1 files changed, 25 insertions, 14 deletions

diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 4c0d0e51d49e..94b3f6b19538 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -1,34 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * lib/smp_processor_id.c
  *
  * DEBUG_PREEMPT variant of smp_processor_id().
  */
 #include <linux/export.h>
-#include <linux/kallsyms.h>
+#include <linux/kprobes.h>
 #include <linux/sched.h>
 
-notrace unsigned int debug_smp_processor_id(void)
+noinstr static
+unsigned int check_preemption_disabled(const char *what1, const char *what2)
 {
-	unsigned long preempt_count = preempt_count();
 	int this_cpu = raw_smp_processor_id();
 
-	if (likely(preempt_count))
+	if (likely(preempt_count()))
 		goto out;
 
 	if (irqs_disabled())
 		goto out;
 
-	/*
-	 * Kernel threads bound to a single CPU can safely use
-	 * smp_processor_id():
-	 */
-	if (cpumask_equal(tsk_cpus_allowed(current), cpumask_of(this_cpu)))
+	if (is_percpu_thread())
+		goto out;
+
+	if (current->migration_disabled)
 		goto out;
 
 	/*
 	 * It is valid to assume CPU-locality during early bootup:
 	 */
-	if (system_state != SYSTEM_RUNNING)
+	if (system_state < SYSTEM_SCHEDULING)
 		goto out;
 
 	/*
@@ -36,20 +36,31 @@ notrace unsigned int debug_smp_processor_id(void)
 	 */
 	preempt_disable_notrace();
 
+	instrumentation_begin();
 	if (!printk_ratelimit())
 		goto out_enable;
 
-	printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
-			"code: %s/%d\n",
-			preempt_count() - 1, current->comm, current->pid);
-	print_symbol("caller is %s\n", (long)__builtin_return_address(0));
+	printk(KERN_ERR "BUG: using %s%s() in preemptible [%08x] code: %s/%d\n",
+		what1, what2, preempt_count() - 1, current->comm, current->pid);
+
+	printk("caller is %pS\n", __builtin_return_address(0));
 	dump_stack();
 
 out_enable:
+	instrumentation_end();
 	preempt_enable_no_resched_notrace();
 out:
 	return this_cpu;
 }
 
+noinstr unsigned int debug_smp_processor_id(void)
+{
+	return check_preemption_disabled("smp_processor_id", "");
+}
 EXPORT_SYMBOL(debug_smp_processor_id);
 
+noinstr void __this_cpu_preempt_check(const char *op)
+{
+	check_preemption_disabled("__this_cpu_", op);
+}
+EXPORT_SYMBOL(__this_cpu_preempt_check);