aboutsummaryrefslogtreecommitdiff
path: root/linuxthreads/sysdeps
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@redhat.com>2002-08-02 01:11:43 +0000
committerUlrich Drepper <drepper@redhat.com>2002-08-02 01:11:43 +0000
commitd7e1ad053b0d742f4f9c632dc0c5feb8315a5b90 (patch)
tree08557c0fe426e9c94e32b171a1ca688bd589091b /linuxthreads/sysdeps
parentb264e1d19a2d83fd6fbd842eddb285bc7b77471d (diff)
downloadglibc-d7e1ad053b0d742f4f9c632dc0c5feb8315a5b90.tar
glibc-d7e1ad053b0d742f4f9c632dc0c5feb8315a5b90.tar.gz
glibc-d7e1ad053b0d742f4f9c632dc0c5feb8315a5b90.tar.bz2
glibc-d7e1ad053b0d742f4f9c632dc0c5feb8315a5b90.zip
(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.
Diffstat (limited to 'linuxthreads/sysdeps')
-rw-r--r--linuxthreads/sysdeps/i386/useldt.h59
1 files changed, 55 insertions, 4 deletions
diff --git a/linuxthreads/sysdeps/i386/useldt.h b/linuxthreads/sysdeps/i386/useldt.h
index 3edcdca26c..4fd226e270 100644
--- a/linuxthreads/sysdeps/i386/useldt.h
+++ b/linuxthreads/sysdeps/i386/useldt.h
@@ -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) \