HardenedBSD/sys/powerpc/include/tls.h
John Baldwin 1a62e9bc00 Add <machine/tls.h> header to hold MD constants and helpers for TLS.
The header exports the following:

- Definition of struct tcb.
- Helpers to get/set the tcb for the current thread.
- TLS_TCB_SIZE (size of TCB)
- TLS_TCB_ALIGN (alignment of TCB)
- TLS_VARIANT_I or TLS_VARIANT_II
- TLS_DTV_OFFSET (bias of pointers in dtv[])
- TLS_TP_OFFSET (bias of "thread pointer" relative to TCB)

Note that TLS_TP_OFFSET does not account for if the unbiased thread
pointer points to the start of the TCB (arm and x86) or the end of the
TCB (MIPS, PowerPC, and RISC-V).

Note also that for amd64, the struct tcb does not include the unused
tcb_spare field included in the current structure in libthr.  libthr
does not use this field, and the existing calls in libc and rtld that
allocate a TCB for amd64 assume it is the size of 3 Elf_Addr's (and
thus do not allocate room for tcb_spare).

A <sys/_tls_variant_i.h> header is used by architectures using
Variant I TLS which uses a common struct tcb.

Reviewed by:	kib (older version of x86/tls.h), jrtc27
Sponsored by:	The University of Cambridge, Google Inc.
Differential Revision:	https://reviews.freebsd.org/D33351
2021-12-09 13:17:13 -08:00

67 lines
2.2 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright 2004 by Peter Grehan. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef _MACHINE_TLS_H_
#define _MACHINE_TLS_H_
#include <sys/_tls_variant_i.h>
#define TLS_DTV_OFFSET 0x8000
#define TLS_TCB_ALIGN TLS_TCB_SIZE
#define TLS_TP_OFFSET 0x7000
static __inline void
_tcb_set(struct tcb *tcb)
{
#ifdef __powerpc64__
__asm __volatile("mr 13,%0" ::
"r" ((uint8_t *)tcb + TLS_TP_OFFSET + TLS_TCB_SIZE));
#else
__asm __volatile("mr 2,%0" ::
"r" ((uint8_t *)tcb + TLS_TP_OFFSET + TLS_TCB_SIZE));
#endif
}
static __inline struct tcb *
_tcb_get(void)
{
struct tcb *tcb;
#ifdef __powerpc64__
__asm __volatile("addi %0,13,%1" : "=r" (tcb) :
"i" (-(TLS_TP_OFFSET + TLS_TCB_SIZE)));
#else
__asm __volatile("addi %0,2,%1" : "=r" (tcb) :
"i" (-(TLS_TP_OFFSET + TLS_TCB_SIZE)));
#endif
return (tcb);
}
#endif /* !_MACHINE_TLS_H_ */