extern int register_perf_hw_breakpoint(struct perf_event *bp);
extern void unregister_hw_breakpoint(struct perf_event *bp);
extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
+extern bool hw_breakpoint_is_used(void);
extern int dbg_reserve_bp_slot(struct perf_event *bp);
extern int dbg_release_bp_slot(struct perf_event *bp);
static inline void unregister_hw_breakpoint(struct perf_event *bp) { }
static inline void
unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
+static inline bool hw_breakpoint_is_used(void) { return false; }
+
static inline int
reserve_bp_slot(struct perf_event *bp) {return -ENOSYS; }
static inline void release_bp_slot(struct perf_event *bp) { }
}
EXPORT_SYMBOL_GPL(unregister_wide_hw_breakpoint);
+/**
+ * hw_breakpoint_is_used - check if breakpoints are currently used
+ *
+ * Returns: true if breakpoints are used, false otherwise.
+ */
+bool hw_breakpoint_is_used(void)
+{
+ int cpu;
+
+ if (!constraints_initialized)
+ return false;
+
+ for_each_possible_cpu(cpu) {
+ for (int type = 0; type < TYPE_MAX; ++type) {
+ struct bp_cpuinfo *info = get_bp_info(cpu, type);
+
+ if (info->cpu_pinned)
+ return true;
+
+ for (int slot = 0; slot < nr_slots[type]; ++slot) {
+ if (info->tsk_pinned[slot])
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
static struct notifier_block hw_breakpoint_exceptions_nb = {
.notifier_call = hw_breakpoint_exceptions_notify,
/* we need to be notified first */
static int test_init(struct kunit *test)
{
/* Most test cases want 2 distinct CPUs. */
- return num_online_cpus() < 2 ? -EINVAL : 0;
+ if (num_online_cpus() < 2)
+ return -EINVAL;
+
+ /* Want the system to not use breakpoints elsewhere. */
+ if (hw_breakpoint_is_used())
+ return -EBUSY;
+
+ return 0;
}
static void test_exit(struct kunit *test)
kthread_stop(__other_task);
__other_task = NULL;
}
+
+ /* Verify that internal state agrees that no breakpoints are in use. */
+ KUNIT_EXPECT_FALSE(test, hw_breakpoint_is_used());
}
static struct kunit_suite hw_breakpoint_test_suite = {