}
#define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON)
+#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK)
static void *find_sym(struct dso *dso, const char *s, int need_def)
{
uint32_t h = hash(s);
+ void *def = 0;
if (h==0x6b366be && !strcmp(s, "dlopen")) rtld_used = 1;
if (h==0x6b3afd && !strcmp(s, "dlsym")) rtld_used = 1;
for (; dso; dso=dso->next) {
if (!dso->global) continue;
sym = lookup(s, h, dso->syms, dso->hashtab, dso->strings);
if (sym && (!need_def || sym->st_shndx) && sym->st_value
- && (1<<(sym->st_info&0xf) & OK_TYPES))
- return dso->base + sym->st_value;
+ && (1<<(sym->st_info&0xf) & OK_TYPES)
+ && (1<<(sym->st_info>>4) & OK_BINDS)) {
+ if (def && sym->st_info>>4 == STB_WEAK) continue;
+ def = dso->base + sym->st_value;
+ if (sym->st_info>>4 == STB_GLOBAL) break;
+ }
}
- return 0;
+ return def;
}
static void do_relocs(unsigned char *base, size_t *rel, size_t rel_size, size_t stride, Sym *syms, char *strings, struct dso *dso)
if (!libc->prev) {
tail->next = libc;
libc->prev = tail;
- tail = libc;
+ tail = libc->next ? libc->next : libc;
}
return libc;
}
size_t *auxv, aux[AUX_CNT] = {0};
size_t app_dyn[DYN_CNT] = {0};
size_t lib_dyn[DYN_CNT] = {0};
+ size_t vdso_dyn[DYN_CNT] = {0};
size_t i;
Phdr *phdr;
Ehdr *ehdr;
- struct dso lib, app;
+ static struct dso builtin_dsos[3];
+ struct dso *const app = builtin_dsos+0;
+ struct dso *const lib = builtin_dsos+1;
+ struct dso *const vdso = builtin_dsos+2;
+ size_t vdso_base=0;
/* Find aux vector just past environ[] */
for (i=argc+1; argv[i]; i++)
decode_vec(auxv, aux, AUX_CNT);
+ for (i=0; auxv[i]; i+=2) {
+ if (auxv[i]==AT_SYSINFO_EHDR) {
+ vdso_base = auxv[i+1];
+ break;
+ }
+ }
+
/* Only trust user/env if kernel says we're not suid/sgid */
if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
|| aux[AT_GID]!=aux[AT_EGID]) {
}
}
- app = (struct dso){
+ *app = (struct dso){
.base = 0,
.strings = (void *)(app_dyn[DT_STRTAB]),
.hashtab = (void *)(app_dyn[DT_HASH]),
.dynv = (void *)(phdr->p_vaddr),
.name = argv[0],
.global = 1,
- .next = &lib
+ .next = lib
};
- lib = (struct dso){
+ *lib = (struct dso){
.base = (void *)aux[AT_BASE],
.strings = (void *)(aux[AT_BASE]+lib_dyn[DT_STRTAB]),
.hashtab = (void *)(aux[AT_BASE]+lib_dyn[DT_HASH]),
.relocated = 1
};
+ if (vdso_base) {
+ ehdr = (void *)vdso_base;
+ phdr = (void *)(vdso_base + ehdr->e_phoff);
+ for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
+ if (phdr->p_type == PT_DYNAMIC)
+ vdso->dynv = (void *)(vdso_base + phdr->p_offset);
+ if (phdr->p_type == PT_LOAD)
+ vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
+ }
+ decode_vec(vdso->dynv, vdso_dyn, DYN_CNT);
+ vdso->syms = (void *)(vdso->base + vdso_dyn[DT_SYMTAB]);
+ vdso->hashtab = (void *)(vdso->base + vdso_dyn[DT_HASH]);
+ vdso->strings = (void *)(vdso->base + vdso_dyn[DT_STRTAB]);
+ vdso->name = "linux-gate.so.1";
+ vdso->global = 1;
+
+ vdso->prev = lib;
+ lib->next = vdso;
+ }
+
/* Relocate the dynamic linker/libc */
do_relocs((void *)aux[AT_BASE], (void *)(aux[AT_BASE]+lib_dyn[DT_REL]),
- lib_dyn[DT_RELSZ], 2, lib.syms, lib.strings, &app);
+ lib_dyn[DT_RELSZ], 2, lib->syms, lib->strings, app);
do_relocs((void *)aux[AT_BASE], (void *)(aux[AT_BASE]+lib_dyn[DT_RELA]),
- lib_dyn[DT_RELASZ], 3, lib.syms, lib.strings, &app);
+ lib_dyn[DT_RELASZ], 3, lib->syms, lib->strings, app);
/* At this point the standard library is fully functional */
- reclaim_gaps(app.base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
- ehdr = (void *)lib.base;
- reclaim_gaps(lib.base, (void *)(lib.base+ehdr->e_phoff),
+ reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
+ ehdr = (void *)lib->base;
+ reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
ehdr->e_phentsize, ehdr->e_phnum);
- head = tail = &app;
- libc = &lib;
- app.next = 0;
+ head = tail = app;
+ libc = lib;
+ app->next = 0;
load_deps(head);
make_global(head);
reloc_all(head->next);
reloc_all(head);
- if (rtld_used) {
- runtime = 1;
- head->next->prev = malloc(sizeof *head);
- *head->next->prev = *head;
- head = head->next->prev;
- libc->prev->next = malloc(sizeof *libc);
- *libc->prev->next = *libc;
- libc = libc->prev->next;
- if (libc->next) libc->next->prev = libc;
- if (tail == &lib) tail = libc;
- } else {
+ runtime = 1;
+ if (!rtld_used) {
free_all(head);
free(sys_path);
+ reclaim((void *)builtin_dsos, 0, sizeof builtin_dsos);
}
errno = 0;