diff options
48 files changed, 781 insertions, 3 deletions
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..ca13778ca9 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. */ @@ -134,6 +134,12 @@ void _dl_determine_tlsoffset (void) { size_t max_align = TLS_TCB_ALIGN; + /* libc.so with rseq has TLS with 32-byte alignment. Since TLS is + initialized before audit modules are loaded and slotinfo + information is available, this is not taken into account below in + the audit case. */ + max_align = MAX (max_align, 32U); + size_t freetop = 0; size_t freebottom = 0; 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..bd22e57469 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 6d6ab88960..f348a6f6dd 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 @@ -580,6 +584,15 @@ 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..55090f9e30 --- /dev/null +++ b/sysdeps/unix/sysv/linux/sys/rseq.h @@ -0,0 +1,203 @@ +/* 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 + +/* Rely on GNU extensions for older standards and tls model. */ +#ifdef __GNUC__ +# 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 + +#ifdef __cplusplus +# if __cplusplus >= 201103L +# define __rseq_tls_storage_class thread_local +# endif +#elif (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) >= 201112L +# define __rseq_tls_storage_class _Thread_local +#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 */ + +/* 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 |