s390/compat: correct check for EFAULT in rt-signal frame creation

The return code of the __put_user call to store the rt_sigreturn
system call to the user stack if not properly checked, the err
variable is only checked before to the __put_user. Use an if
statement instead.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c
index 95e7ba0fbb7e..8b84bc373e94 100644
--- a/arch/s390/kernel/compat_signal.c
+++ b/arch/s390/kernel/compat_signal.c
@@ -412,8 +412,9 @@ static int setup_rt_frame32(int sig, struct k_sigaction *ka, siginfo_t *info,
                 regs->gprs[14] = (__u64 __force) ka->sa.sa_restorer | PSW32_ADDR_AMODE;
         } else {
                 regs->gprs[14] = (__u64 __force) frame->retcode | PSW32_ADDR_AMODE;
-                err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
-                                  (u16 __force __user *)(frame->retcode));
+                if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
+                               (u16 __force __user *)(frame->retcode)))
+                        goto give_sigsegv;
         }
 
         /* Set up backchain. */