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Commit 627c9b62 authored by Vasily Gorbik's avatar Vasily Gorbik Committed by Martin Schwidefsky
Browse files

s390/boot: block uncompressed vmlinux booting attempts 



Since the plain vmlinux ELF file no longer carries all necessary parts
for starting up (like the entry point and decompressor), add a check
which would block boot process and encourage users to use bzImage or
arch/s390/boot/compressed/vmlinux instead.

The check relies on s390 linux entry point ABI definition, which is only
present in bzImage and arch/s390/boot/compressed/vmlinux.

Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
Tested-by: default avatarGuenter Roeck <linux@roeck-us.net>
Acked-by: default avatarCornelia Huck <cohuck@redhat.com>
Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 9acdb3bb

arch/s390/boot/head.S

+2 −2
Original line number Diff line number Diff line
@@ -272,14 +272,14 @@ iplstart: 
	.org	0x10000

ENTRY(startup)

	j	.Lep_startup_normal

	.org	0x10008

	.org	EP_OFFSET

#

# This is a list of s390 kernel entry points. At address 0x1000f the number of

# valid entry points is stored.

#

# IMPORTANT: Do not change this table, it is s390 kernel ABI!

#

	.ascii	"S390EP"

	.ascii	EP_STRING

	.byte	0x00,0x01

#

# kdump startup-code at 0x10010, running in 64 bit absolute addressing mode

arch/s390/include/asm/setup.h

+2 −1
Original line number Diff line number Diff line
@@ -9,7 +9,8 @@ 
#include <linux/const.h>

#include <uapi/asm/setup.h>





#define EP_OFFSET		0x10008

#define EP_STRING		"S390EP"

#define PARMAREA		0x10400

#define PARMAREA_END		0x11000

arch/s390/kernel/early.c

+12 −0
Original line number Diff line number Diff line
@@ -331,8 +331,20 @@ static void __init setup_boot_command_line(void) 
	append_to_cmdline(append_ipl_scpdata);

}



static void __init check_image_bootable(void)

{

	if (!memcmp(EP_STRING, (void *)EP_OFFSET, strlen(EP_STRING)))

		return;



	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");

	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");

	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");

	disabled_wait(0xbadb007);

}



void __init startup_init(void)

{

	check_image_bootable();

	time_early_init();

	init_kernel_storage_key();

	lockdep_off();