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(DO_MODIFY_LDT): Move from INIT_THREAD_SELF. (INIT_THREAD_SELF): Use sys_thread_area syscall instead if available. (FREE_THREAD): Avoid modify_ldt if using GDT.

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This commit is contained in:
Ulrich Drepper 2002-08-02 01:11:43 +00:00
parent b264e1d19a
commit d7e1ad053b
1 changed files with 55 additions and 4 deletions
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59
linuxthreads/sysdeps/i386/useldt.h
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@ -22,6 +22,7 @@
#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
@ -61,24 +62,74 @@ extern int __modify_ldt (int, struct modify_ldt_ldt_s *, size_t);
__self; \
})
/* Initialize the thread-unique value. */
#define INIT_THREAD_SELF(descr, nr) \
{ \
#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 (); \
__asm__ __volatile__ ("movw %w0, %%gs" : : "q" (nr * 8 + 7)); \
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) \