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
|
/* Definitions for thread-local data handling. Hurd/i386 version.
Copyright (C) 2003, 2004, 2006, 2007, 2011 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _I386_TLS_H
#define _I386_TLS_H
/* Some things really need not be machine-dependent. */
#include <sysdeps/mach/hurd/tls.h>
/* 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
#ifndef __ASSEMBLER__
/* Use i386-specific RPCs to arrange that %gs segment register prefix
addresses the TCB in each thread. */
# include <mach/i386/mach_i386.h>
# ifndef HAVE_I386_SET_GDT
# define __i386_set_gdt(thr, sel, desc) ((void) (thr), (void) (sel), (void) (desc), MIG_BAD_ID)
# endif
# include <errno.h>
# include <assert.h>
# define HURD_TLS_DESC_DECL(desc, tcb) \
struct descriptor desc = \
{ /* low word: */ \
0xffff /* limit 0..15 */ \
| (((unsigned int) (tcb)) << 16) /* base 0..15 */ \
, /* high word: */ \
((((unsigned int) (tcb)) >> 16) & 0xff) /* base 16..23 */ \
| ((0x12 | 0x60 | 0x80) << 8) /* access = ACC_DATA_W|ACC_PL_U|ACC_P */ \
| (0xf << 16) /* limit 16..19 */ \
| ((4 | 8) << 20) /* granularity = SZ_32|SZ_G */ \
| (((unsigned int) (tcb)) & 0xff000000) /* base 24..31 */ \
}
static inline const char * __attribute__ ((unused))
_hurd_tls_init (tcbhead_t *tcb, int secondcall)
{
HURD_TLS_DESC_DECL (desc, tcb);
if (!secondcall)
{
/* This field is used by TLS accesses to get our "thread pointer"
from the TLS point of view. */
tcb->tcb = tcb;
/* Cache our thread port. */
tcb->self = __mach_thread_self ();
/* Get the first available selector. */
int sel = -1;
error_t err = __i386_set_gdt (tcb->self, &sel, desc);
if (err == MIG_BAD_ID)
{
/* Old kernel, use a per-thread LDT. */
sel = 0x27;
err = __i386_set_ldt (tcb->self, sel, &desc, 1);
assert_perror (err);
if (err)
return "i386_set_ldt failed";
}
else if (err)
{
assert_perror (err); /* Separate from above with different line #. */
return "i386_set_gdt failed";
}
/* Now install the new selector. */
asm volatile ("mov %w0, %%gs" :: "q" (sel));
}
else
{
/* Fetch the selector set by the first call. */
int sel;
asm ("mov %%gs, %w0" : "=q" (sel) : "0" (0));
if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
{
error_t err = __i386_set_ldt (tcb->self, sel, &desc, 1);
assert_perror (err);
if (err)
return "i386_set_ldt failed";
}
else
{
error_t err = __i386_set_gdt (tcb->self, &sel, desc);
assert_perror (err);
if (err)
return "i386_set_gdt failed";
}
}
return 0;
}
/* 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. */
# define TLS_INIT_TP(descr, secondcall) \
_hurd_tls_init ((tcbhead_t *) (descr), (secondcall))
# define TLS_INIT_TP_EXPENSIVE 1
/* Return the TCB address of the current thread. */
# define THREAD_SELF \
({ tcbhead_t *__tcb; \
__asm__ ("movl %%gs:%c1,%0" : "=r" (__tcb) \
: "i" (offsetof (tcbhead_t, tcb))); \
__tcb;})
/* Install new dtv for current thread. */
# define INSTALL_NEW_DTV(dtvp) \
({ asm volatile ("movl %0,%%gs:%P1" \
: : "ir" (dtvp), "i" (offsetof (tcbhead_t, dtv))); })
/* Return the address of the dtv for the current thread. */
# define THREAD_DTV() \
({ dtv_t *_dtv; \
asm ("movl %%gs:%P1,%0" : "=q" (_dtv) : "i" (offsetof (tcbhead_t, dtv)));\
_dtv; })
# include <mach/machine/thread_status.h>
/* Set up TLS in the new thread of a fork child, copying from our own. */
static inline error_t __attribute__ ((unused))
_hurd_tls_fork (thread_t child, struct i386_thread_state *state)
{
/* Fetch the selector set by _hurd_tls_init. */
int sel;
asm ("mov %%gs, %w0" : "=q" (sel) : "0" (0));
if (sel == state->ds) /* _hurd_tls_init was never called. */
return 0;
tcbhead_t *const tcb = THREAD_SELF;
HURD_TLS_DESC_DECL (desc, tcb);
error_t err;
if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
err = __i386_set_ldt (child, sel, &desc, 1);
else
err = __i386_set_gdt (child, &sel, desc);
state->gs = sel;
return err;
}
#endif /* !__ASSEMBLER__ */
#endif /* i386/tls.h */
|
GitWeb