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Diffstat (limited to 'kernel/trace/trace_functions_graph.c')
-rw-r--r--kernel/trace/trace_functions_graph.c131
1 files changed, 126 insertions, 5 deletions
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 6f233698518e..ef49e9370b25 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -15,15 +15,19 @@
#include "trace.h"
#include "trace_output.h"
+/* When set, irq functions will be ignored */
+static int ftrace_graph_skip_irqs;
+
struct fgraph_cpu_data {
pid_t last_pid;
int depth;
+ int depth_irq;
int ignore;
unsigned long enter_funcs[FTRACE_RETFUNC_DEPTH];
};
struct fgraph_data {
- struct fgraph_cpu_data *cpu_data;
+ struct fgraph_cpu_data __percpu *cpu_data;
/* Place to preserve last processed entry. */
struct ftrace_graph_ent_entry ent;
@@ -41,6 +45,7 @@ struct fgraph_data {
#define TRACE_GRAPH_PRINT_PROC 0x8
#define TRACE_GRAPH_PRINT_DURATION 0x10
#define TRACE_GRAPH_PRINT_ABS_TIME 0x20
+#define TRACE_GRAPH_PRINT_IRQS 0x40
static struct tracer_opt trace_opts[] = {
/* Display overruns? (for self-debug purpose) */
@@ -55,13 +60,15 @@ static struct tracer_opt trace_opts[] = {
{ TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
/* Display absolute time of an entry */
{ TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
+ /* Display interrupts */
+ { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
{ } /* Empty entry */
};
static struct tracer_flags tracer_flags = {
/* Don't display overruns and proc by default */
.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
- TRACE_GRAPH_PRINT_DURATION,
+ TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
.opts = trace_opts
};
@@ -204,6 +211,14 @@ int __trace_graph_entry(struct trace_array *tr,
return 1;
}
+static inline int ftrace_graph_ignore_irqs(void)
+{
+ if (!ftrace_graph_skip_irqs)
+ return 0;
+
+ return in_irq();
+}
+
int trace_graph_entry(struct ftrace_graph_ent *trace)
{
struct trace_array *tr = graph_array;
@@ -218,7 +233,8 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
return 0;
/* trace it when it is-nested-in or is a function enabled. */
- if (!(trace->depth || ftrace_graph_addr(trace->func)))
+ if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
+ ftrace_graph_ignore_irqs())
return 0;
local_irq_save(flags);
@@ -649,8 +665,9 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
/* Print nsecs (we don't want to exceed 7 numbers) */
if (len < 7) {
- snprintf(nsecs_str, min(sizeof(nsecs_str), 8UL - len), "%03lu",
- nsecs_rem);
+ size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
+
+ snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
ret = trace_seq_printf(s, ".%s", nsecs_str);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
@@ -855,6 +872,92 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
return 0;
}
+/*
+ * Entry check for irq code
+ *
+ * returns 1 if
+ * - we are inside irq code
+ * - we just extered irq code
+ *
+ * retunns 0 if
+ * - funcgraph-interrupts option is set
+ * - we are not inside irq code
+ */
+static int
+check_irq_entry(struct trace_iterator *iter, u32 flags,
+ unsigned long addr, int depth)
+{
+ int cpu = iter->cpu;
+ struct fgraph_data *data = iter->private;
+ int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
+ if (flags & TRACE_GRAPH_PRINT_IRQS)
+ return 0;
+
+ /*
+ * We are inside the irq code
+ */
+ if (*depth_irq >= 0)
+ return 1;
+
+ if ((addr < (unsigned long)__irqentry_text_start) ||
+ (addr >= (unsigned long)__irqentry_text_end))
+ return 0;
+
+ /*
+ * We are entering irq code.
+ */
+ *depth_irq = depth;
+ return 1;
+}
+
+/*
+ * Return check for irq code
+ *
+ * returns 1 if
+ * - we are inside irq code
+ * - we just left irq code
+ *
+ * returns 0 if
+ * - funcgraph-interrupts option is set
+ * - we are not inside irq code
+ */
+static int
+check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
+{
+ int cpu = iter->cpu;
+ struct fgraph_data *data = iter->private;
+ int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
+ if (flags & TRACE_GRAPH_PRINT_IRQS)
+ return 0;
+
+ /*
+ * We are not inside the irq code.
+ */
+ if (*depth_irq == -1)
+ return 0;
+
+ /*
+ * We are inside the irq code, and this is returning entry.
+ * Let's not trace it and clear the entry depth, since
+ * we are out of irq code.
+ *
+ * This condition ensures that we 'leave the irq code' once
+ * we are out of the entry depth. Thus protecting us from
+ * the RETURN entry loss.
+ */
+ if (*depth_irq >= depth) {
+ *depth_irq = -1;
+ return 1;
+ }
+
+ /*
+ * We are inside the irq code, and this is not the entry.
+ */
+ return 1;
+}
+
static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
struct trace_iterator *iter, u32 flags)
@@ -865,6 +968,9 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
static enum print_line_t ret;
int cpu = iter->cpu;
+ if (check_irq_entry(iter, flags, call->func, call->depth))
+ return TRACE_TYPE_HANDLED;
+
if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
return TRACE_TYPE_PARTIAL_LINE;
@@ -902,6 +1008,9 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
int ret;
int i;
+ if (check_irq_return(iter, flags, trace->depth))
+ return TRACE_TYPE_HANDLED;
+
if (data) {
struct fgraph_cpu_data *cpu_data;
int cpu = iter->cpu;
@@ -1210,9 +1319,12 @@ void graph_trace_open(struct trace_iterator *iter)
pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
+ int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
*pid = -1;
*depth = 0;
*ignore = 0;
+ *depth_irq = -1;
}
iter->private = data;
@@ -1235,6 +1347,14 @@ void graph_trace_close(struct trace_iterator *iter)
}
}
+static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
+{
+ if (bit == TRACE_GRAPH_PRINT_IRQS)
+ ftrace_graph_skip_irqs = !set;
+
+ return 0;
+}
+
static struct trace_event_functions graph_functions = {
.trace = print_graph_function_event,
};
@@ -1261,6 +1381,7 @@ static struct tracer graph_trace __read_mostly = {
.print_line = print_graph_function,
.print_header = print_graph_headers,
.flags = &tracer_flags,
+ .set_flag = func_graph_set_flag,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_function_graph,
#endif