X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ldso%2Fdynlink.c;h=aaadcce07ac7eebb629b03a3a5cf8da53512f5d7;hb=cfdfd5ea3ce14c6abf7fb22a531f3d99518b5a1b;hp=a124e70449df987b2bf491275a27740a4c2c1051;hpb=f2435263d7366a81b734c8a69877f1359083ce8c;p=musl

diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index a124e704..aaadcce0 100644
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -1,6 +1,5 @@
 #define _GNU_SOURCE
 #define SYSCALL_NO_TLS 1
-#include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <stddef.h>
@@ -21,9 +20,14 @@
 #include <semaphore.h>
 #include <sys/membarrier.h>
 #include "pthread_impl.h"
+#include "fork_impl.h"
 #include "libc.h"
 #include "dynlink.h"
-#include "malloc_impl.h"
+
+#define malloc __libc_malloc
+#define calloc __libc_calloc
+#define realloc __libc_realloc
+#define free __libc_free
 
 static void error(const char *, ...);
 
@@ -79,7 +83,7 @@ struct dso {
 	struct dso **deps, *needed_by;
 	size_t ndeps_direct;
 	size_t next_dep;
-	int ctor_visitor;
+	pthread_t ctor_visitor;
 	char *rpath_orig, *rpath;
 	struct tls_module tls;
 	size_t tls_id;
@@ -107,6 +111,8 @@ struct symdef {
 	struct dso *dso;
 };
 
+typedef void (*stage3_func)(size_t *, size_t *);
+
 static struct builtin_tls {
 	char c;
 	struct pthread pt;
@@ -183,8 +189,14 @@ static void *laddr_pg(const struct dso *p, size_t v)
 	}
 	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 })
+static void (*fdbarrier(void *p))()
+{
+	void (*fd)();
+	__asm__("" : "=r"(fd) : "0"(p));
+	return fd;
+}
+#define fpaddr(p, v) fdbarrier((&(struct funcdesc){ \
+	laddr(p, v), (p)->got }))
 #else
 #define laddr(p, v) (void *)((p)->base + (v))
 #define laddr_pg(p, v) laddr(p, v)
@@ -407,8 +419,6 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
 		}
 
 		switch(type) {
-		case REL_NONE:
-			break;
 		case REL_OFFSET:
 			addend -= (size_t)reloc_addr;
 		case REL_SYMBOLIC:
@@ -551,10 +561,25 @@ static void reclaim_gaps(struct dso *dso)
 	}
 }
 
+static ssize_t read_loop(int fd, void *p, size_t n)
+{
+	for (size_t i=0; i<n; ) {
+		ssize_t l = read(fd, (char *)p+i, n-i);
+		if (l<0) {
+			if (errno==EINTR) continue;
+			else return -1;
+		}
+		if (l==0) return i;
+		i += l;
+	}
+	return n;
+}
+
 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 {
 	static int no_map_fixed;
 	char *q;
+	if (!n) return p;
 	if (!no_map_fixed) {
 		q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 		if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
@@ -1055,13 +1080,17 @@ static struct dso *load_library(const char *name, struct dso *needed_by)
 				snprintf(etc_ldso_path, sizeof etc_ldso_path,
 					"%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 					(int)prefix_len, prefix);
-				FILE *f = fopen(etc_ldso_path, "rbe");
-				if (f) {
-					if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
+				fd = open(etc_ldso_path, O_RDONLY|O_CLOEXEC);
+				if (fd>=0) {
+					size_t n = 0;
+					if (!fstat(fd, &st)) n = st.st_size;
+					if ((sys_path = malloc(n+1)))
+						sys_path[n] = 0;
+					if (!sys_path || read_loop(fd, sys_path, n)<0) {
 						free(sys_path);
 						sys_path = "";
 					}
-					fclose(f);
+					close(fd);
 				} else if (errno != ENOENT) {
 					sys_path = "";
 				}
@@ -1373,7 +1402,7 @@ void __libc_exit_fini()
 {
 	struct dso *p;
 	size_t dyn[DYN_CNT];
-	int self = __pthread_self()->tid;
+	pthread_t self = __pthread_self();
 
 	/* Take both locks before setting shutting_down, so that
 	 * either lock is sufficient to read its value. The lock
@@ -1399,6 +1428,17 @@ void __libc_exit_fini()
 	}
 }
 
+void __ldso_atfork(int who)
+{
+	if (who<0) {
+		pthread_rwlock_wrlock(&lock);
+		pthread_mutex_lock(&init_fini_lock);
+	} else {
+		pthread_mutex_unlock(&init_fini_lock);
+		pthread_rwlock_unlock(&lock);
+	}
+}
+
 static struct dso **queue_ctors(struct dso *dso)
 {
 	size_t cnt, qpos, spos, i;
@@ -1457,6 +1497,13 @@ static struct dso **queue_ctors(struct dso *dso)
 	}
 	queue[qpos] = 0;
 	for (i=0; i<qpos; i++) queue[i]->mark = 0;
+	for (i=0; i<qpos; i++)
+		if (queue[i]->ctor_visitor && queue[i]->ctor_visitor->tid < 0) {
+			error("State of %s is inconsistent due to multithreaded fork\n",
+				queue[i]->name);
+			free(queue);
+			if (runtime) longjmp(*rtld_fail, 1);
+		}
 
 	return queue;
 }
@@ -1465,7 +1512,7 @@ static void do_init_fini(struct dso **queue)
 {
 	struct dso *p;
 	size_t dyn[DYN_CNT], i;
-	int self = __pthread_self()->tid;
+	pthread_t self = __pthread_self();
 
 	pthread_mutex_lock(&init_fini_lock);
 	for (i=0; (p=queue[i]); i++) {
@@ -1574,7 +1621,7 @@ static void install_new_tls(void)
 
 	/* Install new dtv for each thread. */
 	for (j=0, td=self; !j || td!=self; j++, td=td->next) {
-		td->dtv = td->dtv_copy = newdtv[j];
+		td->dtv = newdtv[j];
 	}
 
 	__tl_unlock();
@@ -1594,13 +1641,14 @@ static void install_new_tls(void)
 
 hidden void __dls2(unsigned char *base, size_t *sp)
 {
+	size_t *auxv;
+	for (auxv=sp+1+*sp+1; *auxv; auxv++);
+	auxv++;
 	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++;
+			size_t aux[AUX_CNT];
 			decode_vec(auxv, aux, AUX_CNT);
 			if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
 			else ldso.base = (void *)(aux[AT_PHDR] & -4096);
@@ -1646,8 +1694,8 @@ hidden void __dls2(unsigned char *base, size_t *sp)
 	 * 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);
+	if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp, auxv);
+	else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp, auxv);
 }
 
 /* Stage 2b sets up a valid thread pointer, which requires relocations
@@ -1656,11 +1704,13 @@ hidden void __dls2(unsigned char *base, size_t *sp)
  * so that loads of the thread pointer and &errno can be pure/const and
  * thereby hoistable. */
 
-void __dls2b(size_t *sp)
+void __dls2b(size_t *sp, size_t *auxv)
 {
 	/* 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. */
+	search_vec(auxv, &__hwcap, AT_HWCAP);
+	libc.auxv = auxv;
 	libc.tls_size = sizeof builtin_tls;
 	libc.tls_align = tls_align;
 	if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
@@ -1668,8 +1718,8 @@ void __dls2b(size_t *sp)
 	}
 
 	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);
+	if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp, auxv);
+	else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp, auxv);
 }
 
 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
@@ -1677,10 +1727,10 @@ void __dls2b(size_t *sp)
  * process dependencies and relocations for the main application and
  * transfer control to its entry point. */
 
-void __dls3(size_t *sp)
+void __dls3(size_t *sp, size_t *auxv)
 {
 	static struct dso app, vdso;
-	size_t aux[AUX_CNT], *auxv;
+	size_t aux[AUX_CNT];
 	size_t i;
 	char *env_preload=0;
 	char *replace_argv0=0;
@@ -1693,10 +1743,7 @@ void __dls3(size_t *sp)
 	/* 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];
 	search_vec(auxv, &__sysinfo, AT_SYSINFO);
 	__pthread_self()->sysinfo = __sysinfo;
 	libc.page_size = aux[AT_PAGESZ];
@@ -1889,13 +1936,25 @@ void __dls3(size_t *sp)
 	/* Initial TLS must also be allocated before final relocations
 	 * might result in calloc being a call to application code. */
 	update_tls_size();
+	void *initial_tls = builtin_tls;
 	if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
-		void *initial_tls = calloc(libc.tls_size, 1);
+		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);
 		}
+	}
+	static_tls_cnt = tls_cnt;
+
+	/* The main program must be relocated LAST since it may contain
+	 * copy relocations which depend on libraries' relocations. */
+	reloc_all(app.next);
+	reloc_all(&app);
+
+	/* Actual copying to new TLS needs to happen after relocations,
+	 * since the TLS images might have contained relocated addresses. */
+	if (initial_tls != builtin_tls) {
 		if (__init_tp(__copy_tls(initial_tls)) < 0) {
 			a_crash();
 		}
@@ -1909,12 +1968,6 @@ void __dls3(size_t *sp)
 		if (__copy_tls((void*)builtin_tls) != self) a_crash();
 		libc.tls_size = tmp_tls_size;
 	}
-	static_tls_cnt = tls_cnt;
-
-	/* 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);
 
 	if (ldso_fail) _exit(127);
 	if (ldd_mode) _exit(0);
@@ -1924,6 +1977,8 @@ void __dls3(size_t *sp)
 	 * possibility of incomplete replacement. */
 	if (find_sym(head, "malloc", 1).dso != &ldso)
 		__malloc_replaced = 1;
+	if (find_sym(head, "aligned_alloc", 1).dso != &ldso)
+		__aligned_alloc_replaced = 1;
 
 	/* Switch to runtime mode: any further failures in the dynamic
 	 * linker are a reportable failure rather than a fatal startup
@@ -1934,7 +1989,7 @@ void __dls3(size_t *sp)
 	debug.bp = dl_debug_state;
 	debug.head = head;
 	debug.base = ldso.base;
-	debug.state = 0;
+	debug.state = RT_CONSISTENT;
 	_dl_debug_state();
 
 	if (replace_argv0) argv[0] = replace_argv0;
@@ -1983,6 +2038,9 @@ void *dlopen(const char *file, int mode)
 	pthread_rwlock_wrlock(&lock);
 	__inhibit_ptc();
 
+	debug.state = RT_ADD;
+	_dl_debug_state();
+
 	p = 0;
 	if (shutting_down) {
 		error("Cannot dlopen while program is exiting.");
@@ -2042,8 +2100,9 @@ void *dlopen(const char *file, int mode)
 	load_deps(p);
 	extend_bfs_deps(p);
 	pthread_mutex_lock(&init_fini_lock);
-	if (!p->constructed) ctor_queue = queue_ctors(p);
+	int constructed = p->constructed;
 	pthread_mutex_unlock(&init_fini_lock);
+	if (!constructed) ctor_queue = queue_ctors(p);
 	if (!p->relocated && (mode & RTLD_LAZY)) {
 		prepare_lazy(p);
 		for (i=0; p->deps[i]; i++)
@@ -2075,9 +2134,10 @@ void *dlopen(const char *file, int mode)
 	update_tls_size();
 	if (tls_cnt != orig_tls_cnt)
 		install_new_tls();
-	_dl_debug_state();
 	orig_tail = tail;
 end:
+	debug.state = RT_CONSISTENT;
+	_dl_debug_state();
 	__release_ptc();
 	if (p) gencnt++;
 	pthread_rwlock_unlock(&lock);
@@ -2231,6 +2291,33 @@ hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra
 	return res;
 }
 
+hidden void *__dlsym_redir_time64(void *restrict p, const char *restrict s, void *restrict ra)
+{
+#if _REDIR_TIME64
+	const char *suffix, *suffix2 = "";
+	char redir[36];
+
+	/* Map the symbol name to a time64 version of itself according to the
+	 * pattern used for naming the redirected time64 symbols. */
+	size_t l = strnlen(s, sizeof redir);
+	if (l<4 || l==sizeof redir) goto no_redir;
+	if (s[l-2]=='_' && s[l-1]=='r') {
+		l -= 2;
+		suffix2 = s+l;
+	}
+	if (l<4) goto no_redir;
+	if (!strcmp(s+l-4, "time")) suffix = "64";
+	else suffix = "_time64";
+
+	/* Use the presence of the remapped symbol name in libc to determine
+	 * whether it's one that requires time64 redirection; replace if so. */
+	snprintf(redir, sizeof redir, "__%.*s%s%s", (int)l, s, suffix, suffix2);
+	if (find_sym(&ldso, redir, 1).sym) s = redir;
+no_redir:
+#endif
+	return __dlsym(p, s, ra);
+}
+
 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
 {
 	struct dso *current;