]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - arch/arc/kernel/module.c
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/module.h>
10 #include <linux/moduleloader.h>
11 #include <linux/kernel.h>
12 #include <linux/elf.h>
13 #include <linux/vmalloc.h>
14 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <asm/unwind.h>
19 static inline void arc_write_me(unsigned short *addr
, unsigned long value
)
21 *addr
= (value
& 0xffff0000) >> 16;
22 *(addr
+ 1) = (value
& 0xffff);
25 /* ARC specific section quirks - before relocation loop in generic loader
27 * For dwarf unwinding out of modules, this needs to
28 * 1. Ensure the .debug_frame is allocatable (ARC Linker bug: despite
29 * -fasynchronous-unwind-tables it doesn't).
30 * 2. Since we are iterating thru sec hdr tbl anyways, make a note of
31 * the exact section index, for later use.
33 int module_frob_arch_sections(Elf_Ehdr
*hdr
, Elf_Shdr
*sechdrs
,
34 char *secstr
, struct module
*mod
)
36 #ifdef CONFIG_ARC_DW2_UNWIND
39 mod
->arch
.unw_sec_idx
= 0;
40 mod
->arch
.unw_info
= NULL
;
42 for (i
= 1; i
< hdr
->e_shnum
; i
++) {
43 if (strcmp(secstr
+sechdrs
[i
].sh_name
, ".debug_frame") == 0) {
44 sechdrs
[i
].sh_flags
|= SHF_ALLOC
;
45 mod
->arch
.unw_sec_idx
= i
;
53 void module_arch_cleanup(struct module
*mod
)
55 #ifdef CONFIG_ARC_DW2_UNWIND
56 if (mod
->arch
.unw_info
)
57 unwind_remove_table(mod
->arch
.unw_info
, 0);
61 int apply_relocate_add(Elf32_Shdr
*sechdrs
,
63 unsigned int symindex
, /* sec index for sym tbl */
64 unsigned int relsec
, /* sec index for relo sec */
65 struct module
*module
)
68 Elf32_Rela
*rel_entry
= (void *)sechdrs
[relsec
].sh_addr
;
69 Elf32_Sym
*sym_entry
, *sym_sec
;
70 Elf32_Addr relocation
;
72 Elf32_Addr sec_to_patch
;
75 sec_to_patch
= sechdrs
[sechdrs
[relsec
].sh_info
].sh_addr
;
76 sym_sec
= (Elf32_Sym
*) sechdrs
[symindex
].sh_addr
;
77 n
= sechdrs
[relsec
].sh_size
/ sizeof(*rel_entry
);
79 pr_debug("\n========== Module Sym reloc ===========================\n");
80 pr_debug("Section to fixup %x\n", sec_to_patch
);
81 pr_debug("=========================================================\n");
82 pr_debug("rela->r_off | rela->addend | sym->st_value | ADDR | VALUE\n");
83 pr_debug("=========================================================\n");
85 /* Loop thru entries in relocation section */
86 for (i
= 0; i
< n
; i
++) {
88 /* This is where to make the change */
89 location
= sec_to_patch
+ rel_entry
[i
].r_offset
;
91 /* This is the symbol it is referring to. Note that all
92 undefined symbols have been resolved. */
93 sym_entry
= sym_sec
+ ELF32_R_SYM(rel_entry
[i
].r_info
);
95 relocation
= sym_entry
->st_value
+ rel_entry
[i
].r_addend
;
97 pr_debug("\t%x\t\t%x\t\t%x %x %x [%s]\n",
98 rel_entry
[i
].r_offset
, rel_entry
[i
].r_addend
,
99 sym_entry
->st_value
, location
, relocation
,
100 strtab
+ sym_entry
->st_name
);
102 /* This assumes modules are built with -mlong-calls
103 * so any branches/jumps are absolute 32 bit jmps
104 * global data access again is abs 32 bit.
105 * Both of these are handled by same relocation type
107 relo_type
= ELF32_R_TYPE(rel_entry
[i
].r_info
);
109 if (likely(R_ARC_32_ME
== relo_type
))
110 arc_write_me((unsigned short *)location
, relocation
);
111 else if (R_ARC_32
== relo_type
)
112 *((Elf32_Addr
*) location
) = relocation
;
120 pr_err("%s: unknown relocation: %u\n",
121 module
->name
, ELF32_R_TYPE(rel_entry
[i
].r_info
));
126 /* Just before lift off: After sections have been relocated, we add the
127 * dwarf section to unwinder table pool
128 * This couldn't be done in module_frob_arch_sections() because
129 * relocations had not been applied by then
131 int module_finalize(const Elf32_Ehdr
*hdr
, const Elf_Shdr
*sechdrs
,
134 #ifdef CONFIG_ARC_DW2_UNWIND
136 int unwsec
= mod
->arch
.unw_sec_idx
;
139 unw
= unwind_add_table(mod
, (void *)sechdrs
[unwsec
].sh_addr
,
140 sechdrs
[unwsec
].sh_size
);
141 mod
->arch
.unw_info
= unw
;