mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

elf: Improve symbol lookup (optimize, fix for bsd-user)

Browse Source 
Coverity complained about local variable key which was only partially
initiated. Only key.st_value was set. As this was also the only part
of key which was used in function symfind, the code could be optimized
by directly passing a pointer to orig_addr.

In bsd-user/elfload.c, fix ec822001a2
was missing. This was a simple replacement of > by >= in symfind, so
I fixed it here without creating an additional patch.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Andrzej Zaborowski <andrew.zaborowski@intel.com>
This commit is contained in:
Stefan Weil 2012-01-05 15:39:39 +01:00 committed by Andrzej Zaborowski
parent 563c2bf35c
commit c7c530cd3e
3 changed files with 13 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
bsd-user/elfload.c
View File

@ -993,12 +993,12 @@ static abi_ulong load_elf_interp(struct elfhdr * interp_elf_ex,
static int symfind(const void *s0, const void *s1)
{
struct elf_sym *key = (struct elf_sym *)s0;
target_ulong addr = *(target_ulong *)s0;
struct elf_sym *sym = (struct elf_sym *)s1;
int result = 0;
if (key->st_value < sym->st_value) {
if (addr < sym->st_value) {
result = -1;
} else if (key->st_value > sym->st_value + sym->st_size) {
} else if (addr >= sym->st_value + sym->st_size) {
result = 1;
}
return result;
@ -1013,12 +1013,9 @@ static const char *lookup_symbolxx(struct syminfo *s, target_ulong orig_addr)
#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);
sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms), symfind);
if (sym != NULL) {
return s->disas_strtab + sym->st_name;
}

12
hw/elf_ops.h
View File

@ -62,12 +62,12 @@ static struct elf_shdr *glue(find_section, SZ)(struct elf_shdr *shdr_table,
static int glue(symfind, SZ)(const void *s0, const void *s1)
{
struct elf_sym *key = (struct elf_sym *)s0;
target_phys_addr_t addr = *(target_phys_addr_t *)s0;
struct elf_sym *sym = (struct elf_sym *)s1;
int result = 0;
if (key->st_value < sym->st_value) {
if (addr < sym->st_value) {
result = -1;
} else if (key->st_value >= sym->st_value + sym->st_size) {
} else if (addr >= sym->st_value + sym->st_size) {
result = 1;
}
return result;
@ -77,12 +77,10 @@ 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));
sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms),
glue(symfind, SZ));
if (sym != NULL) {
return s->disas_strtab + sym->st_name;
}

11
linux-user/elfload.c
View File

@ -1683,12 +1683,12 @@ static void load_elf_interp(const char *filename, struct image_info *info,
static int symfind(const void *s0, const void *s1)
{
struct elf_sym *key = (struct elf_sym *)s0;
target_ulong addr = *(target_ulong *)s0;
struct elf_sym *sym = (struct elf_sym *)s1;
int result = 0;
if (key->st_value < sym->st_value) {
if (addr < sym->st_value) {
result = -1;
} else if (key->st_value >= sym->st_value + sym->st_size) {
} else if (addr >= sym->st_value + sym->st_size) {
result = 1;
}
return result;
@ -1703,12 +1703,9 @@ static const char *lookup_symbolxx(struct syminfo *s, target_ulong orig_addr)
#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);
sym = bsearch(&orig_addr, syms, s->disas_num_syms, sizeof(*syms), symfind);
if (sym != NULL) {
return s->disas_strtab + sym->st_name;
}