xref: /DragonStub/gnuefi/reloc_x86_64.c (revision 3dd05c7b21921cae0002ab7964fa0e52dedd7c3f)
1 /* reloc_x86_64.c - position independent x86_64 ELF shared object relocator
2    Copyright (C) 1999 Hewlett-Packard Co.
3 	Contributed by David Mosberger <davidm@hpl.hp.com>.
4    Copyright (C) 2005 Intel Co.
5 	Contributed by Fenghua Yu <fenghua.yu@intel.com>.
6 
7     All rights reserved.
8 
9     Redistribution and use in source and binary forms, with or without
10     modification, are permitted provided that the following conditions
11     are met:
12 
13     * Redistributions of source code must retain the above copyright
14       notice, this list of conditions and the following disclaimer.
15     * Redistributions in binary form must reproduce the above
16       copyright notice, this list of conditions and the following
17       disclaimer in the documentation and/or other materials
18       provided with the distribution.
19     * Neither the name of Hewlett-Packard Co. nor the names of its
20       contributors may be used to endorse or promote products derived
21       from this software without specific prior written permission.
22 
23     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
24     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
25     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
28     BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
29     OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30     PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32     THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
33     TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
34     THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35     SUCH DAMAGE.
36 */
37 
38 #include <efi.h>
39 #include <efilib.h>
40 
41 #include <elf.h>
42 
43 EFI_STATUS _relocate (long ldbase, Elf64_Dyn *dyn,
44 		      EFI_HANDLE image __attribute__((__unused__)),
45 		      EFI_SYSTEM_TABLE *systab __attribute__((__unused__)))
46 {
47 	long relsz = 0, relent = 0;
48 	Elf64_Rel *rel = 0;
49 	unsigned long *addr;
50 	int i;
51 
52 	for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
53 		switch (dyn[i].d_tag) {
54 			case DT_RELA:
55 				rel = (Elf64_Rel*)
56 					((unsigned long)dyn[i].d_un.d_ptr
57 					 + ldbase);
58 				break;
59 
60 			case DT_RELASZ:
61 				relsz = dyn[i].d_un.d_val;
62 				break;
63 
64 			case DT_RELAENT:
65 				relent = dyn[i].d_un.d_val;
66 				break;
67 
68 			default:
69 				break;
70 		}
71 	}
72 
73         if (!rel && relent == 0)
74                 return EFI_SUCCESS;
75 
76 	if (!rel || relent == 0)
77 		return EFI_LOAD_ERROR;
78 
79 	while (relsz > 0) {
80 		/* apply the relocs */
81 		switch (ELF64_R_TYPE (rel->r_info)) {
82 			case R_X86_64_NONE:
83 				break;
84 
85 			case R_X86_64_RELATIVE:
86 				addr = (unsigned long *)
87 					(ldbase + rel->r_offset);
88 				*addr += ldbase;
89 				break;
90 
91 			default:
92 				break;
93 		}
94 		rel = (Elf64_Rel*) ((char *) rel + relent);
95 		relsz -= relent;
96 	}
97 	return EFI_SUCCESS;
98 }
99