diff --git a/NEWS b/NEWS
index a660fc59a8..a12b9378e7 100644
--- a/NEWS
+++ b/NEWS
@@ -31,6 +31,16 @@ Major new features:
   pthread_attr_getsigmask_np have been added.  They allow applications
   to specify the signal mask of a thread created with pthread_create.
 
+* Support for automatically registering threads with the Linux rseq
+  system call has been added.  This system call is implemented starting
+  from Linux 4.18.  The Restartable Sequences ABI accelerates user-space
+  operations on per-cpu data.  It allows user-space to perform updates
+  on per-cpu data without requiring heavy-weight atomic operations.
+  Automatically registering threads allows all libraries, including libc,
+  to make immediate use of the rseq support by using the documented ABI.
+  The GNU C Library manual has details on integration of Restartable
+  Sequences.
+
 Deprecated and removed features, and other changes affecting compatibility:
 
 * The deprecated <sys/sysctl.h> header and the sysctl function have been
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index fa03234610..817bcbbf59 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -31,7 +31,7 @@
 
 /* Amount of excess space to allocate in the static TLS area
    to allow dynamic loading of modules defining IE-model TLS data.  */
-#define TLS_STATIC_SURPLUS	64 + DL_NNS * 100
+#define TLS_STATIC_SURPLUS	64 + DL_NNS * 176
 
 
 /* Out-of-memory handler.  */
diff --git a/elf/libc_early_init.c b/elf/libc_early_init.c
index e6c64fb526..f0fcf6448e 100644
--- a/elf/libc_early_init.c
+++ b/elf/libc_early_init.c
@@ -18,10 +18,14 @@
 
 #include <ctype.h>
 #include <libc-early-init.h>
+#include <rseq-internal.h>
 
 void
 __libc_early_init (_Bool initial)
 {
   /* Initialize ctype data.  */
   __ctype_init ();
+  /* Register rseq ABI to the kernel for the main program's libc.   */
+  if (initial)
+    rseq_register_current_thread ();
 }
diff --git a/manual/threads.texi b/manual/threads.texi
index bb7a42c655..d5069d5581 100644
--- a/manual/threads.texi
+++ b/manual/threads.texi
@@ -628,6 +628,8 @@ the standard.
 * Initial Thread Signal Mask::            Setting the initial mask of threads.
 * Waiting with Explicit Clocks::          Functions for waiting with an
                                           explicit clock specification.
+* Restartable Sequences::                 Linux-specific Restartable Sequences
+                                          integration.
 @end menu
 
 @node Default Thread Attributes
@@ -843,6 +845,68 @@ Behaves like @code{pthread_timedjoin_np} except that the absolute time in
 @var{abstime} is measured against the clock specified by @var{clockid}.
 @end deftypefun
 
+@node Restartable Sequences
+@subsubsection Restartable Sequences
+
+This section describes Restartable Sequences integration for
+@theglibc{}.  This functionality is only available on Linux.
+
+@deftypevar {struct rseq} __rseq_abi
+@standards{Linux, sys/rseq.h}
+@Theglibc{} implements a @code{__rseq_abi} TLS symbol to interact with
+the Restartable Sequences system call.  The layout of this structure is
+defined by the @file{sys/rseq.h} header.  Registration of each thread's
+@code{__rseq_abi} is performed by @theglibc{} at library initialization
+and thread creation. The manual for the rseq system call can be found
+at @uref{https://git.kernel.org/pub/scm/libs/librseq/librseq.git/tree/doc/man/rseq.2}.
+
+The main executable and shared libraries may either have an undefined
+@code{__rseq_abi} TLS symbol, or define their own, with the same
+declaration as the one present in @file{sys/rseq.h}.  The dynamic linker
+will ensure that only one of those available symbols will be used at
+runtime across the process.
+
+If the main executable or shared libraries observe an uninitialized
+@code{__rseq_abi.cpu_id} field (value @code{RSEQ_CPU_ID_UNINITIALIZED}),
+they may perform rseq registration to the kernel: this means either
+glibc was prevented from doing the registration, or an older glibc
+version, which does not include rseq support, is in use.  When the main
+executable or a library thus takes ownership of the registration, the
+memory used to hold the @code{__rseq_abi} TLS variable must stay
+allocated, and is not re-used, until the very end of the thread lifetime
+or until an explicit rseq unregistration for that thread is performed.
+It is not recommended to @code{dlclose} libraries owning the
+@code{__rseq_abi} TLS variable.
+
+Users of the @code{__rseq_abi} TLS symbol can store the address of a
+@code{struct rseq_cs} to the @code{__rseq_abi.rseq_cs} TLS variable,
+thus informing the kernel that it enters a Restartable Sequence critical
+section.  This pointer and the code areas it itself points to must not
+be left pointing to memory areas which are freed or re-used.  Several
+approaches can guarantee this.  If the application or library can
+guarantee that the memory used to hold the @code{struct rseq_cs} and the
+code areas it refers to are never freed or re-used, no special action
+must be taken.  Else, before that memory is re-used of freed, the
+application is responsible for setting the @code{__rseq_abi.rseq_cs} TLS
+variable to @code{NULL} in each thread's TLS to guarantee that it does
+not leak dangling references.  Because the application does not
+typically have knowledge of libraries' use of Restartable Sequences, it
+is recommended that libraries using Restartable Sequences which may end
+up freeing or re-using their memory set the @code{__rseq_abi.rseq_cs}
+TLS variable to @code{NULL} before returning from library functions
+which use Restartable Sequences.
+
+@end deftypevar
+
+@deftypevr Macro int RSEQ_SIG
+@standards{Linux, sys/rseq.h}
+Each supported architecture provides a @code{RSEQ_SIG} macro in
+@file{sys/rseq.h} which contains a signature.  That signature is
+expected to be present in the code before each Restartable Sequences
+abort handler.  Failure to provide the expected signature may terminate
+the process with a segmentation fault.
+@end deftypevr
+
 @c FIXME these are undocumented:
 @c pthread_atfork
 @c pthread_attr_destroy
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index 35a9927cf2..45e7cd0f16 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -33,6 +33,7 @@
 #include <default-sched.h>
 #include <futex-internal.h>
 #include <tls-setup.h>
+#include <rseq-internal.h>
 #include "libioP.h"
 
 #include <shlib-compat.h>
@@ -384,6 +385,9 @@ START_THREAD_DEFN
   /* Initialize pointers to locale data.  */
   __ctype_init ();
 
+  /* Register rseq TLS to the kernel.  */
+  rseq_register_current_thread ();
+
 #ifndef __ASSUME_SET_ROBUST_LIST
   if (__set_robust_list_avail >= 0)
 #endif
@@ -579,6 +583,15 @@ START_THREAD_DEFN
      process is really dead since 'clone' got passed the CLONE_CHILD_CLEARTID
      flag.  The 'tid' field in the TCB will be set to zero.
 
+     rseq TLS is still registered at this point.  Rely on implicit
+     unregistration performed by the kernel on thread teardown.  This is not a
+     problem because the rseq TLS lives on the stack, and the stack outlives
+     the thread.  If TCB allocation is ever changed, additional steps may be
+     required, such as performing explicit rseq unregistration before
+     reclaiming the rseq TLS area memory.  It is NOT sufficient to block
+     signals because the kernel may write to the rseq area even without
+     signals.
+
      The exit code is zero since in case all threads exit by calling
      'pthread_exit' the exit status must be 0 (zero).  */
   __exit_thread ();
diff --git a/sysdeps/generic/rseq-internal.h b/sysdeps/generic/rseq-internal.h
new file mode 100644
index 0000000000..16f197397f
--- /dev/null
+++ b/sysdeps/generic/rseq-internal.h
@@ -0,0 +1,26 @@
+/* Restartable Sequences internal API.  Stub version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef RSEQ_INTERNAL_H
+#define RSEQ_INTERNAL_H
+
+static inline void
+rseq_register_current_thread (void)
+{
+}
+
+#endif /* rseq-internal.h */
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index e02065dc8d..e855db2cb9 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -41,7 +41,7 @@ update-syscall-lists: arch-syscall.h
 endif
 
 ifeq ($(subdir),csu)
-sysdep_routines += errno-loc
+sysdep_routines += errno-loc rseq-sym
 endif
 
 ifeq ($(subdir),assert)
@@ -92,7 +92,8 @@ sysdep_headers += sys/mount.h sys/acct.h \
 		  bits/termios-c_lflag.h bits/termios-tcflow.h \
 		  bits/termios-misc.h \
 		  bits/types/struct_semid_ds.h \
-		  bits/ipc-perm.h
+		  bits/ipc-perm.h \
+		  sys/rseq.h bits/rseq.h
 
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
 	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
diff --git a/sysdeps/unix/sysv/linux/Versions b/sysdeps/unix/sysv/linux/Versions
index 9a58dda9f2..52ca223ab2 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -178,6 +178,7 @@ libc {
     getdents64; gettid; tgkill;
   }
   GLIBC_2.32 {
+    __rseq_abi;
   }
   GLIBC_PRIVATE {
     # functions used in other libraries
diff --git a/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h b/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h
new file mode 100644
index 0000000000..b6f6e536f4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/bits/rseq.h
@@ -0,0 +1,43 @@
+/* Restartable Sequences Linux aarch64 architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.
+
+   aarch64 -mbig-endian generates mixed endianness code vs data:
+   little-endian code and big-endian data.  Ensure the RSEQ_SIG signature
+   matches code endianness.  */
+
+#define RSEQ_SIG_CODE  0xd428bc00  /* BRK #0x45E0.  */
+
+#ifdef __AARCH64EB__
+# define RSEQ_SIG_DATA 0x00bc28d4  /* BRK #0x45E0.  */
+#else
+# define RSEQ_SIG_DATA RSEQ_SIG_CODE
+#endif
+
+#define RSEQ_SIG       RSEQ_SIG_DATA
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc.abilist b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
index 48c790b15d..e6e4f087eb 100644
--- a/sysdeps/unix/sysv/linux/aarch64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/libc.abilist
@@ -2149,6 +2149,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc.abilist b/sysdeps/unix/sysv/linux/alpha/libc.abilist
index cb70cb974f..835897876b 100644
--- a/sysdeps/unix/sysv/linux/alpha/libc.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/libc.abilist
@@ -2231,6 +2231,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc.abilist b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
index 573eca117e..f7a61fc73a 100644
--- a/sysdeps/unix/sysv/linux/arm/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/libc.abilist
@@ -133,6 +133,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/arm/bits/rseq.h b/sysdeps/unix/sysv/linux/arm/bits/rseq.h
new file mode 100644
index 0000000000..2bf780efcd
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/bits/rseq.h
@@ -0,0 +1,83 @@
+/* Restartable Sequences Linux arm architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/*
+   RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.
+
+   - ARM little endian
+
+   RSEQ_SIG uses the udf A32 instruction with an uncommon immediate operand
+   value 0x5de3.  This traps if user-space reaches this instruction by mistake,
+   and the uncommon operand ensures the kernel does not move the instruction
+   pointer to attacker-controlled code on rseq abort.
+
+   The instruction pattern in the A32 instruction set is:
+
+   e7f5def3    udf    #24035    ; 0x5de3
+
+   This translates to the following instruction pattern in the T16 instruction
+   set:
+
+   little endian:
+   def3        udf    #243      ; 0xf3
+   e7f5        b.n    <7f5>
+
+   - ARMv6+ big endian (BE8):
+
+   ARMv6+ -mbig-endian generates mixed endianness code vs data: little-endian
+   code and big-endian data.  The data value of the signature needs to have its
+   byte order reversed to generate the trap instruction:
+
+   Data: 0xf3def5e7
+
+   Translates to this A32 instruction pattern:
+
+   e7f5def3    udf    #24035    ; 0x5de3
+
+   Translates to this T16 instruction pattern:
+
+   def3        udf    #243      ; 0xf3
+   e7f5        b.n    <7f5>
+
+   - Prior to ARMv6 big endian (BE32):
+
+   Prior to ARMv6, -mbig-endian generates big-endian code and data
+   (which match), so the endianness of the data representation of the
+   signature should not be reversed.  However, the choice between BE32
+   and BE8 is done by the linker, so we cannot know whether code and
+   data endianness will be mixed before the linker is invoked.  So rather
+   than try to play tricks with the linker, the rseq signature is simply
+   data (not a trap instruction) prior to ARMv6 on big endian.  This is
+   why the signature is expressed as data (.word) rather than as
+   instruction (.inst) in assembler.  */
+
+#ifdef __ARMEB__
+# define RSEQ_SIG    0xf3def5e7      /* udf    #24035    ; 0x5de3 (ARMv6+) */
+#else
+# define RSEQ_SIG    0xe7f5def3      /* udf    #24035    ; 0x5de3 */
+#endif
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc.abilist b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
index 8a8633f0a4..c84ab6e5c3 100644
--- a/sysdeps/unix/sysv/linux/arm/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/libc.abilist
@@ -130,6 +130,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/bits/rseq.h b/sysdeps/unix/sysv/linux/bits/rseq.h
new file mode 100644
index 0000000000..014c08fe0f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/bits/rseq.h
@@ -0,0 +1,29 @@
+/* Restartable Sequences architecture header.  Stub version.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.  */
diff --git a/sysdeps/unix/sysv/linux/csky/libc.abilist b/sysdeps/unix/sysv/linux/csky/libc.abilist
index 3042a93084..2fadebd7ee 100644
--- a/sysdeps/unix/sysv/linux/csky/libc.abilist
+++ b/sysdeps/unix/sysv/linux/csky/libc.abilist
@@ -2093,6 +2093,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc.abilist b/sysdeps/unix/sysv/linux/hppa/libc.abilist
index a02a576321..c28604ffc7 100644
--- a/sysdeps/unix/sysv/linux/hppa/libc.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libc.abilist
@@ -2052,6 +2052,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/i386/libc.abilist b/sysdeps/unix/sysv/linux/i386/libc.abilist
index f0b9c9e070..4042d2b4e1 100644
--- a/sysdeps/unix/sysv/linux/i386/libc.abilist
+++ b/sysdeps/unix/sysv/linux/i386/libc.abilist
@@ -2218,6 +2218,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc.abilist b/sysdeps/unix/sysv/linux/ia64/libc.abilist
index 1534fd7a24..13a38cbafd 100644
--- a/sysdeps/unix/sysv/linux/ia64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/libc.abilist
@@ -2084,6 +2084,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
index 9a0ada4b52..231e41ed37 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist
@@ -134,6 +134,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
index 333c35bf16..b244e2a327 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist
@@ -2164,6 +2164,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
index 824eceec11..8c53e8b512 100644
--- a/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc.abilist
@@ -2144,6 +2144,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
index 5a6dcdd21b..fa7df5a6d8 100644
--- a/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc.abilist
@@ -2141,6 +2141,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/mips/bits/rseq.h b/sysdeps/unix/sysv/linux/mips/bits/rseq.h
new file mode 100644
index 0000000000..fa945fc7c1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/bits/rseq.h
@@ -0,0 +1,62 @@
+/* Restartable Sequences Linux mips architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.
+
+   RSEQ_SIG uses the break instruction.  The instruction pattern is:
+
+   On MIPS:
+        0350000d        break     0x350
+
+   On nanoMIPS:
+        00100350        break     0x350
+
+   On microMIPS:
+        0000d407        break     0x350
+
+   For nanoMIPS32 and microMIPS, the instruction stream is encoded as
+   16-bit halfwords, so the signature halfwords need to be swapped
+   accordingly for little-endian.  */
+
+#if defined (__nanomips__)
+# ifdef __MIPSEL__
+#  define RSEQ_SIG      0x03500010
+# else
+#  define RSEQ_SIG      0x00100350
+# endif
+#elif defined (__mips_micromips)
+# ifdef __MIPSEL__
+#  define RSEQ_SIG      0xd4070000
+# else
+#  define RSEQ_SIG      0x0000d407
+# endif
+#elif defined (__mips__)
+# define RSEQ_SIG       0x0350000d
+#else
+/* Unknown MIPS architecture.  */
+#endif
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
index 6e5dbb28f1..831251f1fd 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist
@@ -2135,6 +2135,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
index 3ee64614b2..6f3c014ed1 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist
@@ -2133,6 +2133,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
index dc62615524..c3a3931e55 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist
@@ -2141,6 +2141,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
index 8cf78bcf51..bdc9b416b2 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist
@@ -2135,6 +2135,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/nios2/libc.abilist b/sysdeps/unix/sysv/linux/nios2/libc.abilist
index 7817aeb0e2..d8573f6bbe 100644
--- a/sysdeps/unix/sysv/linux/nios2/libc.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/libc.abilist
@@ -2182,6 +2182,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h b/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h
new file mode 100644
index 0000000000..0dc608ebd5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/rseq.h
@@ -0,0 +1,37 @@
+/* Restartable Sequences Linux powerpc architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.
+
+   RSEQ_SIG uses the following trap instruction:
+
+   powerpc-be:    0f e5 00 0b           twui   r5,11
+   powerpc64-le:  0b 00 e5 0f           twui   r5,11
+   powerpc64-be:  0f e5 00 0b           twui   r5,11  */
+
+#define RSEQ_SIG        0x0fe5000b
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
index ca04e8f2d3..77309e8044 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist
@@ -2191,6 +2191,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
index 10cb895639..84da7446ca 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist
@@ -2224,6 +2224,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
index 96ddc448d7..219316b5f4 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc.abilist
@@ -2054,6 +2054,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
index deddb53d83..05c99997a3 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc.abilist
@@ -2291,6 +2291,7 @@ GLIBC_2.32 __qecvtieee128_r F
 GLIBC_2.32 __qfcvtieee128 F
 GLIBC_2.32 __qfcvtieee128_r F
 GLIBC_2.32 __qgcvtieee128 F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 __scanfieee128 F
 GLIBC_2.32 __snprintf_chkieee128 F
 GLIBC_2.32 __snprintfieee128 F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
index 58217dcb13..22db101803 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc.abilist
@@ -2111,6 +2111,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/rseq-internal.h b/sysdeps/unix/sysv/linux/rseq-internal.h
new file mode 100644
index 0000000000..8f6772ca1d
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/rseq-internal.h
@@ -0,0 +1,73 @@
+/* Restartable Sequences internal API.  Linux implementation.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef RSEQ_INTERNAL_H
+#define RSEQ_INTERNAL_H
+
+#include <sysdep.h>
+#include <errno.h>
+#include <kernel-features.h>
+#include <stdio.h>
+#include <sys/rseq.h>
+
+#ifdef RSEQ_SIG
+static inline void
+rseq_register_current_thread (void)
+{
+  int ret;
+
+  if (__rseq_abi.cpu_id != RSEQ_CPU_ID_UNINITIALIZED)
+    __libc_fatal ("glibc fatal error: "
+                  "rseq already initialized for this thread\n");
+  ret = INTERNAL_SYSCALL_CALL (rseq, &__rseq_abi, sizeof (struct rseq),
+                               0, RSEQ_SIG);
+  if (INTERNAL_SYSCALL_ERROR_P (ret))
+    {
+      const char *msg = NULL;
+
+      switch (INTERNAL_SYSCALL_ERRNO (ret))
+        {
+        case ENOSYS:    /* rseq system call not implemented.  */
+        case EPERM:     /* rseq system call filtered by seccomp.  */
+        case EACCES:    /* rseq system call filtered by seccomp.  */
+          __rseq_abi.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
+          break;
+        case EBUSY:
+          msg = "glibc fatal error: rseq already registered for this thread\n";
+          break;
+        case EFAULT:
+          msg = "glibc fatal error: rseq parameter is an invalid address\n";
+          break;
+        case EINVAL:
+          msg = "glibc fatal error: rseq parameters are invalid\n";
+          break;
+        default:
+          msg = "glibc fatal error: unexpected rseq errno\n";
+          break;
+        }
+      if (msg != NULL)
+        __libc_fatal (msg);
+    }
+}
+#else /* RSEQ_SIG */
+static inline void
+rseq_register_current_thread (void)
+{
+}
+#endif /* RSEQ_SIG */
+
+#endif /* rseq-internal.h */
diff --git a/sysdeps/unix/sysv/linux/rseq-sym.c b/sysdeps/unix/sysv/linux/rseq-sym.c
new file mode 100644
index 0000000000..090093408f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/rseq-sym.c
@@ -0,0 +1,26 @@
+/* Restartable Sequences exported symbols.  Linux Implementation.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <sys/syscall.h>
+#include <stdint.h>
+#include <kernel-features.h>
+#include <sys/rseq.h>
+
+__thread struct rseq __rseq_abi =
+  {
+    .cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
+  };
diff --git a/sysdeps/unix/sysv/linux/s390/bits/rseq.h b/sysdeps/unix/sysv/linux/s390/bits/rseq.h
new file mode 100644
index 0000000000..3d6fd0cfb9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/bits/rseq.h
@@ -0,0 +1,37 @@
+/* Restartable Sequences Linux s390 architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   It is a 32-bit value that maps to actual architecture code compiled
+   into applications and libraries.  It needs to be defined for each
+   architecture.  When choosing this value, it needs to be taken into
+   account that generating invalid instructions may have ill effects on
+   tools like objdump, and may also have impact on the CPU speculative
+   execution efficiency in some cases.
+
+   RSEQ_SIG uses the trap4 instruction.  As Linux does not make use of the
+   access-register mode nor the linkage stack this instruction will always
+   cause a special-operation exception (the trap-enabled bit in the DUCT
+   is and will stay 0).  The instruction pattern is
+       b2 ff 0f ff        trap4   4095(%r0)  */
+
+#define RSEQ_SIG        0xB2FF0FFF
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
index c22c29b35a..256ce370ae 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist
@@ -2189,6 +2189,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
index 568f1727c4..5d6304393b 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
@@ -2090,6 +2090,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc.abilist b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
index d9988dae90..bff6c48ae4 100644
--- a/sysdeps/unix/sysv/linux/sh/be/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/libc.abilist
@@ -2059,6 +2059,7 @@ GLIBC_2.30 twalk_r F
 GLIBC_2.31 msgctl F
 GLIBC_2.31 semctl F
 GLIBC_2.31 shmctl F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc.abilist b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
index 39edeffe82..e55f46a5d6 100644
--- a/sysdeps/unix/sysv/linux/sh/le/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/libc.abilist
@@ -2056,6 +2056,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
index 8668e15e8c..96e76c76a3 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist
@@ -2180,6 +2180,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
index eb884afa3e..e6bfb396b2 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist
@@ -2107,6 +2107,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/sys/rseq.h b/sysdeps/unix/sysv/linux/sys/rseq.h
new file mode 100644
index 0000000000..5e118c1781
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sys/rseq.h
@@ -0,0 +1,223 @@
+/* Restartable Sequences exported symbols.  Linux header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+#define _SYS_RSEQ_H	1
+
+/* Architecture-specific rseq signature.  */
+#include <bits/rseq.h>
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+
+#ifdef __has_include
+# if __has_include ("linux/rseq.h")
+#  define __GLIBC_HAVE_KERNEL_RSEQ
+# endif
+#else
+# include <linux/version.h>
+# if LINUX_VERSION_CODE >= KERNEL_VERSION (4, 18, 0)
+#  define __GLIBC_HAVE_KERNEL_RSEQ
+# endif
+#endif
+
+#ifdef __cplusplus
+# if  __cplusplus >= 201103L
+#  define __rseq_static_assert(expr, diagnostic) static_assert (expr, diagnostic)
+#  define __rseq_alignof(type)                   alignof (type)
+#  define __rseq_tls_storage_class               thread_local
+# endif
+#elif (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) >= 201112L
+# define __rseq_static_assert(expr, diagnostic)  _Static_assert (expr, diagnostic)
+# define __rseq_alignof(type)                    _Alignof (type)
+# define __rseq_tls_storage_class                _Thread_local
+#endif
+
+#ifndef __rseq_static_assert
+/* Try to use _Static_assert macro from sys/cdefs.h.  */
+# ifdef _Static_assert
+#  define __rseq_static_assert(expr, diagnostic) _Static_assert (expr, diagnostic)
+# else
+#  define __rseq_static_assert(expr, diagnostic) /* Nothing.  */
+# endif
+#endif
+
+/* Rely on GNU extensions for older standards and tls model.  */
+#ifdef __GNUC__
+# ifndef __rseq_alignof
+#  define __rseq_alignof(x) __alignof__ (x)
+# endif
+# define __rseq_tls_model_ie __attribute__ ((__tls_model__ ("initial-exec")))
+#else
+/* Specifying the TLS model on the declaration is optional.  */
+# define __rseq_tls_model_ie /* Nothing.  */
+#endif
+
+/* Fall back to __thread for TLS storage class.  */
+#ifndef __rseq_tls_storage_class
+# define __rseq_tls_storage_class __thread
+#endif
+
+#ifdef __GLIBC_HAVE_KERNEL_RSEQ
+/* We use the structures declarations from the kernel headers.  */
+# include <linux/rseq.h>
+#else /* __GLIBC_HAVE_KERNEL_RSEQ */
+/* We use a copy of the include/uapi/linux/rseq.h kernel header.  */
+
+# include <asm/byteorder.h>
+
+enum rseq_cpu_id_state
+  {
+    RSEQ_CPU_ID_UNINITIALIZED = -1,
+    RSEQ_CPU_ID_REGISTRATION_FAILED = -2,
+  };
+
+enum rseq_flags
+  {
+    RSEQ_FLAG_UNREGISTER = (1 << 0),
+  };
+
+enum rseq_cs_flags_bit
+  {
+    RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT = 0,
+    RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT = 1,
+    RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT = 2,
+  };
+
+enum rseq_cs_flags
+  {
+    RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT =
+      (1U << RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT),
+    RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL =
+      (1U << RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT),
+    RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE =
+      (1U << RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT),
+  };
+
+/* struct rseq_cs is aligned on 32 bytes to ensure it is always
+   contained within a single cache-line.  It is usually declared as
+   link-time constant data.  */
+struct rseq_cs
+  {
+    /* Version of this structure.  */
+    uint32_t version;
+    /* enum rseq_cs_flags.  */
+    uint32_t flags;
+    uint64_t start_ip;
+    /* Offset from start_ip.  */
+    uint64_t post_commit_offset;
+    uint64_t abort_ip;
+  } __attribute__ ((__aligned__ (32)));
+
+/* struct rseq is aligned on 32 bytes to ensure it is always
+   contained within a single cache-line.
+
+   A single struct rseq per thread is allowed.  */
+struct rseq
+  {
+    /* Restartable sequences cpu_id_start field.  Updated by the
+       kernel.  Read by user-space with single-copy atomicity
+       semantics.  This field should only be read by the thread which
+       registered this data structure.  Aligned on 32-bit.  Always
+       contains a value in the range of possible CPUs, although the
+       value may not be the actual current CPU (e.g. if rseq is not
+       initialized).  This CPU number value should always be compared
+       against the value of the cpu_id field before performing a rseq
+       commit or returning a value read from a data structure indexed
+       using the cpu_id_start value.  */
+    uint32_t cpu_id_start;
+    /* Restartable sequences cpu_id field.  Updated by the kernel.
+       Read by user-space with single-copy atomicity semantics.  This
+       field should only be read by the thread which registered this
+       data structure.  Aligned on 32-bit.  Values
+       RSEQ_CPU_ID_UNINITIALIZED and RSEQ_CPU_ID_REGISTRATION_FAILED
+       have a special semantic: the former means "rseq uninitialized",
+       and latter means "rseq initialization failed".  This value is
+       meant to be read within rseq critical sections and compared
+       with the cpu_id_start value previously read, before performing
+       the commit instruction, or read and compared with the
+       cpu_id_start value before returning a value loaded from a data
+       structure indexed using the cpu_id_start value.  */
+    uint32_t cpu_id;
+    /* Restartable sequences rseq_cs field.
+
+       Contains NULL when no critical section is active for the current
+       thread, or holds a pointer to the currently active struct rseq_cs.
+
+       Updated by user-space, which sets the address of the currently
+       active rseq_cs at the beginning of assembly instruction sequence
+       block, and set to NULL by the kernel when it restarts an assembly
+       instruction sequence block, as well as when the kernel detects that
+       it is preempting or delivering a signal outside of the range
+       targeted by the rseq_cs.  Also needs to be set to NULL by user-space
+       before reclaiming memory that contains the targeted struct rseq_cs.
+
+       Read and set by the kernel.  Set by user-space with single-copy
+       atomicity semantics.  This field should only be updated by the
+       thread which registered this data structure.  Aligned on 64-bit.  */
+    union
+      {
+        uint64_t ptr64;
+# ifdef __LP64__
+        uint64_t ptr;
+# else /* __LP64__ */
+        struct
+          {
+#  if (defined (__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined (__BIG_ENDIAN)
+            uint32_t padding; /* Initialized to zero.  */
+            uint32_t ptr32;
+#  else /* LITTLE */
+            uint32_t ptr32;
+            uint32_t padding; /* Initialized to zero.  */
+#  endif /* ENDIAN */
+          } ptr;
+# endif /* __LP64__ */
+      } rseq_cs;
+
+    /* Restartable sequences flags field.
+
+       This field should only be updated by the thread which
+       registered this data structure.  Read by the kernel.
+       Mainly used for single-stepping through rseq critical sections
+       with debuggers.
+
+       - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT
+           Inhibit instruction sequence block restart on preemption
+           for this thread.
+       - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL
+           Inhibit instruction sequence block restart on signal
+           delivery for this thread.
+       - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE
+           Inhibit instruction sequence block restart on migration for
+           this thread.  */
+    uint32_t flags;
+  } __attribute__ ((__aligned__ (32)));
+
+#endif /* __GLIBC_HAVE_KERNEL_RSEQ */
+
+/* Ensure the compiler supports rseq_align.  */
+__rseq_static_assert (__rseq_alignof (struct rseq_cs) >= 32, "alignment");
+__rseq_static_assert (__rseq_alignof (struct rseq) >= 32, "alignment");
+
+/* Allocations of struct rseq and struct rseq_cs on the heap need to
+   be aligned on 32 bytes.  Therefore, use of malloc is discouraged
+   because it does not guarantee alignment.  posix_memalign should be
+   used instead.  */
+
+extern __rseq_tls_storage_class struct rseq __rseq_abi __rseq_tls_model_ie;
+
+#endif /* sys/rseq.h */
diff --git a/sysdeps/unix/sysv/linux/x86/bits/rseq.h b/sysdeps/unix/sysv/linux/x86/bits/rseq.h
new file mode 100644
index 0000000000..f801d5d0a1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/bits/rseq.h
@@ -0,0 +1,30 @@
+/* Restartable Sequences Linux x86 architecture header.
+   Copyright (C) 2020 Free Software Foundation, Inc.
+
+   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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_RSEQ_H
+# error "Never use <bits/rseq.h> directly; include <sys/rseq.h> instead."
+#endif
+
+/* RSEQ_SIG is a signature required before each abort handler code.
+
+   RSEQ_SIG is used with the following reserved undefined instructions, which
+   trap in user-space:
+
+   x86-32:    0f b9 3d 53 30 05 53      ud1    0x53053053,%edi
+   x86-64:    0f b9 3d 53 30 05 53      ud1    0x53053053(%rip),%edi  */
+
+#define RSEQ_SIG        0x53053053
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
index a208fb3556..168ca03aa2 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc.abilist
@@ -2065,6 +2065,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
index 3eca3493e2..82a5089792 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist
@@ -2162,6 +2162,7 @@ GLIBC_2.30 getdents64 F
 GLIBC_2.30 gettid F
 GLIBC_2.30 tgkill F
 GLIBC_2.30 twalk_r F
+GLIBC_2.32 __rseq_abi T 0x20
 GLIBC_2.32 pthread_attr_getsigmask_np F
 GLIBC_2.32 pthread_attr_setaffinity_np F
 GLIBC_2.32 pthread_attr_setsigmask_np F
