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Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
-rw-r--r--kernel/trace/trace_functions_graph.c108
1 files changed, 80 insertions, 28 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index b1342c5d37cf..9aed1a5cf553 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -9,6 +9,7 @@
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
+#include <linux/slab.h>
#include <linux/fs.h>
#include "trace.h"
@@ -18,6 +19,7 @@ struct fgraph_cpu_data {
pid_t last_pid;
int depth;
int ignore;
+ unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
};
struct fgraph_data {
@@ -187,7 +189,7 @@ static int __trace_graph_entry(struct trace_array *tr,
struct ring_buffer *buffer = tr->buffer;
struct ftrace_graph_ent_entry *entry;
- if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled))))
+ if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
return 0;
event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
@@ -212,13 +214,11 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
int cpu;
int pc;
- if (unlikely(!tr))
- return 0;
-
if (!ftrace_trace_task(current))
return 0;
- if (!ftrace_graph_addr(trace->func))
+ /* trace it when it is-nested-in or is a function enabled. */
+ if (!(trace->depth || ftrace_graph_addr(trace->func)))
return 0;
local_irq_save(flags);
@@ -231,9 +231,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
} else {
ret = 0;
}
- /* Only do the atomic if it is not already set */
- if (!test_tsk_trace_graph(current))
- set_tsk_trace_graph(current);
atomic_dec(&data->disabled);
local_irq_restore(flags);
@@ -241,6 +238,14 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
return ret;
}
+int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
+{
+ if (tracing_thresh)
+ return 1;
+ else
+ return trace_graph_entry(trace);
+}
+
static void __trace_graph_return(struct trace_array *tr,
struct ftrace_graph_ret *trace,
unsigned long flags,
@@ -251,7 +256,7 @@ static void __trace_graph_return(struct trace_array *tr,
struct ring_buffer *buffer = tr->buffer;
struct ftrace_graph_ret_entry *entry;
- if (unlikely(__this_cpu_read(per_cpu_var(ftrace_cpu_disabled))))
+ if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
return;
event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
@@ -281,19 +286,39 @@ void trace_graph_return(struct ftrace_graph_ret *trace)
pc = preempt_count();
__trace_graph_return(tr, trace, flags, pc);
}
- if (!trace->depth)
- clear_tsk_trace_graph(current);
atomic_dec(&data->disabled);
local_irq_restore(flags);
}
+void set_graph_array(struct trace_array *tr)
+{
+ graph_array = tr;
+
+ /* Make graph_array visible before we start tracing */
+
+ smp_mb();
+}
+
+void trace_graph_thresh_return(struct ftrace_graph_ret *trace)
+{
+ if (tracing_thresh &&
+ (trace->rettime - trace->calltime < tracing_thresh))
+ return;
+ else
+ trace_graph_return(trace);
+}
+
static int graph_trace_init(struct trace_array *tr)
{
int ret;
- graph_array = tr;
- ret = register_ftrace_graph(&trace_graph_return,
- &trace_graph_entry);
+ set_graph_array(tr);
+ if (tracing_thresh)
+ ret = register_ftrace_graph(&trace_graph_thresh_return,
+ &trace_graph_thresh_entry);
+ else
+ ret = register_ftrace_graph(&trace_graph_return,
+ &trace_graph_entry);
if (ret)
return ret;
tracing_start_cmdline_record();
@@ -301,11 +326,6 @@ static int graph_trace_init(struct trace_array *tr)
return 0;
}
-void set_graph_array(struct trace_array *tr)
-{
- graph_array = tr;
-}
-
static void graph_trace_reset(struct trace_array *tr)
{
tracing_stop_cmdline_record();
@@ -673,15 +693,21 @@ print_graph_entry_leaf(struct trace_iterator *iter,
duration = graph_ret->rettime - graph_ret->calltime;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
/*
* Comments display at + 1 to depth. Since
* this is a leaf function, keep the comments
* equal to this depth.
*/
- *depth = call->depth - 1;
+ cpu_data->depth = call->depth - 1;
+
+ /* No need to keep this function around for this depth */
+ if (call->depth < FTRACE_RETFUNC_DEPTH)
+ cpu_data->enter_funcs[call->depth] = 0;
}
/* Overhead */
@@ -721,10 +747,15 @@ print_graph_entry_nested(struct trace_iterator *iter,
int i;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
- *depth = call->depth;
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
+ cpu_data->depth = call->depth;
+
+ /* Save this function pointer to see if the exit matches */
+ if (call->depth < FTRACE_RETFUNC_DEPTH)
+ cpu_data->enter_funcs[call->depth] = call->func;
}
/* No overhead */
@@ -854,19 +885,28 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
struct fgraph_data *data = iter->private;
pid_t pid = ent->pid;
int cpu = iter->cpu;
+ int func_match = 1;
int ret;
int i;
if (data) {
+ struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
- int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
+
+ cpu_data = per_cpu_ptr(data->cpu_data, cpu);
/*
* Comments display at + 1 to depth. This is the
* return from a function, we now want the comments
* to display at the same level of the bracket.
*/
- *depth = trace->depth - 1;
+ cpu_data->depth = trace->depth - 1;
+
+ if (trace->depth < FTRACE_RETFUNC_DEPTH) {
+ if (cpu_data->enter_funcs[trace->depth] != trace->func)
+ func_match = 0;
+ cpu_data->enter_funcs[trace->depth] = 0;
+ }
}
if (print_graph_prologue(iter, s, 0, 0))
@@ -891,9 +931,21 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
return TRACE_TYPE_PARTIAL_LINE;
}
- ret = trace_seq_printf(s, "}\n");
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ /*
+ * If the return function does not have a matching entry,
+ * then the entry was lost. Instead of just printing
+ * the '}' and letting the user guess what function this
+ * belongs to, write out the function name.
+ */
+ if (func_match) {
+ ret = trace_seq_printf(s, "}\n");
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ } else {
+ ret = trace_seq_printf(s, "} /* %ps */\n", (void *)trace->func);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+ }
/* Overrun */
if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
generated by cgit v1.2.3 (git 2.25.1) at 2024-09-10 22:13:45 +0000