on failed aio submission, set aiocb error and return value
[musl] / ldso / dynlink.c
index 31c5060..ec921df 100644 (file)
@@ -20,6 +20,7 @@
 #include "pthread_impl.h"
 #include "libc.h"
 #include "dynlink.h"
+#include "malloc_impl.h"
 
 static void error(const char *, ...);
 
@@ -71,7 +72,7 @@ struct dso {
        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;
@@ -95,13 +96,6 @@ struct symdef {
        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;
@@ -133,14 +127,11 @@ static struct dso *const nodeps_dummy;
 
 struct debug *_dl_debug_addr = &debug;
 
-__attribute__((__visibility__("hidden")))
-extern int __malloc_replaced;
+extern hidden int __malloc_replaced;
 
-__attribute__((__visibility__("hidden")))
-void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
+hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 
-__attribute__((__visibility__("hidden")))
-extern void (*const __init_array_end)(void), (*const __fini_array_end)(void);
+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);
@@ -306,9 +297,6 @@ static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
        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;
@@ -385,6 +373,14 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                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;
@@ -438,7 +434,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 #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(
@@ -449,7 +445,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                                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 {
@@ -462,6 +458,13 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                                        + 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",
@@ -499,7 +502,6 @@ static void redo_lazy_relocs()
 
 static void reclaim(struct dso *dso, size_t start, size_t end)
 {
-       void __malloc_donate(char *, char *);
        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;
        if (start >= end) return;
@@ -614,6 +616,12 @@ static void *map_library(int fd, struct dso *dso)
                } 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++;
@@ -1243,6 +1251,12 @@ static void kernel_mapped_dso(struct dso *p)
                } 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)
@@ -1324,17 +1338,16 @@ void __init_tls(size_t *auxv)
 {
 }
 
-__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
@@ -1344,15 +1357,12 @@ void *__tls_get_new(tls_mod_off_t *v)
        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;
@@ -1362,7 +1372,7 @@ void *__tls_get_new(tls_mod_off_t *v)
                        * 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;
        }
@@ -1393,15 +1403,15 @@ 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. */
 
-__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);
@@ -1443,9 +1453,31 @@ void __dls2(unsigned char *base, size_t *sp)
 
        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);
@@ -1480,15 +1512,6 @@ _Noreturn void __dls3(size_t *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");
@@ -1561,7 +1584,7 @@ _Noreturn void __dls3(size_t *sp)
                                "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);
                }
@@ -1852,8 +1875,7 @@ end:
        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;
@@ -1878,15 +1900,22 @@ static void *addr2dso(size_t a)
                                        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;
@@ -1903,7 +1932,7 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
                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);
@@ -1918,7 +1947,7 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
                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))
@@ -1932,7 +1961,7 @@ static void *do_dlsym(struct dso *p, const char *s, void *ra)
                        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))
@@ -1951,6 +1980,7 @@ int dladdr(const void *addr_arg, Dl_info *info)
        uint32_t nsym;
        char *strings;
        size_t best = 0;
+       size_t besterr = -1;
 
        pthread_rwlock_rdlock(&lock);
        p = addr2dso(addr);
@@ -1968,6 +1998,7 @@ int dladdr(const void *addr_arg, Dl_info *info)
                if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
                        best = (size_t)(p->funcdescs + idx);
                        bestsym = sym + idx;
+                       besterr = 0;
                }
        }
 
@@ -1976,20 +2007,21 @@ int dladdr(const void *addr_arg, Dl_info *info)
                 && (1<<(sym->st_info&0xf) & OK_TYPES)
                 && (1<<(sym->st_info>>4) & OK_BINDS)) {
                        size_t symaddr = (size_t)laddr(p, sym->st_value);
-                       if (symaddr > addr || symaddr < best)
+                       if (symaddr > addr || symaddr <= best)
                                continue;
-                       if (sym->st_size && symaddr+sym->st_size <= addr) {
-                               best = 0;
-                               bestsym = 0;
-                               continue;
-                       }
                        best = symaddr;
                        bestsym = sym;
+                       besterr = addr - symaddr;
                        if (addr == symaddr)
                                break;
                }
        }
 
+       if (bestsym && besterr > bestsym->st_size-1) {
+               best = 0;
+               bestsym = 0;
+       }
+
        info->dli_fname = p->name;
        info->dli_fbase = p->map;
 
@@ -2007,8 +2039,7 @@ int dladdr(const void *addr_arg, Dl_info *info)
        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);
@@ -2043,9 +2074,6 @@ int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void
        return ret;
 }
 
-__attribute__((__visibility__("hidden")))
-void __dl_vseterr(const char *, va_list);
-
 static void error(const char *fmt, ...)
 {
        va_list ap;