#include "libc.h"
#include "dynlink.h"
-static int errflag;
-static char errbuf[128];
+static void error(const char *, ...);
#ifdef SHARED
};
struct dso {
+#if DL_FDPIC
+ struct fdpic_loadmap *loadmap;
+#else
unsigned char *base;
+#endif
char *name;
size_t *dynv;
struct dso *next, *prev;
volatile int new_dtv_idx, new_tls_idx;
struct td_index *td_index;
struct dso *fini_next;
- int rel_early_relative, rel_update_got;
char *shortname;
+#if DL_FDPIC
+ unsigned char *base;
+#else
+ struct fdpic_loadmap *loadmap;
+#endif
+ struct funcdesc {
+ void *addr;
+ size_t *got;
+ } *funcdescs;
+ size_t *got;
char buf[];
};
} builtin_tls[1];
#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
+#define ADDEND_LIMIT 4096
+static size_t *saved_addends, *apply_addends_to;
+
static struct dso ldso;
static struct dso *head, *tail, *fini_head;
static char *env_path, *sys_path;
static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
static size_t static_tls_cnt;
static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
+static struct fdpic_loadmap *app_loadmap;
+static struct fdpic_dummy_loadmap app_dummy_loadmap;
struct debug *_dl_debug_addr = &debug;
}
#define strcmp(l,r) dl_strcmp(l,r)
+/* Compute load address for a virtual address in a given dso. */
+#if DL_FDPIC
+static void *laddr(const struct dso *p, size_t v)
+{
+ size_t j=0;
+ if (!p->loadmap) return p->base + v;
+ 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);
+}
+#define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
+ laddr(p, v), (p)->got })
+#else
+#define laddr(p, v) (void *)((p)->base + (v))
+#define fpaddr(p, v) ((void (*)())laddr(p, v))
+#endif
+
static void decode_vec(size_t *v, size_t *a, size_t cnt)
{
size_t i;
return 1;
}
-static void error(const char *fmt, ...)
-{
- va_list ap;
- va_start(ap, fmt);
- vsnprintf(errbuf, sizeof errbuf, fmt, ap);
- va_end(ap);
- if (runtime) longjmp(*rtld_fail, 1);
- dprintf(2, "%s\n", errbuf);
- ldso_fail = 1;
-}
-
static uint32_t sysv_hash(const char *s0)
{
const unsigned char *s = (void *)s0;
const unsigned char *s = (void *)s0;
uint_fast32_t h = 5381;
for (; *s; s++)
- h = h*33 + *s;
+ h += h*32 + *s;
return h;
}
return 0;
}
-static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
+static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
{
- Sym *syms = dso->syms;
- char *strings = dso->strings;
- uint32_t *hashtab = dso->ghashtab;
uint32_t nbuckets = hashtab[0];
uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
- uint32_t h2;
- uint32_t *hashval;
uint32_t i = buckets[h1 % nbuckets];
if (!i) return 0;
- hashval = buckets + nbuckets + (i - hashtab[1]);
+ uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
for (h1 |= 1; ; i++) {
- h2 = *hashval++;
- if ((!dso->versym || dso->versym[i] >= 0)
- && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
- return syms+i;
+ uint32_t h2 = *hashval++;
+ if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
+ && !strcmp(s, dso->strings + dso->syms[i].st_name))
+ return dso->syms+i;
if (h2 & 1) break;
}
return 0;
}
+static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
+{
+ const size_t *bloomwords = (const void *)(hashtab+4);
+ size_t f = bloomwords[fofs & (hashtab[2]-1)];
+ if (!(f & fmask)) return 0;
+
+ f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
+ if (!(f & 1)) return 0;
+
+ return gnu_lookup(h1, hashtab, dso, s);
+}
+
#define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
{
- uint32_t h = 0, gh = 0;
+ uint32_t h = 0, gh, gho, *ght;
+ size_t ghm = 0;
struct symdef def = {0};
for (; dso; dso=dso->next) {
Sym *sym;
if (!dso->global) continue;
- if (dso->ghashtab) {
- if (!gh) gh = gnu_hash(s);
- sym = gnu_lookup(s, gh, dso);
+ if ((ght = dso->ghashtab)) {
+ if (!ghm) {
+ gh = gnu_hash(s);
+ int maskbits = 8 * sizeof ghm;
+ gho = gh / maskbits;
+ ghm = 1ul << gh % maskbits;
+ }
+ sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
} else {
if (!h) h = sysv_hash(s);
sym = sysv_lookup(s, h, dso);
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)
size_t sym_val;
size_t tls_val;
size_t addend;
+ int skip_relative = 0, reuse_addends = 0, save_slot = 0;
+
+ if (dso == &ldso) {
+ /* Only ldso's REL table needs addend saving/reuse. */
+ if (rel == apply_addends_to)
+ reuse_addends = 1;
+ skip_relative = 1;
+ }
for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
- if (dso->rel_early_relative && IS_RELATIVE(rel[1])) continue;
+ if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
type = R_TYPE(rel[1]);
+ if (type == REL_NONE) continue;
sym_index = R_SYM(rel[1]);
- reloc_addr = (void *)(base + rel[0]);
+ reloc_addr = laddr(dso, rel[0]);
if (sym_index) {
sym = syms + sym_index;
name = strings + sym->st_name;
ctx = type==REL_COPY ? head->next : head;
- def = find_sym(ctx, name, type==REL_PLT);
+ def = (sym->st_info&0xf) == STT_SECTION
+ ? (struct symdef){ .dso = dso, .sym = sym }
+ : find_sym(ctx, name, type==REL_PLT);
if (!def.sym && (sym->st_shndx != SHN_UNDEF
|| sym->st_info>>4 != STB_WEAK)) {
error("Error relocating %s: %s: symbol not found",
dso->name, name);
+ if (runtime) longjmp(*rtld_fail, 1);
continue;
}
} else {
def.dso = dso;
}
- int gotplt = (type == REL_GOT || type == REL_PLT);
- if (dso->rel_update_got && !gotplt) continue;
-
- addend = stride>2 ? rel[2]
- : gotplt || type==REL_COPY ? 0
- : *reloc_addr;
+ if (stride > 2) {
+ addend = rel[2];
+ } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
+ addend = 0;
+ } else if (reuse_addends) {
+ /* Save original addend in stage 2 where the dso
+ * chain consists of just ldso; otherwise read back
+ * saved addend since the inline one was clobbered. */
+ if (head==&ldso)
+ saved_addends[save_slot] = *reloc_addr;
+ addend = saved_addends[save_slot++];
+ } else {
+ addend = *reloc_addr;
+ }
- sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
+ sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
tls_val = def.sym ? def.sym->st_value : 0;
switch(type) {
*(uint32_t *)reloc_addr = sym_val + addend
- (size_t)reloc_addr;
break;
+ case REL_FUNCDESC:
+ *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
+ + (def.sym - def.dso->syms)) : 0;
+ break;
+ case REL_FUNCDESC_VAL:
+ if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
+ else *reloc_addr = sym_val;
+ reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
+ break;
case REL_DTPMOD:
*reloc_addr = def.dso->tls_id;
break;
case REL_DTPOFF:
- *reloc_addr = tls_val + addend;
+ *reloc_addr = tls_val + addend - DTP_OFFSET;
break;
#ifdef TLS_ABOVE_TP
case REL_TPOFF:
if (stride<3) addend = reloc_addr[1];
if (runtime && def.dso->tls_id >= static_tls_cnt) {
struct td_index *new = malloc(sizeof *new);
- if (!new) error(
+ if (!new) {
+ error(
"Error relocating %s: cannot allocate TLSDESC for %s",
dso->name, sym ? name : "(local)" );
+ longjmp(*rtld_fail, 1);
+ }
new->next = dso->td_index;
dso->td_index = new;
new->args[0] = def.dso->tls_id;
default:
error("Error relocating %s: unsupported relocation type %d",
dso->name, type);
+ if (runtime) longjmp(*rtld_fail, 1);
continue;
}
}
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 = (size_t *)(dso->base + start);
- z = (size_t *)(dso->base + end);
+ 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;
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;
}
}
+static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
+{
+ char *q = mmap(p, n, prot, flags, fd, off);
+ if (q != MAP_FAILED || errno != EINVAL) return q;
+ /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
+ if (flags & MAP_ANONYMOUS) {
+ memset(p, 0, n);
+ return p;
+ }
+ ssize_t r;
+ if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
+ for (q=p; n; q+=r, off+=r, n-=r) {
+ r = read(fd, q, n);
+ if (r < 0 && errno != EINTR) return MAP_FAILED;
+ if (!r) {
+ memset(q, 0, n);
+ break;
+ }
+ }
+ return p;
+}
+
+static void unmap_library(struct dso *dso)
+{
+ if (dso->loadmap) {
+ size_t i;
+ for (i=0; i<dso->loadmap->nsegs; i++) {
+ if (!dso->loadmap->segs[i].p_memsz)
+ continue;
+ munmap((void *)dso->loadmap->segs[i].addr,
+ dso->loadmap->segs[i].p_memsz);
+ }
+ free(dso->loadmap);
+ } else if (dso->map && dso->map_len) {
+ munmap(dso->map, dso->map_len);
+ }
+}
+
static void *map_library(int fd, struct dso *dso)
{
Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
size_t phsize;
size_t addr_min=SIZE_MAX, addr_max=0, map_len;
size_t this_min, this_max;
+ size_t nsegs = 0;
off_t off_start;
Ehdr *eh;
Phdr *ph, *ph0;
dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
}
if (ph->p_type != PT_LOAD) continue;
+ nsegs++;
if (ph->p_vaddr < addr_min) {
addr_min = ph->p_vaddr;
off_start = ph->p_offset;
}
}
if (!dyn) goto noexec;
+ if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
+ dso->loadmap = calloc(1, sizeof *dso->loadmap
+ + nsegs * sizeof *dso->loadmap->segs);
+ if (!dso->loadmap) goto error;
+ dso->loadmap->nsegs = nsegs;
+ for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
+ if (ph->p_type != PT_LOAD) continue;
+ 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));
+ map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
+ prot, (prot&PROT_WRITE) ? MAP_PRIVATE : MAP_SHARED,
+ fd, ph->p_offset & -PAGE_SIZE);
+ if (map == MAP_FAILED) {
+ unmap_library(dso);
+ goto error;
+ }
+ dso->loadmap->segs[i].addr = (size_t)map +
+ (ph->p_vaddr & PAGE_SIZE-1);
+ dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
+ dso->loadmap->segs[i].p_memsz = ph->p_memsz;
+ i++;
+ }
+ map = (void *)dso->loadmap->segs[0].addr;
+ map_len = 0;
+ goto done_mapping;
+ }
addr_max += PAGE_SIZE-1;
addr_max &= -PAGE_SIZE;
addr_min &= -PAGE_SIZE;
* amount of virtual address space to map over later. */
map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
if (map==MAP_FAILED) goto error;
+ dso->map = map;
+ dso->map_len = map_len;
/* If the loaded file is not relocatable and the requested address is
* not available, then the load operation must fail. */
if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
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(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
+ 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) {
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);
- if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
+ if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
goto error;
}
}
for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
- if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
+ if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
+ && errno != ENOSYS)
goto error;
break;
}
- dso->map = map;
- dso->map_len = map_len;
+done_mapping:
dso->base = base;
- dso->dynv = (void *)(base+dyn);
- if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
+ dso->dynv = laddr(dso, dyn);
+ if (dso->tls_size) dso->tls_image = laddr(dso, tls_image);
if (!runtime) reclaim_gaps(dso);
free(allocated_buf);
return map;
noexec:
errno = ENOEXEC;
error:
- if (map!=MAP_FAILED) munmap(map, map_len);
+ if (map!=MAP_FAILED) unmap_library(dso);
free(allocated_buf);
return 0;
}
{
size_t dyn[DYN_CNT];
decode_vec(p->dynv, dyn, DYN_CNT);
- p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
- p->strings = (void *)(p->base + dyn[DT_STRTAB]);
+ p->syms = laddr(p, dyn[DT_SYMTAB]);
+ p->strings = laddr(p, dyn[DT_STRTAB]);
if (dyn[0]&(1<<DT_HASH))
- p->hashtab = (void *)(p->base + dyn[DT_HASH]);
+ p->hashtab = laddr(p, dyn[DT_HASH]);
if (dyn[0]&(1<<DT_RPATH))
- p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
+ p->rpath_orig = p->strings + dyn[DT_RPATH];
if (dyn[0]&(1<<DT_RUNPATH))
- p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
+ p->rpath_orig = p->strings + dyn[DT_RUNPATH];
+ if (dyn[0]&(1<<DT_PLTGOT))
+ p->got = laddr(p, dyn[DT_PLTGOT]);
if (search_vec(p->dynv, dyn, DT_GNU_HASH))
- p->ghashtab = (void *)(p->base + *dyn);
+ p->ghashtab = laddr(p, *dyn);
if (search_vec(p->dynv, dyn, DT_VERSYM))
- p->versym = (void *)(p->base + *dyn);
+ p->versym = laddr(p, *dyn);
+}
+
+static size_t count_syms(struct dso *p)
+{
+ if (p->hashtab) return p->hashtab[1];
+
+ size_t nsym, i;
+ uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
+ uint32_t *hashval;
+ for (i = nsym = 0; i < p->ghashtab[0]; i++) {
+ if (buckets[i] > nsym)
+ nsym = buckets[i];
+ }
+ if (nsym) {
+ hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
+ do nsym++;
+ while (!(*hashval++ & 1));
+ }
+ return nsym;
+}
+
+static void *dl_mmap(size_t n)
+{
+ void *p;
+ int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
+#ifdef SYS_mmap2
+ p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
+#else
+ p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
+#endif
+ return p == MAP_FAILED ? 0 : p;
+}
+
+static void makefuncdescs(struct dso *p)
+{
+ static int self_done;
+ size_t nsym = count_syms(p);
+ size_t i, size = nsym * sizeof(*p->funcdescs);
+
+ if (!self_done) {
+ p->funcdescs = dl_mmap(size);
+ self_done = 1;
+ } else {
+ p->funcdescs = malloc(size);
+ }
+ if (!p->funcdescs) {
+ if (!runtime) a_crash();
+ error("Error allocating function descriptors for %s", p->name);
+ longjmp(*rtld_fail, 1);
+ }
+ for (i=0; i<nsym; i++) {
+ if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
+ p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
+ p->funcdescs[i].got = p->got;
+ } else {
+ p->funcdescs[i].addr = 0;
+ p->funcdescs[i].got = 0;
+ }
+ }
}
static struct dso *load_library(const char *name, struct dso *needed_by)
}
p = calloc(1, alloc_size);
if (!p) {
- munmap(map, temp_dso.map_len);
+ unmap_library(&temp_dso);
return 0;
}
memcpy(p, &temp_dso, sizeof temp_dso);
p->prev = tail;
tail = p;
+ if (DL_FDPIC) makefuncdescs(p);
+
if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
return p;
if (!dep) {
error("Error loading shared library %s: %m (needed by %s)",
p->strings + p->dynv[i+1], p->name);
+ if (runtime) longjmp(*rtld_fail, 1);
continue;
}
if (runtime) {
size_t i, j, rel[2];
unsigned char *base = p->base;
i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
- if (p->rel_early_relative) {
+ if (p==&ldso) {
got += i;
} else {
while (i--) *got++ += (size_t)base;
if (p->relocated) continue;
decode_vec(p->dynv, dyn, DYN_CNT);
if (NEED_MIPS_GOT_RELOCS)
- do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
- do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
+ do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
+ do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
2+(dyn[DT_PLTREL]==DT_RELA));
- do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
- do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
+ do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
+ do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
if (head != &ldso && p->relro_start != p->relro_end &&
- mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
+ mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
+ && errno != ENOSYS) {
error("Error relocating %s: RELRO protection failed: %m",
p->name);
+ if (runtime) longjmp(*rtld_fail, 1);
}
p->relocated = 1;
Phdr *ph = p->phdr;
for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
if (ph->p_type == PT_DYNAMIC) {
- p->dynv = (void *)(p->base + ph->p_vaddr);
+ p->dynv = laddr(p, ph->p_vaddr);
} 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;
decode_vec(p->dynv, dyn, DYN_CNT);
if (dyn[0] & (1<<DT_FINI_ARRAY)) {
size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
- size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
+ size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
while (n--) ((void (*)(void))*--fn)();
}
#ifndef NO_LEGACY_INITFINI
if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
- ((void (*)(void))(p->base + dyn[DT_FINI]))();
+ fpaddr(p, dyn[DT_FINI])();
#endif
}
}
}
#ifndef NO_LEGACY_INITFINI
if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
- ((void (*)(void))(p->base + dyn[DT_INIT]))();
+ fpaddr(p, dyn[DT_INIT])();
#endif
if (dyn[0] & (1<<DT_INIT_ARRAY)) {
size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
- size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
+ size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
while (n--) ((void (*)(void))*fn++)();
}
if (!need_locking && libc.threads_minus_1) {
if (need_locking) pthread_mutex_unlock(&init_fini_lock);
}
-void _dl_debug_state(void)
+void __libc_start_init(void)
+{
+ do_init_fini(tail);
+}
+
+static void dl_debug_state(void)
{
}
+weak_alias(dl_debug_state, _dl_debug_state);
+
void __reset_tls()
{
pthread_t self = __pthread_self();
__block_all_sigs(&set);
if (v[0]<=(size_t)self->dtv[0]) {
__restore_sigs(&set);
- return (char *)self->dtv[v[0]]+v[1];
+ return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
}
/* This is safe without any locks held because, if the caller
if (p->tls_id == v[0]) break;
}
__restore_sigs(&set);
- return mem + v[1];
+ return mem + v[1] + DTP_OFFSET;
}
static void update_tls_size()
* linker itself, but some of the relocations performed may need to be
* replaced later due to copy relocations in the main program. */
-void __dls2(unsigned char *base)
+void __dls2(unsigned char *base, size_t *sp)
{
- Ehdr *ehdr = (void *)base;
- ldso.base = base;
+ 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++;
+ decode_vec(auxv, aux, AUX_CNT);
+ if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
+ else ldso.base = (void *)(aux[AT_PHDR] & -4096);
+ }
+ app_loadmap = p2 ? p1 : 0;
+ ldso.loadmap = p2 ? p2 : p1;
+ ldso.base = laddr(&ldso, 0);
+ } else {
+ ldso.base = base;
+ }
+ Ehdr *ehdr = (void *)ldso.base;
ldso.name = ldso.shortname = "libc.so";
ldso.global = 1;
ldso.phnum = ehdr->e_phnum;
- ldso.phdr = (void *)(base + ehdr->e_phoff);
+ ldso.phdr = laddr(&ldso, ehdr->e_phoff);
ldso.phentsize = ehdr->e_phentsize;
- ldso.rel_early_relative = 1;
kernel_mapped_dso(&ldso);
decode_dyn(&ldso);
+ if (DL_FDPIC) makefuncdescs(&ldso);
+
+ /* Prepare storage for to save clobbered REL addends so they
+ * can be reused in stage 3. There should be very few. If
+ * something goes wrong and there are a huge number, abort
+ * instead of risking stack overflow. */
+ size_t dyn[DYN_CNT];
+ decode_vec(ldso.dynv, dyn, DYN_CNT);
+ size_t *rel = laddr(&ldso, dyn[DT_REL]);
+ size_t rel_size = dyn[DT_RELSZ];
+ size_t symbolic_rel_cnt = 0;
+ apply_addends_to = rel;
+ for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
+ if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
+ if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
+ size_t addends[symbolic_rel_cnt+1];
+ saved_addends = addends;
+
head = &ldso;
reloc_all(&ldso);
ldso.relocated = 0;
- ldso.rel_update_got = 1;
+
+ /* Call dynamic linker stage-3, __dls3, looking it up
+ * symbolically as a barrier against moving the address
+ * load across the above relocation processing. */
+ 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);
}
/* Stage 3 of the dynamic linker is called with the dynamic linker/libc
char **argv_orig = argv;
char **envp = argv+argc+1;
+ /* Find aux vector just past environ[] and use it to initialize
+ * global data that may be needed before we can make syscalls. */
+ __environ = envp;
+ for (i=argc+1; argv[i]; i++);
+ libc.auxv = auxv = (void *)(argv+i+1);
+ decode_vec(auxv, aux, AUX_CNT);
+ __hwcap = aux[AT_HWCAP];
+ libc.page_size = aux[AT_PAGESZ];
+ 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. */
a_crash();
}
- /* Find aux vector just past environ[] */
- for (i=argc+1; argv[i]; i++)
- if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
- env_path = argv[i]+16;
- else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
- env_preload = argv[i]+11;
- auxv = (void *)(argv+i+1);
-
- decode_vec(auxv, aux, AUX_CNT);
-
/* 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] || aux[AT_SECURE]) {
- env_path = 0;
- env_preload = 0;
- libc.secure = 1;
+ if (!libc.secure) {
+ env_path = getenv("LD_LIBRARY_PATH");
+ env_preload = getenv("LD_PRELOAD");
}
- libc.page_size = aux[AT_PAGESZ];
- libc.auxv = auxv;
/* If the main program was already loaded by the kernel,
* AT_PHDR will point to some location other than the dynamic
app.tls_align = phdr->p_align;
}
}
- if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
- if (interp_off) ldso.name = (char *)app.base + interp_off;
+ if (DL_FDPIC) app.loadmap = app_loadmap;
+ if (app.tls_size) app.tls_image = laddr(&app, tls_image);
+ if (interp_off) ldso.name = laddr(&app, interp_off);
if ((aux[0] & (1UL<<AT_EXECFN))
&& strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
app.name = (char *)aux[AT_EXECFN];
close(fd);
ldso.name = ldname;
app.name = argv[0];
- aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
+ aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
/* Find the name that would have been used for the dynamic
* linker had ldd not taken its place. */
if (ldd_mode) {
for (i=0; i<app.phnum; i++) {
if (app.phdr[i].p_type == PT_INTERP)
- ldso.name = (void *)(app.base
- + app.phdr[i].p_vaddr);
+ ldso.name = laddr(&app, app.phdr[i].p_vaddr);
}
dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
}
}
app.global = 1;
decode_dyn(&app);
+ if (DL_FDPIC) {
+ makefuncdescs(&app);
+ if (!app.loadmap) {
+ app.loadmap = (void *)&app_dummy_loadmap;
+ app.loadmap->nsegs = 1;
+ app.loadmap->segs[0].addr = (size_t)app.map;
+ app.loadmap->segs[0].p_vaddr = (size_t)app.map
+ - (size_t)app.base;
+ app.loadmap->segs[0].p_memsz = app.map_len;
+ }
+ argv[-3] = (void *)app.loadmap;
+ }
/* Attach to vdso, if provided by the kernel */
if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
runtime = 1;
debug.ver = 1;
- debug.bp = _dl_debug_state;
+ debug.bp = dl_debug_state;
debug.head = head;
debug.base = ldso.base;
debug.state = 0;
__init_libc(envp, argv[0]);
atexit(do_fini);
errno = 0;
- do_init_fini(tail);
CRTJMP((void *)aux[AT_ENTRY], argv-1);
for(;;);
p->deps[i]->global = 0;
for (p=orig_tail->next; p; p=next) {
next = p->next;
- munmap(p->map, p->map_len);
while (p->td_index) {
void *tmp = p->td_index->next;
free(p->td_index);
p->td_index = tmp;
}
+ free(p->funcdescs);
if (p->rpath != p->rpath_orig)
free(p->rpath);
free(p->deps);
+ unmap_library(p);
free(p);
}
tls_cnt = orig_tls_cnt;
tail = orig_tail;
tail->next = 0;
p = 0;
- errflag = 1;
goto end;
} else p = load_library(file, head);
if (!p) {
- snprintf(errbuf, sizeof errbuf, noload ?
+ error(noload ?
"Library %s is not already loaded" :
"Error loading shared library %s: %m",
file);
- errflag = 1;
goto end;
}
{
struct dso *p;
for (p=head; p; p=p->next) if (h==p) return 0;
- snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
- errflag = 1;
+ error("Invalid library handle %p", (void *)h);
return 1;
}
+static void *addr2dso(size_t a)
+{
+ struct dso *p;
+ for (p=head; p; p=p->next) {
+ if (DL_FDPIC && p->loadmap) {
+ size_t i;
+ for (i=0; i<p->loadmap->nsegs; i++) {
+ if (a-p->loadmap->segs[i].p_vaddr
+ < p->loadmap->segs[i].p_memsz)
+ return p;
+ }
+ i = count_syms(p);
+ if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
+ return p;
+ } else {
+ if (a-(size_t)p->map < p->map_len)
+ return p;
+ }
+ }
+ return 0;
+}
+
void *__tls_get_addr(size_t *);
static void *do_dlsym(struct dso *p, const char *s, void *ra)
{
size_t i;
- uint32_t h = 0, gh = 0;
+ uint32_t h = 0, gh = 0, *ght;
Sym *sym;
if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
if (p == RTLD_DEFAULT) {
p = head;
} else if (p == RTLD_NEXT) {
- for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
+ p = addr2dso((size_t)ra);
if (!p) p=head;
p = p->next;
}
if (!def.sym) goto failed;
if ((def.sym->st_info&0xf) == STT_TLS)
return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
- return def.dso->base + def.sym->st_value;
+ 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);
}
- if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
+ if (invalid_dso_handle(p))
return 0;
- if (p->ghashtab) {
+ if ((ght = p->ghashtab)) {
gh = gnu_hash(s);
- sym = gnu_lookup(s, gh, p);
+ sym = gnu_lookup(gh, ght, p, s);
} else {
h = sysv_hash(s);
sym = sysv_lookup(s, h, p);
}
if (sym && (sym->st_info&0xf) == STT_TLS)
return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
+ 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))
- return p->base + sym->st_value;
+ return laddr(p, sym->st_value);
if (p->deps) for (i=0; p->deps[i]; i++) {
- if (p->deps[i]->ghashtab) {
+ if ((ght = p->deps[i]->ghashtab)) {
if (!gh) gh = gnu_hash(s);
- sym = gnu_lookup(s, gh, p->deps[i]);
+ sym = gnu_lookup(gh, ght, p->deps[i], s);
} else {
if (!h) h = sysv_hash(s);
sym = sysv_lookup(s, h, p->deps[i]);
}
if (sym && (sym->st_info&0xf) == STT_TLS)
return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
+ 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 p->deps[i]->base + sym->st_value;
+ return laddr(p->deps[i], sym->st_value);
}
failed:
- errflag = 1;
- snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
+ error("Symbol not found: %s", s);
return 0;
}
Sym *sym;
uint32_t nsym;
char *strings;
- size_t i;
void *best = 0;
char *bestname;
pthread_rwlock_rdlock(&lock);
- for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
+ p = addr2dso((size_t)addr);
pthread_rwlock_unlock(&lock);
if (!p) return 0;
sym = p->syms;
strings = p->strings;
- if (p->hashtab) {
- nsym = p->hashtab[1];
- } else {
- uint32_t *buckets;
- uint32_t *hashval;
- buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
- sym += p->ghashtab[1];
- for (i = nsym = 0; i < p->ghashtab[0]; i++) {
- if (buckets[i] > nsym)
- nsym = buckets[i];
- }
- if (nsym) {
- nsym -= p->ghashtab[1];
- hashval = buckets + p->ghashtab[0] + nsym;
- do nsym++;
- while (!(*hashval++ & 1));
- }
- }
+ nsym = count_syms(p);
for (; nsym; nsym--, sym++) {
if (sym->st_value
&& (1<<(sym->st_info&0xf) & OK_TYPES)
&& (1<<(sym->st_info>>4) & OK_BINDS)) {
- void *symaddr = p->base + sym->st_value;
+ void *symaddr = laddr(p, sym->st_value);
if (symaddr > addr || symaddr < best)
continue;
best = symaddr;
#else
static int invalid_dso_handle(void *h)
{
- snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
- errflag = 1;
+ error("Invalid library handle %p", (void *)h);
return 1;
}
void *dlopen(const char *file, int mode)
{
- strcpy(errbuf, "Dynamic loading not supported");
- errflag = 1;
+ error("Dynamic loading not supported");
return 0;
}
void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
{
- errflag = 1;
- snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
+ error("Symbol not found: %s", s);
return 0;
}
int __dladdr (const void *addr, Dl_info *info)
{
if (invalid_dso_handle(dso)) return -1;
if (req != RTLD_DI_LINKMAP) {
- snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
- errflag = 1;
+ error("Unsupported request %d", req);
return -1;
}
*(struct link_map **)res = dso;
char *dlerror()
{
- if (!errflag) return 0;
- errflag = 0;
- return errbuf;
+ pthread_t self = __pthread_self();
+ if (!self->dlerror_flag) return 0;
+ self->dlerror_flag = 0;
+ char *s = self->dlerror_buf;
+ if (s == (void *)-1)
+ return "Dynamic linker failed to allocate memory for error message";
+ else
+ return s;
}
int dlclose(void *p)
{
return invalid_dso_handle(p);
}
+
+void __dl_thread_cleanup(void)
+{
+ pthread_t self = __pthread_self();
+ if (self->dlerror_buf != (void *)-1)
+ free(self->dlerror_buf);
+}
+
+static void error(const char *fmt, ...)
+{
+ va_list ap;
+ va_start(ap, fmt);
+#ifdef SHARED
+ if (!runtime) {
+ vdprintf(2, fmt, ap);
+ dprintf(2, "\n");
+ ldso_fail = 1;
+ va_end(ap);
+ return;
+ }
+#endif
+ pthread_t self = __pthread_self();
+ if (self->dlerror_buf != (void *)-1)
+ free(self->dlerror_buf);
+ size_t len = vsnprintf(0, 0, fmt, ap);
+ va_end(ap);
+ char *buf = malloc(len+1);
+ if (buf) {
+ va_start(ap, fmt);
+ vsnprintf(buf, len+1, fmt, ap);
+ va_end(ap);
+ } else {
+ buf = (void *)-1;
+ }
+ self->dlerror_buf = buf;
+ self->dlerror_flag = 1;
+}