[PATCH] s390: bug in setup_rt_frame

Consider return value of __put_user() when setting up a signal frame
instead of ignoring it.

Cc: Martin Schwidefsky <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/s390/kernel/signal.c

···
 	} else {
                 regs->gprs[14] = (unsigned long)
 			frame->retcode | PSW_ADDR_AMODE;
-		err |= __put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
-	                          (u16 __user *)(frame->retcode));
+		if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn,
+			       (u16 __user *)(frame->retcode)))
+			goto give_sigsegv;
 	}
 
 	/* Set up backchain. */