From: Sven Schnelle <svens@xxxxxxxxxxxxx>
commit ca1f4d702d534387aa1f16379edb3b03cdb6ceda upstream.
The current irq entry code doesn't initialize pt_regs::flags. On exit to
user mode arch_do_signal_or_restart() tests whether PIF_SYSCALL is set,
which might yield wrong results.
Fix this by clearing pt_regs::flags in the entry.S irq handler
code.
Reported-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Sven Schnelle <svens@xxxxxxxxxxxxx>
Reviewed-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Fixes: 56e62a737028 ("s390: convert to generic entry")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.12
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kernel/entry.S | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 9cc71ca9a88f..e84f495e7eb2 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -418,6 +418,7 @@ ENTRY(\name)
xgr %r6,%r6
xgr %r7,%r7
xgr %r10,%r10
+ xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
tm %r8,0x0001 # coming from user space?
--
2.30.2
