glibc/linuxthreads/sysdeps/i386/useldt.h

260 lines
9.2 KiB
C

/* Special definitions for ix86 machine using segment register based
thread descriptor.
Copyright (C) 1998, 2000, 2001, 2002 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. */
#ifndef __ASSEMBLER__
#include <stddef.h> /* For offsetof. */
#include <stdlib.h> /* For abort(). */
#include <sysdep.h> /* For INLINE_SYSCALL. */
/* 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; \
})
#define DO_MODIFY_LDT(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 (); \
nr * 8 + 7; \
})
/* Initialize the thread-unique value. */
#ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
#define INIT_THREAD_SELF(descr, nr) \
{ \
int __gs = INLINE_SYSCALL (set_thread_area, 2, descr, 1); \
if (__gs == -1) \
abort (); \
__asm__ __volatile__ ("movw %w0, %%gs" : : "q" (__gs)); \
}
#elif defined __NR_set_thread_area
/* Defined in pspinlock.c. */
extern int __have_no_set_thread_area;
#define INIT_THREAD_SELF(descr, nr) \
{ \
int __gs = -1; \
if (! __builtin_expect (__have_no_set_thread_area, 0)) \
{ \
if ((__gs = INLINE_SYSCALL (set_thread_area, 2, descr, 1)) == -1 \
&& errno == ENOSYS) \
__have_no_set_thread_area = 1; \
} \
if (__builtin_expect (__gs == -1, 0)) \
__gs = DO_MODIFY_LDT (descr, nr); \
__asm__ __volatile__ ("movw %w0, %%gs" : : "q" (__gs)); \
}
#else
#define INIT_THREAD_SELF(descr, nr) \
{ \
int __gs = DO_MODIFY_LDT (descr, nr); \
__asm__ __volatile__ ("movw %w0, %%gs" : : "q" (__gs)); \
}
#endif
/* Free resources associated with thread descriptor. */
#ifdef __ASSUME_SET_THREAD_AREA_SYSCALL
#define FREE_THREAD(descr, nr) do { } while (0)
#elif defined __NR_set_thread_area
#define FREE_THREAD(descr, nr) \
{ \
int __gs; \
__asm__ __volatile__ ("movw %%gs, %w0" : "=q" (__gs)); \
if (__builtin_expect (__gs & 4, 0)) \
{ \
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)); \
} \
}
#else
#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)); \
}
#endif
/* 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))); \
} \
})
#endif
/* 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