Commit 639886b7 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Heiko Carstens
Browse files

s390/early: fix sclp_early_sccb variable lifetime 



Commit ada1da31 ("s390/sclp: sort out physical vs
virtual pointers usage") fixed the notion of virtual
address for sclp_early_sccb pointer. However, it did
not take into account that kasan_early_init() can also
output messages and sclp_early_sccb should be adjusted
by the time kasan_early_init() is called.

Currently it is not a problem, since virtual and physical
addresses on s390 are the same. Nevertheless, should they
ever differ, this would cause an invalid pointer access.

Fixes: ada1da31 ("s390/sclp: sort out physical vs virtual pointers usage")
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 9c3205b2

arch/s390/kernel/early.c

+0 −1
Original line number Diff line number Diff line
@@ -288,7 +288,6 @@ static void __init sort_amode31_extable(void) 


void __init startup_init(void)

{

	sclp_early_adjust_va();

	reset_tod_clock();

	check_image_bootable();

	time_early_init();

arch/s390/kernel/head64.S

+1 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ ENTRY(startup_continue) 
	larl	%r14,init_task

	stg	%r14,__LC_CURRENT

	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD-__PT_SIZE

	brasl	%r14,sclp_early_adjust_va	# allow sclp_early_printk

#ifdef CONFIG_KASAN

	brasl	%r14,kasan_early_init

#endif

drivers/s390/char/sclp_early.c

+1 −1
Original line number Diff line number Diff line
@@ -163,7 +163,7 @@ static void __init sclp_early_console_detect(struct init_sccb *sccb) 
		sclp.has_linemode = 1;

}



void __init sclp_early_adjust_va(void)

void __init __no_sanitize_address sclp_early_adjust_va(void)

{

	sclp_early_sccb = __va((unsigned long)sclp_early_sccb);

}