tracing/fastboot: get the initcall name before it disappears
After some initcall traces, some initcall names may be inconsistent.
That's because these functions will disappear from the .init section
and also their name from the symbols table.
So we have to copy the name of the function in a buffer large enough
during the trace appending. It is not costly for the ring_buffer because
the number of initcall entries is commonly not really large.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 7c15f3e..b9dc2c0 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -8,6 +8,7 @@
#include <linux/init.h>
#include <linux/debugfs.h>
#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
#include "trace.h"
@@ -56,17 +57,19 @@
struct timespec rettime = ktime_to_timespec(it->rettime);
if (entry->type == TRACE_BOOT) {
- ret = trace_seq_printf(s, "[%5ld.%06ld] calling %pF @ %i\n",
+ ret = trace_seq_printf(s, "[%5ld.%06ld] calling %s @ %i\n",
calltime.tv_sec,
calltime.tv_nsec,
it->func, it->caller);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
- ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %pF "
+
+ ret = trace_seq_printf(s, "[%5ld.%06ld] initcall %s "
"returned %d after %lld msecs\n",
rettime.tv_sec,
rettime.tv_nsec,
it->func, it->result, it->duration);
+
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
@@ -83,8 +86,7 @@
.print_line = initcall_print_line,
};
-
-void trace_boot(struct boot_trace *it)
+void trace_boot(struct boot_trace *it, initcall_t fn)
{
struct ring_buffer_event *event;
struct trace_boot *entry;
@@ -95,6 +97,10 @@
if (!trace_boot_enabled)
return;
+ /* Get its name now since this function could
+ * disappear because it is in the .init section.
+ */
+ sprint_symbol(it->func, (unsigned long)fn);
preempt_disable();
data = tr->data[smp_processor_id()];