[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>

2 files changed, 41 insertions, 0 deletions

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index a1d1b2906e8d..c40bdc770054 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/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;
diff --git a/include/asm-arm/ptrace.h b/include/asm-arm/ptrace.h
index 2bebe3dc0a30..5a8ef787dbf8 100644
--- a/include/asm-arm/ptrace.h
+++ b/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
  */