diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/sys/rseq.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/sys/rseq.h | 203 |
1 files changed, 0 insertions, 203 deletions
diff --git a/sysdeps/unix/sysv/linux/sys/rseq.h b/sysdeps/unix/sysv/linux/sys/rseq.h deleted file mode 100644 index 55090f9e30..0000000000 --- a/sysdeps/unix/sysv/linux/sys/rseq.h +++ /dev/null @@ -1,203 +0,0 @@ -/* 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 */ |