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/*
* Mesa 3-D graphics library
*
* Copyright (C) 2010 LunarG Inc.
* Copyright (c) 2015, NVIDIA CORPORATION.
*
* 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>
* Kyle Brenneman <kbrenneman@nvidia.com>
*/
#include "entry.h"
#include "entry_common.h"
#include <assert.h>
#include <stdint.h>
#include <sys/mman.h>
#include <unistd.h>
#include <string.h>
#include "u_macros.h"
#include "glapi/glapi.h"
#define X86_64_ENTRY_SIZE 64
__asm__(".section wtext,\"ax\",@progbits\n");
__asm__(".balign 4096\n"
".globl public_entry_start\n"
"public_entry_start:");
#define STUB_ASM_ENTRY(func) \
".globl " func "\n" \
".type " func ", @function\n" \
".balign " U_STRINGIFY(X86_64_ENTRY_SIZE) "\n" \
func ":"
/*
* Note that this stub does not exactly match the machine code in
* ENTRY_TEMPLATE[] below. In particular, we take advantage of the GOT and PLT
* to produce RIP-relative relocations for the stubs stamped out by mapi_tmp.h.
* We can't do that in general for the generated stubs since they're emitted
* into malloc()ed memory which may not be within 2GB of %rip, as explained in
* the comment in u_execmem.c.
*/
#define STUB_ASM_CODE(slot) \
"movq _glapi_Current@GOTPCREL(%rip), %rax\n\t" \
"movq (%rax), %rax\n" \
"test %rax, %rax\n\t" \
"jne 1f\n\t" \
"push %rdi\n" \
"push %rsi\n" \
"push %rdx\n" \
"push %rcx\n" \
"push %r8\n" \
"push %r9\n" \
"call _glapi_get_current@PLT\n" \
"pop %r9\n" \
"pop %r8\n" \
"pop %rcx\n" \
"pop %rdx\n" \
"pop %rsi\n" \
"pop %rdi\n" \
"1:\n\t" \
"jmp *(8 * " slot ")(%rax)"
#define MAPI_TMP_STUB_ASM_GCC
#include "mapi_tmp.h"
__asm__(".balign 4096\n"
".globl public_entry_end\n"
"public_entry_end:");
__asm__(".text\n");
const int entry_type = ENTRY_X86_64_TSD;
const int entry_stub_size = X86_64_ENTRY_SIZE;
static const unsigned char ENTRY_TEMPLATE[] =
{
// <ENTRY+0>: movabs ENTRY_CURRENT_TABLE, %rax
0x48, 0xa1, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
0x48, 0x85, 0xc0, // <ENTRY+10>: test %rax,%rax
0x75, 0x1c, // <ENTRY+13>: jne <ENTRY+43>
// <ENTRY+15>: movabs $_glapi_get_current, %rax
0x48, 0xb8, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80,
0x57, // <ENTRY+25>: push %rdi
0x56, // <ENTRY+26>: push %rsi
0x52, // <ENTRY+27>: push %rdx
0x51, // <ENTRY+28>: push %rcx
0x41, 0x50, // <ENTRY+29>: push %r8
0x41, 0x51, // <ENTRY+31>: push %r9
0xff, 0xd0, // <ENTRY+33>: callq *%rax
0x41, 0x59, // <ENTRY+35>: pop %r9
0x41, 0x58, // <ENTRY+37>: pop %r8
0x59, // <ENTRY+39>: pop %rcx
0x5a, // <ENTRY+40>: pop %rdx
0x5e, // <ENTRY+41>: pop %rsi
0x5f, // <ENTRY+42>: pop %rdi
0xff, 0xa0, 0x00, 0x00, 0x00, 0x00 // <ENTRY+43:> jmpq *SLOT(%rax)
};
// These are the offsets in ENTRY_TEMPLATE of the values that we have to patch.
static const int TEMPLATE_OFFSET_CURRENT_TABLE = 2;
static const int TEMPLATE_OFFSET_CURRENT_TABLE_GET = 17;
static const int TEMPLATE_OFFSET_SLOT = 45;
void entry_generate_default_code(char *entry, int slot)
{
char *writeEntry = u_execmem_get_writable(entry);
memcpy(writeEntry, ENTRY_TEMPLATE, sizeof(ENTRY_TEMPLATE));
*((uint32_t *) (writeEntry + TEMPLATE_OFFSET_SLOT)) = slot * sizeof(mapi_func);
*((uintptr_t *) (writeEntry + TEMPLATE_OFFSET_CURRENT_TABLE)) = (uintptr_t) _glapi_Current;
*((uintptr_t *) (writeEntry + TEMPLATE_OFFSET_CURRENT_TABLE_GET)) = (uintptr_t) _glapi_get_current;
}
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