From: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
[ Upstream commit 639886b71ddef085a0e7bb1f225b8ae3eda5c06f ]
Commit ada1da31ce34 ("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: ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage")
Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/s390/kernel/early.c | 1 -
arch/s390/kernel/head64.S | 1 +
drivers/s390/char/sclp_early.c | 2 +-
3 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index 6030fdd6997bc..9693c8630e73f 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -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();
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index d7b8b6ad574dc..3b3bf8329e6c1 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -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
diff --git a/drivers/s390/char/sclp_early.c b/drivers/s390/char/sclp_early.c
index c1c70a161c0e2..f480d6c7fd399 100644
--- a/drivers/s390/char/sclp_early.c
+++ b/drivers/s390/char/sclp_early.c
@@ -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);
}
--
2.39.2
