fix missing synchronization in calls from dynamic linker to global ctors

[musl] / src / ldso / dynlink.c

diff --git a/src/ldso/dynlink.c b/src/ldso/dynlink.c
index e73806c..ac4b669 100644 (file)
--- a/src/ldso/dynlink.c
+++ b/src/ldso/dynlink.c
@@ -99,6 +99,7 @@ static int ssp_used;
 static int runtime;
 static int ldd_mode;
 static int ldso_fail;
+static int noload;
 static jmp_buf rtld_fail;
 static pthread_rwlock_t lock;
 static struct debug debug;
@@ -402,16 +403,16 @@ error:
        return 0;
 }
 
-static int path_open(const char *name, const char *search, char *buf, size_t buf_size)
+static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 {
-       const char *s=search, *z;
-       int l, fd;
+       size_t l;
+       int fd;
        for (;;) {
-               while (*s==':') s++;
-               if (!*s) return -1;
-               z = strchr(s, ':');
-               l = z ? z-s : strlen(s);
-               snprintf(buf, buf_size, "%.*s/%s", l, s, name);
+               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;
                s += l;
        }
@@ -434,7 +435,6 @@ static struct dso *load_library(const char *name)
        char buf[2*NAME_MAX+2];
        const char *pathname;
        unsigned char *map;
-       size_t map_len;
        struct dso *p, temp_dso = {0};
        int fd;
        struct stat st;
@@ -478,10 +478,9 @@ static struct dso *load_library(const char *name)
                        if (!sys_path) {
                                FILE *f = fopen(ETC_LDSO_PATH, "rbe");
                                if (f) {
-                                       if (getline(&sys_path, (size_t[1]){0}, f) > 0) {
-                                               size_t l = strlen(sys_path);
-                                               if (l && sys_path[l-1]=='\n')
-                                                       sys_path[l-1] = 0;
+                                       if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
+                                               free(sys_path);
+                                               sys_path = "";
                                        }
                                        fclose(f);
                                }
@@ -508,7 +507,7 @@ static struct dso *load_library(const char *name)
                        return p;
                }
        }
-       map = map_library(fd, &temp_dso);
+       map = noload ? 0 : map_library(fd, &temp_dso);
        close(fd);
        if (!map) return 0;
 
@@ -527,7 +526,7 @@ static struct dso *load_library(const char *name)
        }
        p = calloc(1, alloc_size);
        if (!p) {
-               munmap(map, map_len);
+               munmap(map, temp_dso.map_len);
                return 0;
        }
        memcpy(p, &temp_dso, sizeof temp_dso);
@@ -541,8 +540,8 @@ static struct dso *load_library(const char *name)
        if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
        if (p->tls_image) {
                if (runtime && !__pthread_self_init()) {
+                       munmap(map, p->map_len);
                        free(p);
-                       munmap(map, map_len);
                        return 0;
                }
                p->tls_id = ++tls_cnt;
@@ -693,6 +692,10 @@ static void do_init_fini(struct dso *p)
                }
                if (dyn[0] & (1<<DT_INIT))
                        ((void (*)(void))(p->base + dyn[DT_INIT]))();
+               if (!need_locking && libc.threads_minus_1) {
+                       need_locking = 1;
+                       pthread_mutex_lock(&init_fini_lock);
+               }
        }
        if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 }
@@ -740,13 +743,13 @@ void *__copy_tls(unsigned char *mem)
 void *__tls_get_addr(size_t *v)
 {
        pthread_t self = __pthread_self();
-       if (self->dtv && v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
+       if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
                return (char *)self->dtv[v[0]]+v[1];
 
        /* Block signals to make accessing new TLS async-signal-safe */
        sigset_t set;
        pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
-       if (self->dtv && v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
+       if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
                pthread_sigmask(SIG_SETMASK, &set, 0);
                return (char *)self->dtv[v[0]]+v[1];
        }
@@ -759,10 +762,10 @@ void *__tls_get_addr(size_t *v)
        for (p=head; p->tls_id != v[0]; p=p->next);
 
        /* Get new DTV space from new DSO if needed */
-       if (!self->dtv || v[0] > (size_t)self->dtv[0]) {
+       if (v[0] > (size_t)self->dtv[0]) {
                void **newdtv = p->new_dtv +
                        (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
-               if (self->dtv) memcpy(newdtv, self->dtv,
+               memcpy(newdtv, self->dtv,
                        ((size_t)self->dtv[0]+1) * sizeof(void *));
                newdtv[0] = (void *)v[0];
                self->dtv = newdtv;
@@ -1027,6 +1030,7 @@ void *dlopen(const char *file, int mode)
        orig_tls_offset = tls_offset;
        orig_tls_align = tls_align;
        orig_tail = tail;
+       noload = mode & RTLD_NOLOAD;
 
        if (setjmp(rtld_fail)) {
                /* Clean up anything new that was (partially) loaded */
@@ -1050,8 +1054,10 @@ void *dlopen(const char *file, int mode)
        } else p = load_library(file);
 
        if (!p) {
-               snprintf(errbuf, sizeof errbuf,
-                       "Error loading shared library %s: %m", file);
+               snprintf(errbuf, sizeof errbuf, noload ?
+                       "Library %s is not already loaded" :
+                       "Error loading shared library %s: %m",
+                       file);
                errflag = 1;
                goto end;
        }