#include <dlfcn.h>
#include "pthread_impl.h"
#include "libc.h"
+#include "dynlink.h"
-static int errflag;
-static char errbuf[128];
+static void error(const char *, ...);
#ifdef SHARED
-#if ULONG_MAX == 0xffffffff
-typedef Elf32_Ehdr Ehdr;
-typedef Elf32_Phdr Phdr;
-typedef Elf32_Sym Sym;
-#define R_TYPE(x) ((x)&255)
-#define R_SYM(x) ((x)>>8)
-#else
-typedef Elf64_Ehdr Ehdr;
-typedef Elf64_Phdr Phdr;
-typedef Elf64_Sym Sym;
-#define R_TYPE(x) ((x)&0xffffffff)
-#define R_SYM(x) ((x)>>32)
-#endif
-
#define MAXP2(a,b) (-(-(a)&-(b)))
#define ALIGN(x,y) ((x)+(y)-1 & -(y))
struct dso *dso;
};
-enum {
- REL_ERR,
- REL_SYMBOLIC,
- REL_GOT,
- REL_PLT,
- REL_RELATIVE,
- REL_OFFSET,
- REL_OFFSET32,
- REL_COPY,
- REL_SYM_OR_REL,
- REL_TLS, /* everything past here is TLS */
- REL_DTPMOD,
- REL_DTPOFF,
- REL_TPOFF,
- REL_TPOFF_NEG,
- REL_TLSDESC,
-};
-
-#include "reloc.h"
-
int __init_tp(void *);
void __init_libc(char **, char *);
} builtin_tls[1];
#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
-static struct dso *head, *tail, *ldso, *fini_head;
+#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 unsigned long long gencnt;
static int runtime;
struct debug *_dl_debug_addr = &debug;
-#define AUX_CNT 38
-#define DYN_CNT 34
+static int dl_strcmp(const char *l, const char *r)
+{
+ for (; *l==*r && *l; l++, r++);
+ return *(unsigned char *)l - *(unsigned char *)r;
+}
+#define strcmp(l,r) dl_strcmp(l,r)
static void decode_vec(size_t *v, size_t *a, size_t cnt)
{
- memset(a, 0, cnt*sizeof(size_t));
- for (; v[0]; v+=2) if (v[0]<cnt) {
- a[0] |= 1ULL<<v[0];
+ size_t i;
+ for (i=0; i<cnt; i++) a[i] = 0;
+ for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
+ a[0] |= 1UL<<v[0];
a[v[0]] = v[1];
}
}
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;
return def;
}
-#define NO_INLINE_ADDEND (1<<REL_COPY | 1<<REL_GOT | 1<<REL_PLT)
-
+__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)
Sym *sym;
const char *name;
void *ctx;
- int astype, type;
+ int type;
int sym_index;
struct symdef def;
size_t *reloc_addr;
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)) {
- astype = R_TYPE(rel[1]);
- if (!astype) continue;
- type = remap_rel(astype);
- if (!type) {
- error("Error relocating %s: unsupported relocation type %d",
- dso->name, astype);
- continue;
- }
+ if (skip_relative && IS_RELATIVE(rel[1])) continue;
+ type = R_TYPE(rel[1]);
+ if (type == REL_NONE) continue;
sym_index = R_SYM(rel[1]);
reloc_addr = (void *)(base + rel[0]);
if (sym_index) {
|| 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;
}
- addend = stride>2 ? rel[2]
- : (1<<type & NO_INLINE_ADDEND) ? 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;
tls_val = def.sym ? def.sym->st_value : 0;
switch(type) {
+ case REL_NONE:
+ break;
case REL_OFFSET:
addend -= (size_t)reloc_addr;
case REL_SYMBOLIC:
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;
#endif
}
break;
+ default:
+ error("Error relocating %s: unsupported relocation type %d",
+ dso->name, type);
+ if (runtime) longjmp(*rtld_fail, 1);
+ continue;
}
}
}
s += strspn(s, ":\n");
l = strcspn(s, ":\n");
if (l-1 >= INT_MAX) return -1;
- if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
- continue;
- if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
+ if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
+ if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
+ switch (errno) {
+ case ENOENT:
+ case ENOTDIR:
+ case EACCES:
+ case ENAMETOOLONG:
+ break;
+ default:
+ /* Any negative value but -1 will inhibit
+ * futher path search. */
+ return -2;
+ }
+ }
s += l;
}
}
size_t n, l;
const char *s, *t, *origin;
char *d;
- if (p->rpath) return 0;
- if (!p->rpath_orig) return -1;
+ if (p->rpath || !p->rpath_orig) return 0;
if (!strchr(p->rpath_orig, '$')) {
p->rpath = p->rpath_orig;
return 0;
s = p->rpath_orig;
while ((t=strchr(s, '$'))) {
if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
- return -1;
+ return 0;
s = t+1;
n++;
}
- if (n > SSIZE_MAX/PATH_MAX) return -1;
+ if (n > SSIZE_MAX/PATH_MAX) return 0;
if (p->kernel_mapped) {
/* $ORIGIN searches cannot be performed for the main program
* since the library's pathname came from a trusted source
* (either system paths or a call to dlopen). */
if (libc.secure)
- return -1;
+ return 0;
l = readlink("/proc/self/exe", buf, buf_size);
- if (l >= buf_size)
+ if (l == -1) switch (errno) {
+ case ENOENT:
+ case ENOTDIR:
+ case EACCES:
+ break;
+ default:
return -1;
+ }
+ if (l >= buf_size)
+ return 0;
buf[l] = 0;
origin = buf;
} else {
static void decode_dyn(struct dso *p)
{
- size_t dyn[DYN_CNT] = {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]);
if (!(reported & mask)) {
reported |= mask;
dprintf(1, "\t%s => %s (%p)\n",
- name, ldso->name,
- ldso->base);
+ name, ldso.name,
+ ldso.base);
}
}
is_self = 1;
}
}
}
- if (!strcmp(name, ldso->name)) is_self = 1;
+ if (!strcmp(name, ldso.name)) is_self = 1;
if (is_self) {
- if (!ldso->prev) {
- tail->next = ldso;
- ldso->prev = tail;
- tail = ldso->next ? ldso->next : ldso;
+ if (!ldso.prev) {
+ tail->next = &ldso;
+ ldso.prev = tail;
+ tail = ldso.next ? ldso.next : &ldso;
}
- return ldso;
+ return &ldso;
}
if (strchr(name, '/')) {
pathname = name;
if (strlen(name) > NAME_MAX) return 0;
fd = -1;
if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
- for (p=needed_by; fd < 0 && p; p=p->needed_by)
- if (!fixup_rpath(p, buf, sizeof buf))
+ for (p=needed_by; fd == -1 && p; p=p->needed_by) {
+ if (fixup_rpath(p, buf, sizeof buf) < 0)
+ fd = -2; /* Inhibit further search. */
+ if (p->rpath)
fd = path_open(name, p->rpath, buf, sizeof buf);
- if (fd < 0) {
+ }
+ if (fd == -1) {
if (!sys_path) {
char *prefix = 0;
size_t prefix_len;
- if (ldso->name[0]=='/') {
+ if (ldso.name[0]=='/') {
char *s, *t, *z;
- for (s=t=z=ldso->name; *s; s++)
+ for (s=t=z=ldso.name; *s; s++)
if (*s=='/') z=t, t=s;
- prefix_len = z-ldso->name;
+ prefix_len = z-ldso.name;
if (prefix_len < PATH_MAX)
- prefix = ldso->name;
+ prefix = ldso.name;
}
if (!prefix) {
prefix = "";
/* Add a shortname only if name arg was not an explicit pathname. */
if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
if (p->tls_image) {
- if (runtime && !libc.has_thread_pointer) {
- munmap(map, p->map_len);
- free(p);
- errno = ENOSYS;
- return 0;
- }
p->tls_id = ++tls_cnt;
tls_align = MAXP2(tls_align, p->tls_align);
#ifdef TLS_ABOVE_TP
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) {
for (; p; p=p->next) p->global = 1;
}
+static void do_mips_relocs(struct dso *p, size_t *got)
+{
+ size_t i, j, rel[2];
+ unsigned char *base = p->base;
+ i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
+ if (p==&ldso) {
+ got += i;
+ } else {
+ while (i--) *got++ += (size_t)base;
+ }
+ j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
+ i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
+ Sym *sym = p->syms + j;
+ rel[0] = (unsigned char *)got - base;
+ for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
+ rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
+ do_relocs(p, rel, sizeof rel, 2);
+ }
+}
+
static void reloc_all(struct dso *p)
{
- size_t dyn[DYN_CNT] = {0};
+ size_t dyn[DYN_CNT];
for (; p; p=p->next) {
if (p->relocated) continue;
decode_vec(p->dynv, dyn, DYN_CNT);
-#ifdef NEED_ARCH_RELOCS
- do_arch_relocs(p, head);
-#endif
+ 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],
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);
- if (p->relro_start != p->relro_end &&
+ if (head != &ldso && p->relro_start != p->relro_end &&
mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
error("Error relocating %s: RELRO protection failed: %m",
p->name);
+ if (runtime) longjmp(*rtld_fail, 1);
}
p->relocated = 1;
static void do_fini()
{
struct dso *p;
- size_t dyn[DYN_CNT] = {0};
+ size_t dyn[DYN_CNT];
for (p=fini_head; p; p=p->fini_next) {
if (!p->constructed) continue;
decode_vec(p->dynv, dyn, DYN_CNT);
static void do_init_fini(struct dso *p)
{
- size_t dyn[DYN_CNT] = {0};
+ size_t dyn[DYN_CNT];
int need_locking = libc.threads_minus_1;
/* Allow recursive calls that arise when a library calls
* dlopen from one of its constructors, but block any
if (need_locking) pthread_mutex_unlock(&init_fini_lock);
}
-void _dl_debug_state(void)
+static void dl_debug_state(void)
{
}
+weak_alias(dl_debug_state, _dl_debug_state);
+
void __reset_tls()
{
pthread_t self = __pthread_self();
{
pthread_t td;
struct dso *p;
-
- void **dtv = (void *)mem;
- dtv[0] = (void *)tls_cnt;
- if (!tls_cnt) {
- td = (void *)(dtv+1);
- td->dtv = dtv;
- return td;
- }
+ void **dtv;
#ifdef TLS_ABOVE_TP
- mem += sizeof(void *) * (tls_cnt+1);
+ dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
+
mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
td = (pthread_t)mem;
mem += sizeof(struct pthread);
memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
}
#else
+ dtv = (void **)mem;
+
mem += libc.tls_size - sizeof(struct pthread);
mem -= (uintptr_t)mem & (tls_align-1);
td = (pthread_t)mem;
memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
}
#endif
- td->dtv = dtv;
+ dtv[0] = (void *)tls_cnt;
+ td->dtv = td->dtv_copy = dtv;
return td;
}
+__attribute__((__visibility__("hidden")))
void *__tls_get_new(size_t *v)
{
pthread_t self = __pthread_self();
memcpy(newdtv, self->dtv,
((size_t)self->dtv[0]+1) * sizeof(void *));
newdtv[0] = (void *)v[0];
- self->dtv = newdtv;
+ self->dtv = self->dtv_copy = newdtv;
}
/* Get new TLS memory from all new DSOs up to the requested one */
tls_align);
}
-void *__dynlink(int argc, char **argv)
+/* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
+ * following stage 2 and stage 3 functions via primitive symbolic lookup
+ * since it does not have access to their addresses to begin with. */
+
+/* Stage 2 of the dynamic linker is called after relative relocations
+ * have been processed. It can make function calls to static functions
+ * and access string literals and static data, but cannot use extern
+ * symbols. Its job is to perform symbolic relocations on the dynamic
+ * 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, size_t *sp)
+{
+ Ehdr *ehdr = (void *)base;
+ ldso.base = base;
+ ldso.name = ldso.shortname = "libc.so";
+ ldso.global = 1;
+ ldso.phnum = ehdr->e_phnum;
+ ldso.phdr = (void *)(base + ehdr->e_phoff);
+ ldso.phentsize = ehdr->e_phentsize;
+ kernel_mapped_dso(&ldso);
+ decode_dyn(&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 = (void *)(base+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])) 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;
+
+ /* 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);
+ ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
+}
+
+/* Stage 3 of the dynamic linker is called with the dynamic linker/libc
+ * fully functional. Its job is to load (if not already loaded) and
+ * process dependencies and relocations for the main application and
+ * transfer control to its entry point. */
+
+_Noreturn void __dls3(size_t *sp)
{
- size_t aux[AUX_CNT] = {0};
+ static struct dso app, vdso;
+ size_t aux[AUX_CNT], *auxv;
size_t i;
- Phdr *phdr;
- Ehdr *ehdr;
- 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;
char *env_preload=0;
size_t vdso_base;
- size_t *auxv;
+ int argc = *sp;
+ char **argv = (void *)(sp+1);
+ char **argv_orig = argv;
char **envp = argv+argc+1;
- void *initial_tls;
-
- /* 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);
+ /* 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. */
+ libc.tls_size = sizeof builtin_tls;
+ if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
+ a_crash();
+ }
/* 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;
- }
- libc.page_size = aux[AT_PAGESZ];
- libc.auxv = auxv;
-
- /* If the dynamic linker was invoked as a program itself, AT_BASE
- * will not be set. In that case, we assume the base address is
- * the start of the page containing the PHDRs; I don't know any
- * better approach... */
- if (!aux[AT_BASE]) {
- aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
- aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
+ if (!libc.secure) {
+ env_path = getenv("LD_LIBRARY_PATH");
+ env_preload = getenv("LD_PRELOAD");
}
- /* The dynamic linker load address is passed by the kernel
- * in the AUX vector, so this is easy. */
- lib->base = (void *)aux[AT_BASE];
- lib->name = lib->shortname = "libc.so";
- lib->global = 1;
- ehdr = (void *)lib->base;
- lib->phnum = ehdr->e_phnum;
- lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
- lib->phentsize = ehdr->e_phentsize;
- kernel_mapped_dso(lib);
- decode_dyn(lib);
-
- if (aux[AT_PHDR]) {
+ /* If the main program was already loaded by the kernel,
+ * AT_PHDR will point to some location other than the dynamic
+ * linker's program headers. */
+ if (aux[AT_PHDR] != (size_t)ldso.phdr) {
size_t interp_off = 0;
size_t tls_image = 0;
/* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
- app->phdr = phdr = (void *)aux[AT_PHDR];
- app->phnum = aux[AT_PHNUM];
- app->phentsize = aux[AT_PHENT];
+ Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
+ app.phnum = aux[AT_PHNUM];
+ app.phentsize = aux[AT_PHENT];
for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
if (phdr->p_type == PT_PHDR)
- app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
+ app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
else if (phdr->p_type == PT_INTERP)
interp_off = (size_t)phdr->p_vaddr;
else if (phdr->p_type == PT_TLS) {
tls_image = phdr->p_vaddr;
- app->tls_len = phdr->p_filesz;
- app->tls_size = phdr->p_memsz;
- app->tls_align = phdr->p_align;
+ app.tls_len = phdr->p_filesz;
+ app.tls_size = phdr->p_memsz;
+ app.tls_align = phdr->p_align;
}
}
- if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
- if (interp_off) lib->name = (char *)app->base + interp_off;
+ if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
+ if (interp_off) ldso.name = (char *)app.base + interp_off;
if ((aux[0] & (1UL<<AT_EXECFN))
&& strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
- app->name = (char *)aux[AT_EXECFN];
+ app.name = (char *)aux[AT_EXECFN];
else
- app->name = argv[0];
- kernel_mapped_dso(app);
+ app.name = argv[0];
+ kernel_mapped_dso(&app);
} else {
int fd;
char *ldname = argv[0];
size_t l = strlen(ldname);
if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
- *argv++ = (void *)-1;
+ argv++;
while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
char *opt = argv[0]+2;
*argv++ = (void *)-1;
} else {
argv[0] = 0;
}
- argv[-1] = (void *)-1;
}
+ argv[-1] = (void *)(argc - (argv-argv_orig));
if (!argv[0]) {
dprintf(2, "musl libc\n"
"Version %s\n"
_exit(1);
}
runtime = 1;
- ehdr = (void *)map_library(fd, app);
+ Ehdr *ehdr = (void *)map_library(fd, &app);
if (!ehdr) {
dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
_exit(1);
}
runtime = 0;
close(fd);
- lib->name = ldname;
- app->name = argv[0];
- aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
+ ldso.name = ldname;
+ app.name = argv[0];
+ aux[AT_ENTRY] = (size_t)app.base + 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)
- lib->name = (void *)(app->base
- + app->phdr[i].p_vaddr);
+ 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);
}
- dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
+ dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
}
}
- if (app->tls_size) {
- app->tls_id = tls_cnt = 1;
+ if (app.tls_size) {
+ app.tls_id = tls_cnt = 1;
#ifdef TLS_ABOVE_TP
- app->tls_offset = 0;
- tls_offset = app->tls_size
- + ( -((uintptr_t)app->tls_image + app->tls_size)
- & (app->tls_align-1) );
+ app.tls_offset = 0;
+ tls_offset = app.tls_size
+ + ( -((uintptr_t)app.tls_image + app.tls_size)
+ & (app.tls_align-1) );
#else
- tls_offset = app->tls_offset = app->tls_size
- + ( -((uintptr_t)app->tls_image + app->tls_size)
- & (app->tls_align-1) );
+ tls_offset = app.tls_offset = app.tls_size
+ + ( -((uintptr_t)app.tls_image + app.tls_size)
+ & (app.tls_align-1) );
#endif
- tls_align = MAXP2(tls_align, app->tls_align);
+ tls_align = MAXP2(tls_align, app.tls_align);
}
- app->global = 1;
- decode_dyn(app);
+ app.global = 1;
+ decode_dyn(&app);
/* Attach to vdso, if provided by the kernel */
if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
- ehdr = (void *)vdso_base;
- vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
- vdso->phnum = ehdr->e_phnum;
- vdso->phentsize = ehdr->e_phentsize;
+ Ehdr *ehdr = (void *)vdso_base;
+ Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
+ vdso.phnum = ehdr->e_phnum;
+ vdso.phentsize = ehdr->e_phentsize;
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);
+ 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);
+ vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
}
- vdso->name = "";
- vdso->shortname = "linux-gate.so.1";
- vdso->global = 1;
- decode_dyn(vdso);
- vdso->prev = lib;
- lib->next = vdso;
+ vdso.name = "";
+ vdso.shortname = "linux-gate.so.1";
+ vdso.global = 1;
+ vdso.relocated = 1;
+ decode_dyn(&vdso);
+ vdso.prev = &ldso;
+ ldso.next = &vdso;
}
- /* Initial dso chain consists only of the app. We temporarily
- * append the dynamic linker/libc so we can relocate it, then
- * restore the initial chain in preparation for loading third
- * party libraries (preload/needed). */
- head = tail = app;
- ldso = lib;
- app->next = lib;
- reloc_all(lib);
- app->next = 0;
-
- /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
+ /* Initial dso chain consists only of the app. */
+ head = tail = &app;
/* Donate unused parts of app and library mapping to malloc */
- reclaim_gaps(app);
- reclaim_gaps(lib);
+ reclaim_gaps(&app);
+ reclaim_gaps(&ldso);
/* Load preload/needed libraries, add their symbols to the global
- * namespace, and perform all remaining relocations. The main
- * program must be relocated LAST since it may contain copy
- * relocations which depend on libraries' relocations. */
+ * namespace, and perform all remaining relocations. */
if (env_preload) load_preload(env_preload);
- load_deps(app);
- make_global(app);
+ load_deps(&app);
+ make_global(&app);
#ifndef DYNAMIC_IS_RO
- for (i=0; app->dynv[i]; i+=2)
- if (app->dynv[i]==DT_DEBUG)
- app->dynv[i+1] = (size_t)&debug;
+ for (i=0; app.dynv[i]; i+=2)
+ if (app.dynv[i]==DT_DEBUG)
+ app.dynv[i+1] = (size_t)&debug;
#endif
- reloc_all(app->next);
- reloc_all(app);
+ /* The main program must be relocated LAST since it may contin
+ * copy relocations which depend on libraries' relocations. */
+ reloc_all(app.next);
+ reloc_all(&app);
update_tls_size();
- if (libc.tls_size > sizeof builtin_tls) {
- initial_tls = calloc(libc.tls_size, 1);
+ if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
+ void *initial_tls = calloc(libc.tls_size, 1);
if (!initial_tls) {
dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
argv[0], libc.tls_size);
_exit(127);
}
+ if (__init_tp(__copy_tls(initial_tls)) < 0) {
+ a_crash();
+ }
} else {
- initial_tls = builtin_tls;
- }
- if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) {
- dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
- _exit(127);
+ size_t tmp_tls_size = libc.tls_size;
+ pthread_t self = __pthread_self();
+ /* Temporarily set the tls size to the full size of
+ * builtin_tls so that __copy_tls will use the same layout
+ * as it did for before. Then check, just to be safe. */
+ libc.tls_size = sizeof builtin_tls;
+ if (__copy_tls((void*)builtin_tls) != self) a_crash();
+ libc.tls_size = tmp_tls_size;
}
static_tls_cnt = tls_cnt;
/* Switch to runtime mode: any further failures in the dynamic
* linker are a reportable failure rather than a fatal startup
- * error. If the dynamic loader (dlopen) will not be used, free
- * all memory used by the dynamic linker. */
+ * error. */
runtime = 1;
debug.ver = 1;
- debug.bp = _dl_debug_state;
+ debug.bp = dl_debug_state;
debug.head = head;
- debug.base = lib->base;
+ debug.base = ldso.base;
debug.state = 0;
_dl_debug_state();
errno = 0;
do_init_fini(tail);
- return (void *)aux[AT_ENTRY];
+ CRTJMP((void *)aux[AT_ENTRY], argv-1);
+ for(;;);
}
void *dlopen(const char *file, int mode)
free(p->td_index);
p->td_index = tmp;
}
+ if (p->rpath != p->rpath_orig)
+ free(p->rpath);
free(p->deps);
free(p);
}
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;
}
return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
return def.dso->base + 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) {
gh = gnu_hash(s);
return p->deps[i]->base + sym->st_value;
}
failed:
- errflag = 1;
- snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
+ error("Symbol not found: %s", s);
return 0;
}
return 1;
}
+__attribute__((__visibility__("hidden")))
void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
{
void *res;
#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;
+}