diff options
Diffstat (limited to 'linuxthreads/sysdeps/i386/useldt.h')
| -rw-r--r-- | linuxthreads/sysdeps/i386/useldt.h | 61 |
1 files changed, 30 insertions, 31 deletions
diff --git a/linuxthreads/sysdeps/i386/useldt.h b/linuxthreads/sysdeps/i386/useldt.h index 4fd226e270..49471d61fa 100644 --- a/linuxthreads/sysdeps/i386/useldt.h +++ b/linuxthreads/sysdeps/i386/useldt.h @@ -62,49 +62,48 @@ extern int __modify_ldt (int, struct modify_ldt_ldt_s *, size_t); __self; \ }) -#define DO_MODIFY_LDT(descr, nr) \ + +/* Initialize the thread-unique value. Two possible ways to do it. */ + +#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; \ + asm ("movw %w0, %%gs" : : "q" (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 +/* When using the new set_thread_area call, we don't need to change %gs + because we inherited the value set up in the main thread by TLS setup. + We need to extract that value and set up the same segment in this + thread. */ +# define DO_SET_THREAD_AREA(descr) \ +({ \ + int __gs; \ + struct modify_ldt_ldt_s ldt_entry = \ + { ({ asm ("movw %%gs, %w0" : "=q" (__gs)); __gs >> 2; }), \ + (unsigned long int) descr, sizeof (struct _pthread_descr_struct), \ + 1, 0, 0, 0, 0, 1, 0 }; \ + __builtin_expect (INLINE_SYSCALL (set_thread_area, 1, &ldt_entry) == 0, 1) \ + ? __gs : -1; \ +}) +#if defined __ASSUME_SET_THREAD_AREA_SYSCALL && defined HAVE_TLS_SUPPORT +# define INIT_THREAD_SELF(descr, nr) DO_SET_THREAD_AREA (descr) +#elif defined __NR_set_thread_area && defined HAVE_TLS_SUPPORT +# define INIT_THREAD_SELF(descr, nr) \ +({ \ + if (__builtin_expect (__have_no_set_thread_area, 0) \ + || (DO_SET_THREAD_AREA (descr) == -1 \ + && (__have_no_set_thread_area = 1))) \ + DO_MODIFY_LDT (descr, nr); \ +}) /* 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)); \ -} +# define INIT_THREAD_SELF(descr, nr) DO_MODIFY_LDT (descr, nr) #endif /* Free resources associated with thread descriptor. */ |