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-rw-r--r--kernel/kprobes.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 3b7653f2e7a..f3ea492ab44 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -155,14 +155,36 @@ void __kprobes free_insn_slot(kprobe_opcode_t *slot)
/* Locks kprobe: irqs must be disabled */
void __kprobes lock_kprobes(void)
{
+ unsigned long flags = 0;
+
+ /* Avoiding local interrupts to happen right after we take the kprobe_lock
+ * and before we get a chance to update kprobe_cpu, this to prevent
+ * deadlock when we have a kprobe on ISR routine and a kprobe on task
+ * routine
+ */
+ local_irq_save(flags);
+
spin_lock(&kprobe_lock);
kprobe_cpu = smp_processor_id();
+
+ local_irq_restore(flags);
}
void __kprobes unlock_kprobes(void)
{
+ unsigned long flags = 0;
+
+ /* Avoiding local interrupts to happen right after we update
+ * kprobe_cpu and before we get a a chance to release kprobe_lock,
+ * this to prevent deadlock when we have a kprobe on ISR routine and
+ * a kprobe on task routine
+ */
+ local_irq_save(flags);
+
kprobe_cpu = NR_CPUS;
spin_unlock(&kprobe_lock);
+
+ local_irq_restore(flags);
}
/* You have to be holding the kprobe_lock */