um: Fix to call read_initrd after init_bootmem

Since read_initrd() invokes alloc_bootmem() for allocating
memory to load initrd image, it must be called after init_bootmem.

This makes read_initrd() called directly from setup_arch()
after init_bootmem() and mem_total_pages().

Cc: <stable@vger.kernel.org>
Fixes: b63236972e1 ("um: Setup physical memory in setup_arch()")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>

arch/um/kernel/initrd.c

@@ -14,7 +14,7 @@
 static char *initrd __initdata = NULL;
 static int load_initrd(char *filename, void *buf, int size);
 
-static int __init read_initrd(void)
+int __init read_initrd(void)
 {
 	void *area;
 	long long size;
@@ -46,8 +46,6 @@ static int __init read_initrd(void)
 	return 0;
 }
 
-__uml_postsetup(read_initrd);
-
 static int __init uml_initrd_setup(char *line, int *add)
 {
 	initrd = line;

arch/um/kernel/um_arch.c

@@ -338,11 +338,17 @@ int __init linux_main(int argc, char **argv)
 	return start_uml();
 }
 
+int __init __weak read_initrd(void)
+{
+	return 0;
+}
+
 void __init setup_arch(char **cmdline_p)
 {
 	stack_protections((unsigned long) &init_thread_info);
 	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 	mem_total_pages(physmem_size, iomem_size, highmem);
+	read_initrd();
 
 	paging_init();
 	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);