/* Definitions for thread-local data handling. Hurd/i386 version.
- Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
#ifndef _I386_TLS_H
#define _I386_TLS_H
-#if defined HAVE_TLS_SUPPORT
/* Some things really need not be machine-dependent. */
-# include <sysdeps/mach/hurd/tls.h>
+#include <sysdeps/mach/hurd/tls.h>
+
+
+#ifndef __ASSEMBLER__
+# include <dl-dtv.h>
+
+/* Type of the TCB. */
+typedef struct
+{
+ void *tcb; /* Points to this structure. */
+ dtv_t *dtv; /* Vector of pointers to TLS data. */
+ thread_t self; /* This thread's control port. */
+ int multiple_threads;
+ uintptr_t sysinfo;
+ uintptr_t stack_guard;
+ uintptr_t pointer_guard;
+ int gscope_flag;
+ int private_futex;
+ /* Reservation of some values for the TM ABI. */
+ void *__private_tm[4];
+ /* GCC split stack support. */
+ void *__private_ss;
+} tcbhead_t;
+#endif
-/* Indiciate that TLS support is available. */
-# define USE_TLS 1
/* The TCB can have any size and the memory following the address the
thread pointer points to is unspecified. Allocate the TCB there. */
-# define TLS_TCB_AT_TP 1
+#define TLS_TCB_AT_TP 1
+#define TLS_DTV_AT_TP 0
-# ifndef ASSEMBLER
+#ifndef __ASSEMBLER__
/* Use i386-specific RPCs to arrange that %gs segment register prefix
addresses the TCB in each thread. */
# include <mach/i386/mach_i386.h>
# ifndef HAVE_I386_SET_GDT
-# define __i386_set_gdt(thr, sel, desc) ((thr), (sel), (desc), MIG_BAD_ID)
+# define __i386_set_gdt(thr, sel, desc) ((void) (thr), (void) (sel), (void) (desc), MIG_BAD_ID)
# endif
# include <errno.h>
# include <assert.h>
+# define HURD_TLS_DESC_DECL(desc, tcb) \
+ struct descriptor desc = \
+ { /* low word: */ \
+ 0xffff /* limit 0..15 */ \
+ | (((unsigned int) (tcb)) << 16) /* base 0..15 */ \
+ , /* high word: */ \
+ ((((unsigned int) (tcb)) >> 16) & 0xff) /* base 16..23 */ \
+ | ((0x12 | 0x60 | 0x80) << 8) /* access = ACC_DATA_W|ACC_PL_U|ACC_P */ \
+ | (0xf << 16) /* limit 16..19 */ \
+ | ((4 | 8) << 20) /* granularity = SZ_32|SZ_G */ \
+ | (((unsigned int) (tcb)) & 0xff000000) /* base 24..31 */ \
+ }
+
+
static inline const char * __attribute__ ((unused))
-_hurd_tls_init (tcbhead_t *tcb, int secondcall)
+_hurd_tls_init (tcbhead_t *tcb)
{
- const unsigned int base = (unsigned int) tcb;
- struct descriptor desc =
- { /* low word: */
- 0xffff /* limit 0..15 */
- | (base << 16) /* base 0..15 */
- , /* high word: */
- ((base >> 16) & 0xff) /* base 16..23 */
- | ((0x12 | 0x60 | 0x80) << 8) /* access = ACC_DATA_W|ACC_PL_U|ACC_P */
- | (0xf << 16) /* limit 16..19 */
- | ((4 | 8) << 20) /* granularity = SZ_32|SZ_G */
- | (base & 0xff000000) /* base 24..31 */
- };
-
- if (!secondcall)
+ HURD_TLS_DESC_DECL (desc, tcb);
+
+ /* This field is used by TLS accesses to get our "thread pointer"
+ from the TLS point of view. */
+ tcb->tcb = tcb;
+
+ /* Cache our thread port. */
+ tcb->self = __mach_thread_self ();
+
+ /* Get the first available selector. */
+ int sel = -1;
+ error_t err = __i386_set_gdt (tcb->self, &sel, desc);
+ if (err == MIG_BAD_ID)
{
- /* Cache our thread port. */
- tcb->self = __mach_thread_self ();
-
- /* Get the first available selector. */
- int sel = -1;
- error_t err = __i386_set_gdt (tcb->self, &sel, desc);
- if (err == MIG_BAD_ID)
- {
- /* Old kernel, use a per-thread LDT. */
- sel = 0x27;
- err = __i386_set_ldt (tcb->self, sel, &desc, 1);
- assert_perror (err);
- return "i386_set_ldt failed";
- }
- else
- {
- assert_perror (err); /* Separate from above with different line #. */
- return "i386_set_gdt failed";
- }
-
- /* Now install the new selector. */
- asm volatile ("mov %w0, %%gs" :: "q" (sel));
+ /* Old kernel, use a per-thread LDT. */
+ sel = 0x27;
+ err = __i386_set_ldt (tcb->self, sel, &desc, 1);
+ assert_perror (err);
+ if (err)
+ return "i386_set_ldt failed";
}
- else
+ else if (err)
{
- /* Fetch the selector set by the first call. */
- int sel;
- asm ("mov %%gs, %w0" : "=q" (sel));
- if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
- {
- error_t err = __i386_set_ldt (tcb->self, sel, &desc, 1);
- assert_perror (err);
- return "i386_set_ldt failed";
- }
- else
- {
- error_t err = __i386_set_gdt (tcb->self, &sel, desc);
- assert_perror (err);
- return "i386_set_gdt failed";
- }
+ assert_perror (err); /* Separate from above with different line #. */
+ return "i386_set_gdt failed";
}
+ /* Now install the new selector. */
+ asm volatile ("mov %w0, %%gs" :: "q" (sel));
+
return 0;
}
/* Code to initially initialize the thread pointer. This might need
special attention since 'errno' is not yet available and if the
operation can cause a failure 'errno' must not be touched. */
-# define TLS_INIT_TP(descr, secondcall) \
- _hurd_tls_init ((tcbhead_t *) (descr), (secondcall))
-# define TLS_INIT_TP_EXPENSIVE 1
+# define TLS_INIT_TP(descr) \
+ _hurd_tls_init ((tcbhead_t *) (descr))
/* Return the TCB address of the current thread. */
-# define THREAD_SELF \
+# define THREAD_SELF \
({ tcbhead_t *__tcb; \
__asm__ ("movl %%gs:%c1,%0" : "=r" (__tcb) \
: "i" (offsetof (tcbhead_t, tcb))); \
: : "ir" (dtvp), "i" (offsetof (tcbhead_t, dtv))); })
/* Return the address of the dtv for the current thread. */
-# define THREAD_DTV() \
+# define THREAD_DTV() \
({ dtv_t *_dtv; \
asm ("movl %%gs:%P1,%0" : "=q" (_dtv) : "i" (offsetof (tcbhead_t, dtv)));\
_dtv; })
-# endif /* !ASSEMBLER */
-#endif /* HAVE_TLS_SUPPORT */
+# include <mach/machine/thread_status.h>
+
+/* Set up TLS in the new thread of a fork child, copying from our own. */
+static inline error_t __attribute__ ((unused))
+_hurd_tls_fork (thread_t child, struct i386_thread_state *state)
+{
+ /* Fetch the selector set by _hurd_tls_init. */
+ int sel;
+ asm ("mov %%gs, %w0" : "=q" (sel) : "0" (0));
+ if (sel == state->ds) /* _hurd_tls_init was never called. */
+ return 0;
+
+ tcbhead_t *const tcb = THREAD_SELF;
+ HURD_TLS_DESC_DECL (desc, tcb);
+ error_t err;
+
+ if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
+ err = __i386_set_ldt (child, sel, &desc, 1);
+ else
+ err = __i386_set_gdt (child, &sel, desc);
+
+ state->gs = sel;
+ return err;
+}
+
+#endif /* !__ASSEMBLER__ */
#endif /* i386/tls.h */