allow i386 __set_thread_area to be called more than once
[musl] / src / ldso / dynlink.c
index aa1b99a..1008e3e 100644 (file)
 #include <dlfcn.h>
 #include "pthread_impl.h"
 #include "libc.h"
+#include "dynlink.h"
 
 static int errflag;
 static char errbuf[128];
 
 #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))
 
@@ -85,9 +72,10 @@ struct dso {
        size_t relro_start, relro_end;
        void **new_dtv;
        unsigned char *new_tls;
-       int new_dtv_idx, new_tls_idx;
+       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;
        char buf[];
 };
@@ -97,32 +85,20 @@ struct symdef {
        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 *);
 
 const char *__libc_get_version(void);
 
-static struct dso *head, *tail, *ldso, *fini_head;
+static struct builtin_tls {
+       char c;
+       struct pthread pt;
+       void *space[16];
+} builtin_tls[1];
+#define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
+
+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;
@@ -132,21 +108,25 @@ static int noload;
 static jmp_buf *rtld_fail;
 static pthread_rwlock_t lock;
 static struct debug debug;
-static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
+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 long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 
 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];
        }
 }
@@ -270,8 +250,6 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
        return def;
 }
 
-#define NO_INLINE_ADDEND (1<<REL_COPY | 1<<REL_GOT | 1<<REL_PLT)
-
 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 
 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
@@ -282,7 +260,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
        Sym *sym;
        const char *name;
        void *ctx;
-       int astype, type;
+       int type;
        int sym_index;
        struct symdef def;
        size_t *reloc_addr;
@@ -291,14 +269,8 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
        size_t addend;
 
        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 (dso->rel_early_relative && IS_RELATIVE(rel[1])) continue;
+               type = R_TYPE(rel[1]);
                sym_index = R_SYM(rel[1]);
                reloc_addr = (void *)(base + rel[0]);
                if (sym_index) {
@@ -318,14 +290,19 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                        def.dso = dso;
                }
 
+               int gotplt = (type == REL_GOT || type == REL_PLT);
+               if (dso->rel_update_got && !gotplt) continue;
+
                addend = stride>2 ? rel[2]
-                       : (1<<type & NO_INLINE_ADDEND) ? 0
+                       : gotplt || type==REL_COPY ? 0
                        : *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:
@@ -389,6 +366,10 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 #endif
                        }
                        break;
+               default:
+                       error("Error relocating %s: unsupported relocation type %d",
+                               dso->name, type);
+                       continue;
                }
        }
 }
@@ -570,9 +551,20 @@ static int path_open(const char *name, const char *s, char *buf, size_t buf_size
                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;
        }
 }
@@ -582,8 +574,7 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
        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, '$')) {
                p->rpath = p->rpath_orig;
                return 0;
@@ -592,11 +583,11 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
        s = p->rpath_orig;
        while ((t=strchr(s, '$'))) {
                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
@@ -606,10 +597,18 @@ static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
                 * 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 {
@@ -645,6 +644,8 @@ static void decode_dyn(struct dso *p)
                p->hashtab = (void *)(p->base + dyn[DT_HASH]);
        if (dyn[0]&(1<<DT_RPATH))
                p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
+       if (dyn[0]&(1<<DT_RUNPATH))
+               p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
        if (search_vec(p->dynv, dyn, DT_GNU_HASH))
                p->ghashtab = (void *)(p->base + *dyn);
        if (search_vec(p->dynv, dyn, DT_VERSYM))
@@ -685,22 +686,22 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
                                        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;
@@ -716,20 +717,23 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
                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 = "";
@@ -881,21 +885,40 @@ static void make_global(struct dso *p)
        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->rel_early_relative) {
+               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};
        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);
@@ -1007,7 +1030,7 @@ void *__copy_tls(unsigned char *mem)
        dtv[0] = (void *)tls_cnt;
        if (!tls_cnt) {
                td = (void *)(dtv+1);
-               td->dtv = dtv;
+               td->dtv = td->dtv_copy = dtv;
                return td;
        }
 
@@ -1033,7 +1056,7 @@ void *__copy_tls(unsigned char *mem)
                memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
        }
 #endif
-       td->dtv = dtv;
+       td->dtv = td->dtv_copy = dtv;
        return td;
 }
 
@@ -1063,7 +1086,7 @@ void *__tls_get_new(size_t *v)
                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 */
@@ -1092,19 +1115,52 @@ static void update_tls_size()
        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)
+{
+       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;
+       ldso.rel_early_relative = 1;
+       kernel_mapped_dso(&ldso);
+       decode_dyn(&ldso);
+
+       head = &ldso;
+       reloc_all(&ldso);
+
+       ldso.relocated = 0;
+       ldso.rel_update_got = 1;
+}
+
+/* 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] = {0}, *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;
 
@@ -1126,61 +1182,44 @@ void *__dynlink(int argc, char **argv)
                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;
-       }
-
-       /* 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;
@@ -1199,8 +1238,8 @@ void *__dynlink(int argc, char **argv)
                        } 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"
@@ -1216,96 +1255,88 @@ void *__dynlink(int argc, char **argv)
                        _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) {
@@ -1329,14 +1360,13 @@ void *__dynlink(int argc, char **argv)
 
        /* 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.head = head;
-       debug.base = lib->base;
+       debug.base = ldso.base;
        debug.state = 0;
        _dl_debug_state();
 
@@ -1345,7 +1375,8 @@ void *__dynlink(int argc, char **argv)
        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)
@@ -1383,6 +1414,8 @@ 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);
                }
@@ -1609,6 +1642,8 @@ void *dlopen(const char *file, int mode)
 }
 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
 {
+       errflag = 1;
+       snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
        return 0;
 }
 int __dladdr (const void *addr, Dl_info *info)