--- /dev/null
+/* Definitions for thread-local data handling. Hurd/x86_64 version.
+ Copyright (C) 2003-2023 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ 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 _X86_64_TLS_H
+#define _X86_64_TLS_H
+
+
+/* Some things really need not be machine-dependent. */
+#include <sysdeps/mach/hurd/tls.h>
+
+
+#ifndef __ASSEMBLER__
+# include <dl-dtv.h>
+# include <mach/machine/thread_status.h>
+# include <errno.h>
+# include <assert.h>
+
+/* Type of the TCB. */
+typedef struct
+{
+ void *tcb; /* Points to this structure. */
+ dtv_t *dtv; /* Vector of pointers to TLS data. */
+ thread_t self; /* This thread's control port. */
+ int __glibc_padding1;
+ int multiple_threads;
+ int gscope_flag;
+ uintptr_t sysinfo;
+ uintptr_t stack_guard;
+ uintptr_t pointer_guard;
+ long __glibc_padding2[2];
+ int private_futex;
+ int __glibc_padding3;
+ /* Reservation of some values for the TM ABI. */
+ void *__private_tm[4];
+ /* GCC split stack support. */
+ void *__private_ss;
+ /* The lowest address of shadow stack. */
+ unsigned long long int ssp_base;
+
+ /* Keep these fields last, so offsets of fields above can continue being
+ compatible with the x86_64 NPTL version. */
+ mach_port_t reply_port; /* This thread's reply port. */
+ struct hurd_sigstate *_hurd_sigstate;
+
+ /* Used by the exception handling implementation in the dynamic loader. */
+ struct rtld_catch *rtld_catch;
+} tcbhead_t;
+
+/* GCC generates %fs:0x28 to access the stack guard. */
+_Static_assert (offsetof (tcbhead_t, stack_guard) == 0x28,
+ "stack guard offset");
+/* libgcc uses %fs:0x70 to access the split stack pointer. */
+_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x70,
+ "split stack pointer offset");
+
+extern unsigned char __libc_tls_initialized;
+
+# define __LIBC_NO_TLS() __builtin_expect (!__libc_tls_initialized, 0)
+
+/* The TCB can have any size and the memory following the address the
+ thread pointer points to is unspecified. Allocate the TCB there. */
+# define TLS_TCB_AT_TP 1
+# define TLS_DTV_AT_TP 0
+
+/* Alignment requirement for TCB.
+
+ Some processors such as Intel Atom pay a big penalty on every
+ access using a segment override if that segment's base is not
+ aligned to the size of a cache line. (See Intel 64 and IA-32
+ Architectures Optimization Reference Manual, section 13.3.3.3,
+ "Segment Base".) On such machines, a cache line is 64 bytes. */
+# define TCB_ALIGNMENT 64
+
+
+# define TLS_INIT_TP(descr) _hurd_tls_init ((tcbhead_t *) (descr))
+
+# define THREAD_SELF \
+ (*(tcbhead_t * __seg_fs *) offsetof (tcbhead_t, tcb))
+/* Read member of the thread descriptor directly. */
+# define THREAD_GETMEM(descr, member) \
+ (*(__typeof (descr->member) __seg_fs *) offsetof (tcbhead_t, member))
+/* Write member of the thread descriptor directly. */
+# define THREAD_SETMEM(descr, member, value) \
+ (*(__typeof (descr->member) __seg_fs *) offsetof (tcbhead_t, member) = value)
+
+
+/* Return the TCB address of a thread given its state.
+ Note: this is expensive. */
+static inline tcbhead_t * __attribute__ ((unused))
+THREAD_TCB (thread_t thread,
+ const void *all_state __attribute__ ((unused)))
+{
+ error_t err;
+ /* Fetch the target thread's state. */
+ struct i386_fsgs_base_state state;
+ mach_msg_type_number_t state_count = i386_FSGS_BASE_STATE_COUNT;
+ err = __thread_get_state (thread, i386_FSGS_BASE_STATE,
+ (thread_state_t) &state,
+ &state_count);
+ assert_perror (err);
+ assert (state_count == i386_FSGS_BASE_STATE_COUNT);
+ return (tcbhead_t *) state.fs_base;
+}
+
+/* Install new dtv for current thread. */
+# define INSTALL_NEW_DTV(dtvp) THREAD_SETMEM (THREAD_SELF, dtv, dtvp)
+
+/* Return the address of the dtv for the current thread. */
+# define THREAD_DTV() THREAD_GETMEM (THREAD_SELF, dtv)
+
+
+/* Set the stack guard field in TCB head. */
+# define THREAD_SET_STACK_GUARD(value) \
+ THREAD_SETMEM (THREAD_SELF, stack_guard, value)
+# define THREAD_COPY_STACK_GUARD(descr) \
+ ((descr)->stack_guard \
+ = THREAD_GETMEM (THREAD_SELF, stack_guard))
+
+/* Set the pointer guard field in the TCB head. */
+# define THREAD_SET_POINTER_GUARD(value) \
+ THREAD_SETMEM (THREAD_SELF, pointer_guard, value)
+# define THREAD_COPY_POINTER_GUARD(descr) \
+ ((descr)->pointer_guard \
+ = THREAD_GETMEM (THREAD_SELF, pointer_guard))
+
+/* Set up TLS in the new thread of a fork child, copying from the original. */
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_fork (thread_t child, thread_t orig,
+ void *machine_state __attribute__ ((unused)))
+{
+ error_t err;
+ struct i386_fsgs_base_state state;
+ mach_msg_type_number_t state_count = i386_FSGS_BASE_STATE_COUNT;
+ err = __thread_get_state (orig, i386_FSGS_BASE_STATE,
+ (thread_state_t) &state,
+ &state_count);
+ if (err)
+ return err;
+ assert (state_count == i386_FSGS_BASE_STATE_COUNT);
+
+ return __thread_set_state (child, i386_FSGS_BASE_STATE,
+ (thread_state_t) &state,
+ state_count);
+}
+
+static inline kern_return_t __attribute__ ((unused))
+_hurd_tls_new (thread_t child, tcbhead_t *tcb)
+{
+ struct i386_fsgs_base_state state;
+
+ tcb->tcb = tcb;
+ tcb->self = child;
+
+ /* Install the TCB address into FS base. */
+ state.fs_base = (uintptr_t) tcb;
+ state.gs_base = 0;
+ return __thread_set_state (child, i386_FSGS_BASE_STATE,
+ (thread_state_t) &state,
+ i386_FSGS_BASE_STATE_COUNT);
+}
+
+static inline bool __attribute__ ((unused))
+_hurd_tls_init (tcbhead_t *tcb)
+{
+ error_t err;
+ thread_t self = __mach_thread_self ();
+
+ /* We always at least start the sigthread anyway. */
+ tcb->multiple_threads = 1;
+
+ err = _hurd_tls_new (self, tcb);
+ __mach_port_deallocate (__mach_task_self (), self);
+ __libc_tls_initialized = 1;
+ return err == 0;
+}
+
+
+/* Global scope switch support. */
+# define THREAD_GSCOPE_FLAG_UNUSED 0
+# define THREAD_GSCOPE_FLAG_USED 1
+# define THREAD_GSCOPE_FLAG_WAIT 2
+
+# define THREAD_GSCOPE_SET_FLAG() \
+ THREAD_SETMEM (THREAD_SELF, gscope_flag, THREAD_GSCOPE_FLAG_USED)
+
+# define THREAD_GSCOPE_RESET_FLAG() \
+ ({ \
+ int __flag; \
+ asm volatile ("xchgl %0, %%fs:%P1" \
+ : "=r" (__flag) \
+ : "i" (offsetof (tcbhead_t, gscope_flag)), \
+ "0" (THREAD_GSCOPE_FLAG_UNUSED)); \
+ if (__flag == THREAD_GSCOPE_FLAG_WAIT) \
+ lll_wake (THREAD_SELF->gscope_flag, LLL_PRIVATE); \
+ })
+
+
+
+#endif /* __ASSEMBLER__ */
+#endif /* x86_64/tls.h */
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