ignore ENOSYS error from mprotect in pthread_create and dynamic linker

this error simply indicated a system without memory protection (NOMMU)
and should not cause failure in the caller.

src/ldso/dynlink.c

@@ -536,7 +536,8 @@ static void *map_library(int fd, struct dso *dso)
 	}
 	for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 		if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
-			if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
+			if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
+			    && errno != ENOSYS)
 				goto error;
 			break;
 		}
@@ -927,7 +928,8 @@ static void reloc_all(struct dso *p)
 		do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 
 		if (head != &ldso && p->relro_start != p->relro_end &&
-		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
+		    mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
+		    && errno != ENOSYS) {
 			error("Error relocating %s: RELRO protection failed: %m",
 				p->name);
 			if (runtime) longjmp(*rtld_fail, 1);

src/thread/pthread_create.c

@@ -232,7 +232,8 @@ int __pthread_create(pthread_t *restrict res, const pthread_attr_t *restrict att
 		if (guard) {
 			map = __mmap(0, size, PROT_NONE, MAP_PRIVATE|MAP_ANON, -1, 0);
 			if (map == MAP_FAILED) goto fail;
-			if (__mprotect(map+guard, size-guard, PROT_READ|PROT_WRITE)) {
+			if (__mprotect(map+guard, size-guard, PROT_READ|PROT_WRITE)
+			    && errno != ENOSYS) {
 				__munmap(map, size);
 				goto fail;
 			}