[PATCH] parisc: Initialise restart_block

Calling sys_restart_syscall without having taking a signal
across a syscall leaves the restart_block uninitialized,
allowing malicious user code to crash the kernel.

FIX:

Define INIT_THREAD_INFO such that restart_block.fn is set to
the default do_not_restart_syscall.
Committed-by: Carlos O'Donell <carlos@parisc-linux.org>

include/asm-parisc/thread_info.h

@@ -18,12 +18,15 @@ struct thread_info {
 
 #define INIT_THREAD_INFO(tsk)			\
 {						\
-	task:		&tsk,			\
-	exec_domain:	&default_exec_domain,	\
-	flags:		0,			\
-	cpu:		0,			\
-	addr_limit:	KERNEL_DS,		\
-	preempt_count:	0,			\
+	.task		= &tsk,			\
+	.exec_domain	= &default_exec_domain,	\
+	.flags		= 0,			\
+	.cpu		= 0,			\
+	.addr_limit	= KERNEL_DS,		\
+	.preempt_count	= 0,			\
+  	.restart_block	= {			\
+		.fn = do_no_restart_syscall	\
+	}					\
 }
 
 #define init_thread_info        (init_thread_union.thread_info)