1 files changed, 29 insertions, 15 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f8cf959bad4..9541c27c1cf 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -41,8 +41,6 @@
 #include "trace.h"
 #include "trace_output.h"
 
-#define TRACE_BUFFER_FLAGS      (RB_FL_OVERWRITE)
-
 /*
  * On boot up, the ring buffer is set to the minimum size, so that
  * we do not waste memory on systems that are not using tracing.
@@ -340,7 +338,7 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 /* trace_flags holds trace_options default values */
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
         TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
-        TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD;
+        TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE;
 
 static int trace_stop_count;
 static DEFINE_SPINLOCK(tracing_start_lock);
@@ -425,6 +423,7 @@ static const char *trace_options[] = {
         "sleep-time",
         "graph-time",
         "record-cmd",
+        "overwrite",
         NULL
 };
 
@@ -780,6 +779,11 @@ __acquires(kernel_lock)
                 tracing_reset_online_cpus(tr);
 
                 current_trace = type;
+
+                /* If we expanded the buffers, make sure the max is expanded too */
+                if (ring_buffer_expanded && type->use_max_tr)
+                        ring_buffer_resize(max_tr.buffer, trace_buf_size);
+
                 /* the test is responsible for initializing and enabling */
                 pr_info("Testing tracer %s: ", type->name);
                 ret = type->selftest(type, tr);
@@ -792,6 +796,10 @@ __acquires(kernel_lock)
                 /* Only reset on passing, to avoid touching corrupted buffers */
                 tracing_reset_online_cpus(tr);
 
+                /* Shrink the max buffer again */
+                if (ring_buffer_expanded && type->use_max_tr)
+                        ring_buffer_resize(max_tr.buffer, 1);
+
                 printk(KERN_CONT "PASSED\n");
         }
 #endif
@@ -1102,7 +1110,6 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 
         entry->preempt_count            = pc & 0xff;
         entry->pid                      = (tsk) ? tsk->pid : 0;
-        entry->lock_depth               = (tsk) ? tsk->lock_depth : 0;
         entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
                 (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -1313,12 +1320,10 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
 
         __this_cpu_inc(user_stack_count);
 
-
-
         event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK,
                                           sizeof(*entry), flags, pc);
         if (!event)
-                return;
+                goto out_drop_count;
         entry   = ring_buffer_event_data(event);
 
         entry->tgid             = current->tgid;
@@ -1333,8 +1338,8 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc)
         if (!filter_check_discard(call, entry, buffer, event))
                 ring_buffer_unlock_commit(buffer, event);
 
+ out_drop_count:
         __this_cpu_dec(user_stack_count);
-
  out:
         preempt_enable();
 }
@@ -1751,10 +1756,9 @@ static void print_lat_help_header(struct seq_file *m)
         seq_puts(m, "#                | / _----=> need-resched    \n");
         seq_puts(m, "#                || / _---=> hardirq/softirq \n");
         seq_puts(m, "#                ||| / _--=> preempt-depth   \n");
-        seq_puts(m, "#                |||| /_--=> lock-depth       \n");
-        seq_puts(m, "#                |||||/     delay             \n");
-        seq_puts(m, "#  cmd     pid   |||||| time  |   caller      \n");
-        seq_puts(m, "#     \\   /      ||||||   \\   |   /           \n");
+        seq_puts(m, "#                |||| /     delay             \n");
+        seq_puts(m, "#  cmd     pid   ||||| time  |   caller      \n");
+        seq_puts(m, "#     \\   /      |||||  \\    |   /           \n");
 }
 
 static void print_func_help_header(struct seq_file *m)
@@ -2531,6 +2535,9 @@ static void set_tracer_flags(unsigned int mask, int enabled)
 
         if (mask == TRACE_ITER_RECORD_CMD)
                 trace_event_enable_cmd_record(enabled);
+
+        if (mask == TRACE_ITER_OVERWRITE)
+                ring_buffer_change_overwrite(global_trace.buffer, enabled);
 }
 
 static ssize_t
@@ -2712,6 +2719,10 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
 
         mutex_lock(&trace_types_lock);
         if (tracer_enabled ^ val) {
+
+                /* Only need to warn if this is used to change the state */
+                WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on");
+
                 if (val) {
                         tracer_enabled = 1;
                         if (current_trace->start)
@@ -4553,9 +4564,11 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 __init static int tracer_alloc_buffers(void)
 {
         int ring_buf_size;
+        enum ring_buffer_flags rb_flags;
         int i;
         int ret = -ENOMEM;
 
+
         if (!alloc_cpumask_var(&tracing_buffer_mask, GFP_KERNEL))
                 goto out;
 
@@ -4568,12 +4581,13 @@ __init static int tracer_alloc_buffers(void)
         else
                 ring_buf_size = 1;
 
+        rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
+
         cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
         cpumask_copy(tracing_cpumask, cpu_all_mask);
 
         /* TODO: make the number of buffers hot pluggable with CPUS */
-        global_trace.buffer = ring_buffer_alloc(ring_buf_size,
-                                                   TRACE_BUFFER_FLAGS);
+        global_trace.buffer = ring_buffer_alloc(ring_buf_size, rb_flags);
         if (!global_trace.buffer) {
                 printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
                 WARN_ON(1);
@@ -4583,7 +4597,7 @@ __init static int tracer_alloc_buffers(void)
 
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-        max_tr.buffer = ring_buffer_alloc(1, TRACE_BUFFER_FLAGS);
+        max_tr.buffer = ring_buffer_alloc(1, rb_flags);
         if (!max_tr.buffer) {
                 printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
                 WARN_ON(1);