Root/scripts/sortextable.h

Source at commit cdde9cf73945d547acd3e96f9508c79e84ad0bf1 created 9 years 4 months ago.
By Maarten ter Huurne, MMC: JZ4740: Added support for CPU frequency changing
1/*
2 * sortextable.h
3 *
4 * Copyright 2011 - 2012 Cavium, Inc.
5 *
6 * Some of this code was taken out of recordmcount.h written by:
7 *
8 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
9 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
10 *
11 *
12 * Licensed under the GNU General Public License, version 2 (GPLv2).
13 */
14
15#undef extable_ent_size
16#undef compare_extable
17#undef do_func
18#undef Elf_Addr
19#undef Elf_Ehdr
20#undef Elf_Shdr
21#undef Elf_Rel
22#undef Elf_Rela
23#undef Elf_Sym
24#undef ELF_R_SYM
25#undef Elf_r_sym
26#undef ELF_R_INFO
27#undef Elf_r_info
28#undef ELF_ST_BIND
29#undef ELF_ST_TYPE
30#undef fn_ELF_R_SYM
31#undef fn_ELF_R_INFO
32#undef uint_t
33#undef _r
34#undef _w
35
36#ifdef SORTEXTABLE_64
37# define extable_ent_size 16
38# define compare_extable compare_extable_64
39# define do_func do64
40# define Elf_Addr Elf64_Addr
41# define Elf_Ehdr Elf64_Ehdr
42# define Elf_Shdr Elf64_Shdr
43# define Elf_Rel Elf64_Rel
44# define Elf_Rela Elf64_Rela
45# define Elf_Sym Elf64_Sym
46# define ELF_R_SYM ELF64_R_SYM
47# define Elf_r_sym Elf64_r_sym
48# define ELF_R_INFO ELF64_R_INFO
49# define Elf_r_info Elf64_r_info
50# define ELF_ST_BIND ELF64_ST_BIND
51# define ELF_ST_TYPE ELF64_ST_TYPE
52# define fn_ELF_R_SYM fn_ELF64_R_SYM
53# define fn_ELF_R_INFO fn_ELF64_R_INFO
54# define uint_t uint64_t
55# define _r r8
56# define _w w8
57#else
58# define extable_ent_size 8
59# define compare_extable compare_extable_32
60# define do_func do32
61# define Elf_Addr Elf32_Addr
62# define Elf_Ehdr Elf32_Ehdr
63# define Elf_Shdr Elf32_Shdr
64# define Elf_Rel Elf32_Rel
65# define Elf_Rela Elf32_Rela
66# define Elf_Sym Elf32_Sym
67# define ELF_R_SYM ELF32_R_SYM
68# define Elf_r_sym Elf32_r_sym
69# define ELF_R_INFO ELF32_R_INFO
70# define Elf_r_info Elf32_r_info
71# define ELF_ST_BIND ELF32_ST_BIND
72# define ELF_ST_TYPE ELF32_ST_TYPE
73# define fn_ELF_R_SYM fn_ELF32_R_SYM
74# define fn_ELF_R_INFO fn_ELF32_R_INFO
75# define uint_t uint32_t
76# define _r r
77# define _w w
78#endif
79
80static int compare_extable(const void *a, const void *b)
81{
82    Elf_Addr av = _r(a);
83    Elf_Addr bv = _r(b);
84
85    if (av < bv)
86        return -1;
87    if (av > bv)
88        return 1;
89    return 0;
90}
91
92static void
93do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort)
94{
95    Elf_Shdr *shdr;
96    Elf_Shdr *shstrtab_sec;
97    Elf_Shdr *strtab_sec = NULL;
98    Elf_Shdr *symtab_sec = NULL;
99    Elf_Shdr *extab_sec = NULL;
100    Elf_Sym *sym;
101    Elf_Sym *sort_needed_sym;
102    Elf_Shdr *sort_needed_sec;
103    Elf_Rel *relocs = NULL;
104    int relocs_size;
105    uint32_t *sort_done_location;
106    const char *secstrtab;
107    const char *strtab;
108    char *extab_image;
109    int extab_index = 0;
110    int i;
111    int idx;
112
113    shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff));
114    shstrtab_sec = shdr + r2(&ehdr->e_shstrndx);
115    secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset);
116    for (i = 0; i < r2(&ehdr->e_shnum); i++) {
117        idx = r(&shdr[i].sh_name);
118        if (strcmp(secstrtab + idx, "__ex_table") == 0) {
119            extab_sec = shdr + i;
120            extab_index = i;
121        }
122        if ((r(&shdr[i].sh_type) == SHT_REL ||
123             r(&shdr[i].sh_type) == SHT_RELA) &&
124            r(&shdr[i].sh_info) == extab_index) {
125            relocs = (void *)ehdr + _r(&shdr[i].sh_offset);
126            relocs_size = _r(&shdr[i].sh_size);
127        }
128        if (strcmp(secstrtab + idx, ".symtab") == 0)
129            symtab_sec = shdr + i;
130        if (strcmp(secstrtab + idx, ".strtab") == 0)
131            strtab_sec = shdr + i;
132    }
133    if (strtab_sec == NULL) {
134        fprintf(stderr, "no .strtab in file: %s\n", fname);
135        fail_file();
136    }
137    if (symtab_sec == NULL) {
138        fprintf(stderr, "no .symtab in file: %s\n", fname);
139        fail_file();
140    }
141    if (extab_sec == NULL) {
142        fprintf(stderr, "no __ex_table in file: %s\n", fname);
143        fail_file();
144    }
145    strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset);
146
147    extab_image = (void *)ehdr + _r(&extab_sec->sh_offset);
148
149    if (custom_sort) {
150        custom_sort(extab_image, _r(&extab_sec->sh_size));
151    } else {
152        int num_entries = _r(&extab_sec->sh_size) / extable_ent_size;
153        qsort(extab_image, num_entries,
154              extable_ent_size, compare_extable);
155    }
156    /* If there were relocations, we no longer need them. */
157    if (relocs)
158        memset(relocs, 0, relocs_size);
159
160    /* find main_extable_sort_needed */
161    sort_needed_sym = NULL;
162    for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) {
163        sym = (void *)ehdr + _r(&symtab_sec->sh_offset);
164        sym += i;
165        if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT)
166            continue;
167        idx = r(&sym->st_name);
168        if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) {
169            sort_needed_sym = sym;
170            break;
171        }
172    }
173    if (sort_needed_sym == NULL) {
174        fprintf(stderr,
175            "no main_extable_sort_needed symbol in file: %s\n",
176            fname);
177        fail_file();
178    }
179    sort_needed_sec = &shdr[r2(&sort_needed_sym->st_shndx)];
180    sort_done_location = (void *)ehdr +
181        _r(&sort_needed_sec->sh_offset) +
182        _r(&sort_needed_sym->st_value) -
183        _r(&sort_needed_sec->sh_addr);
184
185#if 1
186    printf("sort done marker at %lx\n",
187           (unsigned long)((char *)sort_done_location - (char *)ehdr));
188#endif
189    /* We sorted it, clear the flag. */
190    w(0, sort_done_location);
191}
192

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