The patch titled
ACPI/CPUIDLE: prevent setting pm_idle to NULL
has been added to the -mm tree. Its filename is
acpi-cpuidle-prevent-setting-pm_idle-to-null.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: ACPI/CPUIDLE: prevent setting pm_idle to NULL
From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
pm_idle_save resp. pm_idle_old can be NULL when the restore code in
acpi_processor_cst_has_changed() resp. cpuidle_uninstall_idle_handler()
is called. This can set pm_idle unconditinally to NULL, which causes the
kernel to panic when calling pm_idle in the x86 idle code. This was
covered by an extra check for !pm_idle in the x86 idle code, which was
removed during the x86 idle code refactoring.
Instead of restoring the pm_idle check in the x86 code prevent the
acpi/cpuidle code to set pm_idle to NULL.
Based on a debug patch from Ingo Molnar
Reported-by: Dhaval Giani <dhaval@xxxxxxxxxxxxxxxxxx> [http://lkml.org/lkml/2008/7/2/309]
Venkatesch Pallipadi <venkatesh.pallipadi@xxxxxxxxx>
Len Brown <lenb@xxxxxxxxxx>
Andi Kleen <andi@xxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/acpi/processor_idle.c | 15 +++++++++++----
drivers/cpuidle/cpuidle.c | 2 +-
2 files changed, 12 insertions(+), 5 deletions(-)
diff -puN drivers/acpi/processor_idle.c~acpi-cpuidle-prevent-setting-pm_idle-to-null drivers/acpi/processor_idle.c
--- a/drivers/acpi/processor_idle.c~acpi-cpuidle-prevent-setting-pm_idle-to-null
+++ a/drivers/acpi/processor_idle.c
@@ -1332,9 +1332,15 @@ int acpi_processor_cst_has_changed(struc
if (!pr->flags.power_setup_done)
return -ENODEV;
- /* Fall back to the default idle loop */
- pm_idle = pm_idle_save;
- synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
+ /*
+ * Fall back to the default idle loop, when pm_idle_save had
+ * been initialized.
+ */
+ if (pm_idle_save) {
+ pm_idle = pm_idle_save;
+ /* Relies on interrupts forcing exit from idle. */
+ synchronize_sched();
+ }
pr->flags.power = 0;
result = acpi_processor_get_power_info(pr);
@@ -1896,7 +1902,8 @@ int acpi_processor_power_exit(struct acp
/* Unregister the idle handler when processor #0 is removed. */
if (pr->id == 0) {
- pm_idle = pm_idle_save;
+ if (pm_idle_save)
+ pm_idle = pm_idle_save;
/*
* We are about to unload the current idle thread pm callback
diff -puN drivers/cpuidle/cpuidle.c~acpi-cpuidle-prevent-setting-pm_idle-to-null drivers/cpuidle/cpuidle.c
--- a/drivers/cpuidle/cpuidle.c~acpi-cpuidle-prevent-setting-pm_idle-to-null
+++ a/drivers/cpuidle/cpuidle.c
@@ -94,7 +94,7 @@ void cpuidle_install_idle_handler(void)
*/
void cpuidle_uninstall_idle_handler(void)
{
- if (enabled_devices && (pm_idle != pm_idle_old)) {
+ if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
pm_idle = pm_idle_old;
cpuidle_kick_cpus();
}
_
Patches currently in -mm which might be from tglx@xxxxxxxxxxxxx are
origin.patch
acpi-cpuidle-prevent-setting-pm_idle-to-null.patch
linux-next.patch
x86-pci-replace-dbg-with-pr_debug.patch
x86-pci-replace-dbg-with-pr_debug-fix.patch
x86-pci-replace-dbg-with-pr_debug-fix-2.patch
calgary-fix-a-comparison-warning-the-pci-calgary-64-driver.patch
x86-remove-init_mm-export-as-planned-for-2626.patch
include-asm-generic-pgtable-nopmdh-macros-are-noxious-reason-435.patch
arch-x86-pci-i386c-fix-printk-warnings.patch
x86-tracehook_signal_handler.patch
x86-tracehook-syscall.patch
x86-tracehook-asm-syscallh.patch
x86-signals-use-asm-syscallh.patch
x86-tracehook-tif_notify_resume.patch
x86-tracehook-config_have_arch_tracehook.patch
add-time_is_after_jiffies-and-others-which-compare-with-jiffies.patch
ntp-let-update_persistent_clock-sleep.patch
migrate_timers-add-comment-use-spinlock_irq.patch
tick-schedc-suppress-needless-timer-reprogramming.patch
timekeeping-fix-rounding-problem-during-clock-update.patch
aes-x86_64-asm-implementation-optimization.patch
ntp-fix-calculation-of-the-next-jiffie-to-trigger-rtc-sync.patch
clocksource-fix-a-print-format-error-in-the-acpi-pm-clocksource-driver-and-check-range.patch
clocksource-keep-track-of-original-clocksource-frequency.patch
clocksource-introduce-clocksource_forward_now.patch
clocksource-introduce-clock_monotonic_raw.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
