|
|
/* $OpenBSD: tib.h,v 1.2 2016/03/20 02:30:28 guenther Exp $ */
|
|
|
/*
|
|
|
* Copyright (c) 2011,2014 Philip Guenther <guenther@openbsd.org>
|
|
|
*
|
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
|
* copyright notice and this permission notice appear in all copies.
|
|
|
*
|
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
|
*/
|
|
|
|
|
|
/*
|
|
|
* Thread Information Block (TIB) and Thread Local Storage (TLS) handling
|
|
|
* (the TCB, Thread Control Block, is part of the TIB)
|
|
|
*/
|
|
|
|
|
|
#ifndef _TIB_H_
|
|
|
#define _TIB_H_
|
|
|
|
|
|
#include <sys/types.h>
|
|
|
#include <machine/tcb.h>
|
|
|
|
|
|
#include <stddef.h>
|
|
|
|
|
|
|
|
|
/*
|
|
|
* This header defines struct tib and at least eight macros:
|
|
|
* TLS_VARIANT
|
|
|
* Either 1 or 2 (Actually defined by <machine/tcb.h>)
|
|
|
*
|
|
|
* TCB_SET(tcb)
|
|
|
* Set the TCB pointer for this thread to 'tcb'
|
|
|
*
|
|
|
* TCB_GET()
|
|
|
* Return the TCB pointer for this thread
|
|
|
*
|
|
|
* TCB_TO_TIB(tcb)
|
|
|
* Given a TCB pointer, return the matching TIB pointer
|
|
|
*
|
|
|
* TIB_TO_TCB(tib)
|
|
|
* Given a TIB pointer, return the matching TCB pointer
|
|
|
*
|
|
|
* TIB_INIT(tib, dtv)
|
|
|
* Initializes a TIB for a new thread, using the supplied
|
|
|
* value for the dtv pointer
|
|
|
*
|
|
|
* TIB_TO_THREAD(tib)
|
|
|
* Given a TIB pointer, return a pointer to the struct pthread
|
|
|
*
|
|
|
* TIB_GET()
|
|
|
* Short-hand for TCB_TO_TIB(TCB_GET())
|
|
|
*
|
|
|
* TIB_THREAD()
|
|
|
* Returns a pointer to this thread's struct pthread
|
|
|
*
|
|
|
* TIB_EXTRA_ALIGN
|
|
|
* On TLS varaint 2 archs, what alignment is sufficient
|
|
|
* for the extra space that will be used for struct pthread?
|
|
|
*
|
|
|
* The following functions are provided by either ld.so (dynamic) or
|
|
|
* libc (static) for allocating and freeing a common memory block that
|
|
|
* will hold both the TIB and the pthread structure:
|
|
|
* _dl_allocate_tib(sizeof(struct pthread), flags)
|
|
|
* Allocates a combined TIB and pthread memory region.
|
|
|
* The first argument is the amount of space to reserve
|
|
|
* for the pthread structure; the second argument is
|
|
|
* either zero or DAT_UPDATE_CURRENT, the latter meaning
|
|
|
* this call is to update/replace the current thread's
|
|
|
* TIB. Returns a pointer to the TIB inside the
|
|
|
* allocated block.
|
|
|
*
|
|
|
* _dl_free_tib(tib, sizeof(struct pthread))
|
|
|
* Frees a TIB and pthread block previously allocated
|
|
|
* with _dl_allocate_tls(). Must be passed the return
|
|
|
* value of that previous call.
|
|
|
*/
|
|
|
|
|
|
/*
|
|
|
* Regarding <machine/tcb.h>:
|
|
|
* - it must define the TLS_VARIANT macro
|
|
|
* - if there's a faster way to get or set the TCB pointer for the thread
|
|
|
* than the __{get,set}_tcb() syscalls, it should define either or both
|
|
|
* the TCB_{GET,SET} macros to do so.
|
|
|
*/
|
|
|
|
|
|
|
|
|
/* If <machine/tcb.h> doesn't provide a better way, then use the default */
|
|
|
#ifdef TCB_GET
|
|
|
# define TCB_HAVE_MD_GET 1
|
|
|
#else
|
|
|
# define TCB_GET() __get_tcb()
|
|
|
#endif
|
|
|
#ifdef TCB_SET
|
|
|
# define TCB_HAVE_MD_SET 1
|
|
|
#else
|
|
|
# define TCB_SET(tcb) __set_tcb(tcb)
|
|
|
#endif
|
|
|
|
|
|
|
|
|
#if TLS_VARIANT == 1
|
|
|
/*
|
|
|
* ABI specifies that the static TLS data starts two words after the
|
|
|
* (notional) thread pointer, with the first of those two words being
|
|
|
* the TLS dtv pointer. The other (second) word is reserved for the
|
|
|
* implementation, so we place the thread's locale there, but we place
|
|
|
* our thread bits before the TCB, at negative offsets from the
|
|
|
* TCB pointer. Ergo, memory is laid out, low to high, as:
|
|
|
*
|
|
|
* [pthread structure]
|
|
|
* TIB {
|
|
|
* int cancel_flags
|
|
|
* int cancel_requested
|
|
|
* int errno
|
|
|
* void *locale
|
|
|
* TCB {
|
|
|
* void *dtv
|
|
|
* struct pthread *thread
|
|
|
* }
|
|
|
* }
|
|
|
* static TLS data
|
|
|
*/
|
|
|
|
|
|
struct tib {
|
|
|
#ifdef __LP64__
|
|
|
int __tib_padding; /* padding for 8byte alignment */
|
|
|
#endif
|
|
|
int tib_cancel_flags;
|
|
|
int tib_cancel;
|
|
|
int tib_errno;
|
|
|
void *tib_locale;
|
|
|
void *tib_dtv; /* internal to the runtime linker */
|
|
|
void *tib_thread;
|
|
|
};
|
|
|
#ifdef __LP64__
|
|
|
# define _TIB_PREP(tib) ((void)((tib)->__tib_padding = 0))
|
|
|
#endif
|
|
|
|
|
|
#define _TIBO_PTHREAD (- _ALIGN(sizeof(struct pthread)))
|
|
|
|
|
|
#elif TLS_VARIANT == 2
|
|
|
/*
|
|
|
* ABI specifies that the static TLS data occupies the memory before
|
|
|
* the TCB pointer, at negative offsets, and that on i386 and amd64
|
|
|
* the word the TCB points to contains a pointer to itself. So,
|
|
|
* we place errno and our thread bits after that. Memory is laid
|
|
|
* out, low to high, as:
|
|
|
* static TLS data
|
|
|
* TIB {
|
|
|
* TCB {
|
|
|
* self pointer [i386/amd64 only]
|
|
|
* void *dtv
|
|
|
* }
|
|
|
* struct pthread *thread
|
|
|
* void *locale
|
|
|
* int errno
|
|
|
* int cancel_count_flags
|
|
|
* int cancel_requested
|
|
|
* }
|
|
|
* [pthread structure]
|
|
|
*/
|
|
|
|
|
|
struct tib {
|
|
|
#if defined(__i386) || defined(__amd64)
|
|
|
struct tib *__tib_self;
|
|
|
# define __tib_tcb __tib_self
|
|
|
#endif
|
|
|
void *tib_dtv; /* internal to the runtime linker */
|
|
|
void *tib_thread;
|
|
|
void *tib_locale;
|
|
|
int tib_errno;
|
|
|
int tib_cancel; /* set to request cancelation */
|
|
|
int tib_cancel_flags;
|
|
|
#if defined(__LP64__) || defined(__i386)
|
|
|
int __tib_padding; /* padding for 8byte alignment */
|
|
|
#endif
|
|
|
};
|
|
|
|
|
|
#define _TIBO_PTHREAD _ALIGN(sizeof(struct tib))
|
|
|
|
|
|
#if defined(__i386) || defined(__amd64)
|
|
|
# define _TIB_PREP(tib) \
|
|
|
((void)((tib)->__tib_self = (tib), (tib)->__tib_padding = 0))
|
|
|
#elif defined(__LP64__)
|
|
|
# define _TIB_PREP(tib) ((void)((tib)->__tib_padding = 0))
|
|
|
#endif
|
|
|
|
|
|
#define TIB_EXTRA_ALIGN sizeof(void *)
|
|
|
|
|
|
#else
|
|
|
# error "unknown TLS variant"
|
|
|
#endif
|
|
|
|
|
|
/* nothing to do by default */
|
|
|
#ifndef _TIB_PREP
|
|
|
# define _TIB_PREP(tib) ((void)0)
|
|
|
#endif
|
|
|
|
|
|
#define TIB_INIT(tib, dtv, thread) do { \
|
|
|
(tib)->tib_thread = (thread); \
|
|
|
(tib)->tib_locale = NULL; \
|
|
|
(tib)->tib_cancel_flags = 0; \
|
|
|
(tib)->tib_cancel = 0; \
|
|
|
(tib)->tib_dtv = (dtv); \
|
|
|
(tib)->tib_errno = 0; \
|
|
|
_TIB_PREP(tib); \
|
|
|
} while (0)
|
|
|
|
|
|
#ifndef __tib_tcb
|
|
|
# define __tib_tcb tib_dtv
|
|
|
#endif
|
|
|
#define _TIBO_TCB offsetof(struct tib, __tib_tcb)
|
|
|
|
|
|
#define TCB_TO_TIB(tcb) ((struct tib *)((char *)(tcb) - _TIBO_TCB))
|
|
|
#define TIB_TO_TCB(tib) ((char *)(tib) + _TIBO_TCB)
|
|
|
#define TIB_TO_THREAD(tib) ((struct pthread *)(tib)->tib_thread)
|
|
|
#define TIB_GET() TCB_TO_TIB(TCB_GET())
|
|
|
#define TCB_THREAD() TIB_TO_THREAD(TIB_GET())
|
|
|
|
|
|
|
|
|
__BEGIN_DECLS
|
|
|
void *_dl_allocate_tib(size_t _extra) __dso_public;
|
|
|
void _dl_free_tib(void *_tib, size_t _extra) __dso_public;
|
|
|
|
|
|
/* The actual syscalls */
|
|
|
void *__get_tcb(void);
|
|
|
void __set_tcb(void *_tcb);
|
|
|
__END_DECLS
|
|
|
|
|
|
#endif /* _TIB_H_ */
|