This is normally done by the generic entry code, but the
kernel_stack_overflow() flow bypasses it.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 arch/s390/kernel/traps.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 1d2aa448d103..dd7362806dbb 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -27,6 +27,7 @@
 #include <linux/uaccess.h>
 #include <linux/cpu.h>
 #include <linux/entry-common.h>
+#include <linux/kmsan.h>
 #include <asm/asm-extable.h>
 #include <asm/fpu/api.h>
 #include <asm/vtime.h>
@@ -260,6 +261,7 @@ static void monitor_event_exception(struct pt_regs *regs)
 
 void kernel_stack_overflow(struct pt_regs *regs)
 {
+	kmsan_unpoison_entry_regs(regs);
 	bust_spinlocks(1);
 	printk("Kernel stack overflow.\n");
 	show_regs(regs);
-- 
2.41.0

On Wed, Nov 15, 2023 at 9:35 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote:
>
> This is normally done by the generic entry code, but the
> kernel_stack_overflow() flow bypasses it.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>

> ---
>  arch/s390/kernel/traps.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
> index 1d2aa448d103..dd7362806dbb 100644
> --- a/arch/s390/kernel/traps.c
> +++ b/arch/s390/kernel/traps.c
> @@ -27,6 +27,7 @@
>  #include <linux/uaccess.h>
>  #include <linux/cpu.h>
>  #include <linux/entry-common.h>
> +#include <linux/kmsan.h>
>  #include <asm/asm-extable.h>
>  #include <asm/fpu/api.h>
>  #include <asm/vtime.h>
> @@ -260,6 +261,7 @@ static void monitor_event_exception(struct pt_regs *regs)
>
>  void kernel_stack_overflow(struct pt_regs *regs)
>  {
> +       kmsan_unpoison_entry_regs(regs);

I suggest adding a comment here.