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authorLianwei Wang <lianwei.wang@gmail.com>2016-06-09 23:43:28 -0700
committerThomas Gleixner <tglx@linutronix.de>2016-09-02 20:37:17 +0200
commit01b41159066531cc8d664362ff0cd89dd137bbfa (patch)
treeae1514bb4d6e3a845d4b5159629ac730119b4bd8 /kernel/cpu.c
parent8017c279196ab29174bafc104ac4ebbd42c7ca7f (diff)
downloadlinux-01b41159066531cc8d664362ff0cd89dd137bbfa.tar.bz2
cpu/hotplug: Handle unbalanced hotplug enable/disable
When cpu_hotplug_enable() is called unbalanced w/o a preceeding cpu_hotplug_disable() the code emits a warning, but happily decrements the disabled counter. This causes the next operations to malfunction. Prevent the decrement and just emit a warning. Signed-off-by: Lianwei Wang <lianwei.wang@gmail.com> Cc: peterz@infradead.org Cc: linux-pm@vger.kernel.org Cc: oleg@redhat.com Link: http://lkml.kernel.org/r/1465541008-12476-1-git-send-email-lianwei.wang@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index c506485eaa75..c90f839c5b86 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -331,10 +331,17 @@ void cpu_hotplug_disable(void)
}
EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
+static void __cpu_hotplug_enable(void)
+{
+ if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))
+ return;
+ cpu_hotplug_disabled--;
+}
+
void cpu_hotplug_enable(void)
{
cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
+ __cpu_hotplug_enable();
cpu_maps_update_done();
}
EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
@@ -1160,7 +1167,7 @@ void enable_nonboot_cpus(void)
/* Allow everyone to use the CPU hotplug again */
cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
+ __cpu_hotplug_enable();
if (cpumask_empty(frozen_cpus))
goto out;