Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (180 commits)
  powerpc: clean up ssi.txt, add definition for fsl,ssi-asynchronous
  powerpc/85xx: Add support for the "socrates" board (MPC8544).
  powerpc: Fix bugs introduced by sysfs changes
  powerpc: Sanitize stack pointer in signal handling code
  powerpc: Add write barrier before enabling DTL flags
  powerpc/83xx: Update ranges in gianfar node to match other dts
  powerpc/86xx: Move gianfar mdio nodes under the ethernet nodes
  powerpc/85xx: Move gianfar mdio nodes under the ethernet nodes
  powerpc/83xx: Move gianfar mdio nodes under the ethernet nodes
  powerpc/83xx: Add power management support for MPC837x boards
  powerpc/mm: Introduce early_init_mmu() on 64-bit
  powerpc/mm: Add option for non-atomic PTE updates to ppc64
  powerpc/mm: Fix printk type warning in mmu_context_nohash
  powerpc/mm: Rename arch/powerpc/kernel/mmap.c to mmap_64.c
  powerpc/mm: Merge various PTE bits and accessors definitions
  powerpc/mm: Tweak PTE bit combination definitions
  powerpc/cell: Fix iommu exception reporting
  powerpc/mm: e300c2/c3/c4 TLB errata workaround
  powerpc/mm: Used free register to save a few cycles in SW TLB miss handling
  powerpc/mm: Remove unused register usage in SW TLB miss handling
  ...

1 files changed, 75 insertions, 0 deletions

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 930c08e5b38e..dce71a5b51bc 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -42,6 +42,81 @@ static struct tracer_flags tracer_flags = {
 /* pid on the last trace processed */
 static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
 
+/* Add a function return address to the trace stack on thread info.*/
+int
+ftrace_push_return_trace(unsigned long ret, unsigned long long time,
+                         unsigned long func, int *depth)
+{
+        int index;
+
+        if (!current->ret_stack)
+                return -EBUSY;
+
+        /* The return trace stack is full */
+        if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
+                atomic_inc(&current->trace_overrun);
+                return -EBUSY;
+        }
+
+        index = ++current->curr_ret_stack;
+        barrier();
+        current->ret_stack[index].ret = ret;
+        current->ret_stack[index].func = func;
+        current->ret_stack[index].calltime = time;
+        *depth = index;
+
+        return 0;
+}
+
+/* Retrieve a function return address to the trace stack on thread info.*/
+void
+ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
+{
+        int index;
+
+        index = current->curr_ret_stack;
+
+        if (unlikely(index < 0)) {
+                ftrace_graph_stop();
+                WARN_ON(1);
+                /* Might as well panic, otherwise we have no where to go */
+                *ret = (unsigned long)panic;
+                return;
+        }
+
+        *ret = current->ret_stack[index].ret;
+        trace->func = current->ret_stack[index].func;
+        trace->calltime = current->ret_stack[index].calltime;
+        trace->overrun = atomic_read(&current->trace_overrun);
+        trace->depth = index;
+        barrier();
+        current->curr_ret_stack--;
+
+}
+
+/*
+ * Send the trace to the ring-buffer.
+ * @return the original return address.
+ */
+unsigned long ftrace_return_to_handler(void)
+{
+        struct ftrace_graph_ret trace;
+        unsigned long ret;
+
+        ftrace_pop_return_trace(&trace, &ret);
+        trace.rettime = cpu_clock(raw_smp_processor_id());
+        ftrace_graph_return(&trace);
+
+        if (unlikely(!ret)) {
+                ftrace_graph_stop();
+                WARN_ON(1);
+                /* Might as well panic. What else to do? */
+                ret = (unsigned long)panic;
+        }
+
+        return ret;
+}
+
 static int graph_trace_init(struct trace_array *tr)
 {
         int cpu, ret;