/* Definition for thread-local data handling.  nptl/x86_64 version.

   Copyright (C) 2002-2018 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

   <http://www.gnu.org/licenses/>.  */

#ifndef _TLS_H

#define _TLS_H	1

#ifndef __ASSEMBLER__

# include <asm/prctl.h>	/* For ARCH_SET_FS.  */

# include <stdbool.h>

# include <stddef.h>

# include <stdint.h>

# include <stdlib.h>

# include <sysdep.h>

# include <libc-pointer-arith.h> /* For cast_to_integer.  */

# include <kernel-features.h>

# include <dl-dtv.h>

/* Replacement type for __m128 since this file is included by ld.so,

   which is compiled with -mno-sse.  It must not change the alignment

   of rtld_savespace_sse.  */

typedef struct

{

  int i[4];

} __128bits;

typedef struct

{

  void *tcb;		/* Pointer to the TCB.  Not necessarily the

			   thread descriptor used by libpthread.  */

  dtv_t *dtv;

  void *self;		/* Pointer to the thread descriptor.  */

  int multiple_threads;

  int gscope_flag;

  uintptr_t sysinfo;

  uintptr_t stack_guard;

  uintptr_t pointer_guard;

  unsigned long int vgetcpu_cache[2];

  /* Bit 0: X86_FEATURE_1_IBT.

     Bit 1: X86_FEATURE_1_SHSTK.

   */

  unsigned int feature_1;

  int __glibc_unused1;

  /* 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;

  /* Must be kept even if it is no longer used by glibc since programs,

     like AddressSanitizer, depend on the size of tcbhead_t.  */

  __128bits __glibc_unused2[8][4] __attribute__ ((aligned (32)));

  void *__padding[8];

} tcbhead_t;

# ifdef __ILP32__

/* morestack.S in libgcc uses offset 0x40 to access __private_ss,   */

_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x40,

		"offset of __private_ss != 0x40");

/* NB: ssp_base used to be "long int __glibc_reserved2", which was

   changed from 32 bits to 64 bits.  Make sure that the offset of the

   next field, __glibc_unused2, is unchanged.  */

_Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x60,

		"offset of __glibc_unused2 != 0x60");

# else

/* morestack.S in libgcc uses offset 0x70 to access __private_ss,   */

_Static_assert (offsetof (tcbhead_t, __private_ss) == 0x70,

		"offset of __private_ss != 0x70");

_Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,

		"offset of __glibc_unused2 != 0x80");

# endif

#else /* __ASSEMBLER__ */

# include <tcb-offsets.h>

#endif

/* Alignment requirement for the stack.  */

#define STACK_ALIGN	16

#ifndef __ASSEMBLER__

/* Get system call information.  */

# include <sysdep.h>

#ifndef LOCK_PREFIX

# ifdef UP

#  define LOCK_PREFIX	/* nothing */

# else

#  define LOCK_PREFIX	"lock;"

# endif

#endif

/* This is the size of the initial TCB.  Can't be just sizeof (tcbhead_t),

   because NPTL getpid, __libc_alloca_cutoff etc. need (almost) the whole

   struct pthread even when not linked with -lpthread.  */

# define TLS_INIT_TCB_SIZE sizeof (struct pthread)

/* Alignment requirements for the initial TCB.  */

# define TLS_INIT_TCB_ALIGN __alignof__ (struct pthread)

/* This is the size of the TCB.  */

# define TLS_TCB_SIZE sizeof (struct pthread)

/* Alignment requirements for the TCB.  */

# define TLS_TCB_ALIGN __alignof__ (struct pthread)

/* 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

/* Get the thread descriptor definition.  */

# include <nptl/descr.h>

/* Install the dtv pointer.  The pointer passed is to the element with

   index -1 which contain the length.  */

# define INSTALL_DTV(descr, dtvp) \

  ((tcbhead_t *) (descr))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */

# define INSTALL_NEW_DTV(dtvp) \

  ({ struct pthread *__pd;						      \

     THREAD_SETMEM (__pd, header.dtv, (dtvp)); })

/* Return dtv of given thread descriptor.  */

# define GET_DTV(descr) \

  (((tcbhead_t *) (descr))->dtv)

/* Code to initially initialize the thread pointer.  This might need

   special attention since 'errno' is not yet available and if the

   operation can cause a failure 'errno' must not be touched.

   We have to make the syscall for both uses of the macro since the

   address might be (and probably is) different.  */

# define TLS_INIT_TP(thrdescr) \

  ({ void *_thrdescr = (thrdescr);					      \

     tcbhead_t *_head = _thrdescr;					      \

     int _result;							      \

									      \

     _head->tcb = _thrdescr;						      \

     /* For now the thread descriptor is at the same address.  */	      \

     _head->self = _thrdescr;						      \

									      \

     /* It is a simple syscall to set the %fs value for the thread.  */	      \

     asm volatile ("syscall"						      \

		   : "=a" (_result)					      \

		   : "0" ((unsigned long int) __NR_arch_prctl),		      \

		     "D" ((unsigned long int) ARCH_SET_FS),		      \

		     "S" (_thrdescr)					      \

		   : "memory", "cc", "r11", "cx");			      \

									      \

    _result ? "cannot set %fs base address for thread-local storage" : 0;     \

  })

# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd)

/* Return the address of the dtv for the current thread.  */

# define THREAD_DTV() \

  ({ struct pthread *__pd;						      \

     THREAD_GETMEM (__pd, header.dtv); })

/* Return the thread descriptor for the current thread.

   The contained asm must *not* be marked volatile since otherwise

   assignments like

	pthread_descr self = thread_self();

   do not get optimized away.  */

# define THREAD_SELF \

  ({ struct pthread *__self;						      \

     asm ("mov %%fs:%c1,%0" : "=r" (__self)				      \

	  : "i" (offsetof (struct pthread, header.self)));	 	      \

     __self;})

/* Magic for libthread_db to know how to do THREAD_SELF.  */

# define DB_THREAD_SELF_INCLUDE  <sys/reg.h> /* For the FS constant.  */

# define DB_THREAD_SELF CONST_THREAD_AREA (64, FS)

/* Read member of the thread descriptor directly.  */

# define THREAD_GETMEM(descr, member) \

  ({ __typeof (descr->member) __value;					      \

     if (sizeof (__value) == 1)						      \

       asm volatile ("movb %%fs:%P2,%b0"				      \

		     : "=q" (__value)					      \

		     : "0" (0), "i" (offsetof (struct pthread, member)));     \

     else if (sizeof (__value) == 4)					      \

       asm volatile ("movl %%fs:%P1,%0"					      \

		     : "=r" (__value)					      \

		     : "i" (offsetof (struct pthread, member)));	      \

     else								      \

       {								      \

	 if (sizeof (__value) != 8)					      \

	   /* There should not be any value with a size other than 1,	      \

	      4 or 8.  */						      \

	   abort ();							      \

									      \

	 asm volatile ("movq %%fs:%P1,%q0"				      \

		       : "=r" (__value)					      \

		       : "i" (offsetof (struct pthread, member)));	      \

       }								      \

     __value; })

/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */

# define THREAD_GETMEM_NC(descr, member, idx) \

  ({ __typeof (descr->member[0]) __value;				      \

     if (sizeof (__value) == 1)						      \

       asm volatile ("movb %%fs:%P2(%q3),%b0"				      \

		     : "=q" (__value)					      \

		     : "0" (0), "i" (offsetof (struct pthread, member[0])),   \

		       "r" (idx));					      \

     else if (sizeof (__value) == 4)					      \

       asm volatile ("movl %%fs:%P1(,%q2,4),%0"				      \

		     : "=r" (__value)					      \

		     : "i" (offsetof (struct pthread, member[0])), "r" (idx));\

     else								      \

       {								      \

	 if (sizeof (__value) != 8)					      \

	   /* There should not be any value with a size other than 1,	      \

	      4 or 8.  */						      \

	   abort ();							      \

									      \

	 asm volatile ("movq %%fs:%P1(,%q2,8),%q0"			      \

		       : "=r" (__value)					      \

		       : "i" (offsetof (struct pthread, member[0])),	      \

			 "r" (idx));					      \

       }								      \

     __value; })

/* Loading addresses of objects on x86-64 needs to be treated special

   when generating PIC code.  */

#ifdef __pic__

# define IMM_MODE "nr"

#else

# define IMM_MODE "ir"

#endif

/* Set member of the thread descriptor directly.  */

# define THREAD_SETMEM(descr, member, value) \

  ({ if (sizeof (descr->member) == 1)					      \

       asm volatile ("movb %b0,%%fs:%P1" :				      \

		     : "iq" (value),					      \

		       "i" (offsetof (struct pthread, member)));	      \

     else if (sizeof (descr->member) == 4)				      \

       asm volatile ("movl %0,%%fs:%P1" :				      \

		     : IMM_MODE (value),				      \

		       "i" (offsetof (struct pthread, member)));	      \

     else								      \

       {								      \

	 if (sizeof (descr->member) != 8)				      \

	   /* There should not be any value with a size other than 1,	      \

	      4 or 8.  */						      \

	   abort ();							      \

									      \

	 asm volatile ("movq %q0,%%fs:%P1" :				      \

		       : IMM_MODE ((uint64_t) cast_to_integer (value)),	      \

			 "i" (offsetof (struct pthread, member)));	      \

       }})

/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */

# define THREAD_SETMEM_NC(descr, member, idx, value) \

  ({ if (sizeof (descr->member[0]) == 1)				      \

       asm volatile ("movb %b0,%%fs:%P1(%q2)" :				      \

		     : "iq" (value),					      \

		       "i" (offsetof (struct pthread, member[0])),	      \

		       "r" (idx));					      \

     else if (sizeof (descr->member[0]) == 4)				      \

       asm volatile ("movl %0,%%fs:%P1(,%q2,4)" :			      \

		     : IMM_MODE (value),				      \

		       "i" (offsetof (struct pthread, member[0])),	      \

		       "r" (idx));					      \

     else								      \

       {								      \

	 if (sizeof (descr->member[0]) != 8)				      \

	   /* There should not be any value with a size other than 1,	      \

	      4 or 8.  */						      \

	   abort ();							      \

									      \

	 asm volatile ("movq %q0,%%fs:%P1(,%q2,8)" :			      \

		       : IMM_MODE ((uint64_t) cast_to_integer (value)),	      \

			 "i" (offsetof (struct pthread, member[0])),	      \

			 "r" (idx));					      \

       }})

/* Atomic compare and exchange on TLS, returning old value.  */

# define THREAD_ATOMIC_CMPXCHG_VAL(descr, member, newval, oldval) \

  ({ __typeof (descr->member) __ret;					      \

     __typeof (oldval) __old = (oldval);				      \

     if (sizeof (descr->member) == 4)					      \

       asm volatile (LOCK_PREFIX "cmpxchgl %2, %%fs:%P3"		      \

		     : "=a" (__ret)					      \

		     : "0" (__old), "r" (newval),			      \

		       "i" (offsetof (struct pthread, member)));	      \

     else								      \

       /* Not necessary for other sizes in the moment.  */		      \

       abort ();							      \

     __ret; })

/* Atomic logical and.  */

# define THREAD_ATOMIC_AND(descr, member, val) \

  (void) ({ if (sizeof ((descr)->member) == 4)				      \

	      asm volatile (LOCK_PREFIX "andl %1, %%fs:%P0"		      \

			    :: "i" (offsetof (struct pthread, member)),	      \

			       "ir" (val));				      \

	    else							      \

	      /* Not necessary for other sizes in the moment.  */	      \

	      abort (); })

/* Atomic set bit.  */

# define THREAD_ATOMIC_BIT_SET(descr, member, bit) \

  (void) ({ if (sizeof ((descr)->member) == 4)				      \

	      asm volatile (LOCK_PREFIX "orl %1, %%fs:%P0"		      \

			    :: "i" (offsetof (struct pthread, member)),	      \

			       "ir" (1 << (bit)));			      \

	    else							      \

	      /* Not necessary for other sizes in the moment.  */	      \

	      abort (); })

/* Set the stack guard field in TCB head.  */

# define THREAD_SET_STACK_GUARD(value) \

    THREAD_SETMEM (THREAD_SELF, header.stack_guard, value)

# define THREAD_COPY_STACK_GUARD(descr) \

    ((descr)->header.stack_guard					      \

     = THREAD_GETMEM (THREAD_SELF, header.stack_guard))

/* Set the pointer guard field in the TCB head.  */

# define THREAD_SET_POINTER_GUARD(value) \

  THREAD_SETMEM (THREAD_SELF, header.pointer_guard, value)

# define THREAD_COPY_POINTER_GUARD(descr) \

  ((descr)->header.pointer_guard					      \

   = THREAD_GETMEM (THREAD_SELF, header.pointer_guard))

/* Get and set the global scope generation counter in the TCB head.  */

# define THREAD_GSCOPE_IN_TCB      1

# define THREAD_GSCOPE_FLAG_UNUSED 0

# define THREAD_GSCOPE_FLAG_USED   1

# define THREAD_GSCOPE_FLAG_WAIT   2

# define THREAD_GSCOPE_RESET_FLAG() \

  do									      \

    { int __res;							      \

      asm volatile ("xchgl %0, %%fs:%P1"				      \

		    : "=r" (__res)					      \

		    : "i" (offsetof (struct pthread, header.gscope_flag)),    \

		      "0" (THREAD_GSCOPE_FLAG_UNUSED));			      \

      if (__res == THREAD_GSCOPE_FLAG_WAIT)				      \

	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);    \

    }									      \

  while (0)

# define THREAD_GSCOPE_SET_FLAG() \

  THREAD_SETMEM (THREAD_SELF, header.gscope_flag, THREAD_GSCOPE_FLAG_USED)

# define THREAD_GSCOPE_WAIT() \

  GL(dl_wait_lookup_done) ()

#endif /* __ASSEMBLER__ */

#endif	/* tls.h */