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Diffstat (limited to 'linuxthreads/sysdeps/i386/useldt.h')
| -rw-r--r-- | linuxthreads/sysdeps/i386/useldt.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/linuxthreads/sysdeps/i386/useldt.h b/linuxthreads/sysdeps/i386/useldt.h new file mode 100644 index 0000000000..2fdc0ce767 --- /dev/null +++ b/linuxthreads/sysdeps/i386/useldt.h @@ -0,0 +1,124 @@ +/* Special definitions for ix86 machine using segment register based + thread descriptor. + Copyright (C) 1998 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. */ + + +/* 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_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 (*descr), 1, 0, 0, 0, 0, 1, 0 }; \ + if (__modify_ldt (1, &ldt_entry, sizeof (ldt_entry)) != 0) \ + abort (); \ + __asm__ __volatile__ ("movw %w0, %%gs" : : "r" (nr * 8 + 7)); \ +} + +/* Free resources associated with thread descriptor. */ +#define FREE_THREAD_SELF(descr, nr) \ +{ \ + struct modify_ldt_ldt_s ldt_entry = \ + { nr, 0, 0, 0, 0, 1, 0, 1, 0, 0 }; \ + __asm__ __volatile__ ("movw %w0,%%gs" : : "r" (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:%c1,%b0" \ + : "=r" (__value) \ + : "0" (0), \ + "i" (offsetof (struct _pthread_descr_struct, \ + member))); \ + else \ + { \ + if (sizeof (__value) != 4) \ + /* There should not be any value with a size other than 1 or 4. */ \ + abort (); \ + \ + __asm__ __volatile__ ("movl %%gs:%c1,%0" \ + : "=r" (__value) \ + : "i" (offsetof (struct _pthread_descr_struct, \ + member))); \ + } \ + __value; \ +}) + +/* Set member of the thread descriptor directly. */ +#define THREAD_SETMEM(descr, member, value) \ +({ \ + __typeof__ (descr->member) __value = (value); \ + if (sizeof (__value) == 1) \ + __asm__ __volatile__ ("movb %0,%%gs:%c1" : \ + : "r" (__value), \ + "i" (offsetof (struct _pthread_descr_struct, \ + member))); \ + else \ + { \ + if (sizeof (__value) != 4) \ + /* There should not be any value with a size other than 1 or 4. */ \ + abort (); \ + \ + __asm__ __volatile__ ("movl %0,%%gs:%c1" : \ + : "r" (__value), \ + "i" (offsetof (struct _pthread_descr_struct, \ + member))); \ + } \ +}) |