freebsd-dev/lib/libc/i386/gen/getcontextx.c

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/*
* Copyright (c) 2011 Konstantin Belousov <kib@FreeBSD.org>
* 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 ``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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/ucontext.h>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <machine/npx.h>
#include <machine/specialreg.h>
#include <machine/sysarch.h>
static int xstate_sz = -1;
int
__getcontextx_size(void)
{
u_int p[4];
int cpuid_supported;
if (xstate_sz == -1) {
__asm __volatile(
" pushfl\n"
" popl %%eax\n"
" movl %%eax,%%ecx\n"
" xorl $0x200000,%%eax\n"
" pushl %%eax\n"
" popfl\n"
" pushfl\n"
" popl %%eax\n"
" xorl %%eax,%%ecx\n"
" je 1f\n"
" movl $1,%0\n"
" jmp 2f\n"
"1: movl $0,%0\n"
"2:\n"
: "=r" (cpuid_supported) : : "eax", "ecx");
if (cpuid_supported) {
__asm __volatile(
" pushl %%ebx\n"
" cpuid\n"
" movl %%ebx,%1\n"
" popl %%ebx\n"
: "=a" (p[0]), "=r" (p[1]), "=c" (p[2]), "=d" (p[3])
: "0" (0x1));
if ((p[2] & CPUID2_OSXSAVE) != 0) {
__asm __volatile(
" pushl %%ebx\n"
" cpuid\n"
" movl %%ebx,%1\n"
" popl %%ebx\n"
: "=a" (p[0]), "=r" (p[1]), "=c" (p[2]),
"=d" (p[3])
: "0" (0xd), "2" (0x0));
xstate_sz = p[1] - sizeof(struct savexmm);
} else
xstate_sz = 0;
} else
xstate_sz = 0;
}
return (sizeof(ucontext_t) + xstate_sz);
}
int
__fillcontextx2(char *ctx)
{
struct i386_get_xfpustate xfpu;
ucontext_t *ucp;
ucp = (ucontext_t *)ctx;
if (xstate_sz != 0) {
xfpu.addr = (char *)(ucp + 1);
xfpu.len = xstate_sz;
if (sysarch(I386_GET_XFPUSTATE, &xfpu) == -1)
return (-1);
ucp->uc_mcontext.mc_xfpustate = (__register_t)xfpu.addr;
ucp->uc_mcontext.mc_xfpustate_len = xstate_sz;
ucp->uc_mcontext.mc_flags |= _MC_HASFPXSTATE;
} else {
ucp->uc_mcontext.mc_xfpustate = 0;
ucp->uc_mcontext.mc_xfpustate_len = 0;
}
return (0);
}
int
__fillcontextx(char *ctx)
{
ucontext_t *ucp;
ucp = (ucontext_t *)ctx;
if (getcontext(ucp) == -1)
return (-1);
__fillcontextx2(ctx);
return (0);
}
__weak_reference(__getcontextx, getcontextx);
ucontext_t *
__getcontextx(void)
{
char *ctx;
int error;
ctx = malloc(__getcontextx_size());
if (ctx == NULL)
return (NULL);
if (__fillcontextx(ctx) == -1) {
error = errno;
free(ctx);
errno = error;
return (NULL);
}
return ((ucontext_t *)ctx);
}