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 (file)
--- 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 @@ static int create_image(int platform_mode)
 
 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 @@ int hibernation_snapshot(int platform_mode)
                goto Close;
 
        suspend_console();
-       ftrace_save = __ftrace_enabled_save();
        error = device_suspend(PMSG_FREEZE);
        if (error)
                goto Recover_platform;
@@ -299,7 +297,6 @@ int hibernation_snapshot(int platform_mode)
  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 @@ static int resume_target_kernel(void)
 
 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 @@ int hibernation_restore(int platform_mode)
        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_restore(int platform_mode)
 
 int hibernation_platform_enter(void)
 {
-       int error, ftrace_save;
+       int error;
 
        if (!hibernation_ops)
                return -ENOSYS;
@@ -417,7 +412,6 @@ int hibernation_platform_enter(void)
                goto Close;
 
        suspend_console();
-       ftrace_save = __ftrace_enabled_save();
        error = device_suspend(PMSG_HIBERNATE);
        if (error) {
                if (hibernation_ops->recover)
@@ -452,7 +446,6 @@ int hibernation_platform_enter(void)
        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 (file)
--- 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 @@ static int suspend_enter(suspend_state_t state)
  */
 int suspend_devices_and_enter(suspend_state_t state)
 {
-       int error, ftrace_save;
+       int error;
 
        if (!suspend_ops)
                return -ENOSYS;
@@ -328,7 +327,6 @@ int suspend_devices_and_enter(suspend_state_t state)
                        goto Close;
        }
        suspend_console();
-       ftrace_save = __ftrace_enabled_save();
        suspend_test_start();
        error = device_suspend(PMSG_SUSPEND);
        if (error) {
@@ -360,7 +358,6 @@ int suspend_devices_and_enter(suspend_state_t state)
        suspend_test_start();
        device_resume(PMSG_RESUME);
        suspend_test_finish("resume devices");
-       __ftrace_enabled_restore(ftrace_save);
        resume_console();
  Close:
        if (suspend_ops->end)