peter 290cd3dfdf When building the custom i386 libraries for use on amd64 kernels, we
can't use the i386_set_ldt() family of routines, because they are not
implemented.  Instead, use the recently exposed direct access sysarch
routines for setting what %fs and %gs point to.

Use this for the i386 TLS _set_tp() routine, but only when compiling to
run as a 32 bit support binary for amd64 kernels.
2004-11-06 03:28:26 +00:00

57 lines
2.0 KiB
C

/*-
* Copyright (c) 2004 Doug Rabson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*
* $FreeBSD$
*/
#include <string.h>
#include <stdint.h>
#include <machine/segments.h>
#include <machine/sysarch.h>
void
_set_tp(void *tp)
{
#ifndef COMPAT_32BIT
union descriptor ldt;
int sel;
memset(&ldt, 0, sizeof(ldt));
ldt.sd.sd_lolimit = 0xffff; /* 4G limit */
ldt.sd.sd_lobase = ((uintptr_t)tp) & 0xffffff;
ldt.sd.sd_type = SDT_MEMRWA;
ldt.sd.sd_dpl = SEL_UPL;
ldt.sd.sd_p = 1; /* present */
ldt.sd.sd_hilimit = 0xf; /* 4G limit */
ldt.sd.sd_def32 = 1; /* 32 bit */
ldt.sd.sd_gran = 1; /* limit in pages */
ldt.sd.sd_hibase = (((uintptr_t)tp) >> 24) & 0xff;
sel = i386_set_ldt(LDT_AUTO_ALLOC, &ldt, 1);
__asm __volatile("movl %0,%%gs" : : "rm" ((sel << 3) | 7));
#else
_amd64_set_gsbase(tp);
#endif
}