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* Use function pointers for symbol lookup (currently for elf32 and elf64,

Browse source 
could be expanded).  This also fixes the bug with mips elf64 symbols
  in current Qemu trunk.

* Use quicksort and binary search for symbol lookup.

* Remove unneeded entries from symbol table.  This reduced a typical table
  size (linux mips kernel) from 1764487 to 11656 entries.

Signed-off-by: Stefan Weil <weil@mail.berlios.de> 



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5510 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
pbrook 2008-10-22 15:11:31 +00:00
parent f16a0db323
commit 49918a752b
4 changed files with 184 additions and 95 deletions
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142
linux-user/elfload.c
View file

@ -984,80 +984,134 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
return ((abi_ulong) interp_elf_ex->e_entry) + load_addr;
}
static int symfind(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 *lookup_symbolxx(struct syminfo *s, target_ulong orig_addr)
{
#if ELF_CLASS == ELFCLASS32
struct elf_sym *syms = s->disas_symtab.elf32;
#else
struct elf_sym *syms = s->disas_symtab.elf64;
#endif
// binary search
struct elf_sym key;
struct elf_sym *sym;
key.st_value = orig_addr;
sym = bsearch(&key, syms, s->disas_num_syms, sizeof(*syms), symfind);
if (sym != 0) {
return s->disas_strtab + sym->st_name;
}
return "";
}
/* FIXME: This should use elf_ops.h */
static int symcmp(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);
}
/* Best attempt to load symbols from this ELF object. */
static void load_symbols(struct elfhdr *hdr, int fd)
{
unsigned int i;
unsigned int i, nsyms;
struct elf_shdr sechdr, symtab, strtab;
char *strings;
struct syminfo *s;
#if (ELF_CLASS == ELFCLASS64)
// Disas uses 32 bit symbols
struct elf32_sym *syms32 = NULL;
struct elf_sym *sym;
#endif
struct elf_sym *syms;
lseek(fd, hdr->e_shoff, SEEK_SET);
for (i = 0; i < hdr->e_shnum; i++) {
if (read(fd, &sechdr, sizeof(sechdr)) != sizeof(sechdr))
return;
if (read(fd, &sechdr, sizeof(sechdr)) != sizeof(sechdr))
return;
#ifdef BSWAP_NEEDED
bswap_shdr(&sechdr);
bswap_shdr(&sechdr);
#endif
if (sechdr.sh_type == SHT_SYMTAB) {
symtab = sechdr;
lseek(fd, hdr->e_shoff
+ sizeof(sechdr) * sechdr.sh_link, SEEK_SET);
if (read(fd, &strtab, sizeof(strtab))
!= sizeof(strtab))
return;
if (sechdr.sh_type == SHT_SYMTAB) {
symtab = sechdr;
lseek(fd, hdr->e_shoff
+ sizeof(sechdr) * sechdr.sh_link, SEEK_SET);
if (read(fd, &strtab, sizeof(strtab))
!= sizeof(strtab))
return;
#ifdef BSWAP_NEEDED
bswap_shdr(&strtab);
bswap_shdr(&strtab);
#endif
goto found;
}
goto found;
}
}
return; /* Shouldn't happen... */
found:
/* Now know where the strtab and symtab are. Snarf them. */
s = malloc(sizeof(*s));
s->disas_symtab = malloc(symtab.sh_size);
#if (ELF_CLASS == ELFCLASS64)
syms32 = malloc(symtab.sh_size / sizeof(struct elf_sym)
* sizeof(struct elf32_sym));
#endif
syms = malloc(symtab.sh_size);
if (!syms)
return;
s->disas_strtab = strings = malloc(strtab.sh_size);
if (!s->disas_symtab || !s->disas_strtab)
return;
if (!s->disas_strtab)
return;
lseek(fd, symtab.sh_offset, SEEK_SET);
if (read(fd, s->disas_symtab, symtab.sh_size) != symtab.sh_size)
return;
if (read(fd, syms, symtab.sh_size) != symtab.sh_size)
return;
for (i = 0; i < symtab.sh_size / sizeof(struct elf_sym); i++) {
nsyms = symtab.sh_size / sizeof(struct elf_sym);
i = 0;
while (i < nsyms) {
#ifdef BSWAP_NEEDED
bswap_sym(s->disas_symtab + sizeof(struct elf_sym)*i);
bswap_sym(syms + i);
#endif
#if (ELF_CLASS == ELFCLASS64)
sym = s->disas_symtab + sizeof(struct elf_sym)*i;
syms32[i].st_name = sym->st_name;
syms32[i].st_info = sym->st_info;
syms32[i].st_other = sym->st_other;
syms32[i].st_shndx = sym->st_shndx;
syms32[i].st_value = sym->st_value & 0xffffffff;
syms32[i].st_size = sym->st_size & 0xffffffff;
// Throw away entries which we do not need.
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 defined(TARGET_ARM) || defined (TARGET_MIPS)
/* The bottom address bit marks a Thumb or MIPS16 symbol. */
syms[i].st_value &= ~(target_ulong)1;
#endif
i++;
}
syms = realloc(syms, nsyms * sizeof(*syms));
qsort(syms, nsyms, sizeof(*syms), symcmp);
#if (ELF_CLASS == ELFCLASS64)
free(s->disas_symtab);
s->disas_symtab = syms32;
#endif
lseek(fd, strtab.sh_offset, SEEK_SET);
if (read(fd, strings, strtab.sh_size) != strtab.sh_size)
return;
s->disas_num_syms = symtab.sh_size / sizeof(struct elf_sym);
return;
s->disas_num_syms = nsyms;
#if ELF_CLASS == ELFCLASS32
s->disas_symtab.elf32 = syms;
s->lookup_symbol = lookup_symbolxx;
#else
s->disas_symtab.elf64 = syms;
s->lookup_symbol = lookup_symbolxx;
#endif
s->next = syminfos;
syminfos = s;
}