Commit ee5bfa64 authored by Vivek Goyal's avatar Vivek Goyal Committed by Andi Kleen
Browse files

[PATCH] generic: Break init() in two parts to avoid MODPOST warnings 



o init() is a non __init function in .text section but it calls many
  functions which are in .init.text section. Hence MODPOST generates lots
  of cross reference warnings on i386 if compiled with CONFIG_RELOCATABLE=y

WARNING: vmlinux - Section mismatch: reference to .init.text:smp_prepare_cpus from .text between 'init' (at offset 0xc0101049) and 'rest_init'
WARNING: vmlinux - Section mismatch: reference to .init.text:migration_init from .text between 'init' (at offset 0xc010104e) and 'rest_init'
WARNING: vmlinux - Section mismatch: reference to .init.text:spawn_ksoftirqd from .text between 'init' (at offset 0xc0101053) and 'rest_init'

o This patch breaks down init() in two parts. One part which can go
  in .init.text section and can be freed and other part which has to
  be non __init(init_post()). Now init() calls init_post() and init_post()
  does not call any functions present in .init sections. Hence getting
  rid of warnings.

Signed-off-by: default avatarVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent f8657e1b

init/main.c

+45 −36
Original line number Diff line number Diff line
@@ -727,7 +727,49 @@ static void run_init_process(char *init_filename) 
	kernel_execve(init_filename, argv_init, envp_init);

}



static int init(void * unused)

/* This is a non __init function. Force it to be noinline otherwise gcc

 * makes it inline to init() and it becomes part of init.text section

 */

static int noinline init_post(void)

{

	free_initmem();

	unlock_kernel();

	mark_rodata_ro();

	system_state = SYSTEM_RUNNING;

	numa_default_policy();



	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)

		printk(KERN_WARNING "Warning: unable to open an initial console.\n");



	(void) sys_dup(0);

	(void) sys_dup(0);



	if (ramdisk_execute_command) {

		run_init_process(ramdisk_execute_command);

		printk(KERN_WARNING "Failed to execute %s\n",

				ramdisk_execute_command);

	}



	/*

	 * We try each of these until one succeeds.

	 *

	 * The Bourne shell can be used instead of init if we are

	 * trying to recover a really broken machine.

	 */

	if (execute_command) {

		run_init_process(execute_command);

		printk(KERN_WARNING "Failed to execute %s.  Attempting "

					"defaults...\n", execute_command);

	}

	run_init_process("/sbin/init");

	run_init_process("/etc/init");

	run_init_process("/bin/init");

	run_init_process("/bin/sh");



	panic("No init found.  Try passing init= option to kernel.");

}



static int __init init(void * unused)

{

	lock_kernel();

	/*
@@ -775,39 +817,6 @@ static int init(void * unused) 
	 * we're essentially up and running. Get rid of the

	 * initmem segments and start the user-mode stuff..

	 */

	free_initmem();

	unlock_kernel();

	mark_rodata_ro();

	system_state = SYSTEM_RUNNING;

	numa_default_policy();



	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)

		printk(KERN_WARNING "Warning: unable to open an initial console.\n");



	(void) sys_dup(0);

	(void) sys_dup(0);



	if (ramdisk_execute_command) {

		run_init_process(ramdisk_execute_command);

		printk(KERN_WARNING "Failed to execute %s\n",

				ramdisk_execute_command);

	}



	/*

	 * We try each of these until one succeeds.

	 *

	 * The Bourne shell can be used instead of init if we are 

	 * trying to recover a really broken machine.

	 */

	if (execute_command) {

		run_init_process(execute_command);

		printk(KERN_WARNING "Failed to execute %s.  Attempting "

					"defaults...\n", execute_command);

	}

	run_init_process("/sbin/init");

	run_init_process("/etc/init");

	run_init_process("/bin/init");

	run_init_process("/bin/sh");



	panic("No init found.  Try passing init= option to kernel.");

	init_post();

	return 0;

}

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