From: Paul E. McKenney Date: Tue, 28 Feb 2012 21:27:44 +0000 (-0800) Subject: ACPI: Fix unprotected smp_processor_id() in acpi_processor_cst_has_changed() X-Git-Tag: MMI-PSA29.97-13-9~16866^2~3^7~1 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9505626d7bfeb5bd4b85acb483831ac640b2a5e8;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git ACPI: Fix unprotected smp_processor_id() in acpi_processor_cst_has_changed() The acpi_processor_cst_has_changed() function is invoked from a CPU_ONLINE or CPU_DEAD function, which might well execute on CPU 0 even though the CPU being hotplugged is some other CPU. In addition, acpi_processor_cst_has_changed() invokes smp_processor_id() without protection, resulting in splats when onlining CPUs. This commit therefore changes the smp_processor_id() to pr->id, as is used elsewhere in the code, for example, in acpi_processor_add(). Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney Reviewed-by: Srivatsa S. Bhat Tested-by: Yong Zhang Acked-by: Rafael J. Wysocki Signed-off-by: Len Brown --- diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 0e8e2de2ed3e..9e57b06d1f24 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -1159,8 +1159,7 @@ int acpi_processor_cst_has_changed(struct acpi_processor *pr) * to make the code that updates C-States be called once. */ - if (smp_processor_id() == 0 && - cpuidle_get_driver() == &acpi_idle_driver) { + if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) { cpuidle_pause_and_lock(); /* Protect against cpu-hotplug */