avoid using undefined pointer arithmetic in dladdr

This commit is contained in:
Rich Felker 2018-06-27 15:29:12 -04:00
parent a0d64dccbc
commit e829695fcc

View File

@ -1943,16 +1943,17 @@ failed:
return 0;
}
int dladdr(const void *addr, Dl_info *info)
int dladdr(const void *addr_arg, Dl_info *info)
{
size_t addr = (size_t)addr_arg;
struct dso *p;
Sym *sym, *bestsym;
uint32_t nsym;
char *strings;
void *best = 0;
size_t best = 0;
pthread_rwlock_rdlock(&lock);
p = addr2dso((size_t)addr);
p = addr2dso(addr);
pthread_rwlock_unlock(&lock);
if (!p) return 0;
@ -1962,10 +1963,10 @@ int dladdr(const void *addr, Dl_info *info)
nsym = count_syms(p);
if (DL_FDPIC) {
size_t idx = ((size_t)addr-(size_t)p->funcdescs)
size_t idx = (addr-(size_t)p->funcdescs)
/ sizeof(*p->funcdescs);
if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
best = p->funcdescs + idx;
best = (size_t)(p->funcdescs + idx);
bestsym = sym + idx;
}
}
@ -1974,7 +1975,7 @@ int dladdr(const void *addr, Dl_info *info)
if (sym->st_value
&& (1<<(sym->st_info&0xf) & OK_TYPES)
&& (1<<(sym->st_info>>4) & OK_BINDS)) {
void *symaddr = laddr(p, sym->st_value);
size_t symaddr = (size_t)laddr(p, sym->st_value);
if (symaddr > addr || symaddr < best)
continue;
best = symaddr;
@ -1987,12 +1988,12 @@ int dladdr(const void *addr, Dl_info *info)
if (!best) return 0;
if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
best = p->funcdescs + (bestsym - p->syms);
best = (size_t)(p->funcdescs + (bestsym - p->syms));
info->dli_fname = p->name;
info->dli_fbase = p->map;
info->dli_sname = strings + bestsym->st_name;
info->dli_saddr = best;
info->dli_saddr = (void *)best;
return 1;
}