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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 3b7653f2e7ae..f3ea492ab44d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -155,14 +155,36 @@ void __kprobes free_insn_slot(kprobe_opcode_t *slot)
155/* Locks kprobe: irqs must be disabled */ 155/* Locks kprobe: irqs must be disabled */
156void __kprobes lock_kprobes(void) 156void __kprobes lock_kprobes(void)
157{ 157{
158 unsigned long flags = 0;
159
160 /* Avoiding local interrupts to happen right after we take the kprobe_lock
161 * and before we get a chance to update kprobe_cpu, this to prevent
162 * deadlock when we have a kprobe on ISR routine and a kprobe on task
163 * routine
164 */
165 local_irq_save(flags);
166
158 spin_lock(&kprobe_lock); 167 spin_lock(&kprobe_lock);
159 kprobe_cpu = smp_processor_id(); 168 kprobe_cpu = smp_processor_id();
169
170 local_irq_restore(flags);
160} 171}
161 172
162void __kprobes unlock_kprobes(void) 173void __kprobes unlock_kprobes(void)
163{ 174{
175 unsigned long flags = 0;
176
177 /* Avoiding local interrupts to happen right after we update
178 * kprobe_cpu and before we get a a chance to release kprobe_lock,
179 * this to prevent deadlock when we have a kprobe on ISR routine and
180 * a kprobe on task routine
181 */
182 local_irq_save(flags);
183
164 kprobe_cpu = NR_CPUS; 184 kprobe_cpu = NR_CPUS;
165 spin_unlock(&kprobe_lock); 185 spin_unlock(&kprobe_lock);
186
187 local_irq_restore(flags);
166} 188}
167 189
168/* You have to be holding the kprobe_lock */ 190/* You have to be holding the kprobe_lock */