/* pid on the last trace processed */
-static int graph_trace_init(struct trace_array *tr)
+/* 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 cpu, ret;
+ 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(¤t->trace_overrun);
+ return -EBUSY;
+ }
- for_each_online_cpu(cpu)
- tracing_reset(tr, cpu);
+ 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;
- ret = register_ftrace_graph(&trace_graph_return,
+ 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(¤t->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 = trace_clock_local();
+ 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 ret = register_ftrace_graph(&trace_graph_return,
&trace_graph_entry);
if (ret)
return ret;
ret = trace_seq_printf(s,
" ------------------------------------------\n");
if (!ret)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_cpu(s, cpu);
if (ret == TRACE_TYPE_PARTIAL_LINE)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_proc(s, prev_pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s, " => ");
if (!ret)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = print_graph_proc(s, pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
ret = trace_seq_printf(s,
"\n ------------------------------------------\n\n");
if (!ret)
- TRACE_TYPE_PARTIAL_LINE;
+ return TRACE_TYPE_PARTIAL_LINE;
- return ret;
+ return TRACE_TYPE_HANDLED;
}
-static bool
-trace_branch_is_leaf(struct trace_iterator *iter,
+static struct ftrace_graph_ret_entry *
+get_return_for_leaf(struct trace_iterator *iter,
struct ftrace_graph_ent_entry *curr)
{
struct ring_buffer_iter *ring_iter;
ring_iter = iter->buffer_iter[iter->cpu];
- if (!ring_iter)
- return false;
-
- event = ring_buffer_iter_peek(ring_iter, NULL);
+ /* First peek to compare current entry and the next one */
+ if (ring_iter)
+ event = ring_buffer_iter_peek(ring_iter, NULL);
+ else {
+ /* We need to consume the current entry to see the next one */
+ ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL);
+ event = ring_buffer_peek(iter->tr->buffer, iter->cpu,
+ NULL);
+ }
if (!event)
- return false;
+ return NULL;
next = ring_buffer_event_data(event);
if (next->ent.type != TRACE_GRAPH_RET)
- return false;
+ return NULL;
if (curr->ent.pid != next->ent.pid ||
curr->graph_ent.func != next->ret.func)
- return false;
+ return NULL;
+
+ /* this is a leaf, now advance the iterator */
+ if (ring_iter)
+ ring_buffer_read(ring_iter, NULL);
- return true;
+ return next;
}
/* Signal a overhead of time execution to the output */
return trace_seq_printf(s, " ");
}
+static int print_graph_abs_time(u64 t, struct trace_seq *s)
+{
+ unsigned long usecs_rem;
+
+ usecs_rem = do_div(t, NSEC_PER_SEC);
+ usecs_rem /= 1000;
+
+ return trace_seq_printf(s, "%5lu.%06lu | ",
+ (unsigned long)t, usecs_rem);
+}
+
static enum print_line_t
-print_graph_irq(struct trace_seq *s, unsigned long addr,
+print_graph_irq(struct trace_iterator *iter, unsigned long addr,
enum trace_type type, int cpu, pid_t pid)
{
int ret;
+ struct trace_seq *s = &iter->seq;
if (addr < (unsigned long)__irqentry_text_start ||
addr >= (unsigned long)__irqentry_text_end)
return TRACE_TYPE_UNHANDLED;
+ /* Absolute time */
+ if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
+ ret = print_graph_abs_time(iter->ts, s);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
+
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
}
-static int print_graph_abs_time(u64 t, struct trace_seq *s)
-{
- unsigned long usecs_rem;
-
- usecs_rem = do_div(t, 1000000000);
- usecs_rem /= 1000;
-
- return trace_seq_printf(s, "%5lu.%06lu | ",
- (unsigned long)t, usecs_rem);
-}
-
/* Case of a leaf function on its call entry */
static enum print_line_t
print_graph_entry_leaf(struct trace_iterator *iter,
- struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
+ struct ftrace_graph_ent_entry *entry,
+ struct ftrace_graph_ret_entry *ret_entry, struct trace_seq *s)
{
- struct ftrace_graph_ret_entry *ret_entry;
struct ftrace_graph_ret *graph_ret;
- struct ring_buffer_event *event;
struct ftrace_graph_ent *call;
unsigned long long duration;
int ret;
int i;
- event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
- ret_entry = ring_buffer_event_data(event);
graph_ret = &ret_entry->ret;
call = &entry->graph_ent;
duration = graph_ret->rettime - graph_ret->calltime;
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- return TRACE_TYPE_HANDLED;
+ /*
+ * we already consumed the current entry to check the next one
+ * and see if this is a leaf.
+ */
+ return TRACE_TYPE_NO_CONSUME;
}
static enum print_line_t
pid_t *last_entry = iter->private;
struct trace_entry *ent = iter->ent;
struct ftrace_graph_ent *call = &field->graph_ent;
+ struct ftrace_graph_ret_entry *leaf_ret;
/* Pid */
if (verif_pid(s, ent->pid, cpu, last_entry) == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Interrupt */
- ret = print_graph_irq(s, call->func, TRACE_GRAPH_ENT, cpu, ent->pid);
+ ret = print_graph_irq(iter, call->func, TRACE_GRAPH_ENT, cpu, ent->pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_PARTIAL_LINE;
}
- if (trace_branch_is_leaf(iter, field))
- return print_graph_entry_leaf(iter, field, s);
+ leaf_ret = get_return_for_leaf(iter, field);
+ if (leaf_ret)
+ return print_graph_entry_leaf(iter, field, leaf_ret, s);
else
return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
int i;
int ret;
int cpu = iter->cpu;
- pid_t *last_pid = iter->private;
+ pid_t *last_pid = iter->private, pid = ent->pid;
unsigned long long duration = trace->rettime - trace->calltime;
/* Pid */
- if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
+ if (verif_pid(s, pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
/* Absolute time */
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = print_graph_irq(s, trace->func, TRACE_GRAPH_RET, cpu, ent->pid);
+ ret = print_graph_irq(iter, trace->func, TRACE_GRAPH_RET, cpu, pid);
if (ret == TRACE_TYPE_PARTIAL_LINE)
return TRACE_TYPE_PARTIAL_LINE;
int cpu = iter->cpu;
pid_t *last_pid = iter->private;
+ /* Pid */
+ if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
+ return TRACE_TYPE_PARTIAL_LINE;
+
/* Absolute time */
if (tracer_flags.val & TRACE_GRAPH_PRINT_ABS_TIME) {
ret = print_graph_abs_time(iter->ts, s);
return TRACE_TYPE_PARTIAL_LINE;
}
- /* Pid */
- if (verif_pid(s, ent->pid, cpu, last_pid) == TRACE_TYPE_PARTIAL_LINE)
- return TRACE_TYPE_PARTIAL_LINE;
-
/* Cpu */
if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
ret = print_graph_cpu(s, cpu);
}
/* The comment */
- ret = trace_seq_printf(s, "/* %s", trace->buf);
+ ret = trace_seq_printf(s, "/* ");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ ret = trace_seq_bprintf(s, trace->fmt, trace->buf);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
static void graph_trace_close(struct trace_iterator *iter)
{
- percpu_free(iter->private);
+ free_percpu(iter->private);
}
static struct tracer graph_trace __read_mostly = {
.name = "function_graph",
.open = graph_trace_open,
.close = graph_trace_close,
+ .wait_pipe = poll_wait_pipe,
.init = graph_trace_init,
.reset = graph_trace_reset,
.print_line = print_graph_function,
.print_header = print_graph_headers,
.flags = &tracer_flags,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_function_graph,
+#endif
};
static __init int init_graph_trace(void)