1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/*
* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/moduleloader.h>
#include <linux/kernel.h>
#include <linux/elf.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <asm/unwind.h>
static inline void arc_write_me(unsigned short *addr, unsigned long value)
{
*addr = (value & 0xffff0000) >> 16;
*(addr + 1) = (value & 0xffff);
}
/*
* This gets called before relocation loop in generic loader
* Make a note of the section index of unwinding section
*/
int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
char *secstr, struct module *mod)
{
#ifdef CONFIG_ARC_DW2_UNWIND
mod->arch.unw_sec_idx = 0;
mod->arch.unw_info = NULL;
mod->arch.secstr = secstr;
#endif
return 0;
}
void module_arch_cleanup(struct module *mod)
{
#ifdef CONFIG_ARC_DW2_UNWIND
if (mod->arch.unw_info)
unwind_remove_table(mod->arch.unw_info, 0);
#endif
}
int apply_relocate_add(Elf32_Shdr *sechdrs,
const char *strtab,
unsigned int symindex, /* sec index for sym tbl */
unsigned int relsec, /* sec index for relo sec */
struct module *module)
{
int i, n, relo_type;
Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
Elf32_Sym *sym_entry, *sym_sec;
Elf32_Addr relocation, location, tgt_addr;
unsigned int tgtsec;
/*
* @relsec has relocations e.g. .rela.init.text
* @tgtsec is section to patch e.g. .init.text
*/
tgtsec = sechdrs[relsec].sh_info;
tgt_addr = sechdrs[tgtsec].sh_addr;
sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
pr_debug("\nSection to fixup %s @%x\n",
module->arch.secstr + sechdrs[tgtsec].sh_name, tgt_addr);
pr_debug("=========================================================\n");
pr_debug("r_off\tr_add\tst_value ADDRESS VALUE\n");
pr_debug("=========================================================\n");
/* Loop thru entries in relocation section */
for (i = 0; i < n; i++) {
const char *s;
/* This is where to make the change */
location = tgt_addr + rel_entry[i].r_offset;
/* This is the symbol it is referring to. Note that all
undefined symbols have been resolved. */
sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info);
relocation = sym_entry->st_value + rel_entry[i].r_addend;
if (sym_entry->st_name == 0 && ELF_ST_TYPE (sym_entry->st_info) == STT_SECTION) {
s = module->arch.secstr + sechdrs[sym_entry->st_shndx].sh_name;
} else {
s = strtab + sym_entry->st_name;
}
pr_debug(" %x\t%x\t%x %x %x [%s]\n",
rel_entry[i].r_offset, rel_entry[i].r_addend,
sym_entry->st_value, location, relocation, s);
/* This assumes modules are built with -mlong-calls
* so any branches/jumps are absolute 32 bit jmps
* global data access again is abs 32 bit.
* Both of these are handled by same relocation type
*/
relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
if (likely(R_ARC_32_ME == relo_type)) /* ME ( S + A ) */
arc_write_me((unsigned short *)location, relocation);
else if (R_ARC_32 == relo_type) /* ( S + A ) */
*((Elf32_Addr *) location) = relocation;
else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */
*((Elf32_Addr *) location) = relocation - location;
else
goto relo_err;
}
if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
module->arch.unw_sec_idx = tgtsec;
return 0;
relo_err:
pr_err("%s: unknown relocation: %u\n",
module->name, ELF32_R_TYPE(rel_entry[i].r_info));
return -ENOEXEC;
}
/* Just before lift off: After sections have been relocated, we add the
* dwarf section to unwinder table pool
* This couldn't be done in module_frob_arch_sections() because
* relocations had not been applied by then
*/
int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
#ifdef CONFIG_ARC_DW2_UNWIND
void *unw;
int unwsec = mod->arch.unw_sec_idx;
if (unwsec) {
unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
sechdrs[unwsec].sh_size);
mod->arch.unw_info = unw;
}
#endif
return 0;
}
|
