about summary refs log tree commit diff
path: root/linuxthreads/sysdeps/i386/useldt.h
blob: 116e95d042feb2533355a90126417489cbd889e0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/* Special definitions for ix86 machine using segment register based
   thread descriptor.
   Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include <stddef.h>	/* For offsetof.  */
#include <stdlib.h>	/* For abort().  */


/* We don't want to include the kernel header.  So duplicate the
   information.  */

/* Structure passed on `modify_ldt' call.  */
struct modify_ldt_ldt_s
{
  unsigned int entry_number;
  unsigned long int base_addr;
  unsigned int limit;
  unsigned int seg_32bit:1;
  unsigned int contents:2;
  unsigned int read_exec_only:1;
  unsigned int limit_in_pages:1;
  unsigned int seg_not_present:1;
  unsigned int useable:1;
  unsigned int empty:25;
};

/* System call to set LDT entry.  */
extern int __modify_ldt (int, struct modify_ldt_ldt_s *, size_t);


/* 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 \
({									      \
  register pthread_descr __self;					      \
  __asm__ ("movl %%gs:%c1,%0" : "=r" (__self)				      \
	   : "i" (offsetof (struct _pthread_descr_struct,		      \
			    p_header.data.self)));			      \
  __self;								      \
})

/* Initialize the thread-unique value.  */
#define INIT_THREAD_SELF(descr, nr) \
{									      \
  struct modify_ldt_ldt_s ldt_entry =					      \
    { nr, (unsigned long int) descr, sizeof (struct _pthread_descr_struct),   \
      1, 0, 0, 0, 0, 1, 0 };						      \
  if (__modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0)		      \
    abort ();								      \
  __asm__ __volatile__ ("movw %w0, %%gs" : : "q" (nr * 8 + 7));		      \
}

/* Free resources associated with thread descriptor.  */
#define FREE_THREAD(descr, nr) \
{									      \
  struct modify_ldt_ldt_s ldt_entry =					      \
    { nr, 0, 0, 0, 0, 1, 0, 1, 0, 0 };					      \
  __modify_ldt (1, &ldt_entry, sizeof (ldt_entry));			      \
}

/* Read member of the thread descriptor directly.  */
#define THREAD_GETMEM(descr, member) \
({									      \
  __typeof__ (descr->member) __value;					      \
  if (sizeof (__value) == 1)						      \
    __asm__ __volatile__ ("movb %%gs:%P2,%b0"				      \
			  : "=q" (__value)				      \
			  : "0" (0),					      \
			    "i" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else if (sizeof (__value) == 4)					      \
    __asm__ __volatile__ ("movl %%gs:%P1,%0"				      \
			  : "=r" (__value)				      \
			  : "i" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else									      \
    {									      \
      if (sizeof (__value) != 8)					      \
	/* There should not be any value with a size other than 1, 4 or 8.  */\
	abort ();							      \
									      \
      __asm__ __volatile__ ("movl %%gs:%P1,%%eax\n\t"			      \
			    "movl %%gs:%P2,%%edx"			      \
			    : "=A" (__value)				      \
			    : "i" (offsetof (struct _pthread_descr_struct,    \
					     member)),			      \
			      "i" (offsetof (struct _pthread_descr_struct,    \
					     member) + 4));		      \
    }									      \
  __value;								      \
})

/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
#define THREAD_GETMEM_NC(descr, member) \
({									      \
  __typeof__ (descr->member) __value;					      \
  if (sizeof (__value) == 1)						      \
    __asm__ __volatile__ ("movb %%gs:(%2),%b0"				      \
			  : "=q" (__value)				      \
			  : "0" (0),					      \
			    "r" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else if (sizeof (__value) == 4)					      \
    __asm__ __volatile__ ("movl %%gs:(%1),%0"				      \
			  : "=r" (__value)				      \
			  : "r" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else									      \
    {									      \
      if (sizeof (__value) != 8)					      \
	/* There should not be any value with a size other than 1, 4 or 8.  */\
	abort ();							      \
									      \
      __asm__ __volatile__ ("movl %%gs:(%1),%%eax\n\t"			      \
			    "movl %%gs:4(%1),%%edx"			      \
			    : "=&A" (__value)				      \
			    : "r" (offsetof (struct _pthread_descr_struct,    \
					     member)));			      \
    }									      \
  __value;								      \
})

/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
#define THREAD_SETMEM(descr, member, value) \
({									      \
  __typeof__ (descr->member) __value = (value);				      \
  if (sizeof (__value) == 1)						      \
    __asm__ __volatile__ ("movb %0,%%gs:%P1" :				      \
			  : "q" (__value),				      \
			    "i" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else if (sizeof (__value) == 4)					      \
    __asm__ __volatile__ ("movl %0,%%gs:%P1" :				      \
			  : "r" (__value),				      \
			    "i" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else									      \
    {									      \
      if (sizeof (__value) != 8)					      \
	/* There should not be any value with a size other than 1, 4 or 8.  */\
	abort ();							      \
									      \
      __asm__ __volatile__ ("movl %%eax,%%gs:%P1\n\n"			      \
			    "movl %%edx,%%gs:%P2" :			      \
			    : "A" (__value),				      \
			      "i" (offsetof (struct _pthread_descr_struct,    \
					     member)),			      \
			      "i" (offsetof (struct _pthread_descr_struct,    \
					     member) + 4));		      \
    }									      \
})

/* Set member of the thread descriptor directly.  */
#define THREAD_SETMEM_NC(descr, member, value) \
({									      \
  __typeof__ (descr->member) __value = (value);				      \
  if (sizeof (__value) == 1)						      \
    __asm__ __volatile__ ("movb %0,%%gs:(%1)" :				      \
			  : "q" (__value),				      \
			    "r" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else if (sizeof (__value) == 4)					      \
    __asm__ __volatile__ ("movl %0,%%gs:(%1)" :				      \
			  : "r" (__value),				      \
			    "r" (offsetof (struct _pthread_descr_struct,      \
					   member)));			      \
  else									      \
    {									      \
      if (sizeof (__value) != 8)					      \
	/* There should not be any value with a size other than 1, 4 or 8.  */\
	abort ();							      \
									      \
      __asm__ __volatile__ ("movl %%eax,%%gs:(%1)\n\t"			      \
			    "movl %%edx,%%gs:4(%1)" :			      \
			    : "A" (__value),				      \
			      "r" (offsetof (struct _pthread_descr_struct,    \
					     member)));			      \
    }									      \
})

/* We want the OS to assign stack addresses.  */
#define FLOATING_STACKS	1

/* Maximum size of the stack if the rlimit is unlimited.  */
#define ARCH_STACK_MAX_SIZE	8*1024*1024