From dccccd332d028f57358a8b64ca88e691fc8be5b7 Mon Sep 17 00:00:00 2001
From: Vasily Gorbik <gor@linux.ibm.com>
Date: Fri, 13 Apr 2018 18:22:14 +0200
Subject: [PATCH] s390/sclp: avoid potential usage of uninitialized value

sclp_early_printk could be used before .bss section is zeroed
(i.e. from als.c during the decompressor phase), therefore values used
by sclp_early_printk should be located in the .data section.

Another reason for that is to avoid potential initrd corruption, if some
code in future would use sclp_early_printk before initrd is moved from
possibly overlapping with .bss section region to a safe location.

Fixes: 0b0d1173d8ae ("s390/sclp: 32 bit event mask compatibility mode")
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
 drivers/s390/char/sclp_early_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c
index 5f8d9ea69ebd..eceba3858cef 100644
--- a/drivers/s390/char/sclp_early_core.c
+++ b/drivers/s390/char/sclp_early_core.c
@@ -18,7 +18,7 @@ int sclp_init_state __section(.data) = sclp_init_state_uninitialized;
  * Used to keep track of the size of the event masks. Qemu until version 2.11
  * only supports 4 and needs a workaround.
  */
-bool sclp_mask_compat_mode;
+bool sclp_mask_compat_mode __section(.data);
 
 void sclp_early_wait_irq(void)
 {
-- 
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