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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 */
5
6#include <linux/module.h>
7#include <linux/moduleloader.h>
8#include <linux/kernel.h>
9#include <linux/elf.h>
10#include <linux/vmalloc.h>
11#include <linux/slab.h>
12#include <linux/fs.h>
13#include <linux/string.h>
14#include <asm/unwind.h>
15
16static inline void arc_write_me(unsigned short *addr, unsigned long value)
17{
18 *addr = (value & 0xffff0000) >> 16;
19 *(addr + 1) = (value & 0xffff);
20}
21
22/*
23 * This gets called before relocation loop in generic loader
24 * Make a note of the section index of unwinding section
25 */
26int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
27 char *secstr, struct module *mod)
28{
29#ifdef CONFIG_ARC_DW2_UNWIND
30 mod->arch.unw_sec_idx = 0;
31 mod->arch.unw_info = NULL;
32#endif
33 mod->arch.secstr = secstr;
34 return 0;
35}
36
37void module_arch_cleanup(struct module *mod)
38{
39#ifdef CONFIG_ARC_DW2_UNWIND
40 if (mod->arch.unw_info)
41 unwind_remove_table(mod->arch.unw_info, 0);
42#endif
43}
44
45int apply_relocate_add(Elf32_Shdr *sechdrs,
46 const char *strtab,
47 unsigned int symindex, /* sec index for sym tbl */
48 unsigned int relsec, /* sec index for relo sec */
49 struct module *module)
50{
51 int i, n, relo_type;
52 Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
53 Elf32_Sym *sym_entry, *sym_sec;
54 Elf32_Addr relocation, location, tgt_addr;
55 unsigned int tgtsec;
56
57 /*
58 * @relsec has relocations e.g. .rela.init.text
59 * @tgtsec is section to patch e.g. .init.text
60 */
61 tgtsec = sechdrs[relsec].sh_info;
62 tgt_addr = sechdrs[tgtsec].sh_addr;
63 sym_sec = (Elf32_Sym *) sechdrs[symindex].sh_addr;
64 n = sechdrs[relsec].sh_size / sizeof(*rel_entry);
65
66 pr_debug("\nSection to fixup %s @%x\n",
67 module->arch.secstr + sechdrs[tgtsec].sh_name, tgt_addr);
68 pr_debug("=========================================================\n");
69 pr_debug("r_off\tr_add\tst_value ADDRESS VALUE\n");
70 pr_debug("=========================================================\n");
71
72 /* Loop thru entries in relocation section */
73 for (i = 0; i < n; i++) {
74 const char *s;
75
76 /* This is where to make the change */
77 location = tgt_addr + rel_entry[i].r_offset;
78
79 /* This is the symbol it is referring to. Note that all
80 undefined symbols have been resolved. */
81 sym_entry = sym_sec + ELF32_R_SYM(rel_entry[i].r_info);
82
83 relocation = sym_entry->st_value + rel_entry[i].r_addend;
84
85 if (sym_entry->st_name == 0 && ELF_ST_TYPE (sym_entry->st_info) == STT_SECTION) {
86 s = module->arch.secstr + sechdrs[sym_entry->st_shndx].sh_name;
87 } else {
88 s = strtab + sym_entry->st_name;
89 }
90
91 pr_debug(" %x\t%x\t%x %x %x [%s]\n",
92 rel_entry[i].r_offset, rel_entry[i].r_addend,
93 sym_entry->st_value, location, relocation, s);
94
95 /* This assumes modules are built with -mlong-calls
96 * so any branches/jumps are absolute 32 bit jmps
97 * global data access again is abs 32 bit.
98 * Both of these are handled by same relocation type
99 */
100 relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
101
102 if (likely(R_ARC_32_ME == relo_type)) /* ME ( S + A ) */
103 arc_write_me((unsigned short *)location, relocation);
104 else if (R_ARC_32 == relo_type) /* ( S + A ) */
105 *((Elf32_Addr *) location) = relocation;
106 else if (R_ARC_32_PCREL == relo_type) /* ( S + A ) - PDATA ) */
107 *((Elf32_Addr *) location) = relocation - location;
108 else
109 goto relo_err;
110
111 }
112
113#ifdef CONFIG_ARC_DW2_UNWIND
114 if (strcmp(module->arch.secstr+sechdrs[tgtsec].sh_name, ".eh_frame") == 0)
115 module->arch.unw_sec_idx = tgtsec;
116#endif
117
118 return 0;
119
120relo_err:
121 pr_err("%s: unknown relocation: %u\n",
122 module->name, ELF32_R_TYPE(rel_entry[i].r_info));
123 return -ENOEXEC;
124
125}
126
127/* Just before lift off: After sections have been relocated, we add the
128 * dwarf section to unwinder table pool
129 * This couldn't be done in module_frob_arch_sections() because
130 * relocations had not been applied by then
131 */
132int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
133 struct module *mod)
134{
135#ifdef CONFIG_ARC_DW2_UNWIND
136 void *unw;
137 int unwsec = mod->arch.unw_sec_idx;
138
139 if (unwsec) {
140 unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
141 sechdrs[unwsec].sh_size);
142 mod->arch.unw_info = unw;
143 }
144#endif
145 return 0;
146}
1/*
2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 *
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.
7 */
8
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>
15#include <linux/fs.h>
16#include <linux/string.h>
17#include <asm/unwind.h>
18
19static inline void arc_write_me(unsigned short *addr, unsigned long value)
20{
21 *addr = (value & 0xffff0000) >> 16;
22 *(addr + 1) = (value & 0xffff);
23}
24
25/* ARC specific section quirks - before relocation loop in generic loader
26 *
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.
32 */
33int module_frob_arch_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,
34 char *secstr, struct module *mod)
35{
36#ifdef CONFIG_ARC_DW2_UNWIND
37 int i;
38
39 mod->arch.unw_sec_idx = 0;
40 mod->arch.unw_info = NULL;
41
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;
46 break;
47 }
48 }
49#endif
50 return 0;
51}
52
53void module_arch_cleanup(struct module *mod)
54{
55#ifdef CONFIG_ARC_DW2_UNWIND
56 if (mod->arch.unw_info)
57 unwind_remove_table(mod->arch.unw_info, 0);
58#endif
59}
60
61int apply_relocate_add(Elf32_Shdr *sechdrs,
62 const char *strtab,
63 unsigned int symindex, /* sec index for sym tbl */
64 unsigned int relsec, /* sec index for relo sec */
65 struct module *module)
66{
67 int i, n;
68 Elf32_Rela *rel_entry = (void *)sechdrs[relsec].sh_addr;
69 Elf32_Sym *sym_entry, *sym_sec;
70 Elf32_Addr relocation;
71 Elf32_Addr location;
72 Elf32_Addr sec_to_patch;
73 int relo_type;
74
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);
78
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");
84
85 /* Loop thru entries in relocation section */
86 for (i = 0; i < n; i++) {
87
88 /* This is where to make the change */
89 location = sec_to_patch + rel_entry[i].r_offset;
90
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);
94
95 relocation = sym_entry->st_value + rel_entry[i].r_addend;
96
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);
101
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
106 */
107 relo_type = ELF32_R_TYPE(rel_entry[i].r_info);
108
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;
113 else
114 goto relo_err;
115
116 }
117 return 0;
118
119relo_err:
120 pr_err("%s: unknown relocation: %u\n",
121 module->name, ELF32_R_TYPE(rel_entry[i].r_info));
122 return -ENOEXEC;
123
124}
125
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
130 */
131int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
132 struct module *mod)
133{
134#ifdef CONFIG_ARC_DW2_UNWIND
135 void *unw;
136 int unwsec = mod->arch.unw_sec_idx;
137
138 if (unwsec) {
139 unw = unwind_add_table(mod, (void *)sechdrs[unwsec].sh_addr,
140 sechdrs[unwsec].sh_size);
141 mod->arch.unw_info = unw;
142 }
143#endif
144 return 0;
145}