Home | History | Annotate | Download | only in mapi 
      1 /*
      2  * Mesa 3-D graphics library
      3  *
      4  * Copyright (C) 2010 LunarG Inc.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included
     14  * in all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     22  * DEALINGS IN THE SOFTWARE.
     23  *
     24  * Authors:
     25  *    Chia-I Wu <olv (at) lunarg.com>
     26  */
     27 
     28 #ifdef HAVE_FUNC_ATTRIBUTE_VISIBILITY
     29 #define HIDDEN __attribute__((visibility("hidden")))
     30 #else
     31 #define HIDDEN
     32 #endif
     33 
     34 #define X86_ENTRY_SIZE 32
     35 
     36 __asm__(".text\n"
     37         ".balign 32\n"
     38         "x86_entry_start:");
     39 
     40 #define STUB_ASM_ENTRY(func)        \
     41    ".globl " func "\n"              \
     42    ".type " func ", @function\n"    \
     43    ".balign 32\n"                   \
     44    func ":"
     45 
     46 #define STUB_ASM_CODE(slot)         \
     47    "movl " ENTRY_CURRENT_TABLE ", %eax\n\t" \
     48    "testl %eax, %eax\n\t"           \
     49    "je 1f\n\t"                      \
     50    "jmp *(4 * " slot ")(%eax)\n"    \
     51    "1:\n\t"                         \
     52    "call " ENTRY_CURRENT_TABLE_GET "\n\t" \
     53    "jmp *(4 * " slot ")(%eax)"
     54 
     55 #define MAPI_TMP_STUB_ASM_GCC
     56 #include "mapi_tmp.h"
     57 
     58 #ifndef MAPI_MODE_BRIDGE
     59 
     60 __asm__(".balign 32\n"
     61         "x86_entry_end:");
     62 
     63 #include <string.h>
     64 #include "u_execmem.h"
     65 
     66 extern const char x86_entry_start[] HIDDEN;
     67 extern const char x86_entry_end[] HIDDEN;
     68 
     69 void
     70 entry_patch_public(void)
     71 {
     72 }
     73 
     74 mapi_func
     75 entry_get_public(int slot)
     76 {
     77    return (mapi_func) (x86_entry_start + slot * X86_ENTRY_SIZE);
     78 }
     79 
     80 void
     81 entry_patch(mapi_func entry, int slot)
     82 {
     83    char *code = (char *) entry;
     84 
     85    *((unsigned long *) (code + 11)) = slot * sizeof(mapi_func);
     86    *((unsigned long *) (code + 22)) = slot * sizeof(mapi_func);
     87 }
     88 
     89 mapi_func
     90 entry_generate(int slot)
     91 {
     92    const char *code_templ = x86_entry_end - X86_ENTRY_SIZE;
     93    void *code;
     94    mapi_func entry;
     95 
     96    code = u_execmem_alloc(X86_ENTRY_SIZE);
     97    if (!code)
     98       return NULL;
     99 
    100    memcpy(code, code_templ, X86_ENTRY_SIZE);
    101    entry = (mapi_func) code;
    102    entry_patch(entry, slot);
    103 
    104    return entry;
    105 }
    106 
    107 #endif /* MAPI_MODE_BRIDGE */
    108