nptl: Add public rseq symbols and <sys/rseq.h>

The relationship between the thread pointer and the rseq area
is made explicit.  The constant offset can be used by JIT compilers
to optimize rseq access (e.g., for really fast sched_getcpu).

Extensibility is provided through __rseq_size and __rseq_flags.
(In the future, the kernel could request a different rseq size
via the auxiliary vector.)

Co-Authored-By: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>

36 files changed, 145 insertions, 5 deletions

diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c
index b39dfbf..4a73927 100644
--- a/sysdeps/nptl/dl-tls_init_tp.c
+++ b/sysdeps/nptl/dl-tls_init_tp.c
@@ -22,6 +22,7 @@
 #include <pthreadP.h>
 #include <tls.h>
 #include <rseq-internal.h>
+#include <thread_pointer.h>
 
 #define TUNABLE_NAMESPACE pthread
 #include <dl-tunables.h>
@@ -43,6 +44,10 @@ rtld_mutex_dummy (pthread_mutex_t *lock)
 }
 #endif
 
+const unsigned int __rseq_flags;
+const unsigned int __rseq_size attribute_relro;
+const int __rseq_offset attribute_relro;
+
 void
 __tls_pre_init_tp (void)
 {
@@ -100,7 +105,23 @@ __tls_init_tp (void)
 #if HAVE_TUNABLES
     do_rseq = TUNABLE_GET (rseq, int, NULL);
 #endif
-    rseq_register_current_thread (pd, do_rseq);
+    if (rseq_register_current_thread (pd, do_rseq))
+      {
+        /* We need a writable view of the variables.  They are in
+           .data.relro and are not yet write-protected.  */
+        extern unsigned int size __asm__ ("__rseq_size");
+        size = sizeof (pd->rseq_area);
+      }
+
+#ifdef RSEQ_SIG
+    /* This should be a compile-time constant, but the current
+       infrastructure makes it difficult to determine its value.  Not
+       all targets support __thread_pointer, so set __rseq_offset only
+       if thre rseq registration may have happened because RSEQ_SIG is
+       defined.  */
+    extern int offset __asm__ ("__rseq_offset");
+    offset = (char *) &pd->rseq_area - (char *) __thread_pointer ();
+#endif
   }
 
   /* Set initial thread's stack block from 0 up to __libc_stack_end.
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 62a796f..61acc19 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -112,7 +112,8 @@ sysdep_headers += sys/mount.h sys/acct.h \
 		  bits/types/struct_semid64_ds_helper.h \
 		  bits/types/struct_shmid64_ds.h \
 		  bits/types/struct_shmid64_ds_helper.h \
-		  bits/pthread_stack_min.h bits/pthread_stack_min-dynamic.h
+		  bits/pthread_stack_min.h bits/pthread_stack_min-dynamic.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 26452f3..3f8809a 100644
--- a/sysdeps/unix/sysv/linux/Versions
+++ b/sysdeps/unix/sysv/linux/Versions
@@ -316,6 +316,11 @@ librt {
 }
 
 ld {
+  GLIBC_2.35 {
+    __rseq_flags;
+    __rseq_offset;
+    __rseq_size;
+  }
   GLIBC_PRIVATE {
     __nptl_change_stack_perm;
   }
diff --git a/sysdeps/unix/sysv/linux/aarch64/ld.abilist b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
index 80b2fe6..717a35f 100644
--- a/sysdeps/unix/sysv/linux/aarch64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/aarch64/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.17 __stack_chk_guard D 0x8
 GLIBC_2.17 __tls_get_addr F
 GLIBC_2.17 _dl_mcount F
 GLIBC_2.17 _r_debug D 0x28
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/alpha/ld.abilist b/sysdeps/unix/sysv/linux/alpha/ld.abilist
index 98a03f6..76911bd 100644
--- a/sysdeps/unix/sysv/linux/alpha/ld.abilist
+++ b/sysdeps/unix/sysv/linux/alpha/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.0 _r_debug D 0x28
 GLIBC_2.1 __libc_stack_end D 0x8
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x8
diff --git a/sysdeps/unix/sysv/linux/arc/ld.abilist b/sysdeps/unix/sysv/linux/arc/ld.abilist
index 048f17c..71c67f9 100644
--- a/sysdeps/unix/sysv/linux/arc/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arc/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.32 __stack_chk_guard D 0x4
 GLIBC_2.32 __tls_get_addr F
 GLIBC_2.32 _dl_mcount F
 GLIBC_2.32 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/arm/be/ld.abilist b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
index cc8825c..3859433 100644
--- a/sysdeps/unix/sysv/linux/arm/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/be/ld.abilist
@@ -1,3 +1,6 @@
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __libc_stack_end D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/arm/le/ld.abilist b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
index cc8825c..3859433 100644
--- a/sysdeps/unix/sysv/linux/arm/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/arm/le/ld.abilist
@@ -1,3 +1,6 @@
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __libc_stack_end D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/csky/ld.abilist b/sysdeps/unix/sysv/linux/csky/ld.abilist
index 564ac09..6bfc582 100644
--- a/sysdeps/unix/sysv/linux/csky/ld.abilist
+++ b/sysdeps/unix/sysv/linux/csky/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.29 __stack_chk_guard D 0x4
 GLIBC_2.29 __tls_get_addr F
 GLIBC_2.29 _dl_mcount F
 GLIBC_2.29 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/hppa/ld.abilist b/sysdeps/unix/sysv/linux/hppa/ld.abilist
index d155a59..efccd6a 100644
--- a/sysdeps/unix/sysv/linux/hppa/ld.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/i386/ld.abilist b/sysdeps/unix/sysv/linux/i386/ld.abilist
index 0478e22..1eb94ae 100644
--- a/sysdeps/unix/sysv/linux/i386/ld.abilist
+++ b/sysdeps/unix/sysv/linux/i386/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 ___tls_get_addr F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/ia64/ld.abilist b/sysdeps/unix/sysv/linux/ia64/ld.abilist
index 33f9119..2cc68bc 100644
--- a/sysdeps/unix/sysv/linux/ia64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/ia64/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
index cc8825c..3859433 100644
--- a/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/ld.abilist
@@ -1,3 +1,6 @@
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __libc_stack_end D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
 GLIBC_2.4 __tls_get_addr F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
index 3ba474c..e62b274 100644
--- a/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/microblaze/ld.abilist b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
index a4933c3..5d63d74 100644
--- a/sysdeps/unix/sysv/linux/microblaze/ld.abilist
+++ b/sysdeps/unix/sysv/linux/microblaze/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.18 __stack_chk_guard D 0x4
 GLIBC_2.18 __tls_get_addr F
 GLIBC_2.18 _dl_mcount F
 GLIBC_2.18 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
index be09641..53ca22d 100644
--- a/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips32/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
index be09641..53ca22d 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
index 1ea36e1..d1cdd68 100644
--- a/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.0 _r_debug D 0x28
 GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x8
diff --git a/sysdeps/unix/sysv/linux/nios2/ld.abilist b/sysdeps/unix/sysv/linux/nios2/ld.abilist
index 5217880..bcbba18 100644
--- a/sysdeps/unix/sysv/linux/nios2/ld.abilist
+++ b/sysdeps/unix/sysv/linux/nios2/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.21 __stack_chk_guard D 0x4
 GLIBC_2.21 __tls_get_addr F
 GLIBC_2.21 _dl_mcount F
 GLIBC_2.21 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
index 4bbfba7..0d033cb 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist
@@ -4,3 +4,6 @@ GLIBC_2.1 _dl_mcount F
 GLIBC_2.22 __tls_get_addr_opt F
 GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
index 283fb45..9c627b1 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/ld.abilist
@@ -4,3 +4,6 @@ GLIBC_2.3 __libc_stack_end D 0x8
 GLIBC_2.3 __tls_get_addr F
 GLIBC_2.3 _dl_mcount F
 GLIBC_2.3 _r_debug D 0x28
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
index b1f313c..3a748c2 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/ld.abilist
@@ -4,3 +4,6 @@ GLIBC_2.17 _dl_mcount F
 GLIBC_2.17 _r_debug D 0x28
 GLIBC_2.22 __tls_get_addr_opt F
 GLIBC_2.23 __parse_hwcap_and_convert_at_platform F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
index 94ca64c..4c67ea1 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.33 __stack_chk_guard D 0x4
 GLIBC_2.33 __tls_get_addr F
 GLIBC_2.33 _dl_mcount F
 GLIBC_2.33 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
index 845f356..09596f0 100644
--- a/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/ld.abilist
@@ -3,3 +3,6 @@ GLIBC_2.27 __stack_chk_guard D 0x8
 GLIBC_2.27 __tls_get_addr F
 GLIBC_2.27 _dl_mcount F
 GLIBC_2.27 _r_debug D 0x28
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/rseq-internal.h b/sysdeps/unix/sysv/linux/rseq-internal.h
index 15bc7ff..9e8f99f 100644
--- a/sysdeps/unix/sysv/linux/rseq-internal.h
+++ b/sysdeps/unix/sysv/linux/rseq-internal.h
@@ -26,7 +26,7 @@
 #include <sys/rseq.h>
 
 #ifdef RSEQ_SIG
-static inline void
+static inline bool
 rseq_register_current_thread (struct pthread *self, bool do_rseq)
 {
   if (do_rseq)
@@ -35,15 +35,17 @@ rseq_register_current_thread (struct pthread *self, bool do_rseq)
                                        sizeof (self->rseq_area),
                                        0, RSEQ_SIG);
       if (!INTERNAL_SYSCALL_ERROR_P (ret))
-        return;
+        return true;
     }
   THREAD_SETMEM (self, rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
+  return false;
 }
 #else /* RSEQ_SIG */
-static inline void
+static inline bool
 rseq_register_current_thread (struct pthread *self, bool do_rseq)
 {
   THREAD_SETMEM (self, rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
+  return false;
 }
 #endif /* RSEQ_SIG */
 
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
index b56f005..2c47004 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_offset F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
index 6f788a0..385a73a 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_offset F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/sh/be/ld.abilist b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
index d155a59..efccd6a 100644
--- a/sysdeps/unix/sysv/linux/sh/be/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/be/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/sh/le/ld.abilist b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
index d155a59..efccd6a 100644
--- a/sysdeps/unix/sysv/linux/sh/le/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sh/le/ld.abilist
@@ -2,4 +2,7 @@ GLIBC_2.2 __libc_stack_end D 0x4
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x14
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
 GLIBC_2.4 __stack_chk_guard D 0x4
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
index 0c6610e..8fb5ff3 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.0 _r_debug D 0x14
 GLIBC_2.1 __libc_stack_end D 0x4
 GLIBC_2.1 _dl_mcount F
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
index 33f9119..2cc68bc 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.2 __libc_stack_end D 0x8
 GLIBC_2.2 _dl_mcount F
 GLIBC_2.2 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/sys/rseq.h b/sysdeps/unix/sysv/linux/sys/rseq.h
index c8edff5..1215b5d 100644
--- a/sysdeps/unix/sysv/linux/sys/rseq.h
+++ b/sysdeps/unix/sysv/linux/sys/rseq.h
@@ -171,4 +171,14 @@ struct rseq
 
 #endif /* __GLIBC_HAVE_KERNEL_RSEQ */
 
+/* Offset from the thread pointer to the rseq area.  */
+extern const int __rseq_offset;
+
+/* Size of the registered rseq area.  0 if the registration was
+   unsuccessful.  */
+extern const unsigned int __rseq_size;
+
+/* Flags used during rseq registration.  */
+extern const unsigned int __rseq_flags;
+
 #endif /* sys/rseq.h */
diff --git a/sysdeps/unix/sysv/linux/tst-rseq-disable.c b/sysdeps/unix/sysv/linux/tst-rseq-disable.c
index 000e351..6d73f77 100644
--- a/sysdeps/unix/sysv/linux/tst-rseq-disable.c
+++ b/sysdeps/unix/sysv/linux/tst-rseq-disable.c
@@ -21,6 +21,7 @@
 #include <support/namespace.h>
 #include <support/xthread.h>
 #include <sysdep.h>
+#include <thread_pointer.h>
 #include <unistd.h>
 
 #ifdef RSEQ_SIG
@@ -30,6 +31,11 @@ static void
 check_rseq_disabled (void)
 {
   struct pthread *pd = THREAD_SELF;
+
+  TEST_COMPARE (__rseq_flags, 0);
+  TEST_VERIFY ((char *) __thread_pointer () + __rseq_offset
+               == (char *) &pd->rseq_area);
+  TEST_COMPARE (__rseq_size, 0);
   TEST_COMPARE ((int) pd->rseq_area.cpu_id, RSEQ_CPU_ID_REGISTRATION_FAILED);
 
   int ret = syscall (__NR_rseq, &pd->rseq_area, sizeof (pd->rseq_area),
diff --git a/sysdeps/unix/sysv/linux/tst-rseq.c b/sysdeps/unix/sysv/linux/tst-rseq.c
index 926376b..572c111 100644
--- a/sysdeps/unix/sysv/linux/tst-rseq.c
+++ b/sysdeps/unix/sysv/linux/tst-rseq.c
@@ -29,12 +29,20 @@
 # include <stdlib.h>
 # include <string.h>
 # include <syscall.h>
+# include <thread_pointer.h>
+# include <tls.h>
 # include "tst-rseq.h"
 
 static void
 do_rseq_main_test (void)
 {
+  struct pthread *pd = THREAD_SELF;
+
   TEST_VERIFY_EXIT (rseq_thread_registered ());
+  TEST_COMPARE (__rseq_flags, 0);
+  TEST_VERIFY ((char *) __thread_pointer () + __rseq_offset
+               == (char *) &pd->rseq_area);
+  TEST_COMPARE (__rseq_size, sizeof (pd->rseq_area));
 }
 
 static void
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
index d3cdf76..49a8f31 100644
--- a/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/64/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.2.5 __libc_stack_end D 0x8
 GLIBC_2.2.5 _dl_mcount F
 GLIBC_2.2.5 _r_debug D 0x28
 GLIBC_2.3 __tls_get_addr F
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
index c70bccf..ce68cc6 100644
--- a/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/ld.abilist
@@ -2,3 +2,6 @@ GLIBC_2.16 __libc_stack_end D 0x4
 GLIBC_2.16 __tls_get_addr F
 GLIBC_2.16 _dl_mcount F
 GLIBC_2.16 _r_debug D 0x14
+GLIBC_2.35 __rseq_flags D 0x4
+GLIBC_2.35 __rseq_offset D 0x4
+GLIBC_2.35 __rseq_size D 0x4