sh: Fix memory leak in dwarf_unwind_stack()

If we broke out of the while (1) loop because the return address of
"frame" was zero, then "frame" needs to be free'd before we return.

Signed-off-by: Matt Fleming <matt@console-pimps.org>

1 files changed, 16 insertions, 6 deletions

diff --git a/arch/sh/kernel/dwarf.c b/arch/sh/kernel/dwarf.c
index 981315c6d656..ce8bff45d72c 100644
--- a/arch/sh/kernel/dwarf.c
+++ b/arch/sh/kernel/dwarf.c
@@ -530,6 +530,16 @@ static int dwarf_cfa_execute_insns(unsigned char *insn_start,
 }
 
 /**
+ *      dwarf_free_frame - free the memory allocated for @frame
+ *      @frame: the frame to free
+ */
+void dwarf_free_frame(struct dwarf_frame *frame)
+{
+        dwarf_frame_free_regs(frame);
+        mempool_free(frame, dwarf_frame_pool);
+}
+
+/**
  *      dwarf_unwind_stack - recursively unwind the stack
  *      @pc: address of the function to unwind
  *      @prev: struct dwarf_frame of the previous stackframe on the callstack
@@ -649,8 +659,7 @@ struct dwarf_frame * dwarf_unwind_stack(unsigned long pc,
         return frame;
 
 bail:
-        dwarf_frame_free_regs(frame);
-        mempool_free(frame, dwarf_frame_pool);
+        dwarf_free_frame(frame);
         return NULL;
 }
 
@@ -837,10 +846,8 @@ static void dwarf_unwinder_dump(struct task_struct *task,
         while (1) {
                 frame = dwarf_unwind_stack(return_addr, _frame);
 
-                if (_frame) {
-                        dwarf_frame_free_regs(_frame);
-                        mempool_free(_frame, dwarf_frame_pool);
-                }
+                if (_frame)
+                        dwarf_free_frame(_frame);
 
                 _frame = frame;
 
@@ -850,6 +857,9 @@ static void dwarf_unwinder_dump(struct task_struct *task,
                 return_addr = frame->return_addr;
                 ops->address(data, return_addr, 1);
         }
+
+        if (frame)
+                dwarf_free_frame(frame);
 }
 
 static struct unwinder dwarf_unwinder = {