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1 /*
2  * Copyright 2011, The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <stdio.h>
18 #include "GOT.h"
19 
20 void *got_symbol_addresses[NUM_OF_GOT_ENTRY];
21 int got_symbol_indexes[NUM_OF_GOT_ENTRY];
22 size_t got_symbol_count = 0;
23 
got_address()24 void *got_address()
25 {
26   return &got_symbol_addresses[0];
27 }
28 
search_got(int symbol_index,void * addr,uint8_t bind_type)29 int search_got(int symbol_index, void *addr, uint8_t bind_type)
30 {
31   size_t i;
32 
33   // For local symbols (R_MIPS_GOT16), we only store the high 16-bit value
34   // after adding 0x8000.
35   if (bind_type == STB_LOCAL)
36     addr = (void *)(((intptr_t)addr + 0x8000) & 0xFFFF0000);
37 
38   for (i = 0; i < got_symbol_count; i++) {
39     if (got_symbol_indexes[i] == symbol_index) {
40       if (bind_type == STB_LOCAL) {
41         // Check if the value is the same for local symbols.
42         // If yes, we can reuse this entry.
43         // If not, we continue searching.
44         if (got_symbol_addresses[i] == addr) {
45           return i;
46         }
47       }
48       else {
49         // The value must be the same for global symbols .
50         rsl_assert (got_symbol_addresses[i] == addr
51                     && "MIPS GOT address error.");
52         return i;
53       }
54     }
55   }
56 
57   // Cannot find this symbol with correct value, so we need to create one
58   rsl_assert (got_symbol_count < NUM_OF_GOT_ENTRY && "MIPS GOT is full.");
59   got_symbol_indexes[got_symbol_count] = symbol_index;
60   got_symbol_addresses[got_symbol_count] = addr;
61   got_symbol_count++;
62   return (got_symbol_count - 1);
63 }
64