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581c785bf3
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 7061 files FOO. I then removed trailing white space from math/tgmath.h, support/tst-support-open-dev-null-range.c, and sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following obscure pre-commit check failure diagnostics from Savannah. I don't know why I run into these diagnostics whereas others evidently do not. remote: *** 912-#endif remote: *** 913: remote: *** 914- remote: *** error: lines with trailing whitespace found ... remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
231 lines
7.7 KiB
C
231 lines
7.7 KiB
C
/* Definition for thread-local data handling. nptl/x86_64 version.
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Copyright (C) 2002-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#ifndef _TLS_H
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#define _TLS_H 1
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#ifndef __ASSEMBLER__
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# include <asm/prctl.h> /* For ARCH_SET_FS. */
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# include <stdbool.h>
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# include <stddef.h>
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# include <stdint.h>
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# include <stdlib.h>
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# include <sysdep.h>
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# include <libc-pointer-arith.h> /* For cast_to_integer. */
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# include <kernel-features.h>
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# include <dl-dtv.h>
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/* Replacement type for __m128 since this file is included by ld.so,
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which is compiled with -mno-sse. It must not change the alignment
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of rtld_savespace_sse. */
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typedef struct
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{
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int i[4];
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} __128bits;
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typedef struct
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{
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void *tcb; /* Pointer to the TCB. Not necessarily the
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thread descriptor used by libpthread. */
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dtv_t *dtv;
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void *self; /* Pointer to the thread descriptor. */
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int multiple_threads;
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int gscope_flag;
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uintptr_t sysinfo;
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uintptr_t stack_guard;
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uintptr_t pointer_guard;
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unsigned long int unused_vgetcpu_cache[2];
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/* Bit 0: X86_FEATURE_1_IBT.
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Bit 1: X86_FEATURE_1_SHSTK.
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*/
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unsigned int feature_1;
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int __glibc_unused1;
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/* Reservation of some values for the TM ABI. */
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void *__private_tm[4];
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/* GCC split stack support. */
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void *__private_ss;
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/* The lowest address of shadow stack, */
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unsigned long long int ssp_base;
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/* Must be kept even if it is no longer used by glibc since programs,
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like AddressSanitizer, depend on the size of tcbhead_t. */
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__128bits __glibc_unused2[8][4] __attribute__ ((aligned (32)));
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void *__padding[8];
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} tcbhead_t;
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# ifdef __ILP32__
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/* morestack.S in libgcc uses offset 0x40 to access __private_ss, */
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_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x40,
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"offset of __private_ss != 0x40");
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/* NB: ssp_base used to be "long int __glibc_reserved2", which was
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changed from 32 bits to 64 bits. Make sure that the offset of the
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next field, __glibc_unused2, is unchanged. */
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_Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x60,
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"offset of __glibc_unused2 != 0x60");
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# else
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/* morestack.S in libgcc uses offset 0x70 to access __private_ss, */
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_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x70,
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"offset of __private_ss != 0x70");
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_Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
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"offset of __glibc_unused2 != 0x80");
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# endif
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#else /* __ASSEMBLER__ */
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# include <tcb-offsets.h>
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#endif
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/* Alignment requirement for the stack. */
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#define STACK_ALIGN 16
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#ifndef __ASSEMBLER__
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/* Get system call information. */
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# include <sysdep.h>
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#define LOCK_PREFIX "lock;"
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/* This is the size of the initial TCB. Can't be just sizeof (tcbhead_t),
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because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole
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struct pthread even when not linked with -lpthread. */
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# define TLS_INIT_TCB_SIZE sizeof (struct pthread)
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/* This is the size of the TCB. */
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# define TLS_TCB_SIZE sizeof (struct pthread)
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/* The TCB can have any size and the memory following the address the
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thread pointer points to is unspecified. Allocate the TCB there. */
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# define TLS_TCB_AT_TP 1
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# define TLS_DTV_AT_TP 0
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/* Get the thread descriptor definition. */
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# include <nptl/descr.h>
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/* Install the dtv pointer. The pointer passed is to the element with
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index -1 which contain the length. */
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# define INSTALL_DTV(descr, dtvp) \
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((tcbhead_t *) (descr))->dtv = (dtvp) + 1
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/* Install new dtv for current thread. */
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# define INSTALL_NEW_DTV(dtvp) \
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({ struct pthread *__pd; \
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THREAD_SETMEM (__pd, header.dtv, (dtvp)); })
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/* Return dtv of given thread descriptor. */
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# define GET_DTV(descr) \
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(((tcbhead_t *) (descr))->dtv)
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/* Code to initially initialize the thread pointer. This might need
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special attention since 'errno' is not yet available and if the
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operation can cause a failure 'errno' must not be touched.
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We have to make the syscall for both uses of the macro since the
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address might be (and probably is) different. */
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# define TLS_INIT_TP(thrdescr) \
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({ void *_thrdescr = (thrdescr); \
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tcbhead_t *_head = _thrdescr; \
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int _result; \
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\
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_head->tcb = _thrdescr; \
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/* For now the thread descriptor is at the same address. */ \
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_head->self = _thrdescr; \
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\
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/* It is a simple syscall to set the %fs value for the thread. */ \
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asm volatile ("syscall" \
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: "=a" (_result) \
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: "0" ((unsigned long int) __NR_arch_prctl), \
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"D" ((unsigned long int) ARCH_SET_FS), \
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"S" (_thrdescr) \
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: "memory", "cc", "r11", "cx"); \
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\
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_result ? "cannot set %fs base address for thread-local storage" : 0; \
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})
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# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)
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/* Return the address of the dtv for the current thread. */
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# define THREAD_DTV() \
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({ struct pthread *__pd; \
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THREAD_GETMEM (__pd, header.dtv); })
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/* Return the thread descriptor for the current thread.
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The contained asm must *not* be marked volatile since otherwise
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assignments like
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pthread_descr self = thread_self();
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do not get optimized away. */
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# if __GNUC_PREREQ (6, 0)
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# define THREAD_SELF \
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(*(struct pthread *__seg_fs *) offsetof (struct pthread, header.self))
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# else
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# define THREAD_SELF \
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({ struct pthread *__self; \
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asm ("mov %%fs:%c1,%0" : "=r" (__self) \
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: "i" (offsetof (struct pthread, header.self))); \
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__self;})
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# endif
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/* Magic for libthread_db to know how to do THREAD_SELF. */
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# define DB_THREAD_SELF_INCLUDE <sys/reg.h> /* For the FS constant. */
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# define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)
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# include <tcb-access.h>
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/* Set the stack guard field in TCB head. */
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# define THREAD_SET_STACK_GUARD(value) \
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THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)
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# define THREAD_COPY_STACK_GUARD(descr) \
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((descr)->header.stack_guard \
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= THREAD_GETMEM (THREAD_SELF, header.stack_guard))
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/* Set the pointer guard field in the TCB head. */
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# define THREAD_SET_POINTER_GUARD(value) \
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THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)
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# define THREAD_COPY_POINTER_GUARD(descr) \
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((descr)->header.pointer_guard \
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= THREAD_GETMEM (THREAD_SELF, header.pointer_guard))
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/* Get and set the global scope generation counter in the TCB head. */
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# define THREAD_GSCOPE_FLAG_UNUSED 0
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# define THREAD_GSCOPE_FLAG_USED 1
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# define THREAD_GSCOPE_FLAG_WAIT 2
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# define THREAD_GSCOPE_RESET_FLAG() \
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do \
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{ int __res; \
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asm volatile ("xchgl %0, %%fs:%P1" \
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: "=r" (__res) \
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: "i" (offsetof (struct pthread, header.gscope_flag)), \
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"0" (THREAD_GSCOPE_FLAG_UNUSED)); \
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if (__res == THREAD_GSCOPE_FLAG_WAIT) \
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lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE); \
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} \
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while (0)
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# define THREAD_GSCOPE_SET_FLAG() \
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THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)
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#endif /* __ASSEMBLER__ */
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#endif /* tls.h */
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