aboutsummaryrefslogtreecommitdiff
path: root/hw/elf_ops.h
blob: 731a983854bce7fa375e3cc473067c8e70743619 (plain)
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
static void glue(bswap_ehdr, SZ)(struct elfhdr *ehdr)
{
    bswap16s(&ehdr->e_type);			/* Object file type */
    bswap16s(&ehdr->e_machine);		/* Architecture */
    bswap32s(&ehdr->e_version);		/* Object file version */
    bswapSZs(&ehdr->e_entry);		/* Entry point virtual address */
    bswapSZs(&ehdr->e_phoff);		/* Program header table file offset */
    bswapSZs(&ehdr->e_shoff);		/* Section header table file offset */
    bswap32s(&ehdr->e_flags);		/* Processor-specific flags */
    bswap16s(&ehdr->e_ehsize);		/* ELF header size in bytes */
    bswap16s(&ehdr->e_phentsize);		/* Program header table entry size */
    bswap16s(&ehdr->e_phnum);		/* Program header table entry count */
    bswap16s(&ehdr->e_shentsize);		/* Section header table entry size */
    bswap16s(&ehdr->e_shnum);		/* Section header table entry count */
    bswap16s(&ehdr->e_shstrndx);		/* Section header string table index */
}

static void glue(bswap_phdr, SZ)(struct elf_phdr *phdr)
{
    bswap32s(&phdr->p_type);			/* Segment type */
    bswapSZs(&phdr->p_offset);		/* Segment file offset */
    bswapSZs(&phdr->p_vaddr);		/* Segment virtual address */
    bswapSZs(&phdr->p_paddr);		/* Segment physical address */
    bswapSZs(&phdr->p_filesz);		/* Segment size in file */
    bswapSZs(&phdr->p_memsz);		/* Segment size in memory */
    bswap32s(&phdr->p_flags);		/* Segment flags */
    bswapSZs(&phdr->p_align);		/* Segment alignment */
}

static void glue(bswap_shdr, SZ)(struct elf_shdr *shdr)
{
    bswap32s(&shdr->sh_name);
    bswap32s(&shdr->sh_type);
    bswapSZs(&shdr->sh_flags);
    bswapSZs(&shdr->sh_addr);
    bswapSZs(&shdr->sh_offset);
    bswapSZs(&shdr->sh_size);
    bswap32s(&shdr->sh_link);
    bswap32s(&shdr->sh_info);
    bswapSZs(&shdr->sh_addralign);
    bswapSZs(&shdr->sh_entsize);
}

static void glue(bswap_sym, SZ)(struct elf_sym *sym)
{
    bswap32s(&sym->st_name);
    bswapSZs(&sym->st_value);
    bswapSZs(&sym->st_size);
    bswap16s(&sym->st_shndx);
}

static struct elf_shdr *glue(find_section, SZ)(struct elf_shdr *shdr_table,
                                               int n, int type)
{
    int i;
    for(i=0;i<n;i++) {
        if (shdr_table[i].sh_type == type)
            return shdr_table + i;
    }
    return NULL;
}

static int glue(symfind, SZ)(const void *s0, const void *s1)
{
    target_phys_addr_t addr = *(target_phys_addr_t *)s0;
    struct elf_sym *sym = (struct elf_sym *)s1;
    int result = 0;
    if (addr < sym->st_value) {
        result = -1;
    } else if (addr >= sym->st_value + sym->st_size) {
        result = 1;
    }
    return result;
}

static const char *glue(lookup_symbol, SZ)(struct syminfo *s,
                                           target_phys_addr_t orig_addr)
{
    struct elf_sym *syms = glue(s->disas_symtab.elf, SZ);
    struct elf_sym *sym;

    sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms),
                  glue(symfind, SZ));
    if (sym != NULL) {
        return s->disas_strtab + sym->st_name;
    }

    return "";
}

static int glue(symcmp, SZ)(const void *s0, const void *s1)
{
    struct elf_sym *sym0 = (struct elf_sym *)s0;
    struct elf_sym *sym1 = (struct elf_sym *)s1;
    return (sym0->st_value < sym1->st_value)
        ? -1
        : ((sym0->st_value > sym1->st_value) ? 1 : 0);
}

static int glue(load_symbols, SZ)(struct elfhdr *ehdr, int fd, int must_swab,
                                  int clear_lsb)
{
    struct elf_shdr *symtab, *strtab, *shdr_table = NULL;
    struct elf_sym *syms = NULL;
    struct syminfo *s;
    int nsyms, i;
    char *str = NULL;

    shdr_table = load_at(fd, ehdr->e_shoff,
                         sizeof(struct elf_shdr) * ehdr->e_shnum);
    if (!shdr_table)
        return -1;

    if (must_swab) {
        for (i = 0; i < ehdr->e_shnum; i++) {
            glue(bswap_shdr, SZ)(shdr_table + i);
        }
    }

    symtab = glue(find_section, SZ)(shdr_table, ehdr->e_shnum, SHT_SYMTAB);
    if (!symtab)
        goto fail;
    syms = load_at(fd, symtab->sh_offset, symtab->sh_size);
    if (!syms)
        goto fail;

    nsyms = symtab->sh_size / sizeof(struct elf_sym);

    i = 0;
    while (i < nsyms) {
        if (must_swab)
            glue(bswap_sym, SZ)(&syms[i]);
        /* We are only interested in function symbols.
           Throw everything else away.  */
        if (syms[i].st_shndx == SHN_UNDEF ||
                syms[i].st_shndx >= SHN_LORESERVE ||
                ELF_ST_TYPE(syms[i].st_info) != STT_FUNC) {
            nsyms--;
            if (i < nsyms) {
                syms[i] = syms[nsyms];
            }
            continue;
        }
        if (clear_lsb) {
            /* The bottom address bit marks a Thumb or MIPS16 symbol.  */
            syms[i].st_value &= ~(glue(glue(Elf, SZ), _Addr))1;
        }
        i++;
    }
    if (nsyms) {
        syms = g_realloc(syms, nsyms * sizeof(*syms));

        qsort(syms, nsyms, sizeof(*syms), glue(symcmp, SZ));
        for (i = 0; i < nsyms - 1; i++) {
            if (syms[i].st_size == 0) {
                syms[i].st_size = syms[i + 1].st_value - syms[i].st_value;
            }
        }
    } else {
        g_free(syms);
        syms = NULL;
    }

    /* String table */
    if (symtab->sh_link >= ehdr->e_shnum)
        goto fail;
    strtab = &shdr_table[symtab->sh_link];

    str = load_at(fd, strtab->sh_offset, strtab->sh_size);
    if (!str)
        goto fail;

    /* Commit */
    s = g_malloc0(sizeof(*s));
    s->lookup_symbol = glue(lookup_symbol, SZ);
    glue(s->disas_symtab.elf, SZ) = syms;
    s->disas_num_syms = nsyms;
    s->disas_strtab = str;
    s->next = syminfos;
    syminfos = s;
    g_free(shdr_table);
    return 0;
 fail:
    g_free(syms);
    g_free(str);
    g_free(shdr_table);
    return -1;
}

static int glue(load_elf, SZ)(const char *name, int fd,
                              uint64_t (*translate_fn)(void *, uint64_t),
                              void *translate_opaque,
                              int must_swab, uint64_t *pentry,
                              uint64_t *lowaddr, uint64_t *highaddr,
                              int elf_machine, int clear_lsb)
{
    struct elfhdr ehdr;
    struct elf_phdr *phdr = NULL, *ph;
    int size, i, total_size;
    elf_word mem_size;
    uint64_t addr, low = (uint64_t)-1, high = 0;
    uint8_t *data = NULL;
    char label[128];

    if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
        goto fail;
    if (must_swab) {
        glue(bswap_ehdr, SZ)(&ehdr);
    }

    switch (elf_machine) {
        case EM_PPC64:
            if (EM_PPC64 != ehdr.e_machine)
                if (EM_PPC != ehdr.e_machine)
                    goto fail;
            break;
        case EM_X86_64:
            if (EM_X86_64 != ehdr.e_machine)
                if (EM_386 != ehdr.e_machine)
                    goto fail;
            break;
        case EM_MICROBLAZE:
            if (EM_MICROBLAZE != ehdr.e_machine)
                if (EM_MICROBLAZE_OLD != ehdr.e_machine)
                    goto fail;
            break;
        default:
            if (elf_machine != ehdr.e_machine)
                goto fail;
    }

    if (pentry)
   	*pentry = (uint64_t)(elf_sword)ehdr.e_entry;

    glue(load_symbols, SZ)(&ehdr, fd, must_swab, clear_lsb);

    size = ehdr.e_phnum * sizeof(phdr[0]);
    lseek(fd, ehdr.e_phoff, SEEK_SET);
    phdr = g_malloc0(size);
    if (!phdr)
        goto fail;
    if (read(fd, phdr, size) != size)
        goto fail;
    if (must_swab) {
        for(i = 0; i < ehdr.e_phnum; i++) {
            ph = &phdr[i];
            glue(bswap_phdr, SZ)(ph);
        }
    }

    total_size = 0;
    for(i = 0; i < ehdr.e_phnum; i++) {
        ph = &phdr[i];
        if (ph->p_type == PT_LOAD) {
            mem_size = ph->p_memsz;
            /* XXX: avoid allocating */
            data = g_malloc0(mem_size);
            if (ph->p_filesz > 0) {
                if (lseek(fd, ph->p_offset, SEEK_SET) < 0)
                    goto fail;
                if (read(fd, data, ph->p_filesz) != ph->p_filesz)
                    goto fail;
            }
            /* address_offset is hack for kernel images that are
               linked at the wrong physical address.  */
            if (translate_fn) {
                addr = translate_fn(translate_opaque, ph->p_paddr);
            } else {
                addr = ph->p_paddr;
            }

            /* the entry pointer in the ELF header is a virtual
             * address, if the text segments paddr and vaddr differ
             * we need to adjust the entry */
            if (pentry && !translate_fn &&
                    ph->p_vaddr != ph->p_paddr &&
                    ehdr.e_entry >= ph->p_vaddr &&
                    ehdr.e_entry < ph->p_vaddr + ph->p_filesz &&
                    ph->p_flags & PF_X) {
                *pentry = ehdr.e_entry - ph->p_vaddr + ph->p_paddr;
            }

            snprintf(label, sizeof(label), "phdr #%d: %s", i, name);
            rom_add_blob_fixed(label, data, mem_size, addr);

            total_size += mem_size;
            if (addr < low)
                low = addr;
            if ((addr + mem_size) > high)
                high = addr + mem_size;

            g_free(data);
            data = NULL;
        }
    }
    g_free(phdr);
    if (lowaddr)
        *lowaddr = (uint64_t)(elf_sword)low;
    if (highaddr)
        *highaddr = (uint64_t)(elf_sword)high;
    return total_size;
 fail:
    g_free(data);
    g_free(phdr);
    return -1;
}