gstreamer/gst/gstcpu.c
David Schleef c1ce267dd1 gst/gstcpu.c: Add a temporary
Original commit message from CVS:
* gst/gstcpu.c: (illegal_instruction_handler),
(cpu_fault_check_enable), (cpu_fault_check_try),
(cpu_fault_check_disable), (gst_cpuid_i386), (test_cpuid),
(gst_cpuid_test), (_gst_cpu_initialize_i386): Add a temporary
SIGILL handler to check for the existence of cpuid before
using it.  (fixes #166696)
2005-03-26 00:13:34 +00:00

208 lines
4.7 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2003 Colin Walters <walters@verbum.org>
*
* gstcpu.c: CPU detection and architecture-specific routines
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gst_private.h"
#include <glib.h>
#include "gstcpu.h"
#include "gstinfo.h"
#include <setjmp.h>
#include <signal.h>
static guint32 _gst_cpu_flags = 0;
#if defined(HAVE_CPU_I386) && defined(__GNUC__)
#define _gst_cpu_initialize_arch _gst_cpu_initialize_i386
gboolean _gst_cpu_initialize_i386 (gulong * flags, GString * featurelist);
#else
#define _gst_cpu_initialize_arch _gst_cpu_initialize_none
gboolean _gst_cpu_initialize_none (gulong * flags, GString * featurelist);
#endif
void
_gst_cpu_initialize (gboolean opt)
{
GString *featurelist = g_string_new ("");
gulong flags = 0;
if (opt) {
if (!_gst_cpu_initialize_arch (&flags, featurelist))
g_string_append (featurelist, "NONE");
} else
g_string_append (featurelist, "(DISABLED)");
GST_CAT_INFO (GST_CAT_GST_INIT, "CPU features: (%08lx) %s", flags,
featurelist->str);
g_string_free (featurelist, TRUE);
}
gboolean
_gst_cpu_initialize_none (gulong * flags, GString * featurelist)
{
return FALSE;
}
#if defined(HAVE_CPU_I386) && defined(__GNUC__)
/* From liboil */
static jmp_buf jump_env;
static struct sigaction action;
static struct sigaction oldaction;
static int in_try_block;
static void
illegal_instruction_handler (int num)
{
if (in_try_block) {
longjmp (jump_env, 1);
} else {
abort ();
}
}
void
cpu_fault_check_enable (void)
{
memset (&action, 0, sizeof (action));
action.sa_handler = &illegal_instruction_handler;
sigaction (SIGILL, &action, &oldaction);
in_try_block = 0;
}
int
cpu_fault_check_try (void (*func) (void *), void *priv)
{
int ret;
in_try_block = 1;
ret = setjmp (jump_env);
if (!ret) {
func (priv);
}
in_try_block = 0;
return (ret == 0);
}
void
cpu_fault_check_disable (void)
{
sigaction (SIGILL, &oldaction, NULL);
}
/* end of code from liboil */
static void
gst_cpuid_i386 (int x, unsigned int *eax, unsigned int *ebx,
unsigned int *ecx, unsigned int *edx)
{
/* *INDENT-OFF* */
asm (
/* GCC-3.2 (and possibly others) don't clobber ebx properly,
* so we save/restore it directly. */
" pushl %%ebx\n"
" cpuid\n"
" mov %%ebx, %%esi\n"
" popl %%ebx\n"
: "=a" (*eax), "=S" (*ebx), "=c" (*ecx), "=d" (*edx)
: "0" (x));
/* *INDENT-ON* */
}
static void
test_cpuid (void *ignore)
{
unsigned int eax, ebx, ecx, edx;
gst_cpuid_i386 (0, &eax, &ebx, &ecx, &edx);
}
static gboolean
gst_cpuid_test (void)
{
int ret;
cpu_fault_check_enable ();
ret = cpu_fault_check_try (test_cpuid, NULL);
cpu_fault_check_disable ();
return ret;
}
gboolean
_gst_cpu_initialize_i386 (gulong * flags, GString * featurelist)
{
gboolean AMD;
guint eax = 0, ebx = 0, ecx = 0, edx = 0;
if (!gst_cpuid_test ()) {
return FALSE;
}
gst_cpuid_i386 (0, &eax, &ebx, &ecx, &edx);
AMD = (ebx == 0x68747541) && (ecx == 0x444d4163) && (edx == 0x69746e65);
gst_cpuid_i386 (1, &eax, &ebx, &ecx, &edx);
if (edx & (1 << 23)) {
_gst_cpu_flags |= GST_CPU_FLAG_MMX;
g_string_append (featurelist, "MMX ");
if (edx & (1 << 25)) {
_gst_cpu_flags |= GST_CPU_FLAG_SSE;
_gst_cpu_flags |= GST_CPU_FLAG_MMXEXT;
g_string_append (featurelist, "SSE ");
}
gst_cpuid_i386 (0x80000000, &eax, &ebx, &ecx, &edx);
if (eax >= 0x80000001) {
gst_cpuid_i386 (0x80000001, &eax, &ebx, &ecx, &edx);
if (edx & (1 << 31)) {
_gst_cpu_flags |= GST_CPU_FLAG_3DNOW;
g_string_append (featurelist, "3DNOW ");
}
if (AMD && (edx & (1 << 22))) {
_gst_cpu_flags |= GST_CPU_FLAG_MMXEXT;
g_string_append (featurelist, "MMXEXT ");
}
}
}
*flags = _gst_cpu_flags;
if (_gst_cpu_flags)
return TRUE;
return FALSE;
}
#endif
GstCPUFlags
gst_cpu_get_flags (void)
{
return _gst_cpu_flags;
}