s390: remove task_show_regs

task_show_regs used to be a debugging aid in the early bringup days
of Linux on s390. /proc/<pid>/status is a world readable file, it
is not a good idea to show the registers of a process. The only
correct fix is to remove task_show_regs.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/s390/include/asm/processor.h

@@ -148,11 +148,6 @@ extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
  */
 extern unsigned long thread_saved_pc(struct task_struct *t);
 
-/*
- * Print register of task into buffer. Used in fs/proc/array.c.
- */
-extern void task_show_regs(struct seq_file *m, struct task_struct *task);
-
 extern void show_code(struct pt_regs *regs);
 
 unsigned long get_wchan(struct task_struct *p);

arch/s390/kernel/traps.c

@@ -237,43 +237,6 @@ void show_regs(struct pt_regs *regs)
 	show_last_breaking_event(regs);
 }
 
-/* This is called from fs/proc/array.c */
-void task_show_regs(struct seq_file *m, struct task_struct *task)
-{
-	struct pt_regs *regs;
-
-	regs = task_pt_regs(task);
-	seq_printf(m, "task: %p, ksp: %p\n",
-		       task, (void *)task->thread.ksp);
-	seq_printf(m, "User PSW : %p %p\n",
-		       (void *) regs->psw.mask, (void *)regs->psw.addr);
-
-	seq_printf(m, "User GPRS: " FOURLONG,
-			  regs->gprs[0], regs->gprs[1],
-			  regs->gprs[2], regs->gprs[3]);
-	seq_printf(m, "           " FOURLONG,
-			  regs->gprs[4], regs->gprs[5],
-			  regs->gprs[6], regs->gprs[7]);
-	seq_printf(m, "           " FOURLONG,
-			  regs->gprs[8], regs->gprs[9],
-			  regs->gprs[10], regs->gprs[11]);
-	seq_printf(m, "           " FOURLONG,
-			  regs->gprs[12], regs->gprs[13],
-			  regs->gprs[14], regs->gprs[15]);
-	seq_printf(m, "User ACRS: %08x %08x %08x %08x\n",
-			  task->thread.acrs[0], task->thread.acrs[1],
-			  task->thread.acrs[2], task->thread.acrs[3]);
-	seq_printf(m, "           %08x %08x %08x %08x\n",
-			  task->thread.acrs[4], task->thread.acrs[5],
-			  task->thread.acrs[6], task->thread.acrs[7]);
-	seq_printf(m, "           %08x %08x %08x %08x\n",
-			  task->thread.acrs[8], task->thread.acrs[9],
-			  task->thread.acrs[10], task->thread.acrs[11]);
-	seq_printf(m, "           %08x %08x %08x %08x\n",
-			  task->thread.acrs[12], task->thread.acrs[13],
-			  task->thread.acrs[14], task->thread.acrs[15]);
-}
-
 static DEFINE_SPINLOCK(die_lock);
 
 void die(const char * str, struct pt_regs * regs, long err)

fs/proc/array.c

@@ -353,9 +353,6 @@ int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
 	task_cap(m, task);
 	task_cpus_allowed(m, task);
 	cpuset_task_status_allowed(m, task);
-#if defined(CONFIG_S390)
-	task_show_regs(m, task);
-#endif
 	task_context_switch_counts(m, task);
 	return 0;
 }