ACPI: processor_idle: use raw_safe_halt() in acpi_idle_play_dead()
authorDavid Woodhouse <dwmw@amazon.co.uk>
Fri, 27 Oct 2023 18:36:51 +0000 (19:36 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 3 Dec 2023 06:33:06 +0000 (07:33 +0100)
commit 9bb69ba4c177dccaa1f5b5cbdf80b67813328348 upstream.

Xen HVM guests were observed taking triple-faults when attempting to
online a previously offlined vCPU.

Investigation showed that the fault was coming from a failing call
to lockdep_assert_irqs_disabled(), in load_current_idt() which was
too early in the CPU bringup to actually catch the exception and
report the failure cleanly.

This was a false positive, caused by acpi_idle_play_dead() setting
the per-cpu hardirqs_enabled flag by calling safe_halt(). Switch it
to use raw_safe_halt() instead, which doesn't do so.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/acpi/processor_idle.c

index 3a34a8c..55437f5 100644 (file)
@@ -592,7 +592,7 @@ static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
        while (1) {
 
                if (cx->entry_method == ACPI_CSTATE_HALT)
-                       safe_halt();
+                       raw_safe_halt();
                else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
                        io_idle(cx->address);
                } else