3 files changed, 33 insertions, 27 deletions

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index b15153060417..10786af95545 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -89,7 +89,7 @@ EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
 
 struct stack_frame {
         const void __user       *next_fp;
-        unsigned long           return_address;
+        unsigned long           ret_addr;
 };
 
 static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
@@ -108,33 +108,40 @@ static int copy_stack_frame(const void __user *fp, struct stack_frame *frame)
         return ret;
 }
 
+static inline void __save_stack_trace_user(struct stack_trace *trace)
+{
+        const struct pt_regs *regs = task_pt_regs(current);
+        const void __user *fp = (const void __user *)regs->bp;
+
+        if (trace->nr_entries < trace->max_entries)
+                trace->entries[trace->nr_entries++] = regs->ip;
+
+        while (trace->nr_entries < trace->max_entries) {
+                struct stack_frame frame;
+
+                frame.next_fp = NULL;
+                frame.ret_addr = 0;
+                if (!copy_stack_frame(fp, &frame))
+                        break;
+                if ((unsigned long)fp < regs->sp)
+                        break;
+                if (frame.ret_addr) {
+                        trace->entries[trace->nr_entries++] =
+                                frame.ret_addr;
+                }
+                if (fp == frame.next_fp)
+                        break;
+                fp = frame.next_fp;
+        }
+}
+
 void save_stack_trace_user(struct stack_trace *trace)
 {
         /*
          * Trace user stack if we are not a kernel thread
          */
         if (current->mm) {
-                const struct pt_regs *regs = task_pt_regs(current);
-                const void __user *fp = (const void __user *)regs->bp;
-
-                if (trace->nr_entries < trace->max_entries)
-                        trace->entries[trace->nr_entries++] = regs->ip;
-
-                while (trace->nr_entries < trace->max_entries) {
-                        struct stack_frame frame;
-                        frame.next_fp = NULL;
-                        frame.return_address = 0;
-                        if (!copy_stack_frame(fp, &frame))
-                                break;
-                        if ((unsigned long)fp < regs->sp)
-                                break;
-                        if (frame.return_address)
-                                trace->entries[trace->nr_entries++] =
-                                        frame.return_address;
-                        if (fp == frame.next_fp)
-                                break;
-                        fp = frame.next_fp;
-                }
+                __save_stack_trace_user(trace);
         }
         if (trace->nr_entries < trace->max_entries)
                 trace->entries[trace->nr_entries++] = ULONG_MAX;
diff --git a/include/linux/stacktrace.h b/include/linux/stacktrace.h
index 68de51468f5d..fd42d6851109 100644
--- a/include/linux/stacktrace.h
+++ b/include/linux/stacktrace.h
@@ -25,7 +25,7 @@ extern void save_stack_trace_user(struct stack_trace *trace);
 #else
 # define save_stack_trace(trace)                        do { } while (0)
 # define save_stack_trace_tsk(tsk, trace)               do { } while (0)
-# define save_stack_trace_user(trace)              do { } while (0)
+# define save_stack_trace_user(trace)                   do { } while (0)
 # define print_stack_trace(trace, spaces)               do { } while (0)
 #endif
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 62776b71b1c5..dedf35f36971 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -948,9 +948,9 @@ static void ftrace_trace_userstack(struct trace_array *tr,
                    struct trace_array_cpu *data,
                    unsigned long flags, int pc)
 {
+        struct ring_buffer_event *event;
         struct userstack_entry *entry;
         struct stack_trace trace;
-        struct ring_buffer_event *event;
         unsigned long irq_flags;
 
         if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
@@ -1471,8 +1471,7 @@ static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
         if (file) {
                 ret = trace_seq_path(s, &file->f_path);
                 if (ret)
-                        ret = trace_seq_printf(s, "[+0x%lx]",
-                                        ip - vmstart);
+                        ret = trace_seq_printf(s, "[+0x%lx]", ip - vmstart);
         }
         if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
                 ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
@@ -1485,7 +1484,7 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
 {
         struct mm_struct *mm = NULL;
         int ret = 1;
-        unsigned i;
+        unsigned int i;
 
         if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
                 struct task_struct *task;