From: Sven Schnelle svens@linux.ibm.com
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@linux.ibm.com Signed-off-by: Sven Schnelle svens@linux.ibm.com Reviewed-by: Heiko Carstens hca@linux.ibm.com Fixes: 56e62a737028 ("s390: convert to generic entry") Cc: stable@vger.kernel.org # 5.12 Signed-off-by: Vasily Gorbik gor@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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?