLIBC_2.29 pthread_attr_setperthreadfs_np F