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authorSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>2012-06-16 15:30:45 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-08-09 08:27:35 -0700
commit31b1c0850709c77ece1690a8fbc043829717d14c (patch)
treec68906a491f72d1aba7e94e228bb9e407668939f /kernel/power
parentdc525df9895f810ba777feec1540c7b822512c04 (diff)
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ftrace: Disable function tracing during suspend/resume and hibernation, again
commit 443772d408a25af62498793f6f805ce3c559309a upstream. If function tracing is enabled for some of the low-level suspend/resume functions, it leads to triple fault during resume from suspend, ultimately ending up in a reboot instead of a resume (or a total refusal to come out of suspended state, on some machines). This issue was explained in more detail in commit f42ac38c59e0a03d (ftrace: disable tracing for suspend to ram). However, the changes made by that commit got reverted by commit cbe2f5a6e84eebb (tracing: allow tracing of suspend/resume & hibernation code again). So, unfortunately since things are not yet robust enough to allow tracing of low-level suspend/resume functions, suspend/resume is still broken when ftrace is enabled. So fix this by disabling function tracing during suspend/resume & hibernation. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/hibernate.c6
-rw-r--r--kernel/power/suspend.c3
2 files changed, 9 insertions, 0 deletions
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 8884c27..32f1590 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -344,6 +344,7 @@ int hibernation_snapshot(int platform_mode)
goto Complete_devices;
suspend_console();
+ ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend(PMSG_FREEZE);
if (error)
@@ -369,6 +370,7 @@ int hibernation_snapshot(int platform_mode)
if (error || !in_suspend)
pm_restore_gfp_mask();
+ ftrace_start();
resume_console();
Complete_devices:
@@ -471,6 +473,7 @@ int hibernation_restore(int platform_mode)
pm_prepare_console();
suspend_console();
+ ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
@@ -478,6 +481,7 @@ int hibernation_restore(int platform_mode)
dpm_resume_end(PMSG_RECOVER);
}
pm_restore_gfp_mask();
+ ftrace_start();
resume_console();
pm_restore_console();
return error;
@@ -504,6 +508,7 @@ int hibernation_platform_enter(void)
entering_platform_hibernation = true;
suspend_console();
+ ftrace_stop();
error = dpm_suspend_start(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -547,6 +552,7 @@ int hibernation_platform_enter(void)
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
+ ftrace_start();
resume_console();
Close:
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 449ccc9..e40d205 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -23,6 +23,7 @@
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
+#include <linux/ftrace.h>
#include <trace/events/power.h>
#include "power.h"
@@ -210,6 +211,7 @@ int suspend_devices_and_enter(suspend_state_t state)
goto Close;
}
suspend_console();
+ ftrace_stop();
suspend_test_start();
error = dpm_suspend_start(PMSG_SUSPEND);
if (error) {
@@ -226,6 +228,7 @@ int suspend_devices_and_enter(suspend_state_t state)
suspend_test_start();
dpm_resume_end(PMSG_RESUME);
suspend_test_finish("resume devices");
+ ftrace_start();
resume_console();
Close:
if (suspend_ops->end)