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/*
* Mesa 3-D graphics library
*
* Copyright (C) 2010 LunarG Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors:
* Chia-I Wu <olv@lunarg.com>
*/
#include <string.h>
#ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
#define HIDDEN __attribute__((visibility("hidden")))
#else
#define HIDDEN
#endif
#define X86_ENTRY_SIZE 32
__asm__(".text");
__asm__("x86_current_tls:\n\t"
"call 1f\n"
"1:\n\t"
"popl %eax\n\t"
"addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %eax\n\t"
"movl " ENTRY_CURRENT_TABLE "@GOTNTPOFF(%eax), %eax\n\t"
"ret");
#ifndef GLX_X86_READONLY_TEXT
__asm__(".section wtext, \"awx\", @progbits");
#endif /* GLX_X86_READONLY_TEXT */
__asm__(".balign 16\n"
"x86_entry_start:");
#define STUB_ASM_ENTRY(func) \
".globl " func "\n" \
".type " func ", @function\n" \
".balign 16\n" \
func ":"
#define STUB_ASM_CODE(slot) \
"call 1f\n" \
"1:\n\t" \
"popl %eax\n\t" \
"addl $_GLOBAL_OFFSET_TABLE_+[.-1b], %eax\n\t" \
"movl " ENTRY_CURRENT_TABLE "@GOTNTPOFF(%eax), %eax\n\t" \
"movl %gs:(%eax), %eax\n\t" \
"jmp *(4 * " slot ")(%eax)"
#define MAPI_TMP_STUB_ASM_GCC
#include "mapi_tmp.h"
#ifndef GLX_X86_READONLY_TEXT
__asm__(".balign 16\n"
"x86_entry_end:");
__asm__(".text");
#endif /* GLX_X86_READONLY_TEXT */
#ifndef MAPI_MODE_BRIDGE
#include "u_execmem.h"
extern unsigned long
x86_current_tls();
extern char x86_entry_start[] HIDDEN;
extern char x86_entry_end[] HIDDEN;
static inline mapi_func
entry_generate_or_patch(int, char *, size_t);
void
entry_patch_public(void)
{
#ifndef GLX_X86_READONLY_TEXT
char *entry;
int slot = 0;
for (entry = x86_entry_start; entry < x86_entry_end;
entry += X86_ENTRY_SIZE, ++slot)
entry_generate_or_patch(slot, entry, X86_ENTRY_SIZE);
#endif
}
mapi_func
entry_get_public(int slot)
{
return (mapi_func) (x86_entry_start + slot * X86_ENTRY_SIZE);
}
void
entry_patch(mapi_func entry, int slot)
{
char *code = (char *) entry;
*((unsigned long *) (code + 8)) = slot * sizeof(mapi_func);
}
static inline mapi_func
entry_generate_or_patch(int slot, char *code, size_t size)
{
const char code_templ[16] = {
0x65, 0xa1, 0x00, 0x00, 0x00, 0x00, /* movl %gs:0x0, %eax */
0xff, 0xa0, 0x34, 0x12, 0x00, 0x00, /* jmp *0x1234(%eax) */
0x90, 0x90, 0x90, 0x90 /* nop's */
};
mapi_func entry;
if (code == NULL) {
size = sizeof(code_templ);
code = u_execmem_alloc(size);
}
if (!code || size < sizeof(code_templ))
return NULL;
memcpy(code, code_templ, sizeof(code_templ));
*((unsigned long *) (code + 2)) = x86_current_tls();
entry = (mapi_func) code;
entry_patch(entry, slot);
return entry;
}
mapi_func
entry_generate(int slot)
{
return entry_generate_or_patch(slot, NULL, 0);
}
#endif /* MAPI_MODE_BRIDGE */
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