#include "pthread_impl.h"
#include "libc.h"
#include "dynlink.h"
+#include "malloc_impl.h"
static void error(const char *, ...);
struct tls_module tls;
size_t tls_id;
size_t relro_start, relro_end;
- void **new_dtv;
+ uintptr_t *new_dtv;
unsigned char *new_tls;
volatile int new_dtv_idx, new_tls_idx;
struct td_index *td_index;
struct dso *dso;
};
-int __init_tp(void *);
-void __init_libc(char **, char *);
-void *__copy_tls(unsigned char *);
-
-__attribute__((__visibility__("hidden")))
-const char *__libc_get_version(void);
-
static struct builtin_tls {
char c;
struct pthread pt;
struct debug *_dl_debug_addr = &debug;
-__attribute__((__visibility__("hidden")))
-void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
+extern hidden int __malloc_replaced;
-__attribute__((__visibility__("hidden")))
-extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
+hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
+
+extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
weak_alias(__init_array_start, __init_array_end);
weak_alias(__fini_array_start, __fini_array_end);
for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
}
+static void *laddr_pg(const struct dso *p, size_t v)
+{
+ size_t j=0;
+ size_t pgsz = PAGE_SIZE;
+ if (!p->loadmap) return p->base + v;
+ for (j=0; ; j++) {
+ size_t a = p->loadmap->segs[j].p_vaddr;
+ size_t b = a + p->loadmap->segs[j].p_memsz;
+ a &= -pgsz;
+ b += pgsz-1;
+ b &= -pgsz;
+ if (v-a<b-a) break;
+ }
+ return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
+}
#define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
laddr(p, v), (p)->got })
#else
#define laddr(p, v) (void *)((p)->base + (v))
+#define laddr_pg(p, v) laddr(p, v)
#define fpaddr(p, v) ((void (*)())laddr(p, v))
#endif
return def;
}
-__attribute__((__visibility__("hidden")))
-ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
-
static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
{
unsigned char *base = dso->base;
sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
tls_val = def.sym ? def.sym->st_value : 0;
+ if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
+ && runtime && def.dso->tls_id > static_tls_cnt) {
+ error("Error relocating %s: %s: initial-exec TLS "
+ "resolves to dynamic definition in %s",
+ dso->name, name, def.dso->name);
+ longjmp(*rtld_fail, 1);
+ }
+
switch(type) {
case REL_NONE:
break;
#endif
case REL_TLSDESC:
if (stride<3) addend = reloc_addr[1];
- if (runtime && def.dso->tls_id >= static_tls_cnt) {
+ if (runtime && def.dso->tls_id > static_tls_cnt) {
struct td_index *new = malloc(sizeof *new);
if (!new) {
error(
new->next = dso->td_index;
dso->td_index = new;
new->args[0] = def.dso->tls_id;
- new->args[1] = tls_val + addend;
+ new->args[1] = tls_val + addend - DTP_OFFSET;
reloc_addr[0] = (size_t)__tlsdesc_dynamic;
reloc_addr[1] = (size_t)new;
} else {
+ addend;
#endif
}
+#ifdef TLSDESC_BACKWARDS
+ /* Some archs (32-bit ARM at least) invert the order of
+ * the descriptor members. Fix them up here. */
+ size_t tmp = reloc_addr[0];
+ reloc_addr[0] = reloc_addr[1];
+ reloc_addr[1] = tmp;
+#endif
break;
default:
error("Error relocating %s: unsupported relocation type %d",
/* A huge hack: to make up for the wastefulness of shared libraries
* needing at least a page of dirty memory even if they have no global
* data, we reclaim the gaps at the beginning and end of writable maps
- * and "donate" them to the heap by setting up minimal malloc
- * structures and then freeing them. */
+ * and "donate" them to the heap. */
static void reclaim(struct dso *dso, size_t start, size_t end)
{
- size_t *a, *z;
if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
- start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
- end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
- if (start>end || end-start < 4*sizeof(size_t)) return;
- a = laddr(dso, start);
- z = laddr(dso, end);
- a[-2] = 1;
- a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
- z[1] = 1;
- free(a);
+ if (start >= end) return;
+ char *base = laddr_pg(dso, start);
+ __malloc_donate(base, base+(end-start));
}
static void reclaim_gaps(struct dso *dso)
Phdr *ph = dso->phdr;
size_t phcnt = dso->phnum;
- if (DL_FDPIC) return; // FIXME
for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
if (ph->p_type!=PT_LOAD) continue;
if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
} else if (ph->p_type == PT_GNU_RELRO) {
dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
+ } else if (ph->p_type == PT_GNU_STACK) {
+ if (!runtime && ph->p_memsz > __default_stacksize) {
+ __default_stacksize =
+ ph->p_memsz < DEFAULT_STACK_MAX ?
+ ph->p_memsz : DEFAULT_STACK_MAX;
+ }
}
if (ph->p_type != PT_LOAD) continue;
nsegs++;
dso->phnum = eh->e_phnum;
dso->phentsize = eh->e_phentsize;
}
- /* Reuse the existing mapping for the lowest-address LOAD */
- if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
- continue;
this_min = ph->p_vaddr & -PAGE_SIZE;
this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
off_start = ph->p_offset & -PAGE_SIZE;
prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
((ph->p_flags&PF_X) ? PROT_EXEC : 0));
- if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
- goto error;
- if (ph->p_memsz > ph->p_filesz) {
+ /* Reuse the existing mapping for the lowest-address LOAD */
+ if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
+ if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
+ goto error;
+ if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
origin = ".";
l = 1;
}
+ /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
+ if (libc.secure && *origin != '/')
+ return 0;
p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
if (!p->rpath) return -1;
} else if (ph->p_type == PT_GNU_RELRO) {
p->relro_start = ph->p_vaddr & -PAGE_SIZE;
p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
+ } else if (ph->p_type == PT_GNU_STACK) {
+ if (!runtime && ph->p_memsz > __default_stacksize) {
+ __default_stacksize =
+ ph->p_memsz < DEFAULT_STACK_MAX ?
+ ph->p_memsz : DEFAULT_STACK_MAX;
+ }
}
if (ph->p_type != PT_LOAD) continue;
if (ph->p_vaddr < min_addr)
{
}
-__attribute__((__visibility__("hidden")))
-void *__tls_get_new(tls_mod_off_t *v)
+hidden void *__tls_get_new(tls_mod_off_t *v)
{
pthread_t self = __pthread_self();
/* Block signals to make accessing new TLS async-signal-safe */
sigset_t set;
__block_all_sigs(&set);
- if (v[0]<=(size_t)self->dtv[0]) {
+ if (v[0] <= self->dtv[0]) {
__restore_sigs(&set);
- return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
+ return (void *)(self->dtv[v[0]] + v[1]);
}
/* This is safe without any locks held because, if the caller
struct dso *p;
for (p=head; p->tls_id != v[0]; p=p->next);
- /* Get new DTV space from new DSO if needed */
- if (v[0] > (size_t)self->dtv[0]) {
- void **newdtv = p->new_dtv +
- (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
- memcpy(newdtv, self->dtv,
- ((size_t)self->dtv[0]+1) * sizeof(void *));
- newdtv[0] = (void *)v[0];
- self->dtv = self->dtv_copy = newdtv;
- }
+ /* Get new DTV space from new DSO */
+ uintptr_t *newdtv = p->new_dtv +
+ (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
+ memcpy(newdtv, self->dtv, (self->dtv[0]+1) * sizeof(uintptr_t));
+ newdtv[0] = v[0];
+ self->dtv = self->dtv_copy = newdtv;
/* Get new TLS memory from all new DSOs up to the requested one */
unsigned char *mem;
* a_fetch_add(&p->new_tls_idx,1);
mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
& (p->tls.align-1);
- self->dtv[p->tls_id] = mem;
+ self->dtv[p->tls_id] = (uintptr_t)mem + DTP_OFFSET;
memcpy(mem, p->tls.image, p->tls.len);
if (p->tls_id == v[0]) break;
}
* linker itself, but some of the relocations performed may need to be
* replaced later due to copy relocations in the main program. */
-__attribute__((__visibility__("hidden")))
-void __dls2(unsigned char *base, size_t *sp)
+hidden void __dls2(unsigned char *base, size_t *sp)
{
if (DL_FDPIC) {
void *p1 = (void *)sp[-2];
void *p2 = (void *)sp[-1];
if (!p1) {
size_t *auxv, aux[AUX_CNT];
- for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
+ for (auxv=sp+1+*sp+1; *auxv; auxv++);
+ auxv++;
decode_vec(auxv, aux, AUX_CNT);
if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
else ldso.base = (void *)(aux[AT_PHDR] & -4096);
ldso.relocated = 0;
- /* Call dynamic linker stage-3, __dls3, looking it up
+ /* Call dynamic linker stage-2b, __dls2b, looking it up
* symbolically as a barrier against moving the address
* load across the above relocation processing. */
+ struct symdef dls2b_def = find_sym(&ldso, "__dls2b", 0);
+ if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp);
+ else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp);
+}
+
+/* Stage 2b sets up a valid thread pointer, which requires relocations
+ * completed in stage 2, and on which stage 3 is permitted to depend.
+ * This is done as a separate stage, with symbolic lookup as a barrier,
+ * so that loads of the thread pointer and &errno can be pure/const and
+ * thereby hoistable. */
+
+_Noreturn void __dls2b(size_t *sp)
+{
+ /* Setup early thread pointer in builtin_tls for ldso/libc itself to
+ * use during dynamic linking. If possible it will also serve as the
+ * thread pointer at runtime. */
+ libc.tls_size = sizeof builtin_tls;
+ libc.tls_align = tls_align;
+ if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
+ a_crash();
+ }
+
struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
|| aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
- /* Setup early thread pointer in builtin_tls for ldso/libc itself to
- * use during dynamic linking. If possible it will also serve as the
- * thread pointer at runtime. */
- libc.tls_size = sizeof builtin_tls;
- libc.tls_align = tls_align;
- if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
- a_crash();
- }
-
/* Only trust user/env if kernel says we're not suid/sgid */
if (!libc.secure) {
env_path = getenv("LD_LIBRARY_PATH");
"Version %s\n"
"Dynamic Program Loader\n"
"Usage: %s [options] [--] pathname%s\n",
- __libc_get_version(), ldname,
+ __libc_version, ldname,
ldd_mode ? "" : " [args]");
_exit(1);
}
libc.tls_head = tls_tail = &app.tls;
app.tls_id = tls_cnt = 1;
#ifdef TLS_ABOVE_TP
- app.tls.offset = 0;
- tls_offset = app.tls.size
+ app.tls.offset = GAP_ABOVE_TP;
+ app.tls.offset += -GAP_ABOVE_TP & (app.tls.align-1);
+ tls_offset = app.tls.offset + app.tls.size
+ ( -((uintptr_t)app.tls.image + app.tls.size)
& (app.tls.align-1) );
#else
if (ldso_fail) _exit(127);
if (ldd_mode) _exit(0);
+ /* Determine if malloc was interposed by a replacement implementation
+ * so that calloc and the memalign family can harden against the
+ * possibility of incomplete replacement. */
+ if (find_sym(head, "malloc", 1).dso != &ldso)
+ __malloc_replaced = 1;
+
/* Switch to runtime mode: any further failures in the dynamic
* linker are a reportable failure rather than a fatal startup
* error. */
return p;
}
-__attribute__((__visibility__("hidden")))
-int __dl_invalid_handle(void *h)
+hidden int __dl_invalid_handle(void *h)
{
struct dso *p;
for (p=head; p; p=p->next) if (h==p) return 0;
return p;
}
} else {
+ Phdr *ph = p->phdr;
+ size_t phcnt = p->phnum;
+ size_t entsz = p->phentsize;
+ size_t base = (size_t)p->base;
+ for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
+ if (ph->p_type != PT_LOAD) continue;
+ if (a-base-ph->p_vaddr < ph->p_memsz)
+ return p;
+ }
if (a-(size_t)p->map < p->map_len)
- return p;
+ return 0;
}
}
return 0;
}
-void *__tls_get_addr(tls_mod_off_t *);
-
static void *do_dlsym(struct dso *p, const char *s, void *ra)
{
size_t i;
struct symdef def = find_sym(p, s, 0);
if (!def.sym) goto failed;
if ((def.sym->st_info&0xf) == STT_TLS)
- return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
+ return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET});
if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
return def.dso->funcdescs + (def.sym - def.dso->syms);
return laddr(def.dso, def.sym->st_value);
sym = sysv_lookup(s, h, p);
}
if (sym && (sym->st_info&0xf) == STT_TLS)
- return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
+ return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value-DTP_OFFSET});
if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
return p->funcdescs + (sym - p->syms);
if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
sym = sysv_lookup(s, h, p->deps[i]);
}
if (sym && (sym->st_info&0xf) == STT_TLS)
- return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
+ return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value-DTP_OFFSET});
if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
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;
+ size_t besterr = -1;
pthread_rwlock_rdlock(&lock);
- p = addr2dso((size_t)addr);
+ p = addr2dso(addr);
pthread_rwlock_unlock(&lock);
if (!p) return 0;
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;
+ besterr = 0;
}
}
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);
- if (symaddr > addr || symaddr < best)
+ size_t symaddr = (size_t)laddr(p, sym->st_value);
+ if (symaddr > addr || symaddr <= best)
continue;
best = symaddr;
bestsym = sym;
+ besterr = addr - symaddr;
if (addr == symaddr)
break;
}
}
- if (!best) return 0;
-
- if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
- best = p->funcdescs + (bestsym - p->syms);
+ if (bestsym && besterr > bestsym->st_size-1) {
+ best = 0;
+ bestsym = 0;
+ }
info->dli_fname = p->name;
info->dli_fbase = p->map;
+
+ if (!best) {
+ info->dli_sname = 0;
+ info->dli_saddr = 0;
+ return 1;
+ }
+
+ if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
+ best = (size_t)(p->funcdescs + (bestsym - p->syms));
info->dli_sname = strings + bestsym->st_name;
- info->dli_saddr = best;
+ info->dli_saddr = (void *)best;
return 1;
}
-__attribute__((__visibility__("hidden")))
-void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
+hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
{
void *res;
pthread_rwlock_rdlock(&lock);
return ret;
}
-__attribute__((__visibility__("hidden")))
-void __dl_vseterr(const char *, va_list);
-
static void error(const char *fmt, ...)
{
va_list ap;
projects / musl / blobdiff