[ARM] 3665/1: crunch: add ptrace support

Patch from Lennert Buytenhek

This patch makes it possible to get/set a task's Crunch state via
the ptrace(2) system call.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/kernel/ptrace.c

@@ -634,6 +634,32 @@ static int ptrace_setwmmxregs(struct task_struct *tsk, void __user *ufp)
 
 #endif
 
+#ifdef CONFIG_CRUNCH
+/*
+ * Get the child Crunch state.
+ */
+static int ptrace_getcrunchregs(struct task_struct *tsk, void __user *ufp)
+{
+	struct thread_info *thread = task_thread_info(tsk);
+
+	crunch_task_disable(thread);  /* force it to ram */
+	return copy_to_user(ufp, &thread->crunchstate, CRUNCH_SIZE)
+		? -EFAULT : 0;
+}
+
+/*
+ * Set the child Crunch state.
+ */
+static int ptrace_setcrunchregs(struct task_struct *tsk, void __user *ufp)
+{
+	struct thread_info *thread = task_thread_info(tsk);
+
+	crunch_task_release(thread);  /* force a reload */
+	return copy_from_user(&thread->crunchstate, ufp, CRUNCH_SIZE)
+		? -EFAULT : 0;
+}
+#endif
+
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	unsigned long tmp;
@@ -765,6 +791,16 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 			child->ptrace_message = data;
 			break;
 
+#ifdef CONFIG_CRUNCH
+		case PTRACE_GETCRUNCHREGS:
+			ret = ptrace_getcrunchregs(child, (void __user *)data);
+			break;
+
+		case PTRACE_SETCRUNCHREGS:
+			ret = ptrace_setcrunchregs(child, (void __user *)data);
+			break;
+#endif
+
 		default:
 			ret = ptrace_request(child, request, addr, data);
 			break;

include/asm-arm/ptrace.h

@@ -25,6 +25,11 @@
 
 #define PTRACE_SET_SYSCALL	23
 
+/* PTRACE_SYSCALL is 24 */
+
+#define PTRACE_GETCRUNCHREGS	25
+#define PTRACE_SETCRUNCHREGS	26
+
 /*
  * PSR bits
  */