Register rseq(2) TLS for each thread (including main), and unregister
for each thread (excluding main). "rseq" stands for Restartable
Sequences.
See the rseq(2) man page proposed here:
https://lkml.org/lkml/2018/9/19/647
This patch is based on glibc-2.29. The rseq(2) system call was merged
into Linux 4.18.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
CC: Joseph Myers <joseph@codesourcery.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Maurer <bmaurer@fb.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Paul Turner <pjt@google.com>
CC: Rich Felker <dalias@libc.org>
CC: libc-alpha@sourceware.org
CC: linux-kernel@vger.kernel.org
CC: linux-api@vger.kernel.org
---
Changes since v1:
- Move __rseq_refcount to an extra field at the end of __rseq_abi to
eliminate one symbol.
All libraries/programs which try to register rseq (glibc,
early-adopter applications, early-adopter libraries) should use the
rseq refcount. It becomes part of the ABI within a user-space
process, but it's not part of the ABI shared with the kernel per se.
- Restructure how this code is organized so glibc keeps building on
non-Linux targets.
- Use non-weak symbol for __rseq_abi.
- Move rseq registration/unregistration implementation into its own
nptl/rseq.c compile unit.
- Move __rseq_abi symbol under GLIBC_2.29.
Changes since v2:
- Move __rseq_refcount to its own symbol, which is less ugly than
trying to play tricks with the rseq uapi.
- Move __rseq_abi from nptl to csu (C start up), so it can be used
across glibc, including memory allocator and sched_getcpu(). The
__rseq_refcount symbol is kept in nptl, because there is no reason
to use it elsewhere in glibc.
Changes since v3:
- Set __rseq_refcount TLS to 1 on register/set to 0 on unregister
because glibc is the first/last user.
- Unconditionally register/unregister rseq at thread start/exit, because
glibc is the first/last user.
- Add missing abilist items.
- Rebase on glibc master commit a502c5294.
- Add NEWS entry.
Changes since v4:
- Do not use "weak" symbols for __rseq_abi and __rseq_refcount. Based on
"System V Application Binary Interface", weak only affects the link
editor, not the dynamic linker.
- Install a new sys/rseq.h system header on Linux, which contains the
RSEQ_SIG definition, __rseq_abi declaration and __rseq_refcount
declaration. Move those definition/declarations from rseq-internal.h
to the installed sys/rseq.h header.
- Considering that rseq is only available on Linux, move csu/rseq.c to
sysdeps/unix/sysv/linux/rseq-sym.c.
- Move __rseq_refcount from nptl/rseq.c to
sysdeps/unix/sysv/linux/rseq-sym.c, so it is only defined on Linux.
- Move both ABI definitions for __rseq_abi and __rseq_refcount to
sysdeps/unix/sysv/linux/Versions, so they only appear on Linux.
- Document __rseq_abi and __rseq_refcount volatile.
- Document the RSEQ_SIG signature define.
- Move registration functions from rseq.c to rseq-internal.h static
inline functions. Introduce empty stubs in misc/rseq-internal.h,
which can be overridden by architecture code in
sysdeps/unix/sysv/linux/rseq-internal.h.
- Rename __rseq_register_current_thread and __rseq_unregister_current_thread
to rseq_register_current_thread and rseq_unregister_current_thread,
now that those are only visible as internal static inline functions.
- Invoke rseq_register_current_thread() from libc-start.c LIBC_START_MAIN
rather than nptl init, so applications not linked against
libpthread.so have rseq registered for their main() thread. Note that
it is invoked separately for SHARED and !SHARED builds.
Changes since v5:
- Replace __rseq_refcount by __rseq_lib_abi, which contains two
uint32_t: register_state and refcount. The "register_state" field
allows inhibiting rseq registration from signal handlers nested on top
of glibc registration and occuring after rseq unregistration by glibc.
- Introduce enum rseq_register_state, which contains the states allowed
for the struct rseq_lib_abi register_state field.
Changes since v6:
- Introduce bits/rseq.h to define RSEQ_SIG for each architecture.
The generic bits/rseq.h does not define RSEQ_SIG, meaning that each
architecture implementing rseq needs to implement bits/rseq.h.
- Rename enum item RSEQ_REGISTER_NESTED to RSEQ_REGISTER_ONGOING.
- Port to glibc-2.29.
Changes since v7:
- Remove __rseq_lib_abi symbol, including refcount and register_state
fields.
- Remove reference counting and nested signals handling from
registration/unregistration functions.
- Introduce new __rseq_handled exported symbol, which is set to 1
by glibc on C startup when it handles restartable sequences.
This allows glibc to coexist with early adopter libraries and
applications wishing to register restartable sequences when it
is not handled by glibc.
- Introduce rseq_init (), which sets __rseq_handled to 1 from
C startup.
- Update NEWS entry.
- Update comments at the beginning of new files.
- Registration depends on both __NR_rseq and RSEQ_SIG.
- Remove ARM, powerpc, MIPS RSEQ_SIG until we agree with maintainers
on the signature choice.
- Update x86, s390 RSEQ_SIG based on discussion with arch maintainers.
- Remove rseq-internal.h from headers list of misc/Makefile, so it
it not installed by make install.
Changes since v8:
- Introduce RSEQ_SIG_CODE and RSEQ_SIG_DATA on aarch64 to handle
compiling with -mbig-endian.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Carlos O'Donell <carlos@redhat.com>
CC: Florian Weimer <fweimer@redhat.com>
CC: Joseph Myers <joseph@codesourcery.com>
CC: Szabolcs Nagy <szabolcs.nagy@arm.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ben Maurer <bmaurer@fb.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Boqun Feng <boqun.feng@gmail.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Dave Watson <davejwatson@fb.com>
CC: Paul Turner <pjt@google.com>
CC: Rich Felker <dalias@libc.org>
CC: libc-alpha@sourceware.org
CC: linux-kernel@vger.kernel.org
CC: linux-api@vger.kernel.org
---
NEWS | 15 ++++
csu/libc-start.c | 14 ++-
misc/rseq-internal.h | 39 ++++++++
nptl/pthread_create.c | 9 ++
sysdeps/unix/sysv/linux/Makefile | 4 +-
sysdeps/unix/sysv/linux/Versions | 4 +
sysdeps/unix/sysv/linux/aarch64/bits/rseq.h | 44 +++++++++
sysdeps/unix/sysv/linux/aarch64/libc.abilist | 2 +
sysdeps/unix/sysv/linux/alpha/libc.abilist | 2 +
sysdeps/unix/sysv/linux/arm/libc.abilist | 2 +
sysdeps/unix/sysv/linux/bits/rseq.h | 30 +++++++
sysdeps/unix/sysv/linux/csky/libc.abilist | 2 +
sysdeps/unix/sysv/linux/hppa/libc.abilist | 2 +
sysdeps/unix/sysv/linux/i386/libc.abilist | 2 +
sysdeps/unix/sysv/linux/ia64/libc.abilist | 2 +
.../sysv/linux/m68k/coldfire/libc.abilist | 2 +
.../unix/sysv/linux/m68k/m680x0/libc.abilist | 2 +
.../unix/sysv/linux/microblaze/libc.abilist | 2 +
.../sysv/linux/mips/mips32/fpu/libc.abilist | 2 +
.../sysv/linux/mips/mips32/nofpu/libc.abilist | 2 +
.../sysv/linux/mips/mips64/n32/libc.abilist | 2 +
.../sysv/linux/mips/mips64/n64/libc.abilist | 2 +
sysdeps/unix/sysv/linux/nios2/libc.abilist | 2 +
.../linux/powerpc/powerpc32/fpu/libc.abilist | 2 +
.../powerpc/powerpc32/nofpu/libc.abilist | 2 +
.../linux/powerpc/powerpc64/be/libc.abilist | 2 +
.../linux/powerpc/powerpc64/le/libc.abilist | 2 +
.../unix/sysv/linux/riscv/rv64/libc.abilist | 2 +
sysdeps/unix/sysv/linux/rseq-internal.h | 89 +++++++++++++++++++
sysdeps/unix/sysv/linux/rseq-sym.c | 64 +++++++++++++
sysdeps/unix/sysv/linux/s390/bits/rseq.h | 31 +++++++
.../unix/sysv/linux/s390/s390-32/libc.abilist | 2 +
.../unix/sysv/linux/s390/s390-64/libc.abilist | 2 +
sysdeps/unix/sysv/linux/sh/libc.abilist | 2 +
.../sysv/linux/sparc/sparc32/libc.abilist | 2 +
.../sysv/linux/sparc/sparc64/libc.abilist | 2 +
sysdeps/unix/sysv/linux/sys/rseq.h | 51 +++++++++++
sysdeps/unix/sysv/linux/x86/bits/rseq.h | 31 +++++++
.../unix/sysv/linux/x86_64/64/libc.abilist | 2 +
.../unix/sysv/linux/x86_64/x32/libc.abilist | 2 +
40 files changed, 474 insertions(+), 5 deletions(-)
create mode 100644 misc/rseq-internal.h
create mode 100644 sysdeps/unix/sysv/linux/aarch64/bits/rseq.h
create mode 100644 sysdeps/unix/sysv/linux/bits/rseq.h
create mode 100644 sysdeps/unix/sysv/linux/rseq-internal.h
create mode 100644 sysdeps/unix/sysv/linux/rseq-sym.c
create mode 100644 sysdeps/unix/sysv/linux/s390/bits/rseq.h
create mode 100644 sysdeps/unix/sysv/linux/sys/rseq.h
create mode 100644 sysdeps/unix/sysv/linux/x86/bits/rseq.h
@@ -5,6 +5,21 @@ See the end for copying conditions.
Please send GNU C library bug reports via <https://sourceware.org/bugzilla/>
using `glibc' in the "product" field.
+Version 2.30
+
+Major new features:
+
+* Support for automatically registering threads with the Linux rseq(2)
+ 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(2) support by using the documented ABI.
+ See 'man 2 rseq' for the details of the ABI shared between libc and the
+ kernel.
+
+
Version 2.29
Major new features:
@@ -22,6 +22,7 @@
#include <ldsodefs.h>
#include <exit-thread.h>
#include <libc-internal.h>
+#include <rseq-internal.h>
#include <elf/dl-tunables.h>
@@ -140,7 +141,12 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
__libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
-#ifndef SHARED
+ rseq_init ();
+
+#ifdef SHARED
+ /* Register rseq ABI to the kernel. */
+ (void) rseq_register_current_thread ();
+#else
_dl_relocate_static_pie ();
char **ev = &argv[argc + 1];
@@ -218,6 +224,9 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
}
# endif
+ /* Register rseq ABI to the kernel. */
+ (void) rseq_register_current_thread ();
+
/* Initialize libpthread if linked in. */
if (__pthread_initialize_minimal != NULL)
__pthread_initialize_minimal ();
@@ -230,8 +239,7 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
# else
__pointer_chk_guard_local = pointer_chk_guard;
# endif
-
-#endif /* !SHARED */
+#endif
/* Register the destructor of the dynamic linker if there is any. */
if (__glibc_likely (rtld_fini != NULL))
new file mode 100644
@@ -0,0 +1,39 @@
+/* Restartable Sequences internal API. Stub version.
+
+ Copyright (C) 2019 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef RSEQ_INTERNAL_H
+#define RSEQ_INTERNAL_H
+
+static inline int
+rseq_register_current_thread (void)
+{
+ return -1;
+}
+
+static inline int
+rseq_unregister_current_thread (void)
+{
+ return -1;
+}
+
+static inline int
+rseq_init (void)
+{
+}
+
+#endif /* rseq-internal.h */
@@ -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>
@@ -378,6 +379,7 @@ __free_tcb (struct pthread *pd)
START_THREAD_DEFN
{
struct pthread *pd = START_THREAD_SELF;
+ bool has_rseq = false;
#if HP_TIMING_AVAIL
/* Remember the time when the thread was started. */
@@ -396,6 +398,9 @@ START_THREAD_DEFN
if (__glibc_unlikely (atomic_exchange_acq (&pd->setxid_futex, 0) == -2))
futex_wake (&pd->setxid_futex, 1, FUTEX_PRIVATE);
+ /* Register rseq TLS to the kernel. */
+ has_rseq = !rseq_register_current_thread ();
+
#ifdef __NR_set_robust_list
# ifndef __ASSUME_SET_ROBUST_LIST
if (__set_robust_list_avail >= 0)
@@ -573,6 +578,10 @@ START_THREAD_DEFN
}
#endif
+ /* Unregister rseq TLS from kernel. */
+ if (has_rseq && rseq_unregister_current_thread ())
+ abort();
+
advise_stack_range (pd->stackblock, pd->stackblock_size, (uintptr_t) pd,
pd->guardsize);
@@ -1,5 +1,5 @@
ifeq ($(subdir),csu)
-sysdep_routines += errno-loc
+sysdep_routines += errno-loc rseq-sym
endif
ifeq ($(subdir),assert)
@@ -48,7 +48,7 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
bits/termios-c_iflag.h bits/termios-c_oflag.h \
bits/termios-baud.h bits/termios-c_cflag.h \
bits/termios-c_lflag.h bits/termios-tcflow.h \
- bits/termios-misc.h
+ bits/termios-misc.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 \
@@ -174,6 +174,10 @@ libc {
GLIBC_2.29 {
getcpu;
}
+ GLIBC_2.30 {
+ __rseq_abi;
+ __rseq_handled;
+ }
GLIBC_PRIVATE {
# functions used in other libraries
__syscall_rt_sigqueueinfo;
new file mode 100644
@@ -0,0 +1,44 @@
+/* Restartable Sequences Linux aarch64 architecture header.
+
+ Copyright (C) 2019 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
+ <http://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
@@ -2141,3 +2141,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
@@ -2204,6 +2204,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -126,6 +126,8 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _Exit F
GLIBC_2.4 _IO_2_1_stderr_ D 0xa0
GLIBC_2.4 _IO_2_1_stdin_ D 0xa0
new file mode 100644
@@ -0,0 +1,30 @@
+/* Restartable Sequences architecture header. Stub version.
+
+ Copyright (C) 2019 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
+ <http://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. */
@@ -2085,3 +2085,5 @@ GLIBC_2.29 xdrstdio_create F
GLIBC_2.29 xencrypt F
GLIBC_2.29 xprt_register F
GLIBC_2.29 xprt_unregister F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
@@ -2037,6 +2037,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2203,6 +2203,8 @@ GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 vm86 F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2069,6 +2069,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -127,6 +127,8 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _Exit F
GLIBC_2.4 _IO_2_1_stderr_ D 0x98
GLIBC_2.4 _IO_2_1_stdin_ D 0x98
@@ -2146,6 +2146,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2133,3 +2133,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
@@ -2120,6 +2120,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2118,6 +2118,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2126,6 +2126,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2120,6 +2120,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2174,3 +2174,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
@@ -2164,6 +2164,8 @@ GLIBC_2.3.4 siglongjmp F
GLIBC_2.3.4 swapcontext F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2197,6 +2197,8 @@ GLIBC_2.3.4 siglongjmp F
GLIBC_2.3.4 swapcontext F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2027,6 +2027,8 @@ GLIBC_2.3.4 siglongjmp F
GLIBC_2.3.4 swapcontext F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2231,3 +2231,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
@@ -2103,3 +2103,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
new file mode 100644
@@ -0,0 +1,89 @@
+/* Restartable Sequences internal API. Linux implementation.
+
+ Copyright (C) 2019 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef RSEQ_INTERNAL_H
+#define RSEQ_INTERNAL_H
+
+#include <sysdep.h>
+#include <errno.h>
+
+#ifdef __NR_rseq
+#include <sys/rseq.h>
+#endif
+
+#if defined __NR_rseq && defined RSEQ_SIG
+
+static inline int
+rseq_register_current_thread (void)
+{
+ int rc, ret = 0;
+ INTERNAL_SYSCALL_DECL (err);
+
+ if (__rseq_abi.cpu_id == RSEQ_CPU_ID_REGISTRATION_FAILED)
+ return -1;
+ rc = INTERNAL_SYSCALL_CALL (rseq, err, &__rseq_abi, sizeof (struct rseq),
+ 0, RSEQ_SIG);
+ if (!rc)
+ goto end;
+ if (INTERNAL_SYSCALL_ERRNO (rc, err) != EBUSY)
+ __rseq_abi.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
+ ret = -1;
+end:
+ return ret;
+}
+
+static inline int
+rseq_unregister_current_thread (void)
+{
+ int rc, ret = 0;
+ INTERNAL_SYSCALL_DECL (err);
+
+ rc = INTERNAL_SYSCALL_CALL (rseq, err, &__rseq_abi, sizeof (struct rseq),
+ RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
+ if (!rc)
+ goto end;
+ ret = -1;
+end:
+ return ret;
+}
+
+static inline void
+rseq_init (void)
+{
+ __rseq_handled = 1;
+}
+#else
+static inline int
+rseq_register_current_thread (void)
+{
+ return -1;
+}
+
+static inline int
+rseq_unregister_current_thread (void)
+{
+ return -1;
+}
+
+static inline void
+rseq_init (void)
+{
+}
+#endif
+
+#endif /* rseq-internal.h */
new file mode 100644
@@ -0,0 +1,64 @@
+/* Restartable Sequences exported symbols. Linux Implementation.
+
+ Copyright (C) 2019 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
+ <http://www.gnu.org/licenses/>. */
+
+#include <sys/syscall.h>
+#include <stdint.h>
+
+#ifdef __NR_rseq
+#include <sys/rseq.h>
+#else
+
+enum rseq_cpu_id_state {
+ RSEQ_CPU_ID_UNINITIALIZED = -1,
+ RSEQ_CPU_ID_REGISTRATION_FAILED = -2,
+};
+
+/* linux/rseq.h defines struct rseq as aligned on 32 bytes. The kernel ABI
+ size is 20 bytes. */
+struct rseq {
+ uint32_t cpu_id_start;
+ uint32_t cpu_id;
+ uint64_t rseq_cs;
+ uint32_t flags;
+} __attribute__ ((aligned(4 * sizeof(uint64_t))));
+
+#endif
+
+/* volatile because fields can be read/updated by the kernel. */
+__thread volatile struct rseq __rseq_abi = {
+ .cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
+};
+
+/* Advertise Restartable Sequences registration ownership across
+ application and shared libraries.
+
+ Libraries and applications must check whether this variable is zero or
+ non-zero if they wish to perform rseq registration on their own. If it
+ is zero, it means restartable sequence registration is not handled, and
+ the library or application is free to perform rseq registration. In
+ that case, the library or application is taking ownership of rseq
+ registration, and may set __rseq_handled to 1. It may then set it back
+ to 0 after it completes unregistering rseq.
+
+ If __rseq_handled is found to be non-zero, it means that another
+ library (or the application) is currently handling rseq registration.
+
+ Typical use of __rseq_handled is within library constructors and
+ destructors, or at program startup. */
+
+int __rseq_handled;
new file mode 100644
@@ -0,0 +1,31 @@
+/* Restartable Sequences Linux s390 architecture header.
+
+ Copyright (C) 2019 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
+ <http://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 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
@@ -2159,6 +2159,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2063,6 +2063,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2041,6 +2041,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2153,6 +2153,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 _IO_fprintf F
GLIBC_2.4 _IO_printf F
GLIBC_2.4 _IO_sprintf F
@@ -2092,6 +2092,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
new file mode 100644
@@ -0,0 +1,51 @@
+/* Restartable Sequences exported symbols. Linux header.
+
+ Copyright (C) 2019 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
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _SYS_RSEQ_H
+#define _SYS_RSEQ_H 1
+
+/* We use the structures declarations from the kernel headers. */
+#include <linux/rseq.h>
+/* Architecture-specific rseq signature. */
+#include <bits/rseq.h>
+#include <stdint.h>
+
+/* volatile because fields can be read/updated by the kernel. */
+extern __thread volatile struct rseq __rseq_abi
+__attribute__ ((tls_model ("initial-exec")));
+
+/* Advertise Restartable Sequences registration ownership across
+ application and shared libraries.
+
+ Libraries and applications must check whether this variable is zero or
+ non-zero if they wish to perform rseq registration on their own. If it
+ is zero, it means restartable sequence registration is not handled, and
+ the library or application is free to perform rseq registration. In
+ that case, the library or application is taking ownership of rseq
+ registration, and may set __rseq_handled to 1. It may then set it back
+ to 0 after it completes unregistering rseq.
+
+ If __rseq_handled is found to be non-zero, it means that another
+ library (or the application) is currently handling rseq registration.
+
+ Typical use of __rseq_handled is within library constructors and
+ destructors, or at program startup. */
+
+extern int __rseq_handled;
+
+#endif /* sys/rseq.h */
new file mode 100644
@@ -0,0 +1,31 @@
+/* Restartable Sequences Linux x86 architecture header.
+
+ Copyright (C) 2019 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
+ <http://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
@@ -2050,6 +2050,8 @@ GLIBC_2.3.4 setipv4sourcefilter F
GLIBC_2.3.4 setsourcefilter F
GLIBC_2.3.4 xdr_quad_t F
GLIBC_2.3.4 xdr_u_quad_t F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4
GLIBC_2.4 __confstr_chk F
GLIBC_2.4 __fgets_chk F
GLIBC_2.4 __fgets_unlocked_chk F
@@ -2149,3 +2149,5 @@ GLIBC_2.28 thrd_yield F
GLIBC_2.29 getcpu F
GLIBC_2.29 posix_spawn_file_actions_addchdir_np F
GLIBC_2.29 posix_spawn_file_actions_addfchdir_np F
+GLIBC_2.30 __rseq_abi T 0x20
+GLIBC_2.30 __rseq_handled D 0x4