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Commit 0983a88b authored by Jeff Dike's avatar Jeff Dike Committed by Linus Torvalds
Browse files

uml: install panic notifier earlier 



It turns out that if there's a panic early enough, UML will just sit there in
the LED-blinking loop because the panic notifier hadn't been installed yet.

This patch installs it earlier.

It also fixes the problem which exposed the hang, namely that if you give UML
a zero-sized initrd, it will ask alloc_bootmem for zero bytes, and that will
cause the panic.

While I was in initrd.c, I gave it a style makeover.

Prompted by checkpatch, I moved a couple extern declarations of uml_exitcode
to kern_util.h.

Signed-off-by: default avatarJeff Dike <jdike@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8efa3c9d

arch/um/include/kern_util.h

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 
#include "sysdep/ptrace.h"

#include "sysdep/faultinfo.h"



extern int uml_exitcode;



extern int ncpus;

extern int kmalloc_ok;

extern int nsyscalls;

arch/um/kernel/initrd.c

+20 −9
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)

 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)

 * Licensed under the GPL

 */
@@ -27,6 +27,15 @@ static int __init read_initrd(void) 
	if (err)

		return 0;



	/*

	 * This is necessary because alloc_bootmem craps out if you

	 * ask for no memory.

	 */

	if (size == 0) {

		printk(KERN_ERR "\"%\" is a zero-size initrd\n");

		return 0;

	}



	area = alloc_bootmem(size);

	if (area == NULL)

		return 0;
@@ -59,12 +68,14 @@ int load_initrd(char *filename, void *buf, int size) 


	fd = os_open_file(filename, of_read(OPENFLAGS()), 0);

	if (fd < 0) {

		printk("Opening '%s' failed - err = %d\n", filename, -fd);

		printk(KERN_ERR "Opening '%s' failed - err = %d\n", filename,

		       -fd);

		return -1;

	}

	n = os_read_file(fd, buf, size);

	if (n != size) {

		printk("Read of %d bytes from '%s' failed, err = %d\n", size,

		printk(KERN_ERR "Read of %d bytes from '%s' failed, "

		       "err = %d\n", size,

		       filename, -n);

		return -1;

	}

arch/um/kernel/um_arch.c

+20 −21
Original line number Diff line number Diff line
@@ -223,6 +223,23 @@ static void __init uml_postsetup(void) 
	return;

}



static int panic_exit(struct notifier_block *self, unsigned long unused1,

		      void *unused2)

{

	bust_spinlocks(1);

	show_regs(&(current->thread.regs));

	bust_spinlocks(0);

	uml_exitcode = 1;

	os_dump_core();

	return 0;

}



static struct notifier_block panic_exit_notifier = {

	.notifier_call 		= panic_exit,

	.next 			= NULL,

	.priority 		= 0

};



/* Set during early boot */

unsigned long brk_start;

unsigned long end_iomem;
@@ -327,6 +344,9 @@ int __init linux_main(int argc, char **argv) 
		printf("Kernel virtual memory size shrunk to %lu bytes\n",

		       virtmem_size);



	atomic_notifier_chain_register(&panic_notifier_list,

				       &panic_exit_notifier);



	uml_postsetup();



	stack_protections((unsigned long) &init_thread_info);
@@ -335,29 +355,8 @@ int __init linux_main(int argc, char **argv) 
	return start_uml();

}



extern int uml_exitcode;



static int panic_exit(struct notifier_block *self, unsigned long unused1,

		      void *unused2)

{

	bust_spinlocks(1);

	show_regs(&(current->thread.regs));

	bust_spinlocks(0);

	uml_exitcode = 1;

	os_dump_core();

	return 0;

}



static struct notifier_block panic_exit_notifier = {

	.notifier_call 		= panic_exit,

	.next 			= NULL,

	.priority 		= 0

};



void __init setup_arch(char **cmdline_p)

{

	atomic_notifier_chain_register(&panic_notifier_list,

			&panic_exit_notifier);

	paging_init();

	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);

	*cmdline_p = command_line;

arch/um/os-Linux/main.c

+0 −2
Original line number Diff line number Diff line
@@ -111,8 +111,6 @@ static void setup_env_path(void) 
	}

}



extern int uml_exitcode;



extern void scan_elf_aux( char **envp);



int __init main(int argc, char **argv, char **envp)