move the dynamic linker's jmp_buf from static to automatic storage
authorRich Felker <dalias@aerifal.cx>
Wed, 24 Jul 2013 06:38:05 +0000 (02:38 -0400)
committerRich Felker <dalias@aerifal.cx>
Wed, 24 Jul 2013 06:38:05 +0000 (02:38 -0400)
this more than compensates for the size increase of jmp_buf, and
greatly reduces bss/data size on archs with huge jmp_buf.

src/ldso/dynlink.c

index b5e4b72..98a18bb 100644 (file)
@@ -101,7 +101,7 @@ static int runtime;
 static int ldd_mode;
 static int ldso_fail;
 static int noload;
-static jmp_buf rtld_fail;
+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);
@@ -255,7 +255,7 @@ static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stri
                                snprintf(errbuf, sizeof errbuf,
                                        "Error relocating %s: %s: symbol not found",
                                        dso->name, name);
-                               if (runtime) longjmp(rtld_fail, 1);
+                               if (runtime) longjmp(*rtld_fail, 1);
                                dprintf(2, "%s\n", errbuf);
                                ldso_fail = 1;
                                continue;
@@ -613,14 +613,14 @@ static void load_deps(struct dso *p)
                                snprintf(errbuf, sizeof errbuf,
                                        "Error loading shared library %s: %m (needed by %s)",
                                        p->strings + p->dynv[i+1], p->name);
-                               if (runtime) longjmp(rtld_fail, 1);
+                               if (runtime) longjmp(*rtld_fail, 1);
                                dprintf(2, "%s\n", errbuf);
                                ldso_fail = 1;
                                continue;
                        }
                        if (runtime) {
                                tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
-                               if (!tmp) longjmp(rtld_fail, 1);
+                               if (!tmp) longjmp(*rtld_fail, 1);
                                tmp[ndeps++] = dep;
                                tmp[ndeps] = 0;
                                *deps = tmp;
@@ -1057,6 +1057,7 @@ void *dlopen(const char *file, int mode)
        size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
        size_t i;
        int cs;
+       jmp_buf jb;
 
        if (!file) return head;
 
@@ -1071,7 +1072,8 @@ void *dlopen(const char *file, int mode)
        orig_tail = tail;
        noload = mode & RTLD_NOLOAD;
 
-       if (setjmp(rtld_fail)) {
+       rtld_fail = &jb;
+       if (setjmp(*rtld_fail)) {
                /* Clean up anything new that was (partially) loaded */
                if (p && p->deps) for (i=0; p->deps[i]; i++)
                        if (p->deps[i]->global < 0)