qemu/hw/elf_ops.h
Stefan Weil e403e433c1 elf: Calculate symbol size if needed
Symbols with a size of 0 are unusable for the disassembler.

Example:

While running an arm linux kernel, no symbolic names are
used in qemu.log when the cpu is executing an assembler function.

Assume that the size of such symbols is the difference to the
next symbol value.

Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-09-09 19:37:16 +00:00

298 lines
8.9 KiB
C

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)
{
struct elf_sym *key = (struct elf_sym *)s0;
struct elf_sym *sym = (struct elf_sym *)s1;
int result = 0;
if (key->st_value < sym->st_value) {
result = -1;
} else if (key->st_value >= 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 key;
struct elf_sym *sym;
key.st_value = orig_addr;
sym = bsearch(&key, 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 = qemu_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 {
qemu_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 = qemu_mallocz(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;
qemu_free(shdr_table);
return 0;
fail:
qemu_free(syms);
qemu_free(str);
qemu_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 = qemu_mallocz(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 = qemu_mallocz(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;
}
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;
qemu_free(data);
data = NULL;
}
}
qemu_free(phdr);
if (lowaddr)
*lowaddr = (uint64_t)(elf_sword)low;
if (highaddr)
*highaddr = (uint64_t)(elf_sword)high;
return total_size;
fail:
qemu_free(data);
qemu_free(phdr);
return -1;
}