1 files changed, 24 insertions, 0 deletions

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 401e38be1f78..3af34bf4f4df 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -29,6 +29,7 @@
 #include <linux/utsname.h>
 #include <linux/uaccess.h>
 #include <linux/random.h>
+#include <linux/hw_breakpoint.h>
 
 #include <asm/cacheflush.h>
 #include <asm/leds.h>
@@ -135,6 +136,25 @@ EXPORT_SYMBOL(pm_power_off);
 void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
 EXPORT_SYMBOL_GPL(arm_pm_restart);
 
+static void do_nothing(void *unused)
+{
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
+void cpu_idle_wait(void)
+{
+        smp_mb();
+        /* kick all the CPUs so that they exit out of pm_idle */
+        smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
 
 /*
  * This is our default idle handler.  We need to disable
@@ -317,6 +337,8 @@ void flush_thread(void)
         struct thread_info *thread = current_thread_info();
         struct task_struct *tsk = current;
 
+        flush_ptrace_hw_breakpoint(tsk);
+
         memset(thread->used_cp, 0, sizeof(thread->used_cp));
         memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
         memset(&thread->fpstate, 0, sizeof(union fp_state));
@@ -345,6 +367,8 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
         thread->cpu_context.sp = (unsigned long)childregs;
         thread->cpu_context.pc = (unsigned long)ret_from_fork;
 
+        clear_ptrace_hw_breakpoint(p);
+
         if (clone_flags & CLONE_SETTLS)
                 thread->tp_value = regs->ARM_r3;