tracing: allow tracing of suspend/resume & hibernation code again
Impact: widen function-tracing to suspend+resume (and hibernation) sequences
Now that the ftrace kernel thread is gone, we can allow tracing
during suspend/resume again.
So revert these two commits:
f42ac38c5 "ftrace: disable tracing for suspend to ram"
41108eb10 "ftrace: disable tracing for hibernation"
This should be tested very carefully, as it could interact with
altneratives instruction patching, etc.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index c9d7408..f77d381 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -22,7 +22,6 @@
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
-#include <linux/ftrace.h>
#include "power.h"
@@ -257,7 +256,7 @@
int hibernation_snapshot(int platform_mode)
{
- int error, ftrace_save;
+ int error;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
@@ -269,7 +268,6 @@
goto Close;
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
@@ -299,7 +297,6 @@
Resume_devices:
device_resume(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
platform_end(platform_mode);
@@ -370,11 +367,10 @@
int hibernation_restore(int platform_mode)
{
- int error, ftrace_save;
+ int error;
pm_prepare_console();
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_QUIESCE);
if (error)
goto Finish;
@@ -389,7 +385,6 @@
platform_restore_cleanup(platform_mode);
device_resume(PMSG_RECOVER);
Finish:
- __ftrace_enabled_restore(ftrace_save);
resume_console();
pm_restore_console();
return error;
@@ -402,7 +397,7 @@
int hibernation_platform_enter(void)
{
- int error, ftrace_save;
+ int error;
if (!hibernation_ops)
return -ENOSYS;
@@ -417,7 +412,6 @@
goto Close;
suspend_console();
- ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -452,7 +446,6 @@
hibernation_ops->finish();
Resume_devices:
device_resume(PMSG_RESTORE);
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
hibernation_ops->end();
diff --git a/kernel/power/main.c b/kernel/power/main.c
index b8f7ce9..613f169 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -22,7 +22,6 @@
#include <linux/freezer.h>
#include <linux/vmstat.h>
#include <linux/syscalls.h>
-#include <linux/ftrace.h>
#include "power.h"
@@ -317,7 +316,7 @@
*/
int suspend_devices_and_enter(suspend_state_t state)
{
- int error, ftrace_save;
+ int error;
if (!suspend_ops)
return -ENOSYS;
@@ -328,7 +327,6 @@
goto Close;
}
suspend_console();
- ftrace_save = __ftrace_enabled_save();
suspend_test_start();
error = device_suspend(PMSG_SUSPEND);
if (error) {
@@ -360,7 +358,6 @@
suspend_test_start();
device_resume(PMSG_RESUME);
suspend_test_finish("resume devices");
- __ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
if (suspend_ops->end)